WO2022257394A1 - Biodegradable fiber and manufacturing method therefor - Google Patents

Abstract

A biodegradable fiber and a manufacturing method therefor. The biodegradable fiber is prepared by melt-spinning a biodegradable material and a pore former. The biodegradable material comprises the following in parts by weight: 15 to 99 parts of polylactic acid; 1 to 85 parts of polybutylene adipate terephthalate; 0 to 20 parts of polycaprolactone; 0.1 to 5 parts of a rod-shaped, needle-shaped or sheet-shaped nanofiller; and 0.05 to 2 parts of a coupling agent. The aggregate parts by weight of polylactic acid, polybutylene adipate terephthalate and polycaprolactone are 100. The shape of the nanofiller is one or more of a rod shape, a needle shape and a sheet shape. The pore former is an organic pore former, and the mass ratio of the biodegradable material to the pore former is 100:(0.1-10). The biodegradable fiber has excellent air permeability, moisture conduction, and mechanical strength.

Description

A kind of biodegradable fiber and preparation method thereof technical field

The invention belongs to the technical field of fiber materials, in particular to a biodegradable fiber and a preparation method thereof.

Background technique

Polyester fiber is a synthetic fiber made by chemical synthesis and mechanical processing, and is spun into clothes; at the same time, in today's "fast fashion" clothing consumption culture, more and more clothes are bought, cleaned and discarded . However, these fiber products are not decomposed by nature as people think. On the contrary, polyester fibers are very stable and difficult to degrade, so they will stay in the environment for a long time, causing harm to the environment and threatening the health of the human body. healthy.

In order to reduce environmental pollution and promote the sustainable development of the polyester industry, experts and scholars in various fields have carried out basic research and application development of biodegradable materials to replace traditional polyester fiber materials. Biodegradable fibers refer to materials that can be slowly degraded into carbon dioxide and water by microorganisms within a certain period of time, so that they will not pollute the environment. There are mainly biomass-derived protein fibers, cellulose fibers, chitin fibers, and synthetic biodegradable polyester fibers.

Although biodegradable polyester materials such as polylactic acid (PLA), polybutylene adipate/terephthalate (PBAT), polycaprolactone (PCL) have good spinnability, the use of these materials The finished fiber material is still difficult to meet the use requirements in terms of air permeability, moisture permeability and mechanical properties, and needs to be further improved.

Contents of the invention

In view of this, the object of the present invention is to provide a biodegradable fiber and a preparation method thereof. The biodegradable fiber provided by the present invention has good air permeability, moisture permeability and mechanical strength.

In one aspect, the present invention provides a biodegradable fiber, which is made by melt spinning of a biodegradable material and a pore-forming agent. In parts by weight, the biodegradable material includes:

Wherein, the total parts by weight of the polylactic acid, polyadipate/butylene terephthalate and polycaprolactone is 100 parts;

The shape of the nano filler is one or more of rods, needles and flakes;

The pore-forming agent is an organic pore-forming agent, and the mass ratio of the biodegradable material to the pore-forming agent is 100:(0.1-10).

Preferably, the radial dimension of the rod-shaped nanofiller is 1-50 nm, and the axial dimension is 10-200 nm; the radial dimension of the needle-shaped nanofiller is 1-50 nm, and the axial dimension is 10-200 nm; the thickness of the sheet-shaped nanofiller is 1 to 50 nm, and the particle size (ie length and/or width) is 10 to 200 nm.

Preferably, the polylactic acid has a weight average molecular weight of 100,000-600,000.

Preferably, the molar ratio of the repeating units corresponding to the butylene adipate and the repeating units corresponding to the butylene terephthalate in the polyadipate/butylene terephthalate is 1 : (0.25-4); more preferably, the weight-average molecular weight of the polyadipate/butylene terephthalate is 5-300,000.

Preferably, the polycaprolactone has a weight average molecular weight of 50,000 to 250,000.

Preferably, the nano-filler is one or more selected from nano-silica, nano-titanium dioxide, nano-alumina and nano-attapulgite.

Preferably, the coupling agent is selected from 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, polymaleic anhydride, acetylated monoglyceride fatty acid ester and titanic acid One or more of tetrabutyl esters.

Preferably, the pore forming agent is one or more selected from oxalic acid, 2-hydroxysuccinic acid, polyvinyl alcohol, chitosan and dextran; more preferably, the pore forming agent are of biological origin.

The present invention provides a kind of preparation method of above-mentioned biodegradable fiber, comprises the following steps:

a) melt blending polylactic acid, polyadipate/butylene terephthalate, polycaprolactone, nanofillers and coupling agents to obtain biodegradable materials;

b) melt-spinning the biodegradable material and a pore-forming agent to obtain biodegradable fibers.

Preferably, the temperature of the melt-blending is 100-200°C; the temperature of the melt-spinning is 120-300°C.

Preferably, the polylactic acid, polybutylene adipate/terephthalate, polycaprolactone, nanofiller, coupling agent and pore-forming agent are dried to a water content of ≤200ppm before use.

Compared with the prior art, the invention provides a biodegradable fiber and a preparation method thereof. The biodegradable fiber provided by the present invention is made by melt-spinning biodegradable materials and pore-forming agents. In parts by weight, the biodegradable materials include: 15-99 parts of polylactic acid; polyadipic acid/para 1-85 parts of butylene phthalate; 0-20 parts of polycaprolactone; 0.1-5 parts of nano filler; 0.05-2 parts of coupling agent, wherein the polylactic acid, polyadipate/terephthalic acid The total parts by weight of butylene glycol formate and polycaprolactone are 100 parts; the shape of the nano-filler is one or more of rod, needle and sheet; the radial dimension of the rod-shaped nano-filler is 1 ～50nm, the axial dimension is 10～200nm; the radial dimension of the needle-like nanofiller is 1～50nm, the axial dimension is 10～200nm; or width) is 10-200nm; the mass ratio of the biodegradable material to the pore-forming agent is 100:(0.1-10). The present invention significantly improves the air permeability, moisture conductivity and mechanical properties of the obtained biodegradable fibers by optimizing the raw material formula and preparation process of the biodegradable fibers. More specifically: 1) the added rod-shaped, Sheet-like and/or needle-shaped inorganic nanofillers can be coupled or anchored with coupling agents and pore-forming agents to form a continuous three-dimensional micro-mesoporous network at the interface between inorganic nanomaterial fillers and biodegradable fibers, thereby improving fiber materials. 2) The added organic pore-forming agent will be partially or completely thermally decomposed into small molecules in situ during the spinning process, released from the inside to the outside, and formed on the biodegradable material. Micropores, and the porogen will also react with the biodegradable material during the thermal decomposition process to generate hydrophilic functional groups in situ on the inner surface of the pores, which is beneficial to the one-way moisture transfer of water vapor molecules. The biodegradable fiber provided by the invention has excellent air permeability, moisture permeability and mechanical strength, which provides a good foundation for further expanding the functional application of the biodegradable fiber, and has a very broad market prospect.

Detailed ways

The embodiments of the present invention are clearly and completely described below, obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the implementations in the present invention, all other implementations obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

The present invention provides a biodegradable fiber, which is made by melt spinning of biodegradable materials and pore-forming agents. In parts by weight, the biodegradable materials include:

Wherein, the total parts by weight of the polylactic acid, polybutylene adipate/terephthalate and polycaprolactone is 100 parts by weight.

