Bio-based polyamide elastomer fiber as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of bio-based high polymer materials, and particularly relates to a bio-based polyamide elastomer fiber as well as a preparation method and application thereof. The bio-based polyamide elastomer fiber provided by the invention comprises an elastomer and nano cellulose, the elastomer comprises hard-segment polymers and soft-segment polymers which are alternately arranged; the hard segment is a bio-based polyamide prepolymer; the soft segment is bio-based poly (trimethylene ether glycol); the elastomer and the nanocellulose are dynamically crosslinked; the hard segment polymer has a structure as shown in a formula I; the number average molecular weight of the hard segment polymer is 1000 to 5000 g / mol; the mass ratio of the hard segment polymer in the elastomer is 10%-50%. The bio-based polyamide elastomer fiber provided by the invention has good mechanical properties and resilience.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bio-based polymer materials, and particularly relates to a bio-based polyamide elastomer fiber and a preparation method and application thereof. BACKGROUND

[0002] Elastomer fibers play a key role in the fields of textiles and clothing, medical treatment and intelligent materials (such as flexible sensors) due to their excellent tensile properties and recovery ability. Traditional elastomer fibers are mainly prepared by crosslinking petroleum-based polyether or polyester polyols with isocyanate, and the production process is accompanied by problems of toxic monomer residues and high energy consumption, and the waste is difficult to naturally degrade, which aggravates the environmental burden.

[0003] As a kind of polymer material with great application prospect, bio-based polyamide elastomers have made breakthroughs in the development of new monomers and preparation technologies, but still face many challenges in practical applications. For example, the bio-based polyamide elastomer designed by using polyamide 1010 (PA1010) as a hard segment and polytrimethylene glycol ether (PO3G) as a soft segment still faces the problem that the phase separation behavior of the PA1010 hard segment and the PO3G soft segment is difficult to control, resulting in insufficient mechanical properties and elastic recovery ability. SUMMARY

[0004] The purpose of the present application is to provide a bio-based polyamide elastomer fiber and a preparation method and application thereof. The bio-based polyamide elastomer fiber provided by the present application has good mechanical properties and recovery ability.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] The present application provides a bio-based polyamide elastomer fiber, which comprises an elastomer and nanocellulose; the elastomer comprises alternately arranged hard segment polymers and soft segment polymers; the hard segment polymers are bio-based polyamide prepolymers; the soft segment polymers are bio-based polytrimethylene ether glycols; the elastomer and the nanocellulose are dynamically crosslinked.

[0007] The hard segment polymers have the structure shown in Formula I;

[0008]

[0009] The number average molecular weight of the hard segment polymers is 1000-5000 g / mol.

[0010] The mass fraction of the hard segment polymers in the elastomer is 10%-50%.

[0011] Preferably, the mass fraction of the soft segment polymers in the elastomer is 50%-90%, and the number average molecular weight of the soft segment polymers is 2000 g / mol.

[0012] Preferably, the mass content of the elastomer in the bio-based polyamide elastomer fiber is ≥ 90%; the number average molecular weight of the elastomer is 20000-30000 g / mol.

[0013] The application provides a preparation method of the bio-based polyamide elastomer fiber.

[0014] (1) mixing decamethylenediamine, sebacic acid, water and a polycondensation catalyst to perform polycondensation reaction to obtain a bio-based polyamide prepolymer; the decamethylenediamine and the sebacic acid are derived from castor oil;

[0015] (2) mixing the bio-based polyamide prepolymer, bio-based polytrimethylene ether glycol, water and a titanium catalyst to perform block polymerization to obtain a copolymer with a block structure in which soft segments and hard segments are arranged alternately;

[0016] (3) mixing the copolymer and nanocellulose, and then performing extrusion and spinning in sequence, and then performing drawing and heat setting in sequence on the obtained as-spun fiber to obtain the bio-based polyamide elastomer fiber.

[0017] Preferably, the polycondensation reaction is performed under the condition of a polycondensation catalyst, and the polycondensation catalyst comprises sodium hypophosphite and / or sodium hypophosphorous acid;

[0018] The molar ratio of the decamethylenediamine to the sebacic acid is 0.7-0.95:1.0.

