Bio-based parallel composite elastic fiber and preparation method thereof

Abstract

The invention belongs to the technical field of polymers, and discloses a bio-based parallel composite elastic fiber which comprises a first fiber and a second fiber, the first fiber is prepared from diamine monomer modified bio-based polytrimethylene terephthalate; and the second fiber is prepared from diamine monomer modified bio-based polytrimethylene terephthalate with a poly (trimethylene ether glycol) chain segment. According to the fiber, two kinds of polytrimethylene terephthalate are adopted for parallel composite spinning, the comfort and softness, rebound resilience and breaking strength of the fiber are improved through a poly trimethylene ether glycol chain segment, the compatibility, comfort and softness, rebound resilience and breaking strength of the two kinds of fiber are further improved through diamine modification, and a fiber material with excellent performance is obtained. Meanwhile, the invention also provides a preparation method of the fiber material.

Description

Technical Field

[0001] The invention relates to the field of polymers, and in particular to a bio-based parallel composite elastic fiber and a preparation method thereof. Background Art

[0002] Bi-component parallel composite fiber is a kind of elastic fiber with three-dimensional curling structure. It was first proposed by Sisson and Moorbead. Kanebo Co., Ltd. of Japan began to study it in 1962 and realized industrialization in 1965. Bi-component parallel composite fiber is a fiber composed of two polymers with good compatibility and large difference in heat shrinkage performance. Such fibers include polyester, polyamide or polyolefin, but the polyester with high cost performance is better in the market. The representative of such products is T-400Lycra developed by DuPont, also known as "EasyFitLycra", which is a bi-component parallel composite fiber composed of PET / PTT. Compared with "Lycra", this spiral three-dimensional curled elastic fiber has many unique features: short production process, high fiber strength, low modulus, good heat resistance, no loss of elasticity due to dyeing, sunlight resistance, and chlorine bleaching resistance. However, due to the difference in melt spinning temperature, dyeing temperature and dyeing pressure between the two components of PET and PTT in T400 parallel composite fiber, the fabric made from it has a rough feel and high energy consumption.

[0003] Bio-based polymer materials use renewable resources as their main raw materials. While reducing the consumption of fossil resources, they also reduce the impact of the production and use of fossil-based polymer materials on the environment. They are the current key development target of polymer materials and an important way to achieve "carbon neutrality" and develop a "low-carbon economy". They are of great research value and socio-economic benefits.

[0004] The technical problem solved in this case is how to further improve the comfort, softness, resilience and breaking strength of the two-component parallel composite fiber. Summary of the invention

[0005] The purpose of the present invention is to provide a bio-based parallel composite elastic fiber, which is made of two poly(trimethylene terephthalate)s for parallel composite spinning, and the comfort, softness, resilience and breaking strength of the fiber are improved by polytrimethylene ether glycol chain segments, and the compatibility, comfort, softness, resilience and breaking strength of the two fibers are further improved by diamine modification, thereby obtaining a fiber material with excellent performance.

[0006] Meanwhile, the invention also provides a method for preparing the fiber material.

[0007] To achieve the above objectives, this application discloses:

[0008] A bio-based parallel composite elastic fiber comprises a first fiber and a second fiber; the first fiber is made of bio-based poly(trimethylene terephthalate) modified by a diamine monomer; the second fiber is made of bio-based poly(trimethylene terephthalate) modified by a diamine monomer and having a polytrimethylene ether glycol segment.

[0009] In the above-mentioned bio-based parallel composite elastic fiber, the diamine is one or more of 1,6-hexanediamine, 1,10-decanediamine, and 1,12-diaminododecane.

[0010] In the above-mentioned bio-based parallel composite elastic fiber, the bio-based polytrimethylene terephthalate modified by diamine monomer is made of the following monomers:

[0011] Terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, and diamines;

[0012] The molar ratio of terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol and diamine is 1:1.2-1.3:0.02-0.06.

[0013] In the above-mentioned bio-based side-by-side composite elastic fiber, the bio-based poly(trimethylene terephthalate) having a polytrimethylene ether glycol segment modified by a diamine monomer is made of the following monomers:

[0014] Terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, diamines, bio-based polytrimethylene ether glycol;

[0015] The molar ratio of terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, and diamine is: 1:1.2-1.3:0.02-0.06;

[0016] The bio-based polytrimethylene ether glycol accounts for 5 to 50% of the mass of the bio-based polytrimethylene terephthalate having polytrimethylene ether glycol chain segments modified with diamine monomers.

