CN102796251B - Biodegradable polyester-polycarbonate multi-block copolymer and preparation method and application thereof - Google Patents

Abstract

The invention discloses a biodegradable polyester-polycarbonate multi-block copolymer, a preparation method and application thereof. The biodegradable polyester-polycarbonate multi-block copolymer is an AB type block copolymer composed of A segment and B segment; wherein, the A segment is a hydroxyl-terminated polyester prepolymer , the B segment is a hydroxyl-terminated polycarbonate prepolymer. The number average molecular weight of the AB type block copolymer is 5,000-500,000, and the molecular weight distribution is 1-6. The block copolymer has low production cost, simple process, easy operation and correct instrumental analysis and detection results. The tensile strength of the copolymer is 20-60MPa, the elongation at break is 100-1200%, and the impact strength is greater than 5KJ/ ^m2 . It can be used as an impact modifier for environmentally friendly polymer materials and biodegradable polymer materials such as PBS, polylactic acid and polyhydroxybutyric acid, and has high application value.

Description

Biodegradable polyester-polycarbonate multi-block copolymer and its preparation method and application

technical field

The invention relates to a biodegradable polyester-polycarbonate multi-block copolymer and its preparation method and application.

Background technique

With the increasingly serious problem of environmental pollution, biodegradable polymer materials have attracted more and more attention. Among them, aliphatic polyester has become the most economical biodegradable material due to its lower price, better mechanical properties and processing properties.

At present, the application of aliphatic polyesters in high-end products is mainly limited by their properties such as low melt strength, especially because the structure of aliphatic polyesters is similar to that of polyolefins such as polyethylene and polypropylene, showing Highly regular, with fairly high crystallinity and large spherulites, which leads to its biggest defect - the limitation of brittleness. Such as PBS, although it has a lower glass transition temperature (about -42°C), but because the crystallinity is above 40%, the brittleness is very high, and the impact strength of PBS with a weight average molecular weight of 100,000 is only 46J/m. Therefore, overcoming these shortcomings of bioaliphatic polyesters has important scientific value and practical significance.

Copolymerization is a common method for modifying polymers. In order to improve the mechanical properties of aliphatic polyesters, introducing rigid benzene rings into the polyester molecular chain is one of the most commonly used methods at present, but there is a serious transesterification reaction in the copolymerization process, and the copolymers are generally random. Copolymer, so its melting point generally drops more. Moreover, due to the introduction of non-degradable benzene rings, the degradation performance of aliphatic polyesters is severely reduced. Polymer International 2006 55, 545 reported the method of PBS and maleopimaric anhydride to carry out copolymerization to modify PBS, through copolymerization, the flexural strength and tensile strength of PBS are greatly improved, but the impact strength is not significantly improved.

At present, to improve the biodegradability of aliphatic polyester is mainly to introduce polyether prepolymers such as polyethylene glycol and polypropylene glycol into the molecular chain of polyester to prepare block copolymers. However, although such methods can improve the biodegradability of the aliphatic polyester and improve its toughness, its strength is greatly reduced at the same time.

Patents CN101649045 and CN102020772A report introducing an amorphous or glassy aliphatic polyester soft segment into a crystalline aliphatic polyester molecular chain to modify the crystalline aliphatic polyester to prepare a multi-block copolymer, High performance biodegradable materials are available.

Aliphatic polycarbonate has a strong application prospect because of its good biocompatibility, biodegradability and non-polluting decomposition products. The flexibility of the molecular chain of aliphatic polycarbonate is very good, and the polymer has good toughness. Therefore, it is expected to improve the biocompatibility and impact strength of aliphatic polyester through block copolymerization of aliphatic polyester and aliphatic polycarbonate.

Contents of the invention

The object of the present invention is to provide a biodegradable polyester-polycarbonate multi-block copolymer and its preparation method and application.

The biodegradable polyester-polycarbonate multi-block copolymer provided by the present invention is an AB type multi-block copolymer composed of A segment and B segment; wherein, the A segment is a hydroxyl-terminated poly An ester prepolymer, the B segment is a hydroxyl-terminated polycarbonate prepolymer; the number average molecular weight of the A segment is 500-50,000, specifically 1,000-2,800, 1,000-4,000, 1,000-50,000 or 2,800-4,000, preferably 500-35,000, most preferably 1,000-20,000; the number average molecular weight of the B segment is 500-50,000, specifically 2000-6300, 500-2000, 2000-50000, 6300-50000, 6300- 18700 or 18700-50000, preferably 1,000-35,000, most preferably 1,000-30,000; the molar ratio of the A segment to the B segment is 10:90-95:5, specifically 1:0.98-18.98, 1:1 -8.03, 1:1.05-5.09, 1:4.98-5.06 or 1.8-9.08:1, preferably 20:80-95:5.

The number average molecular weight of the AB type multi-block copolymer is 5,000-500,000, specifically 98100-10300, 25600-500300, 28500-102700, 48500-438800, 49200-97600, 68500-89200, 28500-129600, 129600- 368600 or 79400-98100, preferably 10,000-40,000, most preferably 20,000-30,000, molecular weight distribution 1-6, specifically 1.5-5.9, 1.6-4.5, 1.9-3.9, 2.2-2.9, 1.9-3.6 or 2.6-5.9 , preferably 1.2-4.5, most preferably 1.5-4; melting point is 92-110°C, specifically 95-113°C, 96-112°C, 103-111°C or 105-109°C, tensile strength 20-59MPa, specifically It can be 28-57MPa, 30-52MPa, 33-47MPa or 35-46MPa, 32MPa, and the elongation at break is 102-980%, specifically 410-900%, 500-870%, 530-770%, 570- 730% or 610-700%, the impact strength is 5.1-41KJ/m ² , specifically 7-35KJ/m ² , 16-33KJ/m ² , 18-32KJ/m ² or 22-31KJ/m ² .

The method for preparing the above-mentioned block copolymer provided by the invention comprises the following steps:

1) The aliphatic dibasic acid with a total carbon number of 2-12 and the aliphatic dibasic alcohol with a total number of carbon atoms of 2-12 are subjected to an esterification reaction, and after the reaction is completed, a polycondensation reaction is carried out to obtain a hydroxyl-terminated polyester prepolymer;

2) Mix the dibasic carbonate, the aliphatic dihydric alcohol with the total number of carbon atoms of 2-12, and the transesterification reaction catalyst to carry out the transesterification reaction. After the reaction is completed, the polycondensation reaction is carried out, and the hydroxyl-terminated polycarbonate preform is obtained after the reaction is completed. Polymer;

3) carry out chain extension copolymerization reaction with the hydroxyl-terminated polyester prepolymer obtained in step 1) and the hydroxyl-terminated polycarbonate prepolymer obtained in step 2) under the action of a chain extender, and the block copolymerization is obtained after the reaction is completed thing.

In the method, the aliphatic dibasic acid with a total carbon number of 2-12 is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid and dodecanedioic acid At least one of acids, preferably at least one of oxalic acid, succinic acid and adipic acid; the aliphatic dihydric alcohol with a total carbon number of 2-12 is selected from ethylene glycol, 1,3-propanediol, 2- Methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol , at least one of ethylene glycol and triethylene glycol, preferably at least one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol A sort of;

The dibasic carbonate is selected from at least one of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate and diphenyl carbonate, preferably dimethyl carbonate, diethyl carbonate and carbonic acid at least one of diphenyl esters;

The transesterification reaction catalyst is selected from concentrated sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony ethylene glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate , manganese acetate, potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyl tin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, a total of At least one of alkyl germanium with 4-40 and alkoxy germanium with total carbon number of 4-40, preferably tin powder, antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate , at least one of germanium dioxide, zinc acetate, manganese acetate and stannous octoate, more preferably at least one of antimony trioxide, butyl titanate, zinc acetate, potassium carbonate, manganese acetate and stannous octoate;