In the present invention, based on 100 parts by weight of the total amount of polylactic acid, polyadipate/butylene terephthalate and polycaprolactone in the biodegradable material, the polylactic acid in the biodegradable material The content is 15 to 99 parts by weight, specifically 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, 98 parts by weight or 99 parts by weight, or any sub-range or any specific value therebetween. The present inventors have found that when used in the above-mentioned range, suitable strength can be provided, so that good tensile strength can be maintained during the fiber preparation process, and it is useful to form a three-dimensional continuous channel structure. On the contrary, when the content is less than 15 parts by weight, the formed fiber has low tensile strength, and the subsequent spinning process is difficult to form; and when the content is greater than 99 parts by weight, the strength of the resulting fiber is too high, and brittleness is prone to occur in the spinning process. fracture.

In the biodegradable fiber provided by the present invention, the weight average molecular weight of the polylactic acid (PLA) used is preferably 100,000 to 600,000, specifically 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 550,000, or 600,000, or any subrange or any specific value in between. The present inventors have found that when polylactic acid having a weight average molecular weight within the above range is used, stable tensile strength can be further provided to the obtained biodegradable fiber. Such polylactic acid can be synthesized in a laboratory according to methods known in the art, and can also be obtained commercially, for example, from Anhui Fengyuan Futailai Polylactic Acid Co., Ltd.

As used herein, the term "polybutylene adipate/terephthalate (PBAT)" means a random mixture of butylene adipate (BA) and terephthalate (BT). Copolymer, also sometimes referred to as "polybutylene adipate/terephthalate" or "polybutylene adipate-co-butylene terephthalate".

In the present invention, based on 100 parts by weight of polylactic acid, polyadipate/butylene terephthalate and polycaprolactone in the biodegradable material, polyadipate/terephthalate The content of butylene glycol formate in the biodegradable material is 1 to 85 parts by weight, specifically 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, and 30 parts by weight , 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight or 85 parts by weight, or any number in between range or any specific value. The present inventors have found that when used at a content within the above range, the formed biodegradable fiber has excellent toughness, and is useful for forming a stable denier diameter during fiber preparation and drawing. On the contrary, when the content is less than 1 part by weight or greater than 85 parts by weight, the prepared biodegradable fiber has poor toughness controllability and is prone to fracture during the drawing process.

In the biodegradable fiber provided by the present invention, the repeating unit (BA repeating unit) corresponding to butylene adipate in the polyadipate/butylene terephthalate (PBAT) used is the same as that of terephthalate The molar ratio of the repeating unit (BT repeating unit) corresponding to butanediol diformate is preferably 1: (0.25～4), specifically 1:0.25, 1:0.5, 1:0.75, 1:1, 1: 1.5, 1:2, 1:2.5, 1:3, 1:3.5 or 1:4. More preferably, the weight average molecular weight of polyadipate/butylene terephthalate is preferably 50,000 to 300,000, specifically 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 120,000 10,000, 150,000, 170,000, 200,000, 220,000, 250,000, 270,000, or 300,000, or any subrange or any specific value therebetween. The present inventors have found that when polybutylene adipate/terephthalate having a weight-average molecular weight within the above-mentioned range is used, suitable tensile toughness can be further provided to the obtained biodegradable fiber, Maintain the softness of the fiber. In the biodegradable fiber provided by the present invention, the weight average molecular weight of the polycaprolactone (PCL) used is preferably 50,000 to 250,000, specifically 50,000, 60,000, 70,000, 80,000, 90,000, 100,000 10,000, 120,000, 150,000, 170,000, 200,000, 220,000, or 250,000, or any subrange or any specific value therebetween. The present inventors have found that when polycaprolactone having a weight average molecular weight within the above range is used, additional ductility can be further provided to the obtained biodegradable fiber, so that the fiber maintains excellent textile processing performance.

In the present invention, based on 100 parts by weight of the total amount of polylactic acid, polyadipate/butylene terephthalate and polycaprolactone in the biodegradable material, polycaprolactone is biodegradable The content in the material is 0 to 20 parts by weight, specifically 0, 0.1 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, and 8 parts by weight parts, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight or 20 parts by weight, Or any subrange or any specific value in between. When the content of polycaprolactone is 0, it means that no polycaprolactone can be used in the biodegradable material of the present invention. Preferably, polycaprolactone is included in the biodegradable material of the present invention, that is, its content is preferably in the range of 0.1-20 parts by weight. The present inventors have found that when polycaprolactone is used at a content within the above range, it is beneficial to increase the toughness of the biodegradable fiber, providing a three-dimensional network stabilizing structure. On the contrary, when the content is greater than 20 parts by weight, the melt strength in the spinning process of the biofiber is too small, causing sticking and clogging, which is not conducive to production.

In the biodegradable fiber provided by the present invention, the nano-filler used is a nano-inorganic filler, and the shape of the nano-inorganic filler is one or more of rod shape, needle shape and sheet shape. The present inventors unexpectedly found that when using nano-inorganic fillers in the shape of rods, needles and/or plates (that is, with these shapes, the axial dimension of the nano-inorganic filler is different from the radial dimension, or When the thickness dimension is different from the length and/or width dimension), the formed biodegradable material can form a continuous three-dimensional micro-mesoporous network with similar dendritic folds through the high-temperature melt spinning and stretching process, so that it can be used for gas or The gas passes through to provide a good channel, and the formed small droplets or small water droplets cannot return to drip due to the continuous three-dimensional folded channels, realizing the function of one-way air guide or one-way moisture guide. On the contrary, when a shape with the same axial dimension and radial dimension is used, such as but not limited to spherical nano-inorganic fillers, the formed pore structure is a continuous straight-through micro-mesoporous network, which even after the stretching process, but the obtained The pore structure of the fiber is single, and it is easy to form a direct pore, which is not conducive to one-way moisture transfer, and reduces the mechanical properties of the fiber, is easy to break, and has a low elongation at break.

In the biodegradable fiber provided by the present invention, the total amount of polylactic acid, polyadipate/butylene terephthalate and polycaprolactone in the biodegradable material is 100 parts by weight, and the nanofiller The content in the biodegradable material is 0.1 to 5 parts by weight, specifically 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.7 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.7 parts by weight, 2 parts by weight, 2.2 parts by weight, 2.5 parts by weight, 2.7 parts by weight, 3 parts by weight, 3.2 parts by weight, 3.5 parts by weight, 3.7 parts by weight, 4 parts by weight, 4.2 parts by weight, 4.5 parts by weight parts, 4.7 parts by weight or 5 parts by weight, or any sub-range or any specific value therebetween. The inventors have found that when used at a content within the above range, suitable pore size and three-dimensional network structure can be provided for the obtained biodegradable fiber; on the contrary, when the content is less than 0.1 parts by weight or greater than 5 parts by weight , unable to form a pore structure and/or prone to fiber breakage.

In the present invention, preferably, the radial size of the rod-shaped nanofiller used is preferably 1 to 50 nm, specifically 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45nm or 50nm, or any sub-range or any specific value in between, the axial size of the rod-shaped nanofiller is preferably 10-200nm, specifically 10nm, 15nm, 20nm, 25nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm , 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm or 200nm, or any subrange or any specific value therebetween. As understood by those skilled in the art, the radial dimension of the rod-shaped nanofiller is generally smaller than its axial dimension.