[0017] In the above-mentioned bio-based parallel composite elastic fiber, the preparation method of the bio-based poly(trimethylene terephthalate) modified by the diamine monomer is as follows: firstly, terephthalic acid or dimethyl terephthalate, bio-based PDO, and diamine are subjected to an ester exchange reaction, and then a polycondensation reaction is carried out;

[0018] The temperature of the transesterification reaction is 190-240°C, the reaction time is 1-2 hours, the temperature of the polycondensation reaction is 250-260°C, the reaction time is 3-4 hours, and during the polycondensation stage, the pressure is gradually reduced until the reaction is completed;

[0019] The preparation method of the bio-based poly(trimethylene terephthalate) with polytrimethylene ether glycol segments modified by a diamine monomer is as follows: firstly, terephthalic acid or dimethyl terephthalate, bio-based PDO, and a diamine are subjected to an ester exchange reaction, and then bio-based polytrimethylene ether glycol is added to carry out a condensation reaction;

[0020] The temperature of the ester exchange reaction is 190-240°C, the reaction time is 1-2 hours, the temperature of the polycondensation reaction is 250-260°C, the reaction time is 3-4 hours, and during the polycondensation stage, the pressure is gradually reduced until the reaction is completed.

[0021] In the above-mentioned bio-based parallel composite elastic fiber, the catalyst used in the transesterification reaction and the catalyst used in the polycondensation reaction are independently selected from one or a mixture of two or more of tetrabutyl titanate, isopropyl titanate, tetraethyl titanate, magnesium acetate, zinc acetate, manganese acetate, antimony trioxide, and ethylene glycol antimony, and the added amount is 0.01-0.1% of the total mass of the reactants;

[0022] An antioxidant is also added in the polycondensation reaction; the antioxidant is one of trimethyl phosphate, triphenyl phosphite, Irganox1010, Irganox168 and Irganox245, and the added amount is 0.01-0.1% of the total mass of the reactants.

[0023] In the above-mentioned bio-based side-by-side composite elastic fiber, the number average molecular weight of the bio-based polytrimethylene ether glycol is 1000-3000 g / mol.

[0024] In the above-mentioned bio-based parallel composite elastic fiber, the mass ratio of the first fiber to the second fiber is 30:70 to 70:30.

[0025] In the above-mentioned bio-based parallel composite elastic fiber, the intrinsic viscosity of the bio-based poly(trimethylene terephthalate) modified by the diamine monomer is 0.87-0.92 dL / g; the intrinsic viscosity of the bio-based poly(trimethylene terephthalate) having a polytrimethylene ether glycol segment modified by the diamine monomer is 0.90-1.40 dL / g.

[0026] At the same time, the present invention also discloses a method for preparing the bio-based parallel composite elastic fiber as described above, wherein bio-based poly(trimethylene terephthalate) modified by diamine monomer and bio-based poly(trimethylene terephthalate) with polytrimethylene ether glycol chain segment modified by diamine monomer are dried in a drum oven, the pre-crystallization temperature is 120-140°C, the pre-crystallization time is 6-10 hours, the moisture content of the polyester after drying is less than 70ppm, and parallel composite spinning is carried out according to the mass ratio of the two components through a melt spinning machine.

[0027] This application has at least the following beneficial effects:

[0028] In the bio-based parallel composite elastic fiber provided by the present invention, both fibers are PTT-based polymers with excellent interface compatibility. Meanwhile, the difference in melt spinning temperature, dyeing temperature and dyeing pressure is small, and a large shrinkage difference is still maintained between the two components. Therefore, the prepared parallel composite elastic fiber has high breaking strength, high resilience, comfortable and soft hand feel and good fluffiness.

[0029] The bio-based parallel composite elastic fiber provided by the present invention has diamine monomers introduced into both strands of the fiber. The introduction of the amide unit allows hydrogen bonds to be formed between polyester molecular chains, thereby effectively improving the mechanical properties of the polymer. DETAILED DESCRIPTION

[0030] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. In the description of the present invention, it should be noted that, if no specific conditions are specified in the embodiments, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0031] Example 1

[0032] (1) Preparation of Component I

[0033] Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,6-hexanediamine was 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst tetrabutyl titanate was added at 0.01% of the total mass and Irganox1010 was added at 0.01% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0034] The intrinsic viscosity of the prepared component I was 0.88 dL / g.

[0035] (2) Preparation of Component II

[0036] (2.1) Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,6-hexanediamine is 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour.