The chain extender is selected from the group consisting of diepoxides, bisoxazolines, diisocyanates, polycarbodiimides, bisphthalimides, carboxylic anhydrides, bicyclic imide esters, organosilazanes and diacyl At least one of bislactams, preferably bis(3,4-epoxycyclohexylmethyl adipate), N,N-diepoxypropyl benzamide, uracil, barbituric acid, N-N- Diglycidyl diimide, N-N-diglycidyl imidazolinone, 2,2-bis(2-bisoxazoline), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI ), polymerized diphenylmethane diisocyanate, methylene bis(4-cyclohexyl isocyanate), hexamethylene diisocyanate (HDI), dicyclohexylmethane-4-4'-diisocyanate, 2,2,4 - Trimethylhexane diisocyanate, bis(phthalimide), 1,2,4,5-benzenetetracarboxylic dianhydride, phthalic anhydride, succinic anhydride, bisdioxazolone or bis Benzoxazine, octamethylcyclotetrasilazane, hexaphenyltrisilazane, N,N'-carbonyl bispyrrolidone, N,N'-carbonyl biscaprolactam, N,N'-carbonyl bis Lauryl lactam, N,N'-Oxalylbispyrrolidone, N,N'-Oxalylbiscaprolactam, N,N'-Oxalylbispyrrolidone, N,N'-Succinoylbispyrrolidone, N , N'-Adipylbispyrrolidone, N,N'-Adipylbislactam, N,N'-phthaloylbispyrrolidone, N,N'-phthaloylbislaurolactam , N, N'-terephthaloyl bispyrrolidine and N, N'-terephthaloyl dilaurolactam at least one, preferably adipate bis(3,4-epoxycyclohexyl methyl ester), 2,2-bis(2-bisoxazoline), toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, 1,2,4,5-benzenetetracarboxylic dianhydride , phthalic anhydride, succinic anhydride, hexaphenyltrisilazane and N, N'-oxalyl biscaprolactam at least one.

In the step 1), the molar ratio of the aliphatic dibasic alcohol with a total of 2-12 carbon atoms and the aliphatic dibasic acid with a total of 2-12 carbon atoms is 3.0-1.0, specifically 1.0-1.0 2.1, 1.6-3.0, 1.6-2.1, 1.0-1.6 or 2.1-3.0, preferably 2.0-1.0, more preferably 1.5-1.0; in the esterification step, the temperature is 100-300°C, specifically 150-250°C , 150-170°C or 170-250°C, preferably 110-260°C, more preferably 150-230°C, the time is 2-20 hours, specifically 2-6 hours, 6-20 hours, 2-3 hours or 3 hours -6 hours, preferably 3-15 hours; the polycondensation reaction is a negative pressure reaction, and small molecular products need to be removed during the reaction to promote the reaction. In the polycondensation reaction step, the temperature is 150-300 ° C, specifically 180-280°C, 180-230°C, 180-240°C, 230-240°C, 230-280°C or 240-280°C, preferably 150-280°C, more preferably 160-280°C, for 1-20 hours, Specifically, it is 2-8 hours, 2-3 hours or 3-8 hours, preferably 1-10 hours, and the vacuum degree is 1Pa to 3×10 ⁴ Pa, specifically 1-1000Pa, 1-10Pa or 1000-30000Pa, preferably 1Pa～2×10 ⁴ Pa.

In the step 2), the molar ratio of the aliphatic dihydric alcohol with a total of 2-12 carbon atoms and the carbonic acid dibasic ester is 3.0-1.0, specifically 1.0-1.3, 1.0-1.8, 1.3 -1.5, 1.3-1.8 or 1.5-1.8, preferably 2.0-1.0, more preferably 1.5-1.0; in the transesterification step, the temperature is 70-280°C, specifically 160-210°C, 70-160°C, 70°C -210°C or, preferably 80-230°C, more preferably 90-210°C, the time is 2-20 hours, preferably 3-15 hours; the polycondensation reaction is a negative pressure reaction, and small molecule products need to be removed during the reaction , to promote the reaction, in the polycondensation step, the temperature is 150-280°C, specifically 150-180°C or 180-280°C, preferably 150-250°C, more preferably 160-230°C, and the time is 1-20 hours, the degree of vacuum is 1 Pa to 3×10 ⁴ Pa, specifically 1-30 Pa, 10-30 Pa, 10-3×10 ⁴ Pa or 30-3×10 ⁴ Pa, preferably 1 Pa to 2×10 ⁴ Pa.

In the step 3), the ratio of the chain extender to the sum of the molar amounts of the hydroxyl-terminated polyester prepolymer and the polycarbonate prepolymer is 0.3-6, specifically 0.6- 6. 0.85-4 or 1.1-3.3, preferably 0.5-4.

Before the step 1) the esterification step, an esterification catalyst is also added; the esterification catalyst is selected from concentrated sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony ethylene glycol, acetic acid Antimony, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkanes with 4-40 carbon atoms At least one of base tin, tin alkoxide with a total carbon number of 4-40, alkyl germanium with a total number of carbon atoms of 4-40 and alkoxygermanium with a total number of carbon atoms of 4-40, preferably tin powder, At least one of antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate, more preferably antimony trioxide and butyl titanate At least one of esters, zinc acetate, potassium carbonate, manganese acetate and stannous octoate;

The amount of the catalyst for the esterification reaction is 0-2% of the sum of the mass of the aliphatic dibasic acid with a total carbon number of 2-12 and the aliphatic dibasic alcohol with a total number of carbon atoms of 2-12, preferably 0-2%. 0.6%, the consumption of described esterification reaction catalyst is not 0; The consumption of described transesterification reaction catalyst is the 0-0% of the sum of the aliphatic dihydric alcohol mass sum of described carbonic acid dibasic ester and the total number of carbon atoms of 2-12. 2%, specifically 0-0.05%, 0.02-2%, 0.08-0.8%, 0.1-0.6% or 0.2-0.4%, preferably 0-0.6%;

Before the polycondensation reaction step after the step 1) the esterification reaction step, and before the polycondensation reaction step after the step 2) the transesterification reaction step, a polycondensation reaction catalyst can also be added; the polycondensation reaction catalyst is selected from concentrated Sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate, sodium carbonate , calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyltin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, alkylgermanium with a total of 4-40 carbon atoms, carbon At least one of alkoxy germanium with a total number of atoms of 4-40, alkyl zinc with a total number of carbon atoms of 4-40, alkoxyzinc with a total number of carbon atoms of 4-40 and ferrous lactate, preferably tin powder, At least one of antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate, more preferably antimony trioxide and butyl titanate At least one of esters, zinc acetate, potassium carbonate, manganese acetate and stannous octoate;

The amount of the polycondensation reaction catalyst in the step 1) is 0-2% of the sum of the mass of the aliphatic dibasic acid with a total carbon number of 2-12 and the mass of aliphatic dibasic alcohols with a total number of carbon atoms of 2-12, Preferably 0-0.6%, the consumption of the polycondensation reaction catalyst is not 0; the consumption of the polycondensation reaction catalyst in the step 2) is the quality of the aliphatic dibasic alcohol with the total number of carbon atoms of 2-12 in the described carbonate dibasic ester and 0-2% of the sum, specifically can be 0-0.04%, 0.02-2.0%, 0.08-0.8%, 0.1-0.6% or 0.2-0.4%, preferably 0-0.6%, the consumption of described polycondensation reaction catalyst is not is 0;

After step 2) and step 3) before the chain extension copolymerization step, a chain extension reaction catalyst can also be added; the chain extension reaction catalyst is selected from tertiary amine chemicals, inorganic acids, metals, metal oxides, metal chlorides , metal acetate, organic titanium compound, organic germanium compound, organic tin compound, organic aluminum compound and organic iron compound, preferably triethylamine, dimethyl hexadecylamine, stannous octoate, trichloride At least one of butyltin, dibutyltin dilaurate, calcium phosphonate, lithium chloride, anhydrous zinc acetate, zinc undecylenate and zinc soap; 0-5% of the mass of the polyester prepolymer and the hydroxyl-terminated polycarbonate prepolymer, specifically 0.001-5%, 0.04-0.6% or 0.1-0.3%, preferably 0-4%, More preferably 0 to 3%, the amount of the chain extension reaction catalyst is not 0;

In the step 3), the chain extension reaction is chain extension in a molten state, and the reaction device is a reactor or a twin-screw extruder. In the step of carrying out the chain extension reaction in the reactor, the temperature is 80-200°C, specifically 80-160°C, 80-135°C, 80-120°C, 120-200°C, 120-160°C, 120°C -135°C, 135-200°C, 135-160°C or 160-200°C, preferably 90-190°C, the time is 0.5-6 hours, specifically 0.5-4 hours, 0.5-3, 3-4 or 4- 6 hours, preferably 0.5-5 hours.