In the present invention, preferably, the radial size of the needle-like nanofillers used is preferably 1 to 50 nm, specifically 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm , 45nm or 50nm, or any sub-range or any specific value therebetween, the axial size of the needle-like nanofiller is preferably 10-200nm, specifically 10nm, 15nm, 20nm, 25nm, 30nm, 40nm, 50nm, 60nm, 70nm , 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm or 200nm, or any subrange or any specific value therebetween. As understood by those skilled in the art, the radial dimension of acicular nanofillers is generally significantly smaller than its axial dimension.

In the present invention, preferably, the thickness of the flake nanofiller used is preferably 1-50 nm, specifically 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm Or 50nm, or any sub-range or any specific value therebetween, the particle size (ie length and/or width) of the plate-like nanofiller is preferably 10-200nm, specifically 10nm, 15nm, 20nm, 25nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm or 200nm, or any subrange or any specific value therebetween. As understood by those skilled in the art, the particle size (ie, length and/or width) of a platelet nanofiller is generally larger than its thickness dimension.

The present inventors have found that when rod-like, needle-like and/or sheet-like nano-inorganic fillers with radial and axial dimensions within the above-mentioned ranges are used, the pore size distribution of the biodegradable fibers forming a continuous three-dimensional network structure is uniform, While maintaining good mechanical properties.

In the biodegradable fiber provided by the present invention, the nano-filler used is preferably one or more selected from nano-silica, nano-titanium dioxide, nano-alumina and nano-attapulgite. In one embodiment provided by the present invention, the nanofiller used is specifically selected from one of rod-shaped nano-silica, flake-shaped nano-silica, acicular nano-attapulgite, rod-shaped nano-titanium dioxide and rod-shaped nano-alumina or more. Such nano-inorganic fillers can be prepared in the laboratory according to methods known in the art, and can also be obtained commercially, for example, from Shanghai Kaiyin Chemical Co., Ltd.

In the biodegradable fiber provided by the present invention, the total amount of polylactic acid, polyadipate/butylene terephthalate and polycaprolactone in the biodegradable material is 100 parts by weight. The content of the coupling agent in the biodegradable material is 0.05 to 2 parts by weight, specifically 0.05 parts by weight, 0.1 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, and 0.6 parts by weight parts, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 parts by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight or 2 parts by weight, or any sub-range or any specific value therebetween. The present inventors have found that when used at a content within the above range, the mechanical properties of the biodegradable fiber and the dispersion of the three-dimensional pore structure are improved; on the contrary, when the content is less than 0.05 parts by weight or greater than 2 parts by weight, as a raw material The biodegradable resin is prone to phase separation, resulting in a decrease in the tensile properties of the fiber, or causing a discontinuous three-dimensional pore structure to block the channel.

In the biodegradable fiber provided by the present invention, the coupling agent used is preferably selected from 3-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, polymaleic anhydride, acetyl One or more of monoglyceride fatty acid esters and tetrabutyl titanate; wherein, more preferably, the number average molecular weight of the polymaleic anhydride used is preferably 800 to 1200, specifically 800, 850, 900 , 950, 1000, 1050, 1100, 1150, or 1200, or any subrange or any specific value in between. The present inventors have found that when using polymaleic anhydride with a number average molecular weight within the above range, it can further facilitate the compatibility between biodegradable materials, improve the dispersibility of biodegradable resins and inorganic fillers, and improve mechanical properties.

In the biodegradable fiber provided by the present invention, the pore-forming agent used is an organic pore-forming agent, more preferably an organic pore-forming agent of biological origin. The present inventors have found that when an organic pore-forming agent is used, especially an organic pore-forming agent of biological origin, it can form a hydrogen bond-like structure with the biodegradable resin in the early stage of melt spinning, and the subsequent process decomposes to form residues, Promotes vapor conduction, moisture conduction and liquid resistance.

In the present invention, the organic pore forming agent used is preferably one or more selected from oxalic acid, 2-hydroxysuccinic acid, polyvinyl alcohol, chitosan and dextran; wherein, more preferably , the weight-average molecular weight of the polyvinyl alcohol used is preferably 8000～10000, specifically can be 8000, 8500, 9000, 9500 or 10000, or any subrange or any specific value therebetween; the degree of alcoholysis of the polyvinyl alcohol used ( That is, the percentage of hydroxyl groups in the product obtained after alcoholysis to the original group) is preferably 86-90%, specifically 86%, 87%, 88%, 89% or 90%, or any sub-range or range therebetween Any specific value; the chitosan used can be chitosan whose CAS number is 969-33-5, and the molecular formula is C ₂₁ H ₂₁ N; the weight average molecular weight of dextran is preferably 5000～10000, specifically 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, or 10000, or any subrange or any specific value in between. Such organic porogens are commercially available, for example, from Shanghai Kaiyin Chemical Co., Ltd.

In the biodegradable fiber provided by the present invention, the mass ratio of the biodegradable material and the pore-forming agent used is preferably 100: (0.1-10), specifically 100:0.1, 100:0.2, 100:0.5, 100 :1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5, 100:4, 100:4.5, or 100:5, or any subrange or specific ratio in between. The present inventors have found that when the biodegradable material and the pore-forming agent are used at a mass ratio within the above-mentioned range, the resulting biodegradable fiber can form suitable continuous three-dimensional channels, and the pore-forming agent and the biodegradable polyester generate Chemical reaction improves the functionality of the pores and facilitates one-way moisture transfer. On the contrary, when the mass ratio of the biodegradable material and the pore-forming agent is not within the above range, three-dimensional channels cannot be formed effectively or large straight-through channels are formed, and the fibers are easily broken.

In the biodegradable fiber provided by the present invention, the fineness of the obtained biodegradable fiber (also referred to as the thickness of the fiber) is preferably 0.05-2000D (Denier, denier), preferably 0.1-1500D, specifically can be 0.1D, 1D, 10D, 50D, 100D, 200D, 300D, 400D, 500D, 600D, 700D, 800D, 900D, 1000D, 1100D, 1200D, 1300D, 1400D, or 1500D, or any subrange or any specific value therebetween.

The present invention also provides a method for preparing the above-mentioned biodegradable fiber, comprising the following steps:

a) melt blending polylactic acid, polyadipate/butylene terephthalate, polycaprolactone, nanofillers and coupling agents to obtain biodegradable materials;

b) melt-spinning the obtained biodegradable material and a pore-forming agent to obtain a biodegradable fiber.

In the preparation method provided by the present invention, the specific types, physical and chemical indicators and dosage ratio of each raw material have been introduced above, and will not be repeated here.

In the method of the present invention, each raw material is preferably dried to a moisture content of ≤200ppm before use, which can further stabilize the biodegradable material and thereby obtain a biodegradable fiber with stable performance. Preferably, the drying method is preferably vacuum drying; more preferably, the drying temperature is preferably 70-90°C, more preferably 80°C.

In the preparation method provided by the invention, before carrying out melt blending, preferably polylactic acid, polyadipate/butylene terephthalate, polycaprolactone, nanofiller and coupling agent are not heated for pre-mixing. Wherein, the rotational speed of the premixing is preferably relatively high, such as 1000 to 1500r/min, specifically 1000r/min, 1050r/min, 1100r/min, 1150r/min, 1200r/min, 1250r/min, 1300r/min , 1350r/min, 1400r/min, 1450r/min or 1500r/min, or any sub-range or any specific value therebetween; the pre-mixing equipment includes but is not limited to a high-speed mixer.