[0037] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 5% of the total mass, the condensation catalyst tetrabutyl titanate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0038] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 250°C, and the pressure is slowly reduced to 50 Pa, and the reaction is carried out at 250°C for 3 hours.

[0039] The intrinsic viscosity of the prepared component II was 1.02 dL / g.

[0040] (3) Pretreatment

[0041] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0042] (4) The pretreated component I and component II are melt-spun in parallel according to a mass ratio of 70:30. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0043] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the metering pump temperature is 265°C, the screw temperature of component II is 260°C, the metering pump temperature is 265°C, the spinning assembly temperature is 265°C, the pump supply of the metering pump is 40ml / min, the number of holes in the spinneret is 24, and the hole diameter is 0.25mm; the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0044] The obtained bio-based parallel composite elastic fiber has a breaking strength of 3.4 cN / dtex, a breaking elongation of 50%, and an elastic recovery rate of 90% when the elongation is 10%.

[0045] Example 2

[0046] (1) Preparation of Component I

[0047] Terephthalic acid, bio-based PDO, 1,10-decanediamine, and esterification catalyst zinc acetate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,10-decanediamine was 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst zinc acetate was added at a total mass of 0.01%, and Irganox1010 was added at a total mass of 0.01%. Stirring for 30 minutes, the temperature was gradually raised to 250°C, and the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0048] The intrinsic viscosity of the prepared component I was 0.90 dL / g.

[0049] (2) Preparation of Component II

[0050] (2.1) Add terephthalic acid, bio-based PDO, 1,10-decanediamine, and esterification catalyst zinc acetate into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,10-decanediamine is 1:1.26:0.04, and the esterification catalyst zinc acetate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour;

[0051] (2.2) After the reaction in step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 10% of the total mass, the condensation catalyst zinc acetate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0052] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0053] The intrinsic viscosity of the prepared component II copolymer was 1.10 dL / g.

[0054] (3) Pretreatment

[0055] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0056] (4) melt-spinning the pretreated component I and component II in a mass ratio of 50:50, specifically, the two components are melt-extruded into melts by a twin-screw extruder, and the two melts simultaneously enter the composite spinning assembly, are extruded from the parallel composite spinneret therein, are cooled by side blowing and the spinning tunnel, are oiled by an oiling roller, are wound at high speed by a winder to obtain primary fibers, and are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0057] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 265°C, the screw temperature of component II is 255°C, the temperature of the metering pump is 260°C, the spinning assembly temperature is 265°C, the pump supply of the metering pump is 50ml / min, the number of holes of the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 3 times, the temperature of the stretching hot roller is 70°C, and the temperature of the stretching hot roller is 120°C.

[0058] The obtained bio-based parallel composite elastic fiber has a breaking strength of 3.1 cN / dtex, a breaking elongation of 62%, and an elastic recovery rate of 92% when the elongation is 10%.

[0059] Example 3

[0060] (1) Preparation of Component I

[0061] Dimethyl terephthalate, bio-based PDO, 1,6-hexanediamine, and transesterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of dimethyl terephthalate, PDO and 1,6-hexanediamine was 1:1.26:0.04, and the transesterification catalyst tetrabutyl titanate was 0.1% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 190°C for reaction for 1 hour. When no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the polycondensation catalyst tetrabutyl titanate and zinc acetate were added at 0.1% of the total mass, and trimethyl phosphate was added at 0.1% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0062] The intrinsic viscosity of the prepared component I was 0.91 dL / g.

[0063] (2) Preparation of Component II

[0064] (2.1) Dimethyl terephthalate, bio-based PDO, 1,6-hexanediamine, and transesterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of dimethyl terephthalate, PDO, and 1,6-hexanediamine is 1:1.26:0.04, and the transesterification catalyst tetrabutyl titanate accounts for 0.1% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 190°C for reaction for 1 hour.

[0065] (2.2) After the reaction in step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 1000 g / mol) is added accounting for 10% of the total mass, polycondensation catalysts tetrabutyl titanate and zinc acetate are 0.1% of the total mass, and trimethyl phosphate is 0.1% of the total mass. The reaction is carried out at a temperature of 210°C and a stirring speed of 100 r / min for 2 hours.

[0066] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 210°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0067] The intrinsic viscosity of the prepared component II was 1.05 dL / g.

