CN111978687A - Fully biodegradable composite polymer material and its preparation method and application - Google Patents

Abstract

The invention provides a fully biodegradable composite polymer material and a preparation method and application thereof. By introducing grafted cellulose, the compatibility of various synthetic biodegradable materials with natural polymer materials such as starch and cellulose can be effectively improved. The mechanical properties of the material can still be effectively improved when the addition amount of natural polymer material exceeds 66.6 wt%. The uncertain factors such as cross-linking and precipitation in the use of small molecular epoxy compatibilizers are avoided. The cellulose graft compatibilizer synthesized by the invention makes full use of inexpensive and renewable resources such as cellulose and carbon dioxide, can effectively reduce the preparation cost of compatibilizer materials, and is helpful for promoting the scale of biodegradable polymer materials application.

Description

Fully biodegradable composite polymer material and its preparation method and application

technical field

The invention relates to the technical field of environment-friendly polymer materials, in particular to a fully biodegradable composite polymer material and a preparation method and application thereof.

Background technique

The rapid development of polymer material synthesis technology has provided human beings with a large number of new materials that can be used to meet the needs of people's daily life and production and construction. At present, polymer materials and their products have become an indispensable part of our production and life. However, while polymer materials have brought us great convenience, they have also brought many environmental problems. Most of the traditional polymer materials represented by polyolefins are difficult to degrade. After a large number of disorderly use, serious white pollution is caused, which in turn leads to soil pollution and marine pollution, which seriously threatens the safety of the natural environment on which humans and living things depend. Especially in recent years, with the rapid development of express delivery, takeaway services and other industries, the consumption of disposable plastic packaging materials has increased rapidly, which has caused huge pressure on our environment. The development of degradable polymer materials and their products has become a social consensus.

Biodegradable polymer materials refer to a class of polymer materials that can be decomposed by microorganisms and eventually degraded into water and carbon dioxide after use. Therefore, the plastic products prepared by using it as raw materials will gradually degrade in the soil after use, and will not cause a large amount of accumulation, which can avoid its pollution to the soil and the surrounding environment. According to different sources, biodegradable polymer materials are divided into natural degradable polymer plastics, such as starch, cellulose, chitin, etc. Another category is the rapid development of synthetic biodegradable polymer materials in recent years, including polylactic acid, polybutylene terephthalate succinate (PBAT), carbon dioxide-based plastics and polyhydroxyalkanoates (PHA). These two types of materials have their own advantages and disadvantages. Natural polymer materials are derived from renewable earth resources, which are abundant in source and low in price, and can be quickly degraded after use, with little pressure on the environment. However, the structure of such materials is not clear, and the processing and mechanical properties are poor, and the excessively fast degradation rate has also become a bottleneck restricting their use. Synthetic degradable polymer materials are better than natural polymer materials because of controllable parameters such as structure and molecular weight, and processing and mechanical properties. But the problem is that the high cost and the slow degradation rate of some products have become the key problems restricting its large-scale promotion and application.

In view of the above problems, the preparation of fully biodegradable polymer materials by blending natural polymers and synthetic polymers is an important direction in the industry at present. This route can make full use of the advantages of the two types of polymer materials in performance and cost. , to develop degradable materials acceptable to the market. However, when the two types of materials are blended, the differences in hydrophilicity, hydrophobicity and crystallinity caused by the structure make the compatibility between different materials poor. However, most of the compatibilizers used for the modification of traditional polymer materials cannot be directly applied to the degradation system. Therefore, it is necessary to carry out research on compatibilization and modification specially applied to the degradation system.

SUMMARY OF THE INVENTION

In view of this, the present invention aims to realize the preparation of high-performance and low-cost fully biodegradable composite polymer materials by using a cellulose graft compatibilizer. The invention can obviously improve the compatibility between natural macromolecules such as starch and cellulose and many synthetic macromolecular materials, and the modified material has good mechanical properties and can greatly reduce the material preparation cost.

A fully biodegradable composite polymer material, comprising the following components:

Preferably, the biodegradable resin is selected from polybutylene terephthalate adipate (PBAT), polybutylene succinate adipate (PBSA), polylactic acid (PLA), carbon dioxide-based plastic (PPC) ) of one or more of the mixtures.