In the preparation method provided by the present invention, the temperature for melt blending is preferably 100-200°C, more preferably 120-190°C. In one embodiment provided by the present invention, the melt blending is carried out in a twin-screw extruder, and the screw diameter of the twin-screw extruder is preferably 60 to 90 mm, specifically 75 mm; the aspect ratio of the twin-screw extruder It is preferably (20-60):1, specifically 40:1; the rotational speed of the twin-screw extruder is preferably 500-2000r/min, specifically 1000r/min. Although there is no special requirement, preferably, the twin-screw extruder used is preferably divided into or provided with nine zones for temperature control, wherein the temperature of the first zone is preferably 120-150°C, and the temperature of the second zone is preferably 150-160°C. °C, the temperature in the third zone is preferably 155-170°C, the temperature in the fourth zone is preferably 160-175°C, the temperature in the fifth zone is preferably 170-180°C, the temperature in the sixth zone is preferably 175-190°C, and the temperature in the seventh zone is preferably 165-185°C °C, the temperature in the eighth section is preferably 160-170°C, and the temperature in the ninth section is preferably 155-165°C. In the present invention, after the melt blending is finished, it is preferred to carry out cooling and cutting to obtain biodegradable material particles.

In the preparation method provided by the present invention, before melt spinning, the obtained biodegradable material is preferably premixed with the pore-forming agent. Wherein, the rotational speed of the premixing is preferably lower, for example, 300-500r/min, specifically 300r/min, 320r/min, 350r/min, 370r/min, 400r/min, 420r/min, 450r/min , 470r/min or 500r/min, or any sub-range or any specific value therebetween; the pre-mixing equipment includes but is not limited to a low-speed mixer. The inventors have found that premixing can increase the degree of mixing of raw materials, improve the degree of dispersion, uniform and stable hole formation, and make the melt spinning process more stable and easy to roll and shape.

In the preparation method provided by the present invention, the temperature of melt spinning is preferably 120-300°C, more preferably 150-260°C. In one embodiment provided by the present invention, melt spinning can be performed in a melt spinning machine. Although there is no special requirement, preferably, the melt spinning machine used is preferably divided into or provided with five sections for temperature control, wherein the temperature of the first section is preferably 150-170° C., and the temperature of the second section is preferably 160-180° C. The third-stage temperature is preferably 190-220°C, the fourth-stage temperature is preferably 220-250°C, and the fifth-stage temperature is preferably 230-260°C. In the present invention, the spinning speed of melt spinning is preferably 500-1600m/s, specifically 500m/s, 600m/s, 700m/s, 800m/s, 900m/s, 1000m/s, 1100m/s , 1200m/s, 1300m/s, 1400m/s, 1500m/s or 1600m/s, or any sub-range or any specific value therebetween.

The embodiment provided by the present invention significantly improves the air permeability, moisture permeability and mechanical properties of the fiber material by optimizing the raw material formulation and preparation process of the biodegradable fiber. More specifically, the technical solution provided by the present invention has at least the following advantages:

1) By using a combination of specific ratios of raw materials and combining specific shapes of nano-inorganic fillers, the obtained biodegradable fibers can form three-dimensional micro-mesoporous channels, thereby improving the air permeability of the fiber materials while ensuring the tensile properties of the fiber materials sex;

2) Hydrophilic functional groups are generated in situ on the inner surface of the micropores of the biodegradable fiber, which is conducive to the unidirectional moisture conduction of water vapor molecules, thereby improving its moisture permeability;

3) The preparation process steps are simple, the feasibility is high, and it is easy to popularize;

4) It provides a good foundation for further expanding the functional application of biodegradable fibers, and the market prospect is very broad.

For more clarity, the following examples and comparative examples are described in detail below.

In the following examples of the present invention and comparative examples, the performance evaluation method based on is as follows:

1) Tensile properties (including tensile strength and elongation at break): measured according to the national standard GB/T14337-2008.

2) Breathability: Weave the obtained fiber into a fabric with a certain area according to the method of plain weaving, and carry out sampling and testing according to the national standard GB/T 5453-1995 method.

3) Moisture conductivity: Weave the obtained fiber into a fabric with a certain area according to the method of flat weaving, sample and test according to the national standard GB/T21655.2-2019 method, and express it as a one-way transmission coefficient.

4) The stretched micro-mesoporous is tested by a field emission scanning electron microscope (model XL30ESEM FEG, Netherlands FEI company).

5) The three-dimensional hole structure is tested by X-ray tomography scanner (model Xradia 810Ultra, Zeiss, Germany).

The present invention will be illustrated below with the help of specific examples and comparative examples, but those skilled in the art can understand that these examples and comparative examples are only illustrative rather than restrictive.

In the following examples and comparative examples, unless otherwise stated, the equipment and raw materials used are known in the art or commercially available, or can be obtained or prepared by methods known in the art. In addition, unless otherwise stated, the raw materials or reagents used were used as they were without additional treatment.

Example 1

In a high-speed mixer (model GSL100), 50 parts by weight of polylactic acid (weight-average molecular weight is 300,000; purchased from Anhui Fengyuan Futailai Polylactic Acid Co., Ltd.), polyadipate/butylene terephthalate (the weight-average molecular weight is 100,000, and the BA/BT molar ratio is 1:0.5; purchased from Jinhui Zhaolong High-tech Co., Ltd.) 45 parts by weight, polycaprolactone (the weight-average molecular weight is 150,000; purchased from Shenzhen Guanghua Weiye Co., Ltd.) 5 parts by weight, rod-shaped nano-silicon dioxide (the radial dimension is 3nm, and the axial dimension is 15nm; purchased from Sinopharm Chemical Reagent Co., Ltd.) 0.5 parts by weight, polymaleic anhydride (the number average molecular weight is 800; Purchased from Sinopharm Group Chemical Reagent Co., Ltd.) 1 weight part, premixed at a high speed at a rotating speed of 1000r/min; -75) for melt mixing and extrusion granulation, wherein the screw diameter of the twin-screw extruder is 75mm, the aspect ratio is 40:1, the rotating speed is 1000r/min, the temperature in the first zone is 120°C, and the temperature in the second zone is 120°C. 150℃, 160℃ in the third zone, 160℃ in the fourth zone, 170℃ in the fifth zone, 175℃ in the sixth zone, 180℃ in the seventh zone, 160℃ in the eighth zone, 155 in the ninth zone ℃. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, in a low-speed mixer (model DL-100N), 100 parts by weight of the biodegradable material particles and 5 parts by weight of oxalic acid (purchased from Sinopharm Chemical Reagent Co., Ltd.) were pre-mixed at a low speed at a speed of 300r/min. , and then melt spinning is carried out in a five-stage melt spinning machine (model MS12), wherein the temperature of the first stage of the spinning machine is 150°C, the temperature of the second stage is 180°C, the temperature of the third stage is 220°C, and the temperature of the fourth stage The spinning speed is 230°C, the temperature of the fifth stage is 245°C, and the spinning speed is 800m/s. Finally, a biodegradable fiber with a denier of 800D and a continuous three-dimensional micro-mesoporous network is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.29cN/dtex, the elongation at break is 26.1%, the air permeability is 652mm/s, and the one-way transmission coefficient is 306.