[0068] (3) Pretreatment

[0069] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0070] (4) melt-spinning the pretreated component I and component II in a mass ratio of 50:50, specifically, the two components are melt-extruded into melts by a twin-screw extruder, and the two melts simultaneously enter the composite spinning assembly, are extruded from the parallel composite spinneret therein, are cooled by side blowing and the spinning tunnel, are oiled by an oiling roller, are wound at high speed by a winder to obtain primary fibers, and are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0071] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 265°C, the screw temperature of component II is 250°C, the temperature of the metering pump is 260°C, the spinning assembly temperature is 265°C, the pump supply of the metering pump is 40ml / min, the number of holes in the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0072] The obtained bio-based parallel composite elastic fiber has a breaking strength of 3.1 cN / dtex, a breaking elongation of 58%, and an elastic recovery rate of 91% when the elongation is 10%.

[0073] Example 4

[0074] (1) Preparation of Component I

[0075] Dimethyl terephthalate, bio-based PDO, 1,12-diaminododecane, and transesterification catalyst antimony trioxide were added into a polymerization reactor, wherein the molar ratio of dimethyl terephthalate, PDO and 1,12-diaminododecane was 1:1.26:0.04, and the transesterification catalyst antimony trioxide was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 190°C for reaction for 1 hour. When no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the polycondensation catalyst antimony trioxide was added at 0.01% of the total mass, and triphenyl phosphite was added at 0.01% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0076] The intrinsic viscosity of the prepared bio-based PTT is 0.89 dL / g.

[0077] (2) Preparation of Component II

[0078] (2.1) Dimethyl terephthalate, bio-based PDO, 1,12-diaminododecane, and transesterification catalyst antimony trioxide are added into a polymerization reactor, wherein the molar ratio of dimethyl terephthalate, PDO, and 1,12-diaminododecane is 1:1.26:0.04, and the transesterification catalyst antimony trioxide is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 190°C and the reaction is carried out for 1 hour.

[0079] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 1000 g / mol) is added accounting for 10% of the total mass, antimony trioxide as a condensation catalyst is 0.01% of the total mass, and triphenyl phosphite is 0.01% of the total mass. The reaction is carried out at a temperature of 210°C and a stirring speed of 100 r / min for 2 hours.

[0080] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 210°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0081] The intrinsic viscosity of the prepared component II was 1.09 dL / g.

[0082] (3) Pretreatment

[0083] The prepared component I and component II raw materials were placed in a drum oven for drying, the pre-crystallization temperature was 120° C., the pre-crystallization time was 6 hours, and the moisture content of the polyester after drying was less than 70 ppm.

[0084] (4) melt-spinning the pretreated component I and component II in a mass ratio of 50:50, specifically, the two components are melt-extruded into melts by a twin-screw extruder, and the two melts simultaneously enter the composite spinning assembly, are extruded from the parallel composite spinneret therein, are cooled by side blowing and the spinning tunnel, are oiled by an oiling roller, are wound at high speed by a winder to obtain primary fibers, and are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0085] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 260°C, the screw temperature of component II is 255°C, the temperature of the metering pump is 260°C, the spinning assembly temperature is 260°C, the pump supply of the metering pump is 40ml / min, the number of holes in the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0086] The obtained bio-based parallel composite elastic fiber has a breaking strength of 3.0 cN / dtex, a breaking elongation of 63%, and an elastic recovery rate of 92% at an elongation of 10%.

[0087] Example 5

[0088] (1) Preparation of Component I

[0089] Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,6-hexanediamine was 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate was 0.1% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C for reaction for 1 hour. When no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst tetrabutyl titanate was added at 0.1% of the total mass, and Irganox1010 was added at 0.1% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0090] The intrinsic viscosity of the prepared component I was 0.88 dL / g.

[0091] (2) Preparation of Component II

[0092] (2.1) Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,6-hexanediamine is 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate accounts for 0.1% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour.

[0093] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000g / mol) is added accounting for 20% of the total mass, the condensation catalyst tetrabutyl titanate is 0.1% of the total mass, and Irganox1010 is 0.1% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100r / min for 2h.

[0094] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0095] The intrinsic viscosity of the prepared component II was 1.15 dL / g.

[0096] (3) Pretreatment

[0097] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0098] (4) The pretreated component I and component II are melt-spun in parallel according to a mass ratio of 70:30. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0099] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 265°C, the screw temperature of component II is 250°C, the temperature of the metering pump is 260°C, the spinning assembly temperature is 265°C, the pump supply of the metering pump is 50ml / min, the number of holes in the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0100] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.8 cN / dtex, a breaking elongation of 46%, and an elastic recovery rate of 93% at an elongation of 10%.