In the step of carrying out the chain extension reaction in the twin-screw extruder, the screw temperature is 100-280°C, preferably 100-250°C, and the screw speed is 5-500r/min, specifically 20r/min, 80r/min Or 300r/min, preferably 30-300r/min, the residence time is 0.5-30min, specifically 2min, 5min or 15min, preferably 2-15min. In the step of carrying out the chain extension reaction in the twin-screw extruder, the temperatures of the screw from zone I to zone IV and the machine head are: 100-220°C, 100-280°C, 100-280°C, 100-280°C °C and 100-220 °C, preferably 110-200 °C, 120-200 °C, 130-250 °C, 130-200 °C and 100-200 °C in sequence. The method can specifically be: add the hydroxyl-terminated polyester prepolymer, polycarbonate prepolymer, chain extender and catalyst into the twin-screw reactor through a feeder and a metering pump respectively, and the feed amount is adjusted by adjusting the feed The frequency of the metering device and the metering pump is used to control the material. After the material is extruded through the reaction, it is directly cooled into strips and pelletized by a water bath.

The application of the biodegradable polyester-polycarbonate block copolymer provided by the present invention in the preparation of impact modifiers for biodegradable polymer materials also belongs to the protection scope of the present invention.

The biodegradable polyester-polycarbonate multi-block copolymer provided by the invention has low production cost, simple process, easy operation and correct instrumental analysis and detection results. The tensile strength of the copolymer is 20-60MPa, the elongation at break is 100-1200%, and the impact strength is greater than 5KJ/ ^m2 . It can be used as an impact modifier for environmentally friendly polymer materials and biodegradable polymer materials such as PBS, polylactic acid and polyhydroxybutyric acid, and has high application value.

Description of drawings

Fig. 1 is the ¹ H-NMR spectrogram of the hydroxyl-terminated polybutylene succinate prepolymer of embodiment 1 gained;

Fig. 2 is the ¹ H-NMR spectrogram of the hydroxyl-terminated polybutylene carbonate prepolymer of embodiment 1 gained;

Fig. 3 is the ¹ H-NMR spectrum of the block copolymer containing polybutylene succinate and polybutylene carbonate obtained in Example 1.

Detailed ways

The chemical analysis method and analytical instrument adopted in the following examples are specified as follows:

1. Chemical structure, molecular weight and molecular weight distribution

The molecular weight of the polyester prepolymer and the structure of the block copolymer were measured by a 400M nuclear magnetic resonance instrument (BrukerDMX-400), using deuterated chloroform as a solvent and tetramethylsilane as an internal standard. The molecular weight and molecular weight distribution of the multi-block copolymer were determined by gel chromatography (GPC, Waters Company). Polystyrene with a series of molecular weights with a narrow molecular weight distribution is used as a calibration standard sample, chloroform is used as an eluting phase, and the measurement temperature is 40°C.

2. Thermal performance

The melting points of the polyester prepolymer and the block copolymer were measured by differential scanning calorimetry (DSC) at a scan rate of 20°C/min.

3. Testing of tensile and impact properties

The tensile strength and impact strength of the block copolymer were measured according to the test standards of ASTM D638-97 and ASTM D256-97, respectively.

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The reactants can be obtained from public commercial sources unless otherwise specified.

Embodiment 1, preparation biodegradable polyester-polycarbonate block copolymer

This embodiment prepares the method for biodegradable polyester-polycarbonate block copolymer to comprise the steps:

1) Preparation of hydroxyl-terminated polyester prepolymer

At room temperature, 2500 g of succinic acid and 1,4-butanediol in a molar ratio of 1:1.6 were first added to a 5 L reactor replaced with high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 150°C, stirred and reacted with nitrogen for 20 hours, then the temperature was raised to 230°C, the pressure was slowly lowered to 10 Pa, and then polycondensed for 8 hours. Obtain the oligomer of white waxy, be the polybutylene succinate prepolymer (HO-PBS-OH) of the hydroxyl termination shown in formula I structural formula, the fusing point of this prepolymer is 108.2 ℃, Fig. 1 For its H NMR spectrum and its attribution, the number average molecular weight can be calculated as 4,000 according to the integral area of the H NMR spectrum from the following formula.

${\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 90</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2.6</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 3.5</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3.7</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 172</span>}$

(Formula I) HO-PBS-OH

2) Preparation of hydroxyl-terminated polycarbonate prepolymer

At room temperature, 2500 g of 1,4-butanediol and dimethyl carbonate in a molar ratio of 1.8:1, and 20 g of magnesium acetate were sequentially added to a 5 L reactor replaced by high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. Control the above reaction system at 210°C, stir and react with nitrogen gas for 2 hours, then raise the temperature to 280°C, add 5g of antimony trioxide, slowly reduce the pressure to 1Pa, and polycondense for 5 hours to obtain an oligomer, namely It is a hydroxyl-terminated polybutylene carbonate prepolymer (HO-PBC-OH) represented by the structural formula II. Fig. 2 is its proton nuclear magnetic spectrum and its attribution, according to the integrated area of the proton nuclear magnetic spectrum, its number average molecular weight can be calculated as 2000 from the following formula.

${\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 90</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 4.1</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 3.5</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3.7</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 116</span>}$

(Formula II) HO-PBC-OH

3) Preparation of biodegradable polyester-polycarbonate block copolymers

The prepolymer prepared in the above step 1) and step 2) was dried at 100° C. for 3 h. Step 1) prepolymer 1 obtained and step 2) prepolymer 2 (totally 2500g) and MDI obtained according to the molar ratio of 1:1:1.7 and 1.0g chain extension reaction catalyst stannous octoate were added to the high-purity Nitrogen replaced 5L reactor. The above reaction system was heated to 160°C and reacted for 0.5h. Obtain the biodegradable polyester-polycarbonate block copolymer (PBS-b-PBC) provided by the present invention, its structural formula is as shown in formula III (n is 22.7, m is 16.5), and its number average molecular weight is 10,300 , the molecular weight distribution is 2.6, and Fig. 3 is the ¹ H-NMR spectrum of the copolymer. The molar ratio of A segment and B segment in the molecular chain is 1:1, the melting point of the copolymer is 111°C (PBS segment), the tensile strength is 32MPa, the elongation at break is 730%, and the impact strength is 30KJ/ ^m2 .

(Formula III) PBS-b-PBC

Embodiment 2, preparation biodegradable polyester-polycarbonate block copolymer

1) Preparation of hydroxyl-terminated polyester prepolymer

At room temperature, 2500 g of sebacic acid and 1,4-butanediol in a molar ratio of 1:3 and 0.5 g of butyl titanate were added to a 5 L reaction kettle replaced with high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 300° C., stirred and reacted for 2 hours with nitrogen gas, 50 g of butyl titanate was added, the pressure was slowly lowered to 1 Pa, and polycondensation was carried out for another 1 hour. A white waxy oligomer having a melting point of 73° C. and a number average molecular weight of 1,000 was obtained.

2) Preparation of hydroxyl-terminated polycarbonate prepolymer

At room temperature, 2500 g of ethylene glycol and diethyl carbonate in a molar ratio of 1:1, and 0.05 g of potassium carbonate were sequentially added to a 5 L reactor replaced by high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 70°C, stirred and reacted with nitrogen for 20 hours, then the temperature was raised to 150°C, the pressure was slowly lowered to 3×10 ⁴ Pa, and then polycondensed for 1 hour. A polycarbonate oligomer having a melting point of 58° C. and a number average molecular weight of 500 was obtained.