Preferably, the carbon dioxide-based plastic (PPC) is a copolymer of carbon dioxide and propylene oxide, the molecular weight is between 50,000 and 200,000, and the molecular weight distribution is less than 3.3.

Preferably, the cellulose graft compatibilizer is composed of a cellulose derivative containing active hydrogen as a main chain and a hydrophilic end, and a segment containing a carbonate bond and an ether bond structure as a side chain and a hydrophobic end. Cellulose grafted fully biodegradable polymer material.

Preferably, the structure of the cellulose graft compatibilizer is as follows:

CL为纤维素主链，

CL is the main chain of cellulose,

where x is 10% to 90%, the remainder is y, and x+y=1,

wherein R is selected from hydrogen, halogen, aliphatic, substituted aliphatic, substituted heteroaliphatic, aryl, substituted aryl or substituted heteroaryl.

Preferably, the particle size of the lignin or starch is 100-500 mesh.

Preferably, the antioxidant is bisphenol A, 1,4-bis-tert-butylperoxy cumene, N,N'-hexamethylenebis(3,5-di-tert-butyl-4- Hydroxyphenylpropionamide), bisphenol A phosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, tetrakis[β(3,5-di-tert-butyl) yl-4-hydroxyphenyl)propionic acid] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, 4,4'-bis-(α,α'-dimethylbenzyl) At least two of diphenylamine, dodecathiopropyl, and 1,4-bis-tert-butylperoxy cumene.

Preferably, the stabilizer refers to calcium stearate, zinc stearate, zinc oxide, magnesium oxide, epoxy soybean oil, epoxy linseed oil, epoxy tall oil, epoxy butyl stearate at least one.

Preferably, the lubricant is one or a mixture of stearic acid and its salts, montan wax, erucamide, oleic acid amide or ethylene bis-stearamide.

A method for preparing a fully biodegradable composite polymer material, comprising the following steps: mixing according to the component ratios described in any one of claims 1 to 7, then adding it to a mixer and mixing for 3 to 10 minutes, and feeding the double The fully biodegradable composite polymer material is obtained by melting, plasticizing, and extrusion granulation in a screw extruder.

beneficial effect

The invention provides a kind of polybutylene terephthalate adipate (PBAT), polybutylene succinate adipate (PBSA) and polylactic acid (PLA) using cellulose grafted compatibilizers. Synthetic biodegradable polymer materials such as carbon dioxide-based plastics (PPC) and natural polymer materials such as starch and cellulose are blended and modified to solve the problem of poor compatibility between the two types of polymer materials, which can effectively reduce material costs. Help promote the application.

Moreover, the improvement of the compatibility of the synthetic biodegradable polymer material synthesized by the present invention after blending and modification with natural polymer materials such as starch and cellulose can be directly reflected in the obvious improvement of the mechanical properties of the material. The tensile strength of the blend is increased by 30-50%, the elongation at break is increased by 20-40%, and after blow molding, the longitudinal tear resistance is increased by 20-60%, and the transverse elongation at break is increased by 10-30% %, the transverse tear resistance is improved by about 20-50%.

In addition, it should be noted that, after the compatibilizer is added in the present invention, the mechanical properties of the material can still be effectively improved when the added amount of the natural polymer material in the blend exceeds 66.6 wt%.

The cellulose graft compatibilizer synthesized by the invention makes full use of inexpensive and renewable resources such as cellulose and carbon dioxide, and can effectively reduce the preparation cost of the compatibilizer material.

Detailed ways

The innovation of the invention lies in the use of a cellulose grafted compatibilizer, which can effectively improve the compatibility between starch, cellulose and synthetic polymer materials, and the added amount of natural polymer materials exceeds 66.6 wt% It can still effectively improve the mechanical properties of the material, and avoid the uncertain factors such as cross-linking and precipitation existing in the use of small-molecule epoxy compatibilizers. The main reason for the improved compatibility in the present invention is due to the special structure of the grafted cellulose. The structure contains some unsubstituted hydroxyl groups and other groups, and also contains carbonate chain segments, so it can effectively increase carbon dioxide. Compatibility between base plastics, polycarbonates such as polybutylene terephthalate adipate, and polyester biodegradable polymers and natural polymers such as cellulose.