Example 2

With polylactic acid (weight average molecular weight is 150,000) 85 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 250,000, BA/BT molar ratio is 1:1) 15 weight parts, 1 part by weight of flaky nano-silica (thickness is 10nm, particle diameter is 200nm), 4 parts by weight of acicular nano-attapulgite (radial dimension is 1nm, axial dimension is 10nm), 3-aminopropyl triethoxy 1 part by weight of base silane (purchased from Sinopharm Chemical Reagent Co., Ltd.), 1 part by weight of γ-glycidyl etheroxypropyltrimethoxysilane (purchased from Sinopharm Chemical Reagent Co., Ltd.), at a high speed of 1200r/min Pre-mixing; after mixing the above materials, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder equipped with nine zones, wherein the screw diameter of the twin-screw extruder is 75mm, and the aspect ratio The temperature is 40:1, the speed is 1000r/min, the temperature of the first zone is 125°C, the temperature of the second zone is 155°C, the temperature of the third zone is 155°C, the temperature of the fourth zone is 175°C, the temperature of the fifth zone is 180°C, and the temperature of the sixth zone is 190°C, the temperature in the seventh zone is 185°C, the temperature in the eighth zone is 170°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of biodegradable material particles, 2 parts by weight of oxalic acid and chitosan (CAS number is 969-33-5, molecular formula is C ₂₁ H ₂₁ N (purchased from Sinopharm Chemical Reagent Co., Ltd.) 1 The parts by weight are pre-mixed at a low speed at a speed of 500r/min, and then melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine is 170°C, the temperature of the second section is 180°C, and the temperature of the third section is 180°C. The temperature of the first stage is 200°C, the temperature of the fourth stage is 245°C, the temperature of the fifth stage is 250°C, the spinning speed is 1200m/s, and finally a biodegradable fiber with micro-mesoporous denier of 1500D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.32cN/dtex, the elongation at break is 16.3%, the air permeability is 562mm/s, and the one-way transmission coefficient is 287.

Example 3

With polylactic acid (weight average molecular weight is 500,000) 98 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 300,000, BA/BT molar ratio is 1:0.25) 1 weight part, 1 part by weight of polycaprolactone (weight-average molecular weight is 200,000), 1 part by weight of flaky nano-silica (thickness is 10nm, particle diameter is 200nm; purchased from Evonik Industrial Group), acicular nano-attapulgite (diameter The axial dimension is 1nm, and the axial dimension is 10nm; purchased from Jiangsu Nanda Zijin Technology Group Co., Ltd.) 4 parts by weight, 1 part by weight of 3-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxy 1 part by weight of silane, pre-mixed at a high speed at a speed of 1200r/min; after mixing the above materials, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder equipped with nine zones, wherein The screw diameter of the twin-screw extruder is 75mm, the length-to-diameter ratio is 40:1, and the rotation speed is 1000r/min. 180°C, the temperature in the fifth zone is 180°C, the temperature in the sixth zone is 190°C, the temperature in the seventh zone is 185°C, the temperature in the eighth zone is 165°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, 100 parts by weight of biodegradable material particles, 2 parts by weight of 2-hydroxysuccinic acid (purchased from Sinopharm Chemical Reagent Co., Ltd.) and chitosan (CAS No. 969-33-5, molecular formula C ₂₁ H ₂₁ N) 1 part by weight is premixed at a low speed at a speed of 450r/min, and then melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine is 170 ° C, and the temperature of the second section is 180°C, the temperature of the third stage is 200°C, the temperature of the fourth stage is 245°C, the temperature of the fifth stage is 250°C, the spinning speed is 1100m/s, and finally a biodegradable fiber with micro-mesoporous denier of 500D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.39cN/dtex, the elongation at break is 10.7%, the air permeability is 602mm/s, and the one-way transmission coefficient is 298.

Example 4

With polylactic acid (weight average molecular weight is 100,000) 15 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 200,000, BA/BT molar ratio is 1:4) 85 weight parts, Rod-shaped nano-titanium dioxide (radial dimension is 20nm, axial dimension is 150nm) 1 weight part, acicular nano-attapulgite (radial dimension is 5nm, axial dimension is 50nm) 1 weight part, tetrabutyl titanate (purchased from Sinopharm Chemical Reagent Co., Ltd.) 0.5 parts by weight, γ-glycidyl etheroxypropyl trimethoxysilane 0.1 parts by weight, acetylated monoglyceride fatty acid ester (purchased from Sinopharm Chemical Reagent Co., Ltd.) 0.1 parts by weight, at 1500r High-speed pre-mixing at a speed of 1/min; after mixing the above materials, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the screw of the twin-screw extruder The diameter is 75mm, the length-to-diameter ratio is 40:1, and the rotation speed is 1000r/min. 170°C, the temperature in the sixth zone is 185°C, the temperature in the seventh zone is 185°C, the temperature in the eighth zone is 160°C, and the temperature in the ninth zone is 155°C. After extruding, pelletize after cooling down to room temperature through air cooling to obtain biodegradable material particles; then 100 parts by weight of biodegradable material particles and 2 parts by weight of 2-hydroxysuccinic acid, chitosan (CAS No. 969-33-5, molecular formula is C ₂₁ H ₂₁ N) 4 parts by weight, dextran (weight average molecular weight is 5000; purchased from Sinopharm Chemical Reagent Co., Ltd.) 4 parts by weight pre-mixed at a low speed of 400r/min , and then melt spinning is carried out in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine is 170°C, the temperature of the second section is 180°C, the temperature of the third section is 210°C, and the temperature of the fourth section is 250°C 1. The temperature of the fifth stage is 260°C, and the spinning speed is 1000m/s, and finally a biodegradable fiber with micro-mesoporous denier of 10D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.30cN/dtex, the elongation at break is 29.5%, the air permeability is 711mm/s, and the one-way transmission coefficient is 277.

Example 5

With polylactic acid (weight average molecular weight is 250,000) 85 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 250,000, BA/BT molar ratio is 1:2) 10 weight parts, 5 parts by weight of polycaprolactone (weight-average molecular weight is 50,000), 0.1 part by weight of acicular nano-attapulgite (the radial dimension is 5nm, and the axial dimension is 90nm), 1.5 parts by weight of tetrabutyl titanate, at 900r/ High-speed pre-mixing at a speed of min; after mixing the above materials, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the screw diameter of the twin-screw extruder is The temperature of the first zone is 150°C, the temperature of the second zone is 160°C, the temperature of the third zone is 165°C, the temperature of the fourth zone is 170°C, and the temperature of the fifth zone is 175 ℃, the temperature in the sixth zone is 185°C, the temperature in the seventh zone is 190°C, the temperature in the eighth zone is 180°C, and the temperature in the ninth zone is 160°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, 100 parts by weight of biodegradable material particles and 0.5 parts by weight of 2-hydroxysuccinic acid, chitosan (CAS number is 969-33-5, molecular formula is C ₂₁ H ₂₁ N) 0.5 parts by weight, dextran (weight-average molecular weight is 10000) 1 weight part and polyvinyl alcohol (weight-average molecular weight is 8000, alcoholysis degree is 90%; Purchased from Shanghai Petrochemical Co., Ltd.) 1 weight part is premixed at a low speed at a rotating speed of 360r/min , and then carry out melt spinning in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine is 165°C, the temperature of the second section is 180°C, the temperature of the third section is 215°C, and the temperature of the fourth section is 240°C 1. The temperature of the fifth stage is 250°C, and the spinning speed is 1600m/s, and finally a biodegradable fiber with micro-mesoporous denier of 0.1D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.37cN/dtex, the elongation at break is 18.4%, the air permeability is 587mm/s, and the one-way transmission coefficient is 314.