3) Preparation of biodegradable polyester-polycarbonate block copolymers

The prepolymer prepared in step 1) and step 2) was dried at 100° C. for 3 h. The prepolymer 1 obtained in step 1), the prepolymer 2 obtained in step 2) and MDI were added to the high-purity nitrogen replacement process successively according to the molar ratio of 8: 1: 2.7 (wherein the two prepolymers were 2500 g in total). in a 5L reactor. The above reaction system was heated to 80°C and reacted for 6 hours to obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, with a number average molecular weight of 5,000, a molecular weight distribution of 6.0, and a segment A in the molecular chain The molar ratio to the B segment is 8.03:1, the melting point is 95°C (PBS segment), the tensile strength is 20MPa, the elongation at break is 102%, and the impact strength is 5.1KJ/m ² .

Embodiment 3, preparation biodegradable polyester-polycarbonate block copolymer

The prepolymer prepared in step 1) and step 2) of Example 2 was dried at 100° C. for 3 hours. The polyester prepolymer, polycarbonate prepolymer, HDI are added to the high-purity nitrogen replacement in turn according to the molar ratio of 19:1:120 (wherein the two prepolymers have a total weight of 2000g) and 100g chain extension reaction catalyst stannous octoate in a 5L reactor. The above reaction system was heated to 200°C and reacted for 3 hours to obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, with a number average molecular weight of 25,600, a molecular weight distribution of 2.2, and a segment A in the molecular chain The molar ratio to the B segment is 18.98:1, the melting point is 113° C. (PBS segment), the tensile strength is 36 MPa, the elongation at break is 660%, and the sample is continuously punched.

Embodiment 4, preparation biodegradable polyester-polycarbonate block copolymer

The prepolymer prepared in step 1) and step 2) of Example 1 of the present invention was dried at 100° C. for 3 hours. The polyester prepolymer, polycarbonate prepolymer, HDI are added to the high-purity nitrogen replacement in turn according to the molar ratio of 1:9:10 (the total weight of the two prepolymers is 1000g), and 3g of chain extension reaction catalyst triethylamine. in a 5L reactor. The above reaction system was heated to 200°C, stirred and reacted for 1.5h under the protection of nitrogen to obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, the number average molecular weight was 98,100, the molecular weight distribution was 1.9, and the molecular chain The molar ratio of segment A to segment B is 1.02:9, the melting point is 103°C (PBS segment), the tensile strength is 30MPa, the elongation at break is 530%, and the impact strength is 31KJ/m ² .

Embodiment 5, preparation biodegradable polyester-polycarbonate block copolymer

This embodiment prepares the method for biodegradable polyester-polycarbonate block copolymer to comprise the steps:

1) Preparation of hydroxyl-terminated polyester prepolymer

At room temperature, 2500 g of succinic acid and 1,4-butanediol in a molar ratio of 1:1, and 50 g of p-toluenesulfonic acid were sequentially added to a 5 L reactor replaced by high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 100°C, stirred and reacted with nitrogen for 3 hours, then 0.5 g of stannous octoate was added, the temperature was raised to 150°C, the pressure was slowly lowered to 1,000 Pa, and polycondensation was continued for 20 hours. A white waxy oligomer having a melting point of 108° C. and a number average molecular weight of 50,000 was obtained.

2) Preparation of hydroxyl-terminated polycarbonate prepolymer

At room temperature, 2500 g of 1,6-hexanediol and dimethyl carbonate in a molar ratio of 3:1, and 15 g of butyl titanate (titanium alkoxide) were sequentially added to a 5 L reactor replaced by high-purity nitrogen. middle. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 160°C, stirred and reacted for 3 hours with nitrogen gas, and after the temperature rose to 180°C, the pressure was slowly lowered to 30 Pa, and then polycondensed for 20 hours. A polycarbonate oligomer having a melting point of 59° C. and a number average molecular weight of 50,000 was obtained.

3) Preparation of biodegradable polyester-polycarbonate block copolymers

The prepolymers prepared in step 1) and step 2) were dried at 100° C. for 3 h. The polyester prepolymer, polycarbonate prepolymer, and HDI were sequentially added into a 5 L reactor replaced with high-purity nitrogen according to a molar ratio of 8:1:13 (the total mass of the two prepolymers was 1000 g). The above reaction system was heated to 120°C, stirred and reacted for 6 hours under the protection of nitrogen, and the biodegradable polyester-polycarbonate block copolymer provided by the present invention was obtained, with a number average molecular weight of 438,800, a molecular weight distribution of 3.6, and A in the molecular chain The molar ratio of the chain segment to the B segment is 8.02:1, the melting point is 103°C (PBS segment), the tensile strength is 33MPa, the elongation at break is 700%, and the impact strength is 33KJ/m ² .

Embodiment 6, preparation biodegradable polyester-polycarbonate block copolymer

1) Preparation of hydroxyl-terminated polyester prepolymer

At room temperature, 2500 g of succinic acid and 1,4-butanediol in a molar ratio of 1:2.1, and 5 g of manganese acetate were added to a 5 L reactor replaced with high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 170°C, stirred and reacted with nitrogen for 6 hours, then the temperature was raised to 240°C, 30g of tin powder was added, the pressure was slowly reduced to 3×10 ⁴ Pa, and polycondensation was continued for 3 hours. A white waxy oligomer having a melting point of 116° C. and a number average molecular weight of 2,800 was obtained.

2) Preparation of hydroxyl-terminated polycarbonate prepolymer

At room temperature, 2500 g of 1,4-butanediol and diethyl carbonate in a molar ratio of 1.5:1, and 2.5 g of magnesium acetate were sequentially added to a 5 L reactor replaced by high-purity nitrogen. At the same time, the reactor is equipped with a high-purity nitrogen inlet, a mechanical stirrer, and a condenser. The above reaction system was controlled at 280°C, stirred and reacted with nitrogen gas for 5 hours, then the temperature was raised to 180°C, 0.025g of antimony trioxide was added, the pressure was slowly lowered to 10Pa, and then polycondensed for 20 hours. A polycarbonate oligomer having a melting point of 68° C. and a number average molecular weight of 6,300 was obtained.

3) Preparation of biodegradable polyester-polycarbonate block copolymers

The prepolymer prepared in the above step 1) and step 2) was dried at 100° C. for 3 h. This polyester polyester prepolymer, polycarbonate prepolymer, HDI according to molar ratio 1: 5: 24 (wherein two prepolymer quality total 1000g), 0.01g chain extension reaction catalyst dibutyltin dilaurate Add it to a 5L reactor replaced with high-purity nitrogen. The above reaction system was heated to 160°C, stirred and reacted for 3 hours under the protection of nitrogen, and the biodegradable polyester-polycarbonate block copolymer provided by the present invention was obtained. The number average molecular weight was 48,500, and the molecular weight distribution was 1.0. The molar ratio of segment A to segment B in the chain is 1:5.05, the melting point is 109°C (PBS segment), the tensile strength is 38MPa, the elongation at break is 980%, and the impact strength is 35KJ/m ² .

Embodiment 7, preparation biodegradable polyester-polycarbonate block copolymer

Adopt the same prepolymer and chain extension conditions as in Example 6, only change the chain extender from HDI to succinic anhydride, and the chain extension reaction catalyst is changed from dibutyltin dilaurate to triethylamine, the chain extension reaction catalyst The dosage is 3g, after the reaction is completed, the biodegradable polyester-polycarbonate block copolymer provided by the invention is obtained, its number average molecular weight is 28,500, and the molecular weight distribution is 3.9, the A segment and the B chain in the molecular chain The molar ratio of the segment is 1:4.98, the melting point is 112° C. (PBS segment), the tensile strength is 35 MPa, the elongation at break is 770%, and the sample is continuously punched.

Embodiment 8, preparation biodegradable polyester-polycarbonate block copolymer

The polyester prepolymer used in this embodiment is prepared by the step 1 of embodiment 4, and the polycarbonate prepolymer used is prepared according to the following method:

At room temperature, first add 2500 g of 1,5-pentanediol and diphenyl carbonate in a molar ratio of 3:1, and 10 g of p-toluenesulfonic acid into a 5 L reaction kettle replaced with high-purity nitrogen. Others were the same as in Example 3 to obtain a polycarbonate oligomer with a melting point of 63° C. and a number average molecular weight of 500.