[0019] Preferably, the extrusion region is divided into a pre-melt conveying zone, a dynamic crosslinking reaction zone, a micro-phase homogenization zone and a steady-state rheological control zone; the temperature of the pre-melt conveying zone is 180-200℃; the temperature of the dynamic crosslinking reaction zone is 200-210℃; the temperature of the micro-phase homogenization zone is 210-230℃; and the temperature of the steady-state rheological control zone is 230-250℃.

[0020] The temperature of the spinning is 230-250℃.

[0021] Preferably, the drawing comprises primary drawing and secondary drawing performed in sequence; the temperature of the primary drawing is 80-100℃, the drawing ratio of the primary drawing is 2.8-3.2 times, and the temperature of the secondary drawing is 160-180℃; the drawing ratio of the secondary drawing is 1.2-1.5 times.

[0022] Preferably, the heat setting temperature is 180-200℃.

[0023] Preferably, the block polymerization comprises preliminary block polymerization and final block polymerization performed in sequence.

[0024] The temperature of the preliminary block polymerization is 210-230 DEG C, the pressure is 0.1-0.3 MPa, and the time is 1.5-3.0 h.

[0025] The final block polymerization is performed under vacuum, the temperature of the final block polymerization is 240-250 DEG C, and the time is 1.5-3.0 h.

[0026] The application provides application of the bio-based polyamide elastomer fiber prepared by the preparation method in biomedicine, intelligent sensing or sports clothing.

[0027] The application provides a bio-based polyamide elastomer fiber, which comprises an elastomer and nanocellulose; the elastomer comprises alternately arranged hard segment polymers and soft segment polymers; the hard segment polymers are bio-based polyamide prepolymer; the soft segment polymers are bio-based polytrimethylene ether glycol; the elastomer and the nanocellulose are dynamically crosslinked; the hard segment polymers have the structure shown in formula I.

[0028]

[0029] The number average molecular weight of the hard segment polymers is 1000-5000 g / mol.

[0030] The mass percentage of the hard segment polymers in the elastomer is 10%-50%.

[0031] The bio-based polyamide elastomer fiber provided by the application is alternately arranged by bio-based polyamide prepolymer and bio-based polytrimethylene ether glycol (PO3G), and the two are connected by chemical bonds to form a rigid-flexible molecular chain structure. Meanwhile, nanocellulose (CNC) is used as a dynamic crosslinking agent to realize precise regulation of the interaction between molecular chains. The acid-terminated polyamide prepolymer is designed to control the molecular weight of the hard segment, and the ratio of the soft segment and the hard segment is adjusted, so that the hard segment ordered crystallization region and the soft segment amorphous region form a controllable microphase separation structure, and the dispersion of nanocellulose enhances the interaction of the two-phase interface, giving the material multiple regulation in the structural hierarchy. The structural design breaks through the traditional elastomer single crosslinking or simple blending mode, and through the synergistic innovation of bio-based block sequence and dynamic crosslinking network, a new path is provided for the structural design of high-performance elastomers.

[0032] The data of the embodiment show that the bio-based polyamide elastomer fiber provided by the application has a breaking strength of 2.8-4.0 cN / dtex and an elongation at break of 450-600%. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is the infrared spectrum of the bio-based polyamide prepolymer in Example 1. DETAILED DESCRIPTION

[0035] The present invention provides a bio-based polyamide elastomer fiber, comprising an elastomer and nanocellulose; the elastomer comprises hard segment polymers and soft segment polymers arranged alternately; the hard segment polymer is a bio-based polyamide prepolymer; the soft segment polymer is a bio-based polytrimethylene ether glycol; the elastomer and nanocellulose are dynamically cross-linked;

[0036] The hard segment polymer has a structure shown in Formula I;

[0037]

[0038] The number average molecular weight of the hard segment polymer is 1000 to 5000 g / mol; the mass proportion of the hard segment polymer in the elastomer is 10% to 50%.

[0039] As an embodiment of the present invention, the number average molecular weight of the hard segment polymer is 1000 to 5000 g / mol; and the molar ratio of the methylene group to the amide group is 18:1.

[0040] As an embodiment of the present invention, the mass proportion of the hard segment polymer in the elastomer is 10% to 50%, specifically 10%, 20%, 30%, 40% or 50%, and the mass proportion of the soft segment polymer can be 50% to 90%, specifically 90%, 80%, 70%, 60% or 50%. As an embodiment of the present invention, the number average molecular weight of the elastomer is 20,000 to 30,000 g / mol. As an embodiment of the present invention, the melt index of the elastomer is 15 to 25 g / 10 min at 190°C.