The present invention will be described in more detail below, wherein preferred embodiments of the invention are shown, and it should be understood that those skilled in the art can modify the invention described herein and still achieve the beneficial effects of the invention. Therefore, the following description should be construed as widely known to those skilled in the art and not as a limitation of the present invention.

In the interest of clarity, not all features of an actual embodiment are described. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention with unnecessary detail. It should be recognized that in the development of any actual embodiment, a number of implementation details must be made to achieve the developer's specific goals.

Wherein, the carbon dioxide-based plastic (PPC) adopted in the following examples is prepared by the following method: get 2g zinc glutarate catalyst and 200mL propylene oxide and add in the autoclave of fully dried 500mL, in the autoclave Carbon dioxide was introduced to 4.0 MPa, and the reaction was terminated after 8 h of copolymerization at 80° C. The obtained product was precipitated with ethanol and dried in vacuum to obtain 150 g of carbon dioxide-based plastic (PPC). The number average molecular weight is 125000 and the molecular weight distribution is 2.8 by GPC test (mobile phase is THF).

Wherein, the required zinc glutarate catalyst was prepared by the following method: in a 500 mL three-necked reaction flask, 13.2 g of glutaric acid was dissolved in 150 mL of toluene. Then fine powder 8.5g ZnO was added to the above toluene solution. After the addition was completed, a slurry mixture was formed, and the mixture was vigorously stirred at 55° C. for 4 hours. After cooling to room temperature, the reaction mixture was filtered and washed with acetone for several times to obtain a powdery zinc glutarate catalyst.

The cellulose graft compatibilizer used in the embodiment is prepared by the following method: 10g of fully dried carboxymethyl cellulose and 30ml of dioxane are added to a 200ml reactor that has been dewatered and deoxygenated in advance. , fully stirred for 1h. Continue to add 30 ml of propylene oxide and 2 g of zinc glutarate catalyst, continue to stir at room temperature for 1 hour, then fill with carbon dioxide to a pressure of 3 MPa, heat up to 70 ° C and stir for 8 hours. The reactants in the kettle were poured into 200ml of ethanol under stirring conditions, the obtained solid product was filtered, and washed twice with ethanol, and the obtained solid was vacuum-dried to obtain a cellulose graft compatibilizer A, a cellulose graft compatibilizer After A was dissolved in tetrahydrofuran to form a film, the water contact angle was measured to be 55.1°. The results of GPC test (THF as mobile phase) showed that the number average molecular weight was 35600, and the molecular weight distribution was 2.35.

The raw materials used in other embodiments are all commercially available products unless otherwise specified. Among them, polybutylene terephthalate adipate (PBAT) was purchased from BASF in Germany or Zhejiang Xinfu, and polylactic acid was purchased from Zhejiang Hisun.

Example 1:

Prepare the components in the following proportions:

After PBAT and starch are fully vacuum-dried, cellulose graft compatibilizer A, bisphenol A phosphite (antioxidant), dodecyl thiopropyl ester (antioxidant), calcium stearate, mustard are added in proportion acid amide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T 1040.3-2006, and the results showed that the tensile strength of the prepared blend was 50.25MPa, and the elongation at break was 90.25%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance is 820 mN, the transverse elongation at break is 450%, and the transverse tear resistance is 2250 mN.

Example 2:

Prepare the components in the following proportions:

After PPC and starch are fully vacuum-dried, cellulose graft compatibilizer A, tetrakis[beta(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester (antioxidant), Dodecathiopropyl (antioxidant), calcium stearate, erucamide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T1040.3-2006, and the results showed that the tensile strength of the prepared blend was 45.50 MPa, and the elongation at break was 85.60%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 785 mN, the transverse elongation at break was 520%, and the transverse tear resistance was 2050 mN.