The polyester prepolymer prepared in step 1) of Example 4 and the above-mentioned polycarbonate prepolymer were reacted according to the same preparation conditions as in Example 1 of the present invention to obtain the biodegradable polyester provided by the present invention - Polycarbonate block copolymer, the number average molecular weight is 89,200, the molecular weight distribution is 4.5, the molar ratio of the A segment and the B segment in the molecular chain is 1.05:1, the melting point is 92°C (PBS segment), tensile The strength is 28MPa, the elongation at break is 980%, and the impact strength is 41KJ/m ² .

Embodiment 9, preparation biodegradable polyester-polycarbonate block copolymer

The polyester prepolymer used in this embodiment is prepared by the step 1 of embodiment 4, and the polycarbonate prepolymer used is prepared according to the following method:

At room temperature, 2500 g of hexanediol and diphenyl carbonate in a molar ratio of 2.5:1 were sequentially added to a 5 L reactor replaced by high-purity nitrogen. Others are the same as embodiment 4. A polycarbonate oligomer having a melting point of 53° C. and a number average molecular weight of 18,700 was obtained.

The polyester prepolymer prepared in step 1) of Example 4 and the above-mentioned polycarbonate prepolymer were reacted according to the same preparation conditions as in Example 1 of the present invention to obtain the biodegradable polyester- Polycarbonate block copolymer, the number average molecular weight is 102,700, the molecular weight distribution is 5.9, the molar ratio of the A segment and the B segment in the molecular chain is 0.98:1, the melting point is 106°C, the tensile strength is 36MPa, and the elongation at break is The elongation is 500%, and the impact strength is 16KJ/m ² .

Embodiment 10, preparation biodegradable polyester-polycarbonate block copolymer

The polyester prepolymer used in this example was prepared from step 1) of Example 1, the polycarbonate prepolymer used was prepared from Example 8, and the above two prepolymers were dried at 100° C. for 3 hours. Add the above-mentioned polyester prepolymer, polycarbonate prepolymer, and HDI according to the molar ratio of 9:5:16 to a total of 1000 g and 50 g of chain extension reaction catalyst stannous octoate sequentially into a 5 L reactor replaced by high-purity nitrogen. The above reaction system was heated to 135°C, stirred and reacted for 4 hours under the protection of nitrogen to obtain a block copolymer, the number average molecular weight was 500,300, the molecular weight distribution was 1.9, and the molar ratio of the A segment and the B segment in the molecular chain was 9: 5.05, the melting point is 110°C, the tensile strength is 46MPa, the elongation at break is 410%, and the impact strength is 7KJ/m ² .

Embodiment 11, preparation biodegradable polyester-polycarbonate block copolymer

Using the same reactants and preparation conditions as in Example 10, only the chain extender was changed from HDI to hexaphenylcyclotrisilazane, and the chain extension reaction catalyst was changed from stannous octoate to dimethyl hexadecylamine. The consumption of chain extension reaction catalyzer is 1g, and after completion of reaction, obtains biodegradable polyester-polycarbonate block copolymer provided by the present invention, and its number-average molecular weight is 68,500, and molecular weight distribution is 3.9, and A segment in molecular chain The molar ratio to the B segment is 9.03:5, the melting point is 105° C., the tensile strength is 52 MPa, the elongation at break is 900%, and the sample is punched continuously.

Embodiment 12, preparation biodegradable polyester-polycarbonate block copolymer

In this example, a twin-screw extruder is used to prepare the polyester prepolymer used in step 1) of Example 4, and the polycarbonate prepolymer used is prepared in Example 8. The parameters of the twin-screw extruder are set as follows:

Add the polyester prepolymer, polycarbonate prepolymer, HDI, and chain extension reaction catalyst triethylamine into the twin-screw reactor through the feeder and metering pump respectively, and control the frequency by adjusting the frequency of the feeder and metering pump Material, the mol ratio of polyester prepolymer, polycarbonate prepolymer, HDI is 9: 1: 14, totally 2000g, the consumption of chain extension reaction catalyst is 5% of prepolymer gross mass, twin-screw extrusion, Cool and pelletize to obtain the biodegradable polyester-polycarbonate block copolymer provided by the invention. Its number average molecular weight is 79,400, the molecular weight distribution is 1.9, the molar ratio of the A segment and the B segment in the molecular chain is 9.08:1, the melting point is 113°C, the tensile strength is 45MPa, and the elongation at break is 780%. The strength is 20kJ/m ² .

Embodiment 13, preparation biodegradable polyester-polycarbonate block copolymer

The polyester prepolymer used in this example was prepared from step 1) of Example 5, and the polycarbonate prepolymer used was prepared from Example 7.

The used polyester prepolymer, polycarbonate prepolymer, succinic anhydride, and chain extension reaction catalyst stannous octoate are added to the twin-screw reactor through a feeder and a metering pump respectively, and the frequency of the feeder and the metering pump is adjusted to Control material, the molar ratio of polyester prepolymer, polycarbonate prepolymer, succinic anhydride 3:7:13, altogether 2000g, the consumption of chain extension reaction catalyst is 0.6% of prepolymer gross mass. The parameters of the twin-screw extruder were set as follows:

Twin-screw extruding, cooling, pelletizing, obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, its number-average molecular weight is 49,200, and molecular weight distribution is 1.6, and A segment and B in the molecular chain The molar ratio of the segments is 3:7.08, the melting point is 96°C, the tensile strength is 59MPa, the elongation at break is 610%, and the impact strength is 18kJ/m ² .

Embodiment 14, preparation biodegradable polyester-polycarbonate block copolymer

The proportioning of each reactant in this embodiment is identical with embodiment 7, and the parameter setting of used twin-screw extruder is as follows:

Twin-screw extruding, cooling, pelletizing, obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, its number-average molecular weight is 97,600, and molecular weight distribution is 2.9, and A segment and B in the molecular chain The molar ratio of the segments is 1:5.09, the tensile strength is 47MPa, the elongation at break is 770%, and the impact strength is 22KJ/m ² .

Embodiment 15, preparation biodegradable polyester-polycarbonate block copolymer

The proportioning of each reactant in this embodiment is identical with embodiment 7, and the parameter setting of used twin-screw extruder is as follows:

Twin-screw extruding, cooling, pelletizing, obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, its number-average molecular weight is 129,600, and molecular weight distribution is 3.9, and A segment and B in the molecular chain The molar ratio of the segments is 1:5.06, the tensile strength is 37MPa, the elongation at break is 570%, and the impact strength is 32KJ/m ² .

Embodiment 16, preparation biodegradable polyester-polycarbonate block copolymer

The proportioning of each reactant in this embodiment is identical with embodiment 7, and the parameter setting of used twin-screw extruder is as follows:

Twin-screw extruding, cooling, pelletizing, obtain the biodegradable polyester-polycarbonate block copolymer provided by the present invention, its number-average molecular weight is 368,600, and molecular weight distribution is 2.9, and A segment and B in the molecular chain The molar ratio of the segment is 1:5.03, the tensile strength is 57MPa, the elongation at break is 870%, and the impact strength is 32KJ/ ^m2 ; while the tensile strength of the existing PBS homopolymer is only 32.7MPa, the elongation at break The elongation is 190%, and the impact strength is only 3.8KJ/m ² . It can be seen that the polyester-polycarbonate block copolymer provided by the present invention can significantly improve the impact resistance of PBS.