[0101] Example 6

[0102] (1) Preparation of Component I

[0103] Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,6-hexanediamine was 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C for reaction for 1 hour. When no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst tetrabutyl titanate was added at 0.01% of the total mass, and Irganox1010 was added at 0.1% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0104] The intrinsic viscosity of the prepared component I was 0.90 dL / g.

[0105] (2) Preparation of Component II

[0106] (2.1) Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,6-hexanediamine is 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour.

[0107] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000g / mol) is added accounting for 30% of the total mass, the condensation catalyst tetrabutyl titanate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100r / min for 2h.

[0108] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0109] The intrinsic viscosity of the prepared component II was 1.25 dL / g.

[0110] (3) Pretreatment

[0111] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0112] (4) The pretreated component I and component II are melt-spun in parallel according to a mass ratio of 70:30. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0113] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 265°C, the screw temperature of component II is 250°C, the temperature of the metering pump is 260°C, the temperature of the spinning assembly is 265°C, the pump supply of the metering pump is 50ml / min, the number of holes in the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0114] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.6 cN / dtex, a breaking elongation of 36%, and an elastic recovery rate of 96% at an elongation of 10%.

[0115] Example 7

[0116] (1) Preparation of Component I

[0117] Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,6-hexanediamine was 1:1.24:0.06, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst tetrabutyl titanate was added at 0.01% of the total mass and Irganox1010 was added at 0.01% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0118] The intrinsic viscosity of the prepared component I was 0.83 dL / g.

[0119] (2) Preparation of Component II

[0120] (2.1) Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,6-hexanediamine is 1:1.24:0.06, and the esterification catalyst tetrabutyl titanate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour.

[0121] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 5% of the total mass, the condensation catalyst tetrabutyl titanate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0122] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 250°C, and the pressure is slowly reduced to 50 Pa, and the reaction is carried out at 250°C for 3 hours.

[0123] The intrinsic viscosity of the prepared component II was 0.96 dL / g.

[0124] (3) Pretreatment

[0125] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0126] (4) The pretreated component I and component II are melt-spun in parallel according to a mass ratio of 70:30. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0127] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the metering pump temperature is 265°C, the screw temperature of component II is 255°C, the metering pump temperature is 260°C, the spinning assembly temperature is 265°C, the pump supply of the metering pump is 40ml / min, the number of holes in the spinneret is 24, and the hole diameter is 0.25mm; the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0128] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.8 cN / dtex, a breaking elongation of 42%, and an elastic recovery rate of 91% when the elongation is 10%.

[0129] Example 8

[0130] (1) Preparation of Component I

[0131] Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,6-hexanediamine was 1:1.28:0.02, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst tetrabutyl titanate was added at 0.01% of the total mass and Irganox1010 was added at 0.01% of the total mass. The mixture was stirred for 30 minutes, and the temperature was gradually raised to 250°C. At the same time, the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0132] The intrinsic viscosity of the prepared component I was 0.79 dL / g.

[0133] (2) Preparation of Component II

[0134] (2.1) Terephthalic acid, bio-based PDO, 1,6-hexanediamine, and esterification catalyst tetrabutyl titanate are placed in a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,6-hexanediamine is 1:1.28:0.02, and the esterification catalyst tetrabutyl titanate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour.

[0135] (2.2) After the reaction of step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 5% of the total mass, the condensation catalyst tetrabutyl titanate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0136] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, the temperature is slowly increased from 240°C to 250°C, and the pressure is slowly reduced to 50 Pa, and the reaction is carried out at 250°C for 3 hours.

[0137] The intrinsic viscosity of the prepared component II was 0.94 dL / g.

[0138] (3) Pretreatment

[0139] The prepared component I and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0140] (4) The pretreated component I and component II are melt-spun in parallel according to a mass ratio of 70:30. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0141] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 255°C, the metering pump temperature is 260°C, the screw temperature of component II is 250°C, the metering pump temperature is 260°C, the spinning assembly temperature is 260°C, the pump supply of the metering pump is 40ml / min, the number of holes in the spinneret is 24, and the hole diameter is 0.25mm; the winding speed is 2000m / min, the stretching multiple is 2 times, the temperature of the stretching hot roller one is 70°C, and the temperature of the stretching hot roller two is 120°C.

[0142] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.6 cN / dtex, a breaking elongation of 37%, and an elastic recovery rate of 91% at an elongation of 10%.

[0143] Comparative Example 1

[0144] (1) Preparation of bio-based PTT

[0145] Terephthalic acid, bio-based PDO, and esterification catalyst zinc acetate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid to PDO was 1:1.30, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst zinc acetate was added at a total mass of 0.01%, and Irganox1010 was added at a total mass of 0.01%. Stirring for 30 minutes, the temperature was gradually raised to 250°C, and the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0146] The intrinsic viscosity of the prepared bio-based PTT is 0.76 dL / g.