Example 6

With polylactic acid (weight average molecular weight is 300,000) 70 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 300,000, BA/BT molar ratio is 1:2.5) 20 weight parts, 10 parts by weight of polycaprolactone (weight-average molecular weight is 50,000), 0.05 parts by weight of rod-shaped nano-alumina (radial dimension is 15nm, axial dimension is 90nm), needle-shaped nano-attapulgite (radial dimension is 10nm , the axial dimension is 100nm) 0.05 parts by weight, tetrabutyl titanate 0.05 parts by weight, polymaleic anhydride (number average molecular weight is 1200) 0.1 parts by weight, high-speed premixing under the rotating speed of 1400r/min; Mix the above materials Finally, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the screw diameter of the twin-screw extruder is 75mm, the aspect ratio is 40:1, and the speed 1000r/min, the temperature of the first zone is 130°C, the temperature of the second zone is 155°C, the temperature of the third zone is 165°C, the temperature of the fourth zone is 175°C, the temperature of the fifth zone is 175°C, the temperature of the sixth zone is 180°C, and the temperature of the seventh zone The temperature in the eighth zone is 180°C, and the temperature in the ninth zone is 155°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, 100 parts by weight of the biodegradable material particles, 3 parts by weight of dextran (the weight average molecular weight is 9000) and 0.5 parts by weight of polyvinyl alcohol (the weight average molecular weight is 10000, and the degree of alcoholysis is 86%) at 450r/min Mix at a low speed at a certain speed, and then carry out melt spinning in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine is 170°C, the temperature of the second section is 180°C, the temperature of the third section is 220°C, and the temperature of the fourth section is 220°C. The temperature of the first stage is 235°C, the temperature of the fifth stage is 250°C, and the spinning speed is 1200m/s, finally a biodegradable fiber with micro-mesoporous denier of 100D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.34cN/dtex, the elongation at break is 20.6%, the air permeability is 643mm/s, and the one-way transmission coefficient is 392.

Example 7

Polylactic acid (weight average molecular weight is 600,000) 97 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 300,000, BA/BT molar ratio is 1:1) 2.9 weight parts, Polycaprolactone (weight-average molecular weight is 50,000) 0.1 weight part, rod-shaped nano aluminum oxide (radial dimension is 50nm, axial dimension is 200nm) 0.1 weight part, polymaleic anhydride (number-average molecular weight is 1200) 0.05 parts by weight, high-speed pre-mixing at a speed of 1400r/min; after mixing the above materials, the resulting pre-mixture is melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the two The screw diameter of the screw extruder is 75mm, the length-to-diameter ratio is 60:1, and the rotation speed is 1500r/min. ℃, the temperature in the fifth zone is 180 ℃, the temperature in the sixth zone is 190 ℃, the temperature in the seventh zone is 185 ℃, the temperature in the eighth zone is 170 ℃, and the temperature in the ninth zone is 165 ℃. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, 100 parts by weight of biodegradable material particles and 10 parts by weight of dextran (weight average molecular weight is 5000) are mixed at a low speed at a rotating speed of 500r/min, and then melted in a melt spinning machine provided with five sections Spinning, wherein the temperature of the first stage of the spinning machine is 170°C, the temperature of the second stage is 180°C, the temperature of the third stage is 220°C, the temperature of the fourth stage is 240°C, the temperature of the fifth stage is 260°C, and the spinning speed is 1600m/s. Finally, a biodegradable fiber with micro-mesoporous size of 0.1D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.39cN/dtex, the elongation at break is 16.6%, the air permeability is 479mm/s, and the one-way transmission coefficient is 317.

Example 8

With polylactic acid (weight-average molecular weight is 100,000) 40 weight parts, polyadipate/butylene terephthalate (weight-average molecular weight is 300,000, BA/BT molar ratio is 1:1) 40 weight parts, Polycaprolactone (weight-average molecular weight is 250,000) 20 weight parts, rod-shaped nano attapulgite (radial dimension is 1nm, axial dimension is 10nm) 5 weight parts, polymaleic anhydride (number-average molecular weight is 1200) 0.05 weight Parts, 1.95 parts by weight of acetylated monoglyceride fatty acid ester, pre-mixed at a high speed at a speed of 1300r/min; after mixing the above materials, the resulting pre-mixture is melted in a twin-screw extruder with nine zones Mixing and extrusion granulation, wherein the screw diameter of the twin-screw extruder is 75mm, the length-to-diameter ratio is 20:1, the speed is 1000r/min, the temperature in the first zone is 150°C, the temperature in the second zone is 160°C, and the temperature in the third zone The temperature in the fourth zone is 170°C, the temperature in the fifth zone is 180°C, the temperature in the sixth zone is 190°C, the temperature in the seventh zone is 180°C, the temperature in the eighth zone is 160°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, 100 parts by weight of biodegradable material particles and 5 parts by weight of dextran (weight-average molecular weight is 10000), 2.5 parts by weight of 2-hydroxysuccinic acid are mixed at a low speed at a speed of 370r/min, and then are set to five parts by weight. Melt spinning is carried out in a melt-spinning machine of three sections, wherein the temperature of the first section of the spinning machine is 170°C, the temperature of the second section is 180°C, the temperature of the third section is 200°C, the temperature of the fourth section is 260°C, and the temperature of the fifth section is 300 °C, the spinning speed is 100m/s, and finally a biodegradable fiber with micro-mesoporous denier of 1500D is obtained.

The performance test of the biodegradable fiber prepared in this example shows that the tensile strength is 0.21cN/dtex, the elongation at break is 31.8%, the air permeability is 386mm/s, and the one-way transmission coefficient is 329.

Comparative example 1

With polylactic acid (weight average molecular weight is 500,000) 50 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 250,000, BA/BT molar ratio is 1:1) 45 weight parts, 5 parts by weight of polycaprolactone (weight average molecular weight is 200,000), premixed at a high speed at a speed of 1000r/min; Melt mixing and extrusion granulation in a twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 75mm, the length-to-diameter ratio is 40:1, the speed is 1000r/min, the temperature of the first zone is 130°C, the temperature of the second zone is 150°C, The temperature in the third zone is 170°C, the temperature in the fourth zone is 175°C, the temperature in the fifth zone is 175°C, the temperature in the sixth zone is 180°C, the temperature in the seventh zone is 185°C, the temperature in the eighth zone is 180°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of the biodegradable material particles were melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine was 170°C, the temperature of the second section was 180°C, and the temperature of the third section was 220°C, the temperature of the fourth stage is 235°C, the temperature of the fifth stage is 250°C, the spinning speed is 1000m/s, and finally a biodegradable fiber with a denier of 100D is obtained. Although the fiber has been stretched, there is no stretched micropore and three-dimensional channel structure because there is no inorganic filler and pore forming agent.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.39cN/dtex, the elongation at break is 9.6%, the air permeability is 23mm/s, and the one-way transmission coefficient is -46. It can be seen from this that the biodegradable resin itself does not have the function of moisture conduction after being spun into fibers.

