CN102392318B - Biobased biodegradable fiber and preparation method thereof - Google Patents

Abstract

The invention relates to a bio-based degradable fiber and a preparation method thereof. The current bio-based biodegradable polymer spinning technology has various deficiencies. The bio-based degradable fiber of the present invention is a composition comprising a PHA homopolymer or copolymer with a volume crystallinity of 5-75% and a PLA homopolymer or copolymer with a volume crystallinity of 5-65%. PLA homopolymers or copolymers account for 5-55% of the fiber weight, and PLA homopolymers or copolymers account for 45-95% of the fiber weight. The specific preparation method is first to vacuum-dry the PHA homopolymer or copolymer and the PLA homopolymer or copolymer respectively, then perform physical mixing in proportion, melt spinning, and finally carry out post-treatment. The bio-based degradable fiber disclosed in the present invention has better spinnability at a lower spinning temperature and a higher spinning speed, and has higher mechanical strength and a softer hand feeling that is sustained and stable. The preparation method can effectively improve the production efficiency and reduce the cost.

Description

A kind of bio-based degradable fiber and preparation method thereof

technical field

The invention belongs to the technical field of polymer materials, and relates to a bio-based degradable fiber and a preparation method thereof.

Background technique

Chemical fiber has become an indispensable and huge amount of chemical products in people's daily life, industrial and agricultural production. Traditional chemical fibers mainly use petroleum-based polymers as raw materials. As petroleum is a non-renewable resource, it is increasingly depleted, which brings a huge crisis to the sustainable development of chemical fibers. In addition, the waste of traditional chemical fibers is usually not easy to degrade, which brings great harm to the ecological environment. to bear. In order to solve the above problems, there is an urgent need to develop and utilize renewable resources, especially bio-based degradable fibers.

The raw material of bio-based degradable fibers can be a single bio-based degradable polymer, a mixture of two or more bio-based degradable polymers, or a mixture of bio-based degradable polymers and petroleum-based polymers. The carbon content can be determined by radiocarbon dating technology in accordance with ASTM D6866, ISO/NP13833 and other standards. According to the relevant regulations of developed countries and regions such as the United States, Japan, and Europe, the use of star or environmental protection labels (such as EcoLogo, OK Biobased, etc.) is granted to bio-based products (including bio-based degradable fibers) that meet the bio-based carbon content standards. , and then included in the priority procurement plan for biological products. These policies have created opportunities for the promotion and application of bio-based degradable fibers.

In the family of bio-based degradable polymers, polylactic acid (PLA) (L-polylactic acid, D-polylactic acid, D,L-polylactic acid) or PLA copolymer is known as the most promising environmentally friendly polymer in this century. One of the molecular materials. With the maturity of large-scale production technology of PLA resin and the reduction of production cost, the application of PLA homopolymer or copolymer in packaging, textile and other fields has attracted more and more attention in recent years. However, certain chemical and physical properties of PLA, such as relatively low heat distortion temperature, high melt viscosity, easy degradation at higher temperatures, slow degradation rate under natural conditions, hard hand, etc., severely restrict the use of PLA homopolymers. Or the promotion and application of copolymers as new environmentally friendly fiber materials.

Polyhydroxyalkanoate (PHA) homopolymers or copolymers are another class of biodegradable polymer materials with good mechanical properties, biocompatibility and biodegradability. There are many kinds of PHA homopolymers or copolymers, mainly including poly 3-hydroxybutyrate (P-3HB), poly 4-hydroxybutyrate (P-4HB), poly 3-hydroxyvalerate (P-3HV) , Poly3-hydroxybutyrate-4-hydroxybutyrate copolyester (P-3HB-4HB), polyhydroxybutyrate valerate copolyester (PHBV) and dozens of homopolymers and copolymers. PHA homopolymers or copolymers are mainly prepared from biomass raw materials such as starch through biological fermentation methods, and can be decomposed into carbon dioxide, water and biomass under soil or composting conditions. The preparation of bio-based degradable fibers from PHA homopolymers or copolymers is conducive to providing a chemical fiber variety that meets the requirements of environmental protection and sustainable development, and at the same time expands its application fields, so it has very important market value.