Claims (23)

1. AB type block copolymers composed of A segment and B segment; wherein, the A segment is a hydroxyl-terminated polyester prepolymer, and the B segment is a hydroxyl-terminated polycarbonate prepolymer matter; the number average molecular weight of the A segment is 500-50,000; The number average molecular weight of the B segment is 500-50,000; the molar ratio of the A segment to the B segment is 10:90-95:5; The number-average molecular weight of the AB-type block copolymer is 5,000-500,000, and the molecular weight distribution is 1-6; The AB type block copolymer is prepared according to the method comprising the following steps: 1) The aliphatic dibasic acid with a total of 2-12 carbon atoms and the aliphatic dibasic alcohol with a total of 2-12 carbon atoms are subjected to esterification reaction, and then polycondensation reaction is carried out after the reaction is completed, and the hydroxyl-terminated polyol is obtained after the reaction is completed. Ester prepolymers; 2) Mix the dibasic carbonate, the aliphatic dihydric alcohol with the total number of carbon atoms of 2-12, and the transesterification reaction catalyst to carry out the transesterification reaction, and then conduct the polycondensation reaction after the reaction is completed, and the hydroxyl-terminated polyol Carbonate prepolymer; 3) The hydroxyl-terminated polyester prepolymer obtained in step 1) and the hydroxyl-terminated polycarbonate prepolymer obtained in step 2) are subjected to a chain extension copolymerization reaction under the action of a chain extender. After the reaction is completed, the AB-type embedded segment copolymers. 2. The block copolymer according to claim 1, characterized in that: the number average molecular weight of the A segment is 500-35,000; The number average molecular weight of the B segment is 1,000-35,000; the molar ratio of the A segment to the B segment is 20:80-95:5; The number average molecular weight of the AB type block copolymer is 10,000-40,000, the molecular weight distribution is 1.2-4.; the melting point is 92-110°C, the tensile strength is 20-59MPa, and the elongation at break is 102- 980%, the impact strength is 5.1-41KJ/m ² . 3. The block copolymer according to claim 2, characterized in that: the number average molecular weight of the A segment is 1,000-20,000; The number average molecular weight of the B segment is 2,000-30,000; The number average molecular weight of the AB type block copolymer is 20,000-30,000, and the molecular weight distribution is 1.5-4. 4. The block copolymer according to any one of claims 1-3, characterized in that: the aliphatic dibasic acid whose total number of carbon atoms is 2-12 is selected from oxalic acid, malonic acid, succinic acid, pentanoic acid At least one of diacid, adipic acid, suberic acid, sebacic acid and dodecanedioic acid; the aliphatic dihydric alcohol with a total carbon number of 2-12 is selected from ethylene glycol, 1, 3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,4 -at least one of cyclohexanedimethanol, ethylene glycol and triethylene glycol; The dibasic carbonate is selected from at least one of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate and diphenyl carbonate; The transesterification reaction catalyst is selected from concentrated sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony ethylene glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate , manganese acetate, potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyl tin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, a total of At least one of alkyl germanium with 4-40 and alkoxy germanium with total carbon atoms of 4-40; The chain extender is selected from the group consisting of diepoxides, bisoxazolines, diisocyanates, polycarbodiimides, bisphthalimides, carboxylic anhydrides, bicyclic imide esters, organosilazanes and diacyl At least one of the bislactams. 5. The block copolymer according to claim 4, characterized in that: the aliphatic dibasic acid whose total carbon number is 2-12 is selected from at least one of oxalic acid, succinic acid and adipic acid; The aliphatic dihydric alcohols with a total of 2-12 carbon atoms are all selected from at least one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol; The dibasic carbonate is selected from at least one of dimethyl carbonate, diethyl carbonate and diphenyl carbonate; The transesterification catalyst is at least one selected from tin powder, antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate ; The chain extender is selected from bis(3,4-epoxycyclohexylmethyl) adipate, N, N-diepoxypropyl benzamide, uracil, barbituric acid, N-N-diepoxypropylene Diimide, N-N-diepoxypropyl imidazolinone, 2,2-bis(2-bisoxazoline), toluene diisocyanate, diphenylmethane diisocyanate, polymerized diphenylmethane diisocyanate, Methylene bis(4-cyclohexyl isocyanate), hexamethylene diisocyanate, dicyclohexylmethane-4-4'-diisocyanate, 2,2,4-trimethylhexane diisocyanate, bis(o-phenyl dicarboximide), 1,2,4,5-benzenetetracarboxylic dianhydride, phthalic anhydride, succinic anhydride, bisdioxazolone or bisbenzoxazine, octamethylcyclotetrasilazane , Hexaphenyltrisilazane, N, N'-carbonylbispyrrolidone, N,N'-carbonylbiscaprolactam, N,N'-carbonylbislaurolactam, N,N'-oxalylbis Pyrrolidone, N,N'-Oxalylbiscaprolactam, N,N'-Oxalylbislaurolactam, N,N'-Succinoylbispyrrolidone, N,N'-Adipylbispyrrolidone, N,N '-Adipylbislactam, N,N'-phthaloylbispyrrolidone, N,N'-phthaloylbislaurolactam, N,N'-terephthaloylbispyrrole At least one of alkanes and N,N'-terephthaloyl dilaurolactam. 6. The block copolymer according to any one of claims 1-3, characterized in that: in step 1), the aliphatic diol with a total number of carbon atoms of 2-12 and the total number of carbon atoms The molar ratio of the aliphatic dibasic acid of 2-12 is 3.0-1.0; in the esterification reaction step, the temperature is 100-300°C, and the time is 2-20 hours; in the polycondensation reaction step, the temperature is 150-300℃, the time is 1-20 hours, the vacuum degree is 1Pa～3×10 ⁴ Pa; In the step 2), the molar ratio of the aliphatic dihydric alcohol with a total carbon number of 2-12 to the carbonic acid dibasic ester is 3.0-1.0; the amount of the transesterification catalyst used is the carbonic acid 0-2% of the sum of the mass of dibasic ester and the total number of carbon atoms of 2-12 aliphatic diols, the amount of the transesterification catalyst is not 0; in the transesterification step, the temperature is 70- 300°C, the time is 2-20 hours; in the polycondensation reaction step, the temperature is 150-280°C, the time is 1-20 hours, and the vacuum degree is 1Pa～3×10 ⁴ Pa; In the step 3), the ratio of the chain extender to the sum of the molar amounts of the hydroxyl-terminated polyester prepolymer and the polycarbonate prepolymer is 0.3-6. 7. The block copolymer according to claim 6, characterized in that: in the step 1), the aliphatic diol with a total of 2-12 carbon atoms and the fat with a total of 2-12 carbon atoms The feeding molar ratio of the tribasic dibasic acid is 2.0-1.0; in the esterification reaction step, the temperature is 110-260°C, and the time is 3-15 hours; in the polycondensation reaction step, the temperature is 150-280°C, and the time is 1-10 hours, the vacuum degree is 1Pa～2×10 ⁴ Pa; In the step 2), the molar ratio of the aliphatic dihydric alcohol with a total carbon number of 2-12 to the carbonic acid dibasic ester is 2.0-1.0; the amount of the transesterification reaction catalyst is 0-0.6% of the sum of the mass of dibasic ester and the total number of carbon atoms of 2-12 aliphatic diols, the amount of the transesterification catalyst is not 0; in the transesterification step, the temperature is 80- 230°C, the time is 3-15 hours; in the polycondensation reaction step, the temperature is 150-250°C, the time is 1-10 hours, and the vacuum degree is 1Pa～2×10 ⁴ Pa; In the step 3), the ratio of the chain extender to the sum of the molar amounts of the hydroxyl-terminated polyester prepolymer and the polycarbonate prepolymer is 0.5-4. 