Comparative example 2

With polylactic acid (weight average molecular weight is 300,000) 50 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 100,000, BA/BT molar ratio is 1:0.5) 45 weight parts, 5 parts by weight of polycaprolactone (weight average molecular weight is 150,000), premixed at a high speed at a speed of 1000r/min; Melt mixing and extrusion granulation in a twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 75mm, the aspect ratio is 40:1, the speed is 1000r/min, the temperature of the first zone is 120°C, the temperature of the second zone is 150°C, The temperature in the third zone is 160°C, the temperature in the fourth zone is 160°C, the temperature in the fifth zone is 170°C, the temperature in the sixth zone is 175°C, the temperature in the seventh zone is 180°C, the temperature in the eighth zone is 160°C, and the temperature in the ninth zone is 155°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of the biodegradable material particles were melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine was 150°C, the temperature of the second section was 180°C, and the temperature of the third section was 220°C, the temperature of the fourth stage is 230°C, the temperature of the fifth stage is 245°C, the spinning speed is 800m/s, and finally a biodegradable fiber with a denier of 800D is obtained. Although the fiber has been stretched, there is no stretched micropore and three-dimensional channel structure because there is no inorganic filler and pore-forming agent.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.37cN/dtex, the elongation at break is 10.1%, the air permeability is 21mm/s, and the one-way transmission coefficient is -50. It can be seen that, although the fineness of the fiber can be adjusted by changing the processing technology, effective moisture permeability cannot be obtained.

From Comparative Example 1 and Comparative Example 2, it can be seen that only the fibers prepared by biodegradable resins do not add inorganic fillers and pore-forming agents to the fibers, so there is no stretching and three-dimensional pore structure in the fibers obtained, especially It makes the one-way transmission coefficient low and does not have effective moisture conductivity.

Comparative example 3

With polylactic acid (weight-average molecular weight is 300,000) 40 weight parts, polyadipate/butylene terephthalate (weight-average molecular weight is 250,000, BA/BT molar ratio is 1:2) 40 weight parts, 10 parts by weight of polycaprolactone (weight-average molecular weight is 150,000), 1.5 parts by weight of rod-shaped nano silicon dioxide (radial dimension is 10nm, and axial dimension is 50 nanometers), mixes at a high speed at a rotating speed of 1000r/min; After the above-mentioned materials were mixed, the pre-mixture obtained was melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the screw diameter of the twin-screw extruder was 75 mm, and the aspect ratio was 40: 1. The speed is 1000r/min, the temperature of the first zone is 130°C, the temperature of the second zone is 150°C, the temperature of the third zone is 170°C, the temperature of the fourth zone is 175°C, the temperature of the fifth zone is 175°C, the temperature of the sixth zone is 180°C, The temperature in the seventh zone is 185°C, the temperature in the eighth zone is 180°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of the modified biodegradable material particles were melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine was 170°C, the temperature of the second section was 180°C, The temperature of the third stage is 220°C, the temperature of the fourth stage is 235°C, the temperature of the fifth stage is 250°C, the spinning speed is 1000m/s, and finally a biodegradable fiber with stretched micropores with a denier of 100D is obtained.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.38cN/dtex, the elongation at break is 11.6%, the air permeability is 31mm/s, and the one-way transmission coefficient is -10. It can be seen that after adding the inorganic filler, due to the phase separation between the inorganic filler and the biodegradable resin itself, the inorganic filler cannot be stretched during the fiber drawing process, while the biodegradable resin can be stretched, so although it can form Stretched microporous, but still not enough for effective moisture transfer.

Comparative example 4

With polylactic acid (weight average molecular weight is 300,000) 50 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 100,000, BA/BT molar ratio is 1:0.5) 45 weight parts, 5 parts by weight of polycaprolactone (weight-average molecular weight is 150,000), 0.5 parts by weight of rod-shaped nano silicon dioxide (the radial dimension is 3nm, and the axial dimension is 15nm), premixed at a high speed at a speed of 1000r/min; After the above-mentioned materials were mixed, the pre-mixture obtained was melt-mixed and extruded into pellets in a twin-screw extruder with nine zones, wherein the screw diameter of the twin-screw extruder was 75 mm, and the aspect ratio was 40: 1. The speed is 1000r/min, the temperature of the first zone is 120°C, the temperature of the second zone is 150°C, the temperature of the third zone is 160°C, the temperature of the fourth zone is 160°C, the temperature of the fifth zone is 170°C, the temperature of the sixth zone is 175°C, The temperature in the seventh zone is 180°C, the temperature in the eighth zone is 160°C, and the temperature in the ninth zone is 155°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of the biodegradable material particles were melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine was 150°C, the temperature of the second section was 180°C, and the temperature of the third section was 220°C, the temperature of the fourth stage is 230°C, the temperature of the fifth stage is 245°C, and the spinning speed is 800m/s. Finally, a biodegradable fiber with stretched micropores with a fineness of 800D is obtained.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.28cN/dtex, the elongation at break is 9.1%, the air permeability is 26mm/s, and the one-way transmission coefficient is -17. It can be seen that after the addition of inorganic fillers, stretched micropores can be formed, but the improvement of the moisture-conducting function is not obvious.

Comparative example 5

With polylactic acid (weight average molecular weight is 400,000) 40 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 200,000, BA/BT molar ratio is 1:0.5) 40 weight parts, 10 parts by weight of polycaprolactone (weight-average molecular weight is 150,000), premixed at a high speed at a speed of 1000r/min; Melt mixing and extrusion granulation in a twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 75mm, the length-to-diameter ratio is 40:1, the speed is 1000r/min, the temperature of the first zone is 130°C, the temperature of the second zone is 150°C, The temperature in the third zone is 170°C, the temperature in the fourth zone is 175°C, the temperature in the fifth zone is 175°C, the temperature in the sixth zone is 180°C, the temperature in the seventh zone is 185°C, the temperature in the eighth zone is 180°C, and the temperature in the ninth zone is 165°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. After that, 100 parts by weight of biodegradable material particles and 5 parts by weight of 2-hydroxysuccinic acid were melt-spun in a melt spinning machine with five sections, wherein the temperature of the first section of the spinning machine was 170 ° C, and the temperature of the second section was 170 ° C. The temperature in the first stage is 180°C, the temperature in the third stage is 220°C, the temperature in the fourth stage is 235°C, the temperature in the fifth stage is 250°C, and the spinning speed is 1000m/s. Finally, a biodegradable fiber with pores with a fineness of 100D is obtained.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.31cN/dtex, the elongation at break is 21.0%, the air permeability is 79mm/s, and the one-way transmission coefficient is 96. It can be seen from this that the addition of suitable pore-forming agents to biodegradable resins can maintain the mechanical properties of the original fibers and improve the air permeability and moisture permeability, but it is still not sufficient.