Compared with PLA homopolymers or copolymers, PHA homopolymers or copolymers usually have lower melt viscosity, higher heat distortion temperature and faster natural degradation rate, so PHA homopolymers or copolymers are compatible with PLA homopolymers or copolymers have certain complementary properties. However, the melt spinning performance of PHA homopolymer or copolymer is poor. Taking PHBV as an example, fibers are often prepared by solution spinning.

Fang Zhuangxi et al. (Acta Polymer Sinica, 2004, 4:500) prepared PHBV ultrafine fibers by electrospinning. Before spinning, PHBV/chloroform solution needs to be prepared, and the average diameter of the obtained PHBV fibers is 0.83-1.73 microns.

Qi Zhonghua et al. (Synthesis Technology and Application, 2008, 23:16) prepared PHBV/Ecoflex ultrafine blended fiber felt by electrospinning method. Before spinning, PHBV/Ecoflex/dichloromethane solution needs to be prepared to obtain PHBV The average diameter of the /Ecoflex blended fiber is 0.09-1.85 microns.

Zhu Shuqi et al. (Synthetic Fibers, 2009, 7:13) prepared PHBV fibers by dry spinning. Before spinning, PHBV/chloroform solution needs to be prepared, and the as-spun fibers are obtained at a spinning speed of 20m/min. Stretch 2 to 5 times at 70°C, and heat-set at 120°C to obtain a PHBV fiber with a breaking strength of about 1.8cN/dtex and an elongation at break of more than 40%.

Tang Jian et al. (National Polymer Academic Papers Conference, C24, 2003, Hangzhou) prepared PHBV/CO ₂ polymer blend fibers by melt spinning method, the mass ratio of PHBV and CO ₂ polymer was 60/40, when When the content of hydroxyvalerate (HV) in PHBV was 7.5%, the fiber forming property of the fiber was better.

Wang Xijian et al. (Synthetic Fiber Industry, 2008, 31:46) prepared PHBV/PCL blended fibers by melt spinning method, the spinning temperature was 175°C, and the spinning speed was 50-80m/min.

He Jing et al. (Synthetic Fibers, 2008, 1:10) prepared PHBV/TiO ₂ fibers by melt spinning. TiO ₂ acts as a nucleating agent. A hot water bath is placed under the spinneret to ensure that the fibers have better Excellent spinnability and mechanical properties, the strength of the prepared fiber is 1.052cN/dtex, and the elongation is 157%.

Obviously, people have realized the significance and importance of PLA homopolymer or copolymer and PHA homopolymer or copolymer, two types of biodegradable polymers as fiber materials. However, certain chemical and physical defects of PLA homopolymers or copolymers such as relatively low heat distortion temperature, high melt viscosity, easy degradation at higher temperatures, slow degradation rate under natural conditions, hard hand, etc., and PHA Some inherent defects of homopolymers or copolymers, such as easy degradation at higher temperatures, slow crystallization speed, and high brittleness, seriously restrict the development of bio-based degradable fiber preparation technology and the application of bio-based degradable fiber materials. Taking PHBV as an example, electrospinning and dry spinning methods are used to prepare PHBV fibers. Although the thermal degradation of PHBV is avoided to a certain extent, it is necessary to prepare PHBV solution before spinning, use volatile and toxic solvents, and spin The speed is low, resulting in lower productivity and higher costs. PHBV fiber is prepared by melt spinning, but it faces problems such as PHBV thermal degradation, slow crystallization speed, and high brittleness. It can be blended with other polymers (such as CO ₂ polymers, PCL) or added nucleating agents (such as TiO ₂ ) to be improved. However, the CO ₂ polymer is an amorphous polymer, which is not conducive to the improvement of the mechanical strength of the fiber; the melting point of PCL is about 60°C, which is quite different from the melting point of PHBV (150-160°C). 175°C), PCL degrades, which is also not conducive to the preparation of fibers with higher mechanical strength; adding a nucleating agent (TiO ₂ ) can improve the crystallinity of PHBV, but it still needs to place a hot water bath under the spinneret, which limits With the increase of spinning speed, the nucleating agent is also likely to cause blockage of spinning components, which is not conducive to long-term continuous production. Therefore, the mechanical strength of PHBV-containing fibers produced by the current known methods generally does not exceed 1.8cN/dtex, and it is urgent to develop new bio-based degradable fiber varieties and improve fiber production technology to improve fiber performance, reduce production costs, and meet Requirements.