8. The block copolymer according to any one of claims 1-3, characterized in that: in step 1) before the esterification step, an esterification catalyst is added; the esterification catalyst Concentrated sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate , sodium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyl tin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, alkyl tin with a total of 4-40 carbon atoms At least one of germanium and alkoxygermanium with total carbon atoms of 4-40; 0-2% of the sum of the aliphatic dihydric alcohol quality of -12, the consumption of described esterification reaction catalyst is not 0; In the step 1) after the esterification reaction step and before the polycondensation reaction step, and in the step 2) after the transesterification reaction step and before the polycondensation reaction step, a polycondensation reaction catalyst can also be added; the polycondensation reaction catalysts are all selected from concentrated Sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate, sodium carbonate , calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyltin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, alkylgermanium with a total of 4-40 carbon atoms, carbon At least one of alkoxygermanium with a total number of atoms of 4-40, an alkylzinc with a total number of carbon atoms of 4-40, alkoxyzinc with a total number of carbon atoms of 4-40, and ferrous lactate; the step 1 ) in the amount of the polycondensation reaction catalyst is 0-2% of the sum of the mass of the aliphatic dibasic acid with a total carbon number of 2-12 and the aliphatic dibasic alcohol with a total number of carbon atoms of 2-12, and the polycondensation reaction The amount of the catalyst is not 0; the amount of the polycondensation reaction catalyst in the step 2) is 0-2% of the sum of the mass of the dibasic carbonate and the aliphatic diol with a total carbon number of 2-12. The amount of polycondensation reaction catalyst is not 0; After step 2) and step 3) before the chain extension copolymerization reaction step, a chain extension reaction catalyst can also be added; the chain extension reaction catalyst is selected from tertiary amine chemicals, inorganic acids, metals, metal oxides, and metal chlorides , metal acetate, organic titanium compound, organic germanium compound, organic tin compound, organic aluminum compound and organic iron compound; and 0-5% of the sum of the mass of the hydroxyl-terminated polycarbonate prepolymer, and the amount of the chain extension reaction catalyst is not zero. 9. The block copolymer according to claim 8, characterized in that: in the step 1) before the esterification step, an esterification catalyst is added; the esterification catalyst is selected from tin powder, three At least one of antimony oxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate; the amount of the esterification catalyst is the 0-0.6% of the mass sum of aliphatic dibasic acid with 2-12 carbon atoms and aliphatic dibasic alcohol with 2-12 carbon atoms, the amount of esterification catalyst is not 0; In the step 1) after the esterification reaction step and before the polycondensation reaction step, and in the step 2) after the transesterification reaction step and before the polycondensation reaction step, a polycondensation reaction catalyst can also be added; the polycondensation reaction catalysts are all selected from tin powder, antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate; polycondensation reaction in step 1) The amount of catalyst used is 0-0.6% of the sum of the mass sum of the aliphatic dibasic acid with 2-12 carbon atoms and the aliphatic dibasic alcohol with 2-12 carbon atoms, and the amount of the polycondensation reaction catalyst is not is 0; the amount of the polycondensation reaction catalyst in the step 2) is 0-0.6% of the sum of the mass of the dibasic carbonate and the total number of carbon atoms of 2-12 aliphatic dihydric alcohols, and the amount of the polycondensation reaction catalyst The usage amount is not 0; After step 2) and step 3) before the chain extension copolymerization reaction step, a chain extension reaction catalyst can also be added; the chain extension reaction catalyst is selected from triethylamine, dimethyl hexadecylamine, stannous octoate, trichloride At least one of butyltin, dibutyltin dilaurate, calcium phosphonate, lithium chloride, anhydrous zinc acetate, zinc undecylenate and zinc soap; 0-4% of the sum of the weight of the polyester prepolymer and the hydroxyl-terminated polycarbonate prepolymer, and the amount of the chain extension reaction catalyst is not 0. 10. The block copolymer according to any one of claims 1-3, characterized in that: the reaction device for the chain extension copolymerization reaction is a reactor or a twin-screw extruder. 11. The block copolymer according to claim 10, characterized in that: in the step of carrying out the chain extension reaction in the reactor, the temperature is 80-200°C, and the time is 0.5-6 hours; In the step of carrying out the chain extension copolymerization reaction in the twin-screw extruder, the screw temperature is 100-280°C, the screw speed is 5-500r/min, and the residence time is 0.5-30min; In the step of carrying out the chain extension copolymerization reaction in the machine, the temperatures of the screw from zone I to zone IV and the machine head are: 100-220°C, 100-280°C, 100-280°C, 100-280°C and 100-220°C . 12. The block copolymer according to claim 11, characterized in that: in the step of carrying out the chain extension reaction in the reactor, the temperature is 90-190° C., and the time is 0.5-5 hours; In the step of carrying out the chain extension copolymerization reaction in the twin-screw extruder, the screw temperature is 100-250°C, the screw speed is 30-300r/min, and the residence time is 2-15min; In the step of carrying out the chain extension copolymerization reaction in the machine, the temperatures of the screw from zone I to zone IV and the machine head are: 110-200°C, 120-200°C, 130-250°C, 130-200°C and 100-200°C . 13. A method for preparing the block copolymer described in any one of claims 1-3, comprising the steps of: 1) The aliphatic dibasic acid with a total of 2-12 carbon atoms and the aliphatic dibasic alcohol with a total of 2-12 carbon atoms are subjected to esterification reaction, and then polycondensation reaction is carried out after the reaction is completed, and the hydroxyl-terminated polyol is obtained after the reaction is completed. Ester prepolymers; 2) Mix the dibasic carbonate, the aliphatic dihydric alcohol with the total number of carbon atoms of 2-12, and the transesterification reaction catalyst to carry out the transesterification reaction, and then conduct the polycondensation reaction after the reaction is completed, and the hydroxyl-terminated polyol Carbonate prepolymer; 3) The hydroxyl-terminated polyester prepolymer obtained in step 1) and the hydroxyl-terminated polycarbonate prepolymer obtained in step 2) are subjected to a chain extension copolymerization reaction under the action of a chain extender, and the block copolymerization is obtained after the reaction is completed. things. 14. The method according to claim 13, characterized in that: the aliphatic dibasic acid whose total carbon number is 2-12 is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, octane At least one of diacid, sebacic acid and dodecanedioic acid; the aliphatic dihydric alcohols with a total carbon number of 2-12 are all selected from ethylene glycol, 1,3-propanediol, 2-methyl -1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, a At least one of ethylene glycol and triethylene glycol; The dibasic carbonate is selected from at least one of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate and diphenyl carbonate; The transesterification reaction catalyst is selected from concentrated sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony ethylene glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate , manganese acetate, potassium carbonate, sodium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyl tin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, a total of At least one of alkyl germanium with 4-40 and alkoxy germanium with total carbon atoms of 4-40; The chain extender is selected from the group consisting of diepoxides, bisoxazolines, diisocyanates, polycarbodiimides, bisphthalimides, carboxylic anhydrides, bicyclic imide esters, organosilazanes and diacyl At least one of the bislactams. 15. The method according to claim 14, characterized in that: the total number of carbon atoms is 2-12 aliphatic dibasic acid selected from at least one of oxalic acid, succinic acid and adipic acid; the total number of carbon atoms The aliphatic dihydric alcohols of 2-12 are all selected from at least one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol; The dibasic carbonate is selected from at least one of dimethyl carbonate, diethyl carbonate and diphenyl carbonate; The transesterification catalyst is at least one selected from tin powder, antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate ; The chain extender is selected from bis(3,4-epoxycyclohexylmethyl) adipate, N, N-diepoxypropyl benzamide, uracil, barbituric acid, N-N-diepoxypropylene Diimide, N-N-diepoxypropyl imidazolinone, 2,2-bis(2-bisoxazoline), toluene diisocyanate, diphenylmethane diisocyanate, polymerized diphenylmethane diisocyanate, Methylene bis(4-cyclohexyl isocyanate), hexamethylene diisocyanate, dicyclohexylmethane-4-4'-diisocyanate, 2,2,4-trimethylhexane diisocyanate, bis(o-phenyl dicarboximide), 1,2,4,5-benzenetetracarboxylic dianhydride, phthalic anhydride, succinic anhydride, bisdioxazolone or bisbenzoxazine, octamethylcyclotetrasilazane , Hexaphenyltrisilazane, N, N'-carbonylbispyrrolidone, N,N'-carbonylbiscaprolactam, N,N'-carbonylbislaurolactam, N,N'-oxalylbis Pyrrolidone, N,N'-Oxalylbiscaprolactam, N,N'-Oxalylbislaurolactam, N,N'-Succinoylbispyrrolidone, N,N'-Adipylbispyrrolidone, N,N '-Adipylbislactam, N,N'-phthaloylbispyrrolidone, N,N'-phthaloylbislaurolactam, N,N'-terephthaloylbispyrrole At least one of alkanes and N,N'-terephthaloyl dilaurolactam. 