[0041] The bio-based polyamide elastomer fiber of the present invention jointly determines the critical conditions (phase separation driving force) and phase deformation of microphase separation through the hard segment molecular weight and ratio. By precisely adjusting the two parameters, the microphase separation structure is optimized, thereby regulating the mechanical properties and elastic recovery characteristics of the material.

[0042] As an embodiment of the present invention, the elastomer mass content in the bio-based polyamide elastomer fiber is ≥90%.

[0043] As an embodiment of the present application, the bio-based polyamide elastomer fiber can have a breaking strength of 2.8-4.0 cN / dtex, and an elongation at break of 450-600%.

[0044] As an embodiment of the present application, the bio-based polyamide elastomer fiber can have an intrinsic viscosity of 1.2-1.4 dL / g, a tensile strength of 35-45 MPa, and an elastic retention rate of 80-90%.

[0045] The present application also provides a preparation method of the bio-based polyamide elastomer fiber as described above, comprising the following steps:

[0046] (1) mixing decanediamine, sebacic acid, water and a polycondensation catalyst to perform a polycondensation reaction, to obtain a bio-based polyamide prepolymer; the decanediamine and the sebacic acid are derived from castor oil;

[0047] (2) mixing the bio-based polyamide prepolymer, a bio-based polytrimethylene ether glycol, water and a titanium-based catalyst to perform a block polymerization, to obtain a copolymer with a block structure of soft-hard segment alternately arranged;

[0048] (3) mixing the copolymer and nanocellulose, and then performing extrusion and spinning in sequence, and then performing drawing and heat setting in sequence on the obtained as-spun fiber, to obtain the bio-based polyamide elastomer fiber.

[0049] The present application performs polycondensation on decanediamine and sebacic acid to obtain a bio-based polyamide prepolymer.

[0050] Structure of decanediamine

[0051] Structure of sebacic acid:

[0052] The present application mixes decanediamine, sebacic acid, water and a polycondensation catalyst to perform a polycondensation reaction, to obtain a bio-based polyamide prepolymer.

[0053] As an embodiment of the present application, the polycondensation catalyst comprises sodium hypophosphite and / or sodium hypophosphorous acid. Specifically, the polycondensation reaction is preferably a process of mixing decanediamine, sebacic acid, water and a polycondensation catalyst, and then performing salification and polymerization.

[0054] As an embodiment of the present application, the sebacic acid and decamethylenediamine are derived from castor oil. As an embodiment of the present application, the molar ratio of the sebacic acid and decamethylenediamine can be 0.7-0.95:1.0, specifically 0.71:1, 0.85:1, 0.89:1, 0.92:1 and 0.94:1; the mass of the water can be 10% of the mass sum of the sebacic acid and decamethylenediamine; the mass of the polycondensation catalyst can be 0.15% of the mass sum of the sebacic acid, decamethylenediamine and water.

[0055] As an embodiment of the present application, the salting temperature can be 100℃ and the pressure can be 0.2MPa; before the salting reaction, pre-activation is further included; the pre-activation is preferably carried out under the condition of nitrogen and stirring; the heating rate for heating to the pre-activation temperature can be 5℃ / min; the stirring speed can be 50rpm.

[0056] As an embodiment of the present application, the polymerization includes first polymerization, second polymerization, third polymerization and fourth polymerization in sequence.

[0057] As an embodiment of the present application, the temperature of the first polymerization can be 180℃, the pressure can be 0.9-1.1MPa, specifically 1.0MPa, and the time can be 1.0h. As an embodiment of the present application, the temperature of the second polymerization can be 220-240℃, specifically 220℃, 230℃ or 240℃, the pressure can be 1.6-1.8MPa, specifically 1.6MPa, 1.7MPa or 1.8MPa, and the time can be 1.0-1.2h, specifically 1.0h, 1.1h or 1.2h; as an embodiment of the present application, the temperature of the third polymerization can be 220-240℃, specifically 220℃, 230℃ or 240℃, the pressure can be atmospheric pressure, and the time can be 1.0-1.2h, specifically 1h, 1.1h or 1.2h; as an embodiment of the present application, the fourth polymerization is carried out under vacuum, the vacuum pressure is -80kPa, the temperature of the fourth polymerization can be 220-240℃, specifically 220℃, 230℃ or 240℃, and the time can be 0.5-0.6h, specifically 0.5h or 0.6h.