Contents of the invention

The first object of the present invention is to provide a bio-based degradable fiber in view of the above-mentioned technical status.

The bio-based degradable fiber of the present invention is a composition comprising Substance A and Substance B;

Wherein substance A is a PHA homopolymer or copolymer with a volume crystallinity of 5 to 75%, and substance B is a PLA homopolymer or copolymer with a volume crystallinity of 5 to 65%; the content of substance A accounts for the weight of the fiber 5-55% of the weight of the fiber, and the content of substance B accounts for 45-95% of the weight of the fiber;

Substance A has the following general structural formula:

In the formula: R ₁ is H or methyl CH ₃ or ethyl C ₂ H ₅ ; R ₂ is methyl CH ₃ or ethyl C ₂ H ₅ ; m1 is 1 or 2; m2 is 1 or 2; x is 0 Or any natural number from 200 to 25000, y is 0 or any natural number from 200 to 25000, and x and y are not 0 at the same time.

Preferably, the substance A in the general formula is poly 3-hydroxybutyrate (P-3HB) when R ₁ is methyl CH ₃ , m1 is 1, x is any natural number from 200 to 25000, and y is 0. , the volume crystallinity is 5-75%, and the weight-average molecular weight is 9-1.05 million;

As a preference, the substance A in the general formula is poly 4-hydroxybutyrate (P-4HB) when _R1 is H, m1 is 2, x is any natural number from 200 to 25000, and y is 0. Its volume The crystallinity is 5-75%, and the weight-average molecular weight is 9-1.1 million;

As a preference, the substance _A in the general _formula is poly 3 _- hydroxyvalerate (P- 3HV), the volume crystallinity is 5-75%, and the weight-average molecular weight is 9-1.05 million;

As a preference, the substance A in the general formula when R ₁ is methyl CH ₃ , R ₂ is ethyl C ₂ H ₅ , m1 and m2 are both 1, and x and y are any natural numbers ranging from 200 to 25000 is Polyhydroxybutyrate-valeric acid copolyester (PHBV) has a volume crystallinity of 5-75%, a weight-average molecular weight of 9-1.05 million, and the molar content of 3-hydroxyvalerate (P-3HV) is 1~45%;

The weight average molecular weight of the PLA homopolymer or copolymer is 60,000-180,000, and the molar content of L optical isomer is 42%-98%.

The second object of the present invention is to provide a preparation method of this bio-based degradable fiber.

The method of the present invention comprises the following steps: (1) Homopolymerizing the PHA homopolymer or copolymer with a volume crystallinity of 5 to 75% and the PLA with a volume crystallinity of 5 to 65% in the aforementioned bio-based degradable fiber component (2) the dried PHA homopolymer or copolymer and PLA homopolymer or copolymer are physically mixed according to the aforementioned ratio; (3) the mixture is injected into a heating device Melt in extrusion equipment, and then collect long fibers at a spinning temperature of 176-225°C and a spinning speed of 300-3000m/min, or collect melted fibers at a spinning temperature of 176-225°C by melt blowing. Spray the non-woven fabric, or use the spunbond method to collect the spunbonded non-woven fabric at a spinning temperature of 176-225°C; (4) post-process the long fiber or non-woven fabric.

The advantage of the present invention is: compared with ordinary PHA homopolymer or copolymer fiber and PLA homopolymer or copolymer fiber, the bio-based degradable fiber disclosed by the present invention can be processed at a lower spinning temperature (176～225°C) ) and higher spinning speed (300-3000m/min) have better melt spinnability, and the partially crystalline PHA homopolymer or copolymer and partially crystalline PLA homopolymer or copolymer are spinning , Crystallization during the post-treatment process, so that the bio-based degradable fiber has high mechanical strength (reaching or exceeding 1.4cN/dtex) and a continuous and stable soft hand feeling, so it can meet the requirements of use and expand the application field. In addition, the melt viscosity of PHA homopolymer or copolymer is low, which can "lubricate" PLA homopolymer or copolymer with higher melt viscosity, so that the melt spinning performance is significantly lower than that of PLA homopolymer or copolymer. Copolymer spinning is carried out at a temperature of 176-225°C, so as to effectively avoid or alleviate the thermal degradation of raw materials, improve the mechanical properties of melt-spun long fibers, and reduce the energy consumption of melt-spinning. The invention also discloses a preparation method of the bio-based degradable fiber, which is carried out at a lower spinning temperature (176-225°C) and a higher spinning speed (300-3000m/min) by melt spinning The production of long fibers, or the production of non-woven fabrics at a spinning temperature of 176-225°C by melt blown method, can effectively improve production efficiency and reduce costs.