16. The method according to claim 13, characterized in that: in the step 1), the aliphatic dihydric alcohol with a total of 2-12 carbon atoms and the aliphatic dihydric alcohol with a total of 2-12 carbon atoms The feeding molar ratio of the acid is 3.0-1.0; in the esterification reaction step, the temperature is 100-300°C, and the time is 2-20 hours; in the polycondensation reaction step, the temperature is 150-300°C, and the time is 1-20 hours. 20 hours, the vacuum degree is 1Pa～3×10 ⁴ Pa; In the step 2), the molar ratio of the aliphatic dihydric alcohol with a total carbon number of 2-12 to the carbonic acid dibasic ester is 3.0-1.0; the amount of the transesterification catalyst used is the carbonic acid 0-2% of the sum of the mass of dibasic ester and the total number of carbon atoms of 2-12 aliphatic diols, the amount of the transesterification catalyst is not 0; in the transesterification step, the temperature is 70- 300°C, the time is 2-20 hours; in the polycondensation reaction step, the temperature is 150-280°C, the time is 1-20 hours, and the vacuum degree is 1Pa～3×10 ⁴ Pa; In the step 3), the ratio of the chain extender to the sum of the molar amounts of the hydroxyl-terminated polyester prepolymer and the polycarbonate prepolymer is 0.3-6. 17. The method according to claim 16, characterized in that: in step 1), the aliphatic dihydric alcohol with a total of 2-12 carbon atoms and the aliphatic dihydric alcohol with a total of 2-12 carbon atoms The feeding molar ratio of the acid is 2.0-1.0; in the esterification reaction step, the temperature is 110-260°C, and the time is 3-15 hours; in the polycondensation reaction step, the temperature is 150-280°C, and the time is 1- 10 hours, the vacuum degree is 1Pa～2×10 ⁴ Pa; In the step 2), the molar ratio of the aliphatic dihydric alcohol with a total carbon number of 2-12 to the carbonic acid dibasic ester is 2.0-1.0; the amount of the transesterification reaction catalyst is 0-0.6% of the sum of the mass of dibasic ester and the total number of carbon atoms of 2-12 aliphatic diols, the amount of the transesterification catalyst is not 0; in the transesterification step, the temperature is 80- 230°C, the time is 3-15 hours; in the polycondensation reaction step, the temperature is 150-250°C, the time is 1-10 hours, and the vacuum degree is 1Pa～2×10 ⁴ Pa; In the step 3), the ratio of the chain extender to the sum of the molar amounts of the hydroxyl-terminated polyester prepolymer and the polycarbonate prepolymer is 0.5-4. 18. The method according to claim 13, characterized in that: in step 1) before the esterification step, an esterification catalyst is added; the esterification catalyst is selected from concentrated sulfuric acid, p-toluenesulfonic acid , tin powder, antimony trioxide, antimony glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate, sodium carbonate, calcium carbonate, bicarbonate Sodium, potassium bicarbonate, alkyltin with a total of 4-40 carbon atoms, tin alkoxide with a total of 4-40 carbon atoms, alkylgermanium with a total of 4-40 carbon atoms and 4-40 carbon atoms At least one of the alkoxy germanium; the amount of the esterification catalyst is the quality of the aliphatic dibasic acid with a total carbon number of 2-12 and the aliphatic dibasic alcohol with a total number of carbon atoms of 2-12 0-2% of the sum, the amount of the esterification catalyst is not 0; In the step 1) after the esterification reaction step and before the polycondensation reaction step, and in the step 2) after the transesterification reaction step and before the polycondensation reaction step, a polycondensation reaction catalyst can also be added; the polycondensation reaction catalysts are all selected from concentrated Sulfuric acid, p-toluenesulfonic acid, tin powder, antimony trioxide, antimony glycol, antimony acetate, germanium dioxide, germanium chloride, tin tetrachloride, magnesium acetate, zinc acetate, manganese acetate, potassium carbonate, sodium carbonate , calcium carbonate, sodium bicarbonate, potassium bicarbonate, alkyltin with a total of 4-40 carbon atoms, alkoxytin with a total of 4-40 carbon atoms, alkylgermanium with a total of 4-40 carbon atoms, carbon At least one of alkoxygermanium with a total number of atoms of 4-40, an alkylzinc with a total number of carbon atoms of 4-40, alkoxyzinc with a total number of carbon atoms of 4-40, and ferrous lactate; the step 1 ) in the amount of the polycondensation reaction catalyst is 0-2% of the sum of the mass of the aliphatic dibasic acid with a total carbon number of 2-12 and the aliphatic dibasic alcohol with a total number of carbon atoms of 2-12, and the polycondensation reaction The amount of the catalyst is not 0; the amount of the polycondensation reaction catalyst in the step 2) is 0-2% of the sum of the mass of the dibasic carbonate and the aliphatic diol with a total carbon number of 2-12. The amount of polycondensation reaction catalyst is not 0; After step 2) and step 3) before the chain extension copolymerization reaction step, a chain extension reaction catalyst can also be added; the chain extension reaction catalyst is selected from tertiary amine chemicals, inorganic acids, metals, metal oxides, and metal chlorides , metal acetate, organic titanium compound, organic germanium compound, organic tin compound, organic aluminum compound and organic iron compound; and 0-5% of the sum of the mass of the hydroxyl-terminated polycarbonate prepolymer, and the amount of the chain extension reaction catalyst is not zero. 19. The method according to claim 18, characterized in that: in step 1) before the esterification step, an esterification catalyst is added; the esterification catalyst is selected from tin powder, antimony trioxide , at least one of butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate; the amount of catalyst for the esterification reaction is the total number of carbon atoms 0-0.6% of the sum of the mass of aliphatic dibasic acid with 2-12 carbon atoms and aliphatic dibasic alcohol with total carbon atoms of 2-12, and the amount of the esterification catalyst is not 0; In the step 1) after the esterification reaction step and before the polycondensation reaction step, and in the step 2) after the transesterification reaction step and before the polycondensation reaction step, a polycondensation reaction catalyst can also be added; the polycondensation reaction catalysts are all selected from tin powder, antimony trioxide, butyl titanate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, germanium dioxide, zinc acetate, manganese acetate and stannous octoate; polycondensation reaction in step 1) The amount of catalyst used is 0-0.6% of the sum of the mass sum of the aliphatic dibasic acid with 2-12 carbon atoms and the aliphatic dibasic alcohol with 2-12 carbon atoms, and the amount of the polycondensation reaction catalyst is not is 0; the amount of the polycondensation reaction catalyst in the step 2) is 0-0.6% of the sum of the mass of the dibasic carbonate and the total number of carbon atoms of 2-12 aliphatic dihydric alcohols, and the amount of the polycondensation reaction catalyst The usage amount is not 0; After step 2) and step 3) before the chain extension copolymerization reaction step, a chain extension reaction catalyst can also be added; the chain extension reaction catalyst is selected from triethylamine, dimethyl hexadecylamine, stannous octoate, trichloride At least one of butyltin, dibutyltin dilaurate, calcium phosphonate, lithium chloride, anhydrous zinc acetate, zinc undecylenate and zinc soap; 0-4% of the sum of the weight of the polyester prepolymer and the hydroxyl-terminated polycarbonate prepolymer, and the amount of the chain extension reaction catalyst is not 0. 20. The method according to claim 13, characterized in that: the reaction device for the chain extension copolymerization reaction is a reactor or a twin-screw extruder. 21. The method according to claim 20, characterized in that: in the step of carrying out the chain extension reaction in the reactor, the temperature is 80-200°C, and the time is 0.5-6 hours; In the step of carrying out the chain extension copolymerization reaction in the twin-screw extruder, the screw temperature is 100-280°C, the screw speed is 5-500r/min, and the residence time is 0.5-30min; In the step of carrying out the chain extension copolymerization reaction in the machine, the temperatures of the screw from zone I to zone IV and the machine head are: 100-220°C, 100-280°C, 100-280°C, 100-280°C and 100-220°C . 22. The method according to claim 21, characterized in that: in the step of carrying out the chain extension reaction in the reactor, the temperature is 90-190° C., and the time is 0.5-5 hours; In the step of carrying out the chain extension copolymerization reaction in the twin-screw extruder, the screw temperature is 100-250°C, the screw speed is 30-300r/min, and the residence time is 2-15min; In the step of carrying out the chain extension copolymerization reaction in the machine, the temperatures of the screw from zone I to zone IV and the machine head are: 110-200°C, 120-200°C, 130-250°C, 130-200°C and 100-200°C . 23. The use of any one of claims 1-12 block copolymers in the preparation of impact modifiers for biodegradable polymer materials.