Comparative example 6

With polylactic acid (weight average molecular weight is 300,000) 50 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 100,000, BA/BT molar ratio is 1:0.5) 45 weight parts, 5 parts by weight of polycaprolactone (weight average molecular weight is 150,000), premixed at a high speed at a speed of 1000r/min; Melt mixing and extrusion granulation in a twin-screw extruder, wherein the screw diameter of the twin-screw extruder is 75mm, the aspect ratio is 40:1, the speed is 1000r/min, the temperature of the first zone is 120°C, the temperature of the second zone is 150°C, The temperature in the third zone is 160°C, the temperature in the fourth zone is 160°C, the temperature in the fifth zone is 170°C, the temperature in the sixth zone is 175°C, the temperature in the seventh zone is 180°C, the temperature in the eighth zone is 160°C, and the temperature in the ninth zone is 155°C. After extrusion, it is air-cooled to room temperature and then cut into pellets to obtain biodegradable material pellets. Afterwards, after mixing 100 parts by weight of biodegradable material particles and 5 parts by weight of oxalic acid at a low speed at a speed of 300 r/min, melt spinning is carried out in a melt spinning machine equipped with five sections, wherein the spinning machine The temperature of the first stage is 150°C, the temperature of the second stage is 180°C, the temperature of the third stage is 220°C, the temperature of the fourth stage is 230°C, the temperature of the fifth stage is 245°C, the spinning speed is 800m/s, and finally the fiber with a fineness of 800D is obtained. Pore biodegradable fibers.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.32cN/dtex, the elongation at break is 19.8%, the air permeability is 68mm/s, and the one-way transmission coefficient is 87. It can be seen that adding a pore-forming agent can form a pore structure and improve the one-way transmission coefficient, but it is still not sufficient and significant.

Comparative example 7

In addition to using 10 parts by weight of polylactic acid, 85 parts by weight of poly(butylene adipate/terephthalate), and 5 parts by weight of polycaprolactone, with the same procedure as in Example 1, it is finally obtained that the fineness is 100D. Biodegradable fiber, and does not have tensile micropores and three-dimensional channel structure.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.2cN/dtex, the elongation at break is 28.7%, the air permeability is 21mm/s, and the one-way transmission coefficient is -49. It can be seen that because the amount of polylactic acid used is too small, the resulting fiber does not form stretched micropores, the unidirectional moisture-wicking functionality cannot be effectively obtained, and the tensile strength decreases.

Comparative example 8

Except using only 100 parts by weight of polylactic acid (i.e. not using poly(butylene adipate/terephthalate) and polycaprolactone), with the same procedure as in Example 1, finally obtained fineness is 1500D Biodegradable fiber, and does not have tensile micropores and three-dimensional channel structure.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.45cN/dtex, the elongation at break is 4.7%, the air permeability is 15mm/s, and the one-way transmission coefficient is -55. It can be seen that the resulting fibers do not form due to the use of only polylactic acid alone rather than a combination of polylactic acid with polybutylene adipate/terephthalate and/or polycaprolactone. Stretching micropores cannot effectively obtain unidirectional moisture-wicking functionality. Although the tensile strength of the fiber is increased, the elongation at break is greatly reduced, and the fiber is easy to break, which is not conducive to winding.

Comparative example 9

With polylactic acid (weight average molecular weight is 300,000) 20 weight parts, polyadipate/butylene terephthalate (weight average molecular weight is 250,000, BA/BT molar ratio is 1:1) 55 weight parts, Using 25 parts by weight of polycaprolactone (weight average molecular weight: 150,000), the same procedure as in Example 3 was used to finally obtain a stretched microporous biodegradable fiber with a fineness of 100D.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.09cN/dtex, the elongation at break is 34.7%, the air permeability is 9mm/s, and the one-way transmission coefficient is -25. It can be seen that, because the amount of polycaprolactone used is too much, although the obtained fiber will form stretched micropores, the unidirectional moisture-wicking function is still not improved, and the tensile strength of the fiber decreases sharply at the same time. The elongation at break increases, and it is easy to deform during the subsequent spinning process.

Comparative example 10

Except for 6 parts by weight of rod-shaped nano-silica (3nm in radial direction and 15nm in axial direction), the same procedure as in Example 3 was used to finally obtain a biodegradable fiber with stretched micropores with a fineness of 100D.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.39cN/dtex, the elongation at break is 2.5%, the air permeability is 37mm/s, and the one-way transmission coefficient is -17. It can be seen that due to the excessive amount of rod-shaped nano-silica used, although the obtained fibers will form stretched micropores, the unidirectional moisture-wicking function has not been improved, and due to the increase in the content of inorganic fillers, the elongation at break The length decreases sharply, and the spinning process is prone to breakage.

Comparative example 11

Except for 12 parts by weight of oxalic acid, the same procedure as in Example 6 was used to finally obtain a biodegradable fiber with stretched micropores with a fineness of 800D.

The performance test of the biodegradable fiber prepared in this comparative example shows that the tensile strength is 0.15cN/dtex, the elongation at break is 2.3%, the air permeability is 128mm/s, and the one-way transmission coefficient is 135. It can be seen that adding a pore-forming agent can effectively form a pore structure and improve the one-way transmission coefficient, but because the pore-forming dose used is too high, the tensile strength and elongation at break of the obtained fiber are reduced, and spinning and Breakage has occurred during the weaving process.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (13)

A biodegradable fiber, made by melt spinning of biodegradable materials and pore-forming agents, in parts by weight, said biodegradable materials include:

Wherein, the total parts by weight of the polylactic acid, polyadipate/butylene terephthalate and polycaprolactone is 100 parts; The shape of the nano filler is one or more of rods, needles and flakes; The pore-forming agent is an organic pore-forming agent, and the mass ratio of the biodegradable material to the pore-forming agent is 100:(0.1-10). The biodegradable fiber according to claim 1, characterized in that the polylactic acid has a weight average molecular weight of 100,000-600,000. The biodegradable fiber according to claim 1, wherein the repeating unit corresponding to butylene adipate in the polyadipate/butylene terephthalate is the same as that of butylene terephthalate The molar ratio of the repeating units corresponding to the glycol ester is 1:(0.25-4); the weight average molecular weight of the polyadipate/butylene terephthalate is 50,000-300,000. The biodegradable fiber according to claim 1, characterized in that the weight average molecular weight of the polycaprolactone is 50,000-250,000. The biodegradable fiber according to claim 1, wherein the nano-filler is one or more selected from nano-silica, nano-titanium dioxide, nano-alumina and nano-attapulgite. The biodegradable fiber according to claim 1, wherein the coupling agent is selected from 3-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, polymaline One or more of toric anhydride, acetylated monoglyceride fatty acid ester and tetrabutyl titanate. The biodegradable fiber according to claim 1, wherein the pore forming agent is selected from oxalic acid, 2-hydroxysuccinic acid, polyvinyl alcohol, chitosan and dextran or more, preferably the pore forming agent is of biological origin. The biodegradable fiber according to claim 1, characterized in that, the radial dimension of the rod-shaped or needle-shaped nanofiller is 1-50 nm and the axial dimension is 10-200 nm; The thickness is 1-50 nm and the particle size is 10-200 nm. A method for preparing the biodegradable fiber according to any one of claims 1 to 8, comprising the following steps: a) melt blending polylactic acid, polyadipate/butylene terephthalate, polycaprolactone, nanofillers and coupling agents to obtain biodegradable materials; b) melt-spinning the biodegradable material and a pore-forming agent to obtain biodegradable fibers. The preparation method according to claim 9, characterized in that the temperature of the melt blending is 100-200°C; the temperature of the melt spinning is 120-300°C. The preparation method according to claim 9, wherein the polylactic acid, polyadipate/butylene terephthalate, polycaprolactone, nanofiller, coupling agent and pore-forming agent are used Before drying, dry to moisture content ≤ 200ppm. The preparation method according to claim 9, characterized in that, in step a), before melt blending, the polylactic acid, polyadipate/butylene terephthalate, polycaprolactone The ester, nanofiller and coupling agent are stirred and mixed in advance. The preparation method according to claim 9, characterized in that, in step b), prior to melt spinning, the biodegradable material and the pore-forming agent are pre-stirred and mixed.