Detailed ways

The technical solutions and effects of the present invention will be further described below in conjunction with the embodiments.

Comparative example 1:

Partially crystalline poly-3-hydroxybutyrate (P-3HB) with a volume crystallinity of 43% and a weight-average molecular weight of 760,000 was vacuum-dried at a drying temperature of 50±5°C and a drying time of 16 hours. 100 Pa; take 100 kg of dried P-3HB, pour it into a single-screw extruder to melt, and extrude it into fibers through a metering pump and a spinneret hole. When the spinning temperature is 187°C and the spinning speed is 300m/min Long fibers are collected, the fibers are severely bonded and frequently broken, and it is difficult to obtain continuous long fibers. Comparative Example 1 shows that it is difficult to obtain P-3HB long fibers by the usual melt spinning method.

Comparative example 2:

Partially crystalline polyhydroxybutyrate-valerate (PHBV) with a volume crystallinity of 40%, a weight average molecular weight of 570,000, and a molar content of hydroxyvalerate of 3% was vacuum-dried at 60±5°C 1. The drying time is 16 hours, and the vacuum degree is 100 Pa; 100 kilograms of PHBV after drying are taken, injected into a single-screw extruder and melted, extruded into fibers through a metering pump and a spinneret hole, and the spinning temperature is 173 ° C and spun When the filament speed is 300m/min, the long fibers are collected, the fibers are seriously bonded and frequently broken, and it is difficult to obtain continuous long fibers. Comparative Example 2 shows that it is difficult to obtain PHBV long fibers by the usual melt spinning method.

Comparative example 3:

Partially crystallized polylactic acid with a volume crystallinity of 65%, a weight average molecular weight of 120,000, and a molar content of L optical isomer of 98% was vacuum-dried at a drying temperature of 60±5°C and a drying time of 16 hours. The density is 100Pa; take 100 kg of dried polylactic acid, pour it into a single-screw extruder to melt, and extrude it into fibers through a metering pump and a spinneret hole. The spinning temperature is 235°C and the spinning speed is 1000m/min. Collect continuous long fibers at the same time, draw 1.6 times at 54°C, and then heat set at 60°C. The polylactic acid in the long fiber has been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is 1.7cN/dtex measured by a universal material testing machine , The elongation at break is 18%, and the fiber feels hard. Comparative Example 3 shows that polylactic acid long fibers can be obtained by the usual melt spinning method, but due to the high melt viscosity of polylactic acid, a higher spinning temperature is required, and the fiber feels hard.

Comparative example 4:

Take a partially crystalline poly-3-hydroxybutyrate-4-hydroxybutyrate copolyester (P-3HB-4HB) with a volume crystallinity of 52%, a weight-average molecular weight of 700,000, and a molar content of 4-hydroxybutyrate of 5%. Carry out vacuum drying, the drying temperature is 50±5°C, the drying time is 16 hours, and the vacuum degree is 100Pa; take 100 kg of dried P-3HB-4HB, inject it into a single-screw extruder and melt it, pass the metering pump and spinneret The holes are extruded into fibers, and the non-woven fabric is collected when the spinning temperature is 154° C. by the melt blown method; the non-woven fabric is heat-set at 60° C. The P-3HB-4HB in the non-woven fabric was partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the non-woven fabric felt hard, and it was stored at room temperature for 4 weeks become noticeably brittle. Comparative Example 4 shows that the P-3HB-4HB non-woven fabric can be obtained by the usual melt-blowing method, but the non-woven fabric feels hard and has unstable performance.