[0058] After obtaining the bio-based polyamide prepolymer, the bio-based polyamide prepolymer, bio-based polytrimethylene ether glycol, water and titanium catalyst are mixed to carry out block polymerization to obtain a copolymer with a block structure of soft-hard segment alternately arranged.

[0059] As an embodiment of the present application, the bio-based polytrimethylene ether glycol has the following structural formula:

[0060]

[0061] As an embodiment of the present application, the molecular weight of the bio-based polytrimethylene glycol ether can be 2000 g / mol; as an embodiment of the present application, the bio-based polytrimethylene glycol ether is preferably obtained by polymerization of 1,3-propanediol fermented from corn sugar.

[0062] As an embodiment of the present application, the mass ratio of the bio-based polyamide prepolymer and the bio-based polytrimethylene ether glycol can be 0.1-1.0:1.0, and specifically can be 0.43:1; the water can be deionized water; the mass of the water can be 15% of the mass of the bio-based polyamide prepolymer and the bio-based polytrimethylene ether glycol.

[0063] As an embodiment of the present application, the titanium-based catalyst can be tetrabutyl titanate; the amount of the titanium-based catalyst can be 0.25% of the total mass of the bio-based polyamide prepolymer, the bio-based polytrimethylene ether glycol, and the water.

[0064] As an embodiment of the present application, the block polymerization is preferably mixing the bio-based polyamide prepolymer, the bio-based polytrimethylene ether glycol, the water, and the polymerization catalyst, and sequentially performing preliminary block polymerization and final block polymerization;

[0065] As an embodiment of the present application, the temperature of the preliminary block polymerization can be 210-230℃, and specifically can be 210℃, 220℃, or 230℃; the pressure can be 0.1-0.3 MPa, and specifically can be 0.25 MPa; the time can be 1.5-3.0 h; the temperature of the final block polymerization can be 240-250℃, and specifically can be 240℃, 245℃, or 250℃; the final block polymerization is performed under vacuum conditions.

[0066] After obtaining the copolymer, the present application mixes the copolymer and nanocellulose, and then sequentially performs extrusion and spinning, and the obtained nascent fiber is sequentially drawn and heat set to obtain the bio-based polyamide elastomer fiber.

[0067] The present application introduces nanocellulose (CNC) as a crosslinking agent to construct a dynamic reversible crosslinking network, increase the hydrogen bond density and the degree of dynamic crosslinking, and improve the mechanical properties and structural stability of the material.

[0068] In the present application, the extrusion and spinning are preferably performed under antioxidant conditions; specifically, the copolymer and nanocellulose and an antioxidant are mixed in the present application before extrusion. The antioxidant is preferably antioxidant 1098. In the present application, the mass of the antioxidant is preferably 1% of the mass of the copolymer and nanocellulose.

[0069] In the present application, the temperature of the spinning can be 230-250℃, specifically, in the present application, the spinning temperature can be adjusted according to the melting point of the elastomer, the higher the melting point, the higher the spinning temperature.

[0070] The present application establishes a stable spinning processing window through a dynamic low-temperature extrusion process, according to the melt flow characteristics of the elastomer resin, the extrusion area is divided into a pre-melt conveying zone, a dynamic crosslinking reaction zone, a micro-phase homogenization zone and a steady-state rheological control zone; as an embodiment of the present application, the pre-melt conveying zone functions to convey the block copolyamide premix and establish the basic rheological characteristics, the temperature thereof can be 180-200℃; the dynamic crosslinking reaction zone functions to in-situ construct a hydrogen bond network and induce soft and hard segment nanoscale dispersion by shearing, the temperature thereof can be 200-210℃; the micro-phase homogenization zone functions to realize micro-phase structure homogenization through temperature and pressure gradient control, the temperature thereof can be 210-230℃; the steady-state rheological control zone functions to precisely control the melt rheological behavior, the temperature thereof can be 230-250℃.

[0071] In the present application, the gradient extrusion and spinning can reduce the structural defects of the nascent fiber and facilitate industrial production.