[0147] (2) Preparation of bio-based PTT-PO3G

[0148] (2.1) Add terephthalic acid, bio-based PDO, and esterification catalyst zinc acetate into a polymerization reactor, wherein the molar ratio of terephthalic acid to PDO is 1:1.30, and the esterification catalyst zinc acetate is 0.01% of the total mass. Pass nitrogen into the reactor to replace the air in the reactor, pressurize it to 2 bar, and heat it to 240°C at a stirring speed of 100 r / min for 1 hour;

[0149] (2.2) After the reaction in step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 10% of the total mass, the condensation catalyst zinc acetate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0150] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0151] The intrinsic viscosity of the prepared bio-based PTT-PO3G copolymer is 0.88 dL / g.

[0152] The prepared bio-based PTT and bio-based PTT-PO3G raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0153] (4) The pretreated bio-based PTT and bio-based PTT-PO3G are melt-spun in parallel at a mass ratio of 50:50. Specifically, the two components are melt-extruded into melts using a twin-screw extruder. The two melts simultaneously enter the composite spinning assembly and are extruded from the parallel composite spinneret therein. The fibers are cooled by side blowing and the spinning tunnel, and then oiled by an oiling roller. The fibers are then wound at high speed by a winder to obtain primary fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0154] Among them, the parallel composite spinning process parameters include: the screw temperature of bio-based PTT is 250°C, the temperature of the metering pump is 255°C, the screw temperature of bio-based PTT-PO3G is 250°C, the temperature of the metering pump is 260°C, the spinning component temperature is 260°C, the pump supply of the metering pump is 50ml / min, the number of holes in the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 3 times, the temperature of the stretching hot roller is 70°C, and the temperature of the stretching hot roller is 120°C.

[0155] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.0 cN / dtex, a breaking elongation of 54%, and an elastic recovery rate of 80% when the elongation is 10%.

[0156] Comparative Example 2

[0157] (1) Preparation of bio-based PTT

[0158] Terephthalic acid, bio-based PDO, and esterification catalyst zinc acetate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid to PDO was 1:1.30, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst zinc acetate was added at a total mass of 0.01%, and Irganox1010 was added at a total mass of 0.01%. Stirring for 30 minutes, the temperature was gradually raised to 250°C, and the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0159] The intrinsic viscosity of the prepared bio-based PTT is 0.76 dL / g.

[0160] (2) Preparation of Component II

[0161] (2.1) Add terephthalic acid, bio-based PDO, 1,10-decanediamine, and esterification catalyst zinc acetate into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO, and 1,10-decanediamine is 1:1.26:0.04, and the esterification catalyst zinc acetate is 0.01% of the total mass. Nitrogen is introduced into the reactor to replace the air in the reactor, and then the pressure is increased to 2 bar. At a stirring speed of 100 r / min, the temperature is raised to 240°C and the reaction is carried out for 1 hour;

[0162] (2.2) After the reaction in step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 10% of the total mass, the condensation catalyst zinc acetate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0163] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0164] The intrinsic viscosity of the prepared component II copolymer was 1.10 dL / g.

[0165] (3) Pretreatment

[0166] The prepared bio-based PTT and component II raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0167] (4) The pretreated bio-based PTT and component II are melt-spun in parallel at a mass ratio of 50:50. Specifically, the two components are melt-extruded into melts by a twin-screw extruder respectively, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, and are cooled by side blowing and spinning tunnel. The fibers are oiled by an oiling roller, and are wound at high speed by a winder to obtain nascent fibers. The fibers are then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0168] Among them, the parallel composite spinning process parameters include: the screw temperature of bio-based PTT is 250°C, the temperature of the metering pump is 255°C, the screw temperature of component II is 255°C, the temperature of the metering pump is 260°C, the temperature of the spinning assembly is 265°C, the pump supply of the metering pump is 50ml / min, the number of holes of the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 3 times, the temperature of the stretching hot roller is 70°C, and the temperature of the stretching hot roller is 120°C.

[0169] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.3 cN / dtex, a breaking elongation of 46%, and an elastic recovery rate of 85% when the elongation is 10%.