Comparative example 5:

Partially crystallized polylactic acid with a volume crystallinity of 35%, a weight average molecular weight of 60,000, and a molar content of L optical isomer of 42% was vacuum-dried at a drying temperature of 60±5°C and a drying time of 16 hours. The density is 100 Pa; take 100 kg of dried polylactic acid, pour it into a single-screw extruder to melt, extrude it into fibers through a metering pump and a spinneret hole, and collect non-woven fabrics at a spinning temperature of 230°C by melt-blowing method. Cloth; The non-woven fabric was heat-set at 55°C. The polylactic acid in the non-woven fabric has been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the non-woven fabric feels hard. Comparative Example 5 shows that polylactic acid non-woven fabrics can be obtained by using the usual melt-blown method, but due to the high melt viscosity of polylactic acid, a higher spinning temperature is required, and the non-woven fabrics feel hard.

Example 1:

Take partially crystalline poly 3-hydroxybutyrate (P-3HB) with a volume crystallinity of 75% and a weight average molecular weight of 570,000, and a volume crystallinity of 35% with a weight average molecular weight of 60,000 and the moles of L optical isomers Partially crystallized polylactic acid with a content of 42% was vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 55 kg of dried P-3HB and 45 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 190°C. The wire speed is 300m/min; it is drawn 3.0 times at 58°C, and then heat-set at 60°C. The P-3HB and polylactic acid in the long fiber were partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength in the long fiber was measured by a universal material testing machine The strength is 1.4cN/dtex, and the elongation at break is 23%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 2:

Take partially crystalline poly 3-hydroxybutyrate (P-3HB) with a volume crystallinity of 5% and a weight average molecular weight of 1.05 million and a volume crystallinity of 65% with a weight average molecular weight of 120,000 and the moles of L optical isomers Partially crystallized polylactic acid with a content of 98% is vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 30 kg of dried P-3HB and 70 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 211 ° C, spinning The wire speed is 1500m/min; it is drawn 2.5 times at 60°C, and then heat-set at 63°C. The P-3HB and polylactic acid in the long fiber were partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber was measured by a universal material testing machine It is 2.1cN/dtex, and the elongation at break is 21%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 3:

Take partially crystalline poly 3-hydroxybutyrate (P-3HB) with a volume crystallinity of 40% and a weight average molecular weight of 90,000, and a volume crystallinity of 5% with a weight average molecular weight of 180,000 and a mole of L optical isomer Partially crystalline polylactic acid with a content of 70% was vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 5 kg of dried P-3HB and 95 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 225°C, spinning The wire speed was 2500m/min; it was drawn 2.0 times at 64°C and heat set at 66°C. The P-3HB and polylactic acid in the long fiber were partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber was measured by a universal material testing machine It is 2.0cN/dtex, and the elongation at break is 20%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 4:

Take partially crystalline poly-4-hydroxybutyrate (P-4HB) with a volume crystallinity of 40% and a weight average molecular weight of 570,000, and a volume crystallinity of 55% with a weight average molecular weight of 120,000 and the moles of L optical isomers Partially crystalline polylactic acid with a content of 98% is vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 30 kg of dried P-4HB and 70 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 204°C. The wire speed is 1500m/min; it is drawn 2.7 times at 60°C, and then heat-set at 62°C. Both P-4HB and polylactic acid in the long fiber have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is measured by a universal material testing machine It is 2.4cN/dtex, and the elongation at break is 25%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 5:

Take partially crystalline poly-4-hydroxybutyrate (P-4HB) with a volume crystallinity of 5% and a weight average molecular weight of 90,000, and a volume crystallinity of 15%, a weight average molecular weight of 180,000, and a mole of L optical isomer Partially crystalline polylactic acid with a content of 70% was vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 55 kg of dried P-4HB and 45 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 218°C. The wire speed is 1200m/min; it is drawn 2.8 times at 63°C, and then heat-set at 65°C. Both P-4HB and polylactic acid in the long fiber have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is measured by a universal material testing machine It is 2.1cN/dtex, and the elongation at break is 27%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Embodiment 6:

Take partially crystalline poly 3-hydroxyvalerate (P-3HV) with a volume crystallinity of 75% and a weight average molecular weight of 1.05 million and a volume crystallinity of 25% with a weight average molecular weight of 60,000 and the moles of L optical isomers Partially crystallized polylactic acid with a content of 42% was vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 5 kg of dried P-3HV and 95 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 220°C. The wire speed is 1000m/min; it is drawn 2.8 times at 60°C, and then heat-set at 62°C. Both P-3HV and polylactic acid in the long fiber have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is measured by a universal material testing machine It is 1.7cN/dtex, and the elongation at break is 30%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Embodiment 7:

Take partially crystalline poly-3-hydroxyvalerate (P-3HV) with a volume crystallinity of 20% and a weight average molecular weight of 570,000, and a volume crystallinity of 35% with a weight average molecular weight of 180,000 and the moles of L optical isomers Partially crystalline polylactic acid with a content of 70% is vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 55 kg of dried P-3HV and 45 kg of dried polylactic acid in Physical mixing is carried out in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected to obtain bio-based degradable continuous long fibers. The spinning temperature is 211 ° C, spinning The wire speed was 500m/min; it was drawn 3.0 times at 64°C, and heat-set at 66°C. Both P-3HV and polylactic acid in the long fiber have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is measured by a universal material testing machine It is 2.0cN/dtex, and the elongation at break is 28%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Embodiment 8:

Take partially crystalline poly-3-hydroxybutyrate-4-hydroxybutyrate copolyester ( P-3HB-4HB) and partially crystalline polylactic acid with a volume crystallinity of 40%, a weight-average molecular weight of 60,000, and a molar content of L optical isomer of 42% were vacuum-dried at a drying temperature of 55±5°C. The time is 16 hours, and the vacuum degree is 100Pa; Take 5 kg of dried P-3HB-4HB and 95 kg of dried polylactic acid for physical mixing in a high-speed mixer; inject the mixture into a single-screw extruder to melt, and measure The pump and spinneret hole are extruded into fibers, and the bio-based degradable continuous long fibers are collected. The spinning temperature is 176°C and the spinning speed is 1200m/min; C for heat setting. The P-3HB-4HB and polylactic acid in the long fiber were partially crystallized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber was measured by a universal material testing machine. The tensile strength is 1.5cN/dtex, and the elongation at break is 32%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Embodiment 9:

Partially crystalline poly-3-hydroxybutyrate-4-hydroxybutyrate copolyester ( P-3HB-4HB) and partially crystalline polylactic acid with a volume crystallinity of 65%, a weight-average molecular weight of 120,000, and a molar content of L optical isomer of 98% were vacuum-dried at a drying temperature of 55±5°C. The time is 16 hours, and the vacuum degree is 100 Pa; take 30 kg of dried P-3HB-4HB and 70 kg of dried polylactic acid for physical mixing in a high-speed mixer; inject the mixture into a single-screw extruder to melt, and measure The pump and spinneret holes are extruded into fibers, and the bio-based degradable continuous long fibers are collected. The spinning temperature is 183°C and the spinning speed is 2000m/min; C for heat setting. The P-3HB-4HB and polylactic acid in the long fiber were partially crystallized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber was measured by a universal material testing machine. The tensile strength is 1.6cN/dtex, and the elongation at break is 30%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 10:

Take partially crystalline polyhydroxybutyrate-valerate (PHBV) with a volume crystallinity of 45%, a weight-average molecular weight of 1.05 million, and a molar content of 3-hydroxyvalerate (3-HV) of 23%, and a volume crystallinity of 45%, the weight-average molecular weight is 60,000, and the partially crystalline polylactic acid with a molar content of L optical isomer of 42% is vacuum-dried at a drying temperature of 65±5°C, a drying time of 16 hours, and a vacuum degree of 100Pa; 5 kg of dried PHBV and 95 kg of dried polylactic acid are physically mixed in a high-speed mixer; the mixture is injected into a twin-screw extruder to melt, extruded into fibers through metering pumps and spinneret holes, and collected to obtain bio-based To degrade continuous long fibers, the spinning temperature is 204°C, and the spinning speed is 750m/min; it is drawn 2.4 times at 68°C, and then heat-set at 70°C. Both PHBV and polylactic acid in the long fiber have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is 1.8 measured by a universal material testing machine cN/dtex, the elongation at break is 27%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 11:

Take partially crystalline polyhydroxybutyrate-valerate (PHBV) with a volume crystallinity of 55%, a weight average molecular weight of 570,000, and a molar content of 3-hydroxyvalerate (3-HV) of 1%, and a volume crystallinity of 65%, the weight-average molecular weight is 120,000, and the partially crystalline polylactic acid with a molar content of L optical isomer of 98% is vacuum-dried at a drying temperature of 65±5°C, a drying time of 16 hours, and a vacuum degree of 100Pa; 30 kg of dried PHBV and 70 kg of dried polylactic acid are physically mixed in a high-speed mixer; the mixture is injected into a twin-screw extruder to melt, extruded into fibers through metering pumps and spinneret holes, and collected to obtain bio-based To degrade continuous long fibers, the spinning temperature is 211°C, and the spinning speed is 3000m/min; it is drawn 2.0 times at 68°C, and then heat-set at 70°C. The PHBV and polylactic acid in the long fiber have been partially crystallized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD), and the tensile strength of the long fiber is 2.3 cN/dtex, the elongation at break is 24%. At the same time, the fiber feels soft, and it still feels soft after being placed at room temperature for 4 weeks.

Example 12:

Take partially crystalline poly-4-hydroxybutyrate (P-4HB) with a volume crystallinity of 50% and a weight average molecular weight of 1.1 million and a volume crystallinity of 35% with a weight average molecular weight of 60,000 and the moles of L optical isomers Partially crystalline polylactic acid with a content of 42% is vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 5 kg of dried P-4HB and 95 kg of dried polylactic acid in Physical mixing in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected by a melt blown method at a spinning temperature of 210°C to obtain biodegradable Melt blown nonwoven fabric; the nonwoven fabric was heat set at 70°C. The P-4HB and polylactic acid in the non-woven fabric have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). At the same time, the non-woven fabric feels soft and can be placed at room temperature After 4 weeks it still feels softer.

Example 13:

Take partially crystalline poly 3-hydroxyvalerate (P-3HV) with a volume crystallinity of 40% and a weight average molecular weight of 90,000, and a volume crystallinity of 65%, a weight average molecular weight of 120,000, and a mole of L optical isomer Partially crystalline polylactic acid with a content of 98% is vacuum-dried at a drying temperature of 60±5°C, a drying time of 16 hours, and a vacuum of 100 Pa; take 30 kg of dried P-3HV and 70 kg of dried polylactic acid in Physical mixing in a high-speed mixer; the mixture is injected into a single-screw extruder to melt, extruded into fibers through a metering pump and a spinneret hole, and collected by a spunbond method at a spinning temperature of 225°C to obtain biodegradable Spunbond nonwoven; the nonwoven was heat set at 65°C. The P-3HV and polylactic acid in the non-woven fabric have been partially crystallized as measured by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). At the same time, the non-woven fabric feels soft and can be placed at room temperature After 4 weeks it still feels softer.

Example 14:

Partially crystalline poly-3-hydroxybutyrate-4-hydroxybutyrate copolyester ( P-3HB-4HB) and partially crystalline polylactic acid with a volume crystallinity of 5%, a weight-average molecular weight of 180,000, and a molar content of L optical isomer of 70% were vacuum-dried at a drying temperature of 55±5°C. The time is 16 hours, and the vacuum degree is 100Pa; Take 55 kg of dried P-3HB-4HB and 45 kg of dried polylactic acid for physical mixing in a high-speed mixer; inject the mixture into a single-screw extruder to melt, and measure The pump and spinneret hole are extruded into fibers, and the bio-based degradable melt-blown non-woven fabric is collected when the spinning temperature is 190 ° C by the melt-blowing method; the non-woven fabric is heat-set at 60 ° C. The P-3HB-4HB and polylactic acid in the non-woven fabric have been partially crystallized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). After 4 weeks of storage, the hand feel is still relatively soft.