Example 3:

Prepare the components in the following proportions:

PLA/PPC and starch are fully vacuum-dried and then added in proportion to cellulose graft compatibilizer A, 1,4-bis-tert-butylperoxy cumene (antioxidant), tris(2,4- phosphite) Di-tert-butylphenyl) ester (antioxidant), calcium stearate, erucamide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T1040.3-2006, and the results showed that the tensile strength of the prepared blend was 41.50 MPa, and the elongation at break was 95.30%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 845 mN, the transverse elongation at break was 560%, and the transverse tear resistance was 2045 mN.

Example 4:

Prepare the components in the following proportions:

After PBAT/PPC and starch are fully vacuum dried, add cellulose graft compatibilizer A, bisphenol A phosphite (antioxidant), dodecylthiopropyl ester (antioxidant), calcium stearate in proportion , Erucamide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T 1040.3-2006, and the results showed that the tensile strength of the prepared blend was 52.5MPa, and the elongation at break was 78.5%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 753 mN, the transverse elongation at break was 425%, and the transverse tear resistance was 1920 mN.

Example 5:

Prepare the components in the following proportions:

After PBAT and starch are fully vacuum-dried, cellulose graft compatibilizer A, bisphenol A phosphite (antioxidant), dodecyl thiopropyl ester (antioxidant), calcium stearate, mustard are added in proportion acid amide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T 1040.3-2006, and the results showed that the tensile strength of the prepared blend was 52.3 MPa, and the elongation at break was 102.3%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance is 850 mN, the transverse elongation at break is 510%, and the transverse tear resistance is 2200 mN.

Example 6:

Prepare the components in the following proportions:

After PBAT and starch are fully vacuum-dried, cellulose graft compatibilizer A, bisphenol A phosphite (antioxidant), dodecyl thiopropyl ester (antioxidant), calcium stearate, mustard are added in proportion acid amide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T 1040.3-2006, and the results showed that the tensile strength of the prepared blend was 45.6 MPa, and the elongation at break was 95.6%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 856 mN, the transverse elongation at break was 510%, and the transverse tear resistance was 2100 mN.

Example 7:

Prepare the components in the following proportions:

After PBAT and starch are fully vacuum-dried, cellulose graft compatibilizer A, bisphenol A phosphite (antioxidant), dodecyl thiopropyl ester (antioxidant), calcium stearate, mustard are added in proportion acid amide. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained material were tested according to GB/T 1040.3-2006, and the results showed that the tensile strength of the prepared blend was 48.5MPa, and the elongation at break was 75.5%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 750 mN, the transverse elongation at break was 420%, and the transverse tear resistance was 1900 mN.

Comparative Example 1 (Comparative Example 1):

Prepare the components in the following proportions:

After PBAT and starch are fully vacuum-dried, bisphenol A phosphite (antioxidant), dodecylthiopropyl (antioxidant), calcium stearate and erucamide are added in proportion. After mixing, add it into the mixer and continue to fully mix for 3 minutes. After the mixing is completed, it is fed into a twin-screw extruder for melting, plasticizing, extrusion and granulation, so as to obtain the fully biodegradable composite polymer material. The mechanical properties of the obtained materials were tested according to GB/T 1040.3-2006.

The results showed that the tensile strength of the prepared blend was 42.0 MPa and the elongation at break was 70.2%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 620 mN, the transverse elongation at break was 385%, and the transverse tear resistance was 1800 mN.

Comparative Example 2 (Comparative Example 2):

The same components as Example 2, the difference is only that no cellulose graft compatibilizer A is added, and then the obtained material is tested for its mechanical properties according to GB/T 1040.3-2006.

The results showed that the tensile strength of the prepared blend was 30.5 MPa and the elongation at break was 45.2%. The above-mentioned materials obtained were blown into a film on a single-screw film blowing machine to obtain a fully biodegradable mulch film with a thickness of 12 microns. The longitudinal tear resistance was 480 mN, the transverse elongation at break was 320%, and the transverse tear resistance was 1350 mN.

Comparative Example 3 (Comparative Example 6):

The same components as Example 6, the difference is only that no cellulose graft compatibilizer A is added, and then the obtained material is tested for its mechanical properties according to GB/T 1040.3-2006.

The results showed that the tensile strength of the prepared blend was 25.5 MPa and the elongation at break was 12.3%. The above-mentioned materials obtained are blown into a film on a single-screw film blowing machine, and it is difficult to form a film, which shows that the compatibility between the materials is poor, the toughness is poor, and it is difficult to form a film.