[0170] Comparative Example 3

[0171] (1) Preparation of Component I

[0172] Terephthalic acid, bio-based PDO, 1,10-decanediamine, and esterification catalyst zinc acetate were added into a polymerization reactor, wherein the molar ratio of terephthalic acid, PDO and 1,10-decanediamine was 1:1.26:0.04, and the esterification catalyst tetrabutyl titanate was 0.01% of the total mass. Nitrogen was introduced into the reactor to replace the air in the reactor, and then the pressure was increased to 2 bar. At a stirring speed of 100 r / min, the temperature was raised to 240°C and reacted for 1 hour. After no liquid flowed out of the reactor, the pressure in the reactor was reduced to normal pressure, and the condensation catalyst zinc acetate was added at a total mass of 0.01%, and Irganox1010 was added at a total mass of 0.01%. Stirring for 30 minutes, the temperature was gradually raised to 250°C, and the pressure was slowly reduced to 50 Pa, and the reaction was carried out at 250°C for 3 hours.

[0173] The intrinsic viscosity of the prepared component I was 0.90 dL / g.

[0174] (2) Preparation of bio-based PTT-PO3G

[0175] (2.1) Add terephthalic acid, bio-based PDO, and esterification catalyst zinc acetate into a polymerization reactor, wherein the molar ratio of terephthalic acid to PDO is 1:1.30, and the esterification catalyst zinc acetate is 0.01% of the total mass. Pass nitrogen into the reactor to replace the air in the reactor, pressurize it to 2 bar, and heat it to 240°C at a stirring speed of 100 r / min for 1 hour;

[0176] (2.2) After the reaction in step (2.1) is completed, the pressure is adjusted to normal pressure, PO3G (molecular weight 2000 g / mol) is added accounting for 10% of the total mass, the condensation catalyst zinc acetate is 0.01% of the total mass, and Irganox1010 is 0.01% of the total mass. The reaction is carried out at a temperature of 240°C and a stirring speed of 100 r / min for 2 hours.

[0177] (2.3) After the reaction in step (2.2) is completed, the pressure in the reactor is reduced to normal pressure, and the temperature is slowly increased from 240°C to 250°C, while the pressure is slowly reduced to 50 Pa. The reaction is carried out at 250°C for 3 hours.

[0178] The intrinsic viscosity of the prepared bio-based PTT-PO3G copolymer is 0.88 dL / g.

[0179] (3) Pretreatment

[0180] The prepared component I and bio-based PTT-PO3G raw materials were placed in a drum oven for drying. The pre-crystallization temperature was 120° C. and the pre-crystallization time was 6 h. After drying, the moisture content of the polyester was less than 70 ppm.

[0181] (4) The pretreated component I and the bio-based PTT-PO3G are melt-spun in parallel at a mass ratio of 50:50. Specifically, the two components are melt-extruded into melts by a twin-screw extruder, and the two melts enter the composite spinning assembly at the same time, and are extruded from the parallel composite spinneret therein, cooled by side blowing and spinning tunnel, and oiled by an oiling roller. The primary fibers are wound by a winder at high speed to obtain primary fibers, and then stretched, heat-set, and wound into filaments to obtain bio-based parallel composite elastic fibers.

[0182] Among them, the parallel composite spinning process parameters include: the screw temperature of component I is 260°C, the temperature of the metering pump is 265°C, the screw temperature of the bio-based PTT-PO3G is 250°C, the temperature of the metering pump is 260°C, the spinning assembly temperature is 260°C, the pump supply of the metering pump is 50ml / min, the number of holes of the spinneret is 24, the hole diameter is 0.25mm, the winding speed is 2000m / min, the stretching multiple is 3 times, the temperature of the stretching hot roller is 70°C, and the temperature of the stretching hot roller is 120°C.

[0183] The obtained bio-based parallel composite elastic fiber has a breaking strength of 2.6 cN / dtex, a breaking elongation of 50%, and an elastic recovery rate of 87% when the elongation is 10%.

[0184] Summarize:

[0185] It can be seen from Examples 1 to 8 that the present invention can maintain the breaking strength of the product above 2.6 cN / dtex through polytrimethylene ether glycol block and diamine modification, and the elastic recovery rate is not less than 90% when the elongation is 10%;

[0186] It can be seen from Comparative Examples 1 to 3 that when neither of the two fibers is modified with diamine, it cannot meet the above performance requirements. Among them, when neither of the two fibers is modified with diamine, the breaking strength and elastic recovery rate are poor;

[0187] When PTT is not modified with diamine, its performance is slightly enhanced compared with Comparative Example 1, but not as good as that of the Examples;

[0188] When PTT-PO3G is not modified with diamine, the elastic recovery rate is not as good as that of each example. It differs from Example 2 in breaking strength by 0.5 cN / dtex and elastic recovery rate by 5%, but is better than Comparative Examples 1 and 2.