Example 15:

Take partially crystalline polyhydroxybutyrate-valerate (PHBV) with a volume crystallinity of 10%, a weight average molecular weight of 90,000, and a molar content of 3-hydroxyvalerate (3-HV) of 45%, and a volume crystallinity of 10%, the weight-average molecular weight is 180,000, and the partially crystallized polylactic acid with a molar content of L optical isomer of 70% is vacuum-dried at a drying temperature of 65±5°C, a drying time of 16 hours, and a vacuum degree of 100Pa; 55 kg of dried PHBV and 45 kg of dried polylactic acid are physically mixed in a high-speed mixer; the mixture is injected into a twin-screw extruder to melt, and extruded into fibers through metering pumps and spinneret holes. The bio-based degradable spunbonded nonwoven fabric was collected when the spinning temperature was 197°C; the nonwoven fabric was heat-set at 63°C. The PHBV and polylactic acid in the non-woven fabric have been partially crystallized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). At the same time, the non-woven fabric feels soft and can be stored at room temperature for 4 weeks. The back feel is still soft.

Claims (6)

1. a Biobased biodegradable fiber, is characterized in that this fiber is the composition that comprises substance A and substance B; Described substance A is that volume crystallinity is PHA homopolymers or the copolymer of 5～75 ﹪, and substance B is that volume crystallinity is PLA homopolymers or the copolymer of 5～65 ﹪; The content of substance A accounts for 5～55 ﹪ of described fibre weight, and the content of substance B accounts for 45～95 ﹪ of described fibre weight;

Substance A has following general structure:

In formula: R ₁For H or methyl CH ₃Or ethyl C ₂H ₅R ₂For methyl CH ₃Or ethyl C ₂H ₅M1 is 1 or 2; M2 is 1 or 2; X is that 0 or 200～25000 natural number, y are 0 or 200～25000 natural number, and x, y are 0 when different;

The weight average molecular weight of described substance B is 6～180,000, and L optical isomer molar content wherein is 42～98%.

2. the preparation method of a Biobased biodegradable fiber, it is characterized in that method comprises the following steps: (1) carries out respectively vacuumize by substance A and substance B; (2) by dried substance A and substance B in proportion physical mixed become compound; (3) compound is injected to the extrusion equipment melting with heater, then under the spinning temperature of 176～225 ℃, spinning speed that 300～3000m/ divides, collect long fiber, or adopt meltblown to collect melt spraying non-woven fabrics under the spinning temperature of 176～225 ℃, or adopt spun-bond process to collect spun-bonded non-woven fabrics under the spinning temperature of 176～225 ℃; (4) long fiber or nonwoven fabric are carried out to post processing;

Described substance A is that volume crystallinity is PHA homopolymers or the copolymer of 5～75 ﹪, and substance B is that volume crystallinity is PLA homopolymers or the copolymer of 5～65 ﹪; Wherein the content of substance A accounts for 5～55 ﹪ of compound weight, and the content of substance B accounts for 45～95 ﹪ of compound weight;

Described substance A has following general structure:

In formula: R ₁For H or methyl CH ₃Or ethyl C ₂H ₅R ₂For methyl CH ₃Or ethyl C ₂H ₅M1 is 1 or 2; M2 is 1 or 2; X is that 0 or 200～25000 natural number, y are 0 or 200～25000 natural number, and x, y are 0 when different;

The weight average molecular weight of described substance B is 6～180,000, and L optical isomer molar content wherein is 42～98%.

3. a kind of Biobased biodegradable fiber as claimed in claim 1, it is characterized in that: described substance A is poly 3-hydroxy butyrate, R in general formula ₁For methyl CH ₃, m1 is 1, x is that 200～25000 natural number, y are 0, its weight average molecular weight is 9～1,050,000.

4. a kind of Biobased biodegradable fiber as claimed in claim 1 is characterized in that: described substance A is poly-4 hydroxybutyric acid ester, R in general formula ₁For H, m1 are 2, x is that 200～25000 natural number, y are 0, its weight average molecular weight is 9～1,100,000.

5. a kind of Biobased biodegradable fiber as claimed in claim 1 is characterized in that: described substance A is poly-3-hydroxyl valerate, R in general formula ₁For ethyl C ₂H ₅, m1 is 1, x is that 200～25000 natural number, y are 0, its weight average molecular weight is 9～1,050,000.

6. a kind of Biobased biodegradable fiber as claimed in claim 1, it is characterized in that: described substance A is poly butyric-valeric acid copolyesters, R in general formula ₁For methyl CH ₃, R ₂For ethyl C ₂H ₅, m1 and m2 be 1, x and y are 200～25000 natural number, its weight average molecular weight is 9～1,050,000, wherein the molar content of 3-hydroxyl valerate is 1～45%.