By comparing the examples and the comparative examples, it can be shown that the tensile strength of the material without the cellulose graft compatibilizer is low, and the parameters such as tear resistance and elongation at break after being processed into a film are obviously reduced, which fully proves that this It is found that the addition of cellulose graft compatibilizer can effectively improve synthetic biodegradable polymer materials (such as polybutylene terephthalate adipate (PBAT), polybutylene succinate adipate (PBSA) , polylactic acid (PLA), carbon dioxide-based plastics (PPC), etc.) and natural polymer materials such as starch and cellulose compatibility, improve mechanical properties, avoid the small molecular epoxy compatibilizers disclosed in the prior art Crosslinking and precipitation during use. Moreover, the mechanical properties of the material can still be effectively improved when the natural polymer material is added in an amount exceeding 66.6 wt%.

The preferred embodiments of the present invention have been described above, but are not intended to limit the present invention. Modifications and variations of the embodiments disclosed herein may be made by those skilled in the art without departing from the scope and spirit of the invention.

Claims (10)

1. The full-biodegradable composite high polymer material is characterized by comprising the following components:

。

2. the fully biodegradable composite polymer material according to claim 1, wherein said biodegradable resin is selected from the group consisting of polybutylene terephthalate adipate (PBAT), polybutylene adipate succinate (PBSA), polylactic acid (PLA), and carbon dioxide-based plastics (PPC).

3. The fully biodegradable composite polymer material according to claim 2, wherein said carbon dioxide-based plastic (PPC) is a copolymer of carbon dioxide and propylene oxide, the molecular weight is 50000-200000, and the molecular weight distribution is less than 3.

4. The fully biodegradable composite polymer material according to claim 1, wherein the cellulose graft compatibilizer is: the cellulose grafted full-biodegradable polymer material is formed by taking a cellulose derivative containing active hydrogen as a main chain and a hydrophilic end, and taking a chain segment containing a carbonate bond and an ether bond structure as a side chain and a hydrophobic end.

5. The fully biodegradable composite polymer material according to claim 4, wherein the structure of the cellulose graft compatibilizer is as follows:

and CL is the main chain of cellulose,

wherein x is 10% -90%, the balance is y, and x + y =1,

wherein R is selected from the group consisting of hydrogen, halogen, aliphatic, substituted heteroaliphatic, aryl, substituted aryl, and substituted heteroaryl.

6. The fully biodegradable composite polymer material according to claim 1, wherein the particle size of the lignin or starch is 100-500 mesh.

7. The fully biodegradable composite polymeric material according to claim 1, wherein the antioxidant is at least two selected from the group consisting of bisphenol A, 1, 4-bis-tert-butylperoxyisopropyl benzene, N ' -hexamethylenebis (3, 5-di-tert-butyl-4-hydroxy-phenylacrylamide), bisphenol A phosphite, octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol tetrakis [ beta (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], tris (2, 4-di-tert-butylphenyl) phosphite, 4 ' -bis- (alpha, alpha ' -dimethylbenzyl) diphenylamine, dodecathiopropyl ester, and 1, 4-bis-tert-butylperoxyisopropyl benzene.

8. The fully biodegradable composite polymer material according to claim 1, wherein said stabilizer is at least one selected from the group consisting of calcium stearate, zinc oxide, magnesium oxide, epoxidized soybean oil, epoxidized linseed oil, epoxidized tall oil, and epoxidized butyl stearate.

9. The fully biodegradable composite polymer material according to claim 1, wherein the lubricant is one or more selected from stearic acid and its salts, montan wax, erucamide, oleamide, and ethylene bis-stearamide.

10. The preparation method of the fully biodegradable composite polymer material as claimed in any one of claims 1 to 7, characterized by comprising the following steps: the components are mixed according to the proportion of any one of claims 1 to 7, then the mixture is added into a mixer to be mixed for 3 to 10 minutes, and after the mixture is finished, the mixture is fed into a double-screw extruder to be melted, plasticized, extruded and granulated, so that the fully biodegradable composite polymer material is obtained.