[0189] It can be seen that the modification of PTT with diamine is the key to achieving performance improvement. When both fibers are modified, significant performance improvement can be achieved.

[0190] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A bio-based parallel composite elastic fiber, characterized in that: The invention comprises a first fiber and a second fiber; the first fiber is made of bio-based poly(trimethylene terephthalate) modified by a diamine monomer; the second fiber is made of bio-based poly(trimethylene terephthalate) modified by a diamine monomer and having a polytrimethylene ether glycol chain segment.

2. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The diamine is one or more of 1,6-hexanediamine, 1,10-decanediamine, and 1,12-diaminododecane.

3. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The bio-based polytrimethylene terephthalate modified with diamine monomer is prepared from the following monomers: Terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, and diamines; The molar ratio of terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol and diamine is 1:1.2-1.3:0.02-0.

06.

4. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The bio-based poly(trimethylene terephthalate) modified with diamine monomer and having polytrimethylene ether glycol chain segment is prepared from the following monomers: Terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, diamines, bio-based polytrimethylene ether glycol; The molar ratio of terephthalic acid or dimethyl terephthalate, bio-based 1,3-propylene glycol, and diamine is: 1:1.2-1.3:0.02-0.06; The bio-based polytrimethylene ether glycol accounts for 5 to 50% of the mass of the bio-based polytrimethylene terephthalate having polytrimethylene ether glycol chain segments modified with diamine monomers.

5. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The preparation method of the bio-based poly(trimethylene terephthalate) modified by the diamine monomer is as follows: firstly, terephthalic acid or dimethyl terephthalate, bio-based PDO and diamine are subjected to an ester exchange reaction, and then a polycondensation reaction is carried out; The temperature of the transesterification reaction is 190-240°C, the reaction time is 1-2 hours, the temperature of the polycondensation reaction is 250-260°C, the reaction time is 3-4 hours, and during the polycondensation stage, the pressure is gradually reduced until the reaction is completed; The preparation method of the bio-based poly(trimethylene terephthalate) with polytrimethylene ether glycol segments modified by a diamine monomer is as follows: firstly, terephthalic acid or dimethyl terephthalate, bio-based PDO, and a diamine are subjected to an ester exchange reaction, and then bio-based polytrimethylene ether glycol is added to carry out a condensation reaction; The temperature of the ester exchange reaction is 190-240°C, the reaction time is 1-2 hours, the temperature of the polycondensation reaction is 250-260°C, the reaction time is 3-4 hours, and during the polycondensation stage, the pressure is gradually reduced until the reaction is completed.

6. The bio-based parallel composite elastic fiber according to claim 5, characterized in that: The catalyst used in the transesterification reaction and the catalyst used in the polycondensation reaction are independently selected from one or a mixture of two or more of tetrabutyl titanate, isopropyl titanate, tetraethyl titanate, magnesium acetate, zinc acetate, manganese acetate, antimony trioxide, and ethylene glycol antimony, and the added amount is 0.01-0.1% of the total mass of the reactants; An antioxidant is also added in the polycondensation reaction; the antioxidant is one of trimethyl phosphate, triphenyl phosphite, Irganox1010, Irganox168 and Irganox245, and the added amount is 0.01-0.1% of the total mass of the reactants.

7. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The number average molecular weight of the bio-based polytrimethylene ether glycol is 1000 to 3000 g / mol.

8. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The mass ratio of the first fibers to the second fibers is 30:70 to 70:

30.

9. The bio-based parallel composite elastic fiber according to claim 1, characterized in that: The intrinsic viscosity of the bio-based poly(trimethylene terephthalate) modified by the diamine monomer is 0.87-0.92 dL / g; the intrinsic viscosity of the bio-based poly(trimethylene terephthalate) modified by the diamine monomer and having a polytrimethylene ether glycol segment is 0.90-1.40 dL / g.

10. A method for preparing the bio-based parallel composite elastic fiber according to any one of claims 1 to 9, characterized in that: Bio-based poly(trimethylene terephthalate) modified by diamine monomer and bio-based poly(trimethylene terephthalate) with polytrimethylene ether glycol chain segment modified by diamine monomer are dried in a drum oven, the pre-crystallization temperature is 120-140°C, the pre-crystallization time is 6-10 hours, and the moisture content of the polyester after drying is less than 70ppm. The two components are composite-spun in parallel according to the mass ratio of the two components through a melt spinning machine.