[0072] As an embodiment of the present application, the drawing includes first drawing and second drawing performed in sequence; the temperature of the first drawing can be 80-100℃, specifically, 80℃, 90℃ or 100℃; the draw ratio of the first drawing can be 2.8-3.2 times, specifically, 3.0 times; the temperature of the second drawing can be 160-180℃, specifically, 160℃; the draw ratio of the second drawing can be 1.2-1.5 times, specifically, 1.2 times, 1.3 times, 1.4 times or 1.5 times; the heat setting temperature can be 180-200℃, specifically, 190℃.

[0073] The present application also provides the application of the bio-based polyamide elastomer fiber in biomedicine, intelligent sensing or sports clothing.

[0074] As an embodiment of the present application, the use temperature range of the bio-based polyamide elastomer fiber is -70-210℃, when used at the above temperature, the bio-based polyamide elastomer fiber provided by the present application has good stability.

[0075] In order to further illustrate the present application, the schemes of the present application are described in detail below in combination with the drawings and examples, but they should not be understood as limiting the scope of protection of the present application.

[0076] Example 1

[0077] (1) Take 3.36 mol of sebacic acid and 3.01 mol of decanediamine, add 10 wt% of deionized water based on the mass of sebacic acid and decanediamine, and 0.15% of sodium hypophosphite based on the mass of sebacic acid, decanediamine and deionized water. Add all the above raw materials to the polymerization kettle, heat at a rate of 5°C / min under nitrogen pressure of 0.2 MPa, start stirring at 100°C, control the stirring rate at 50 rpm, and stir for 0.5 h to promote the salt formation of diacid and diamine monomers in the solution.

[0078] The second stage continues to heat at a rate of 5°C / min to 180°C, the pressure rises to 1.0 MPa, and the pressure is stabilized by appropriate exhaust. After keeping the pressure for 1 h, it is heated again to 240°C, and the pressure is adjusted to 1.7 MPa. After keeping the pressure for 1 h, it is depressurized to atmospheric pressure, and the reaction continues for 1 h. Then it is vacuumed (vacuum pressure -80 kPa) for 0.5 h. When the water output reaches 95 wt% of the theoretical mass of water (water added + reaction generated), the discharge valve is opened to flash off the material. After crushing and drying, a bio-based polyamide prepolymer (denoted as Pre-PA1010, whose infrared spectrum is shown in FIG. 1) is obtained. Figure 1 ).

[0079] (2) Take 300 g of Pre-PA1010 and 700 g of PO3G, add 15% of deionized water based on the mass of Pre-PA1010 and PO3G, and 0.25% of tetrabutyl titanate based on the mass of Pre-PA1010, PO3G and deionized water. Add it to the polymerization kettle, then purge the air in the reactor and fill it with 0.25 MPa of N2. Raise the temperature to 210°C and continue polymerization for 2 h. Vacuumize and heat the high-pressure reactor to 240°C. After further reaction of the mixture under vacuum for 2 h, the material is discharged to obtain a bio-based polyamide elastomer.

[0080] (3) After drying, the bio-based polyamide elastomer is mixed with nanocellulose (the mass of nanocellulose is 0.5% of the mass of nanocellulose and bio-based polyamide elastomer), antioxidant 1098 (the mass of antioxidant 1098 is 1% of the mass of nanocellulose and bio-based polyamide elastomer), and then added to a twin-screw extruder. The settings are pre-melt conveying at 190°C, dynamic cross-linking reaction zone at 210°C, micro-phase homogenization zone at 230°C, and steady-state rheological control zone at 240°C. The spinning temperature is 240°C, and the melt stream extruded through the spinneret is cooled by the cooling system to obtain the nascent fiber.

[0081] (6) The nascent fiber is drawn through the first roll of the take-up heat roller, the spinneret draw ratio is 30-50 times, the first collection roller temperature is 100°C, and the speed is 500 m / min to obtain the undrawn yarn.

[0082] (7) The undrafted yarn is subjected to primary and secondary drafting, the primary drafting temperature is 80°C, the drafting multiple is 3.0, the secondary drafting temperature is 180°C, the drafting multiple is 1.5, the heat setting temperature is 190°C, the second heat setting temperature is 200°C, and the final winding speed is 2500 m / min.

[0083] Example 2

[0084] (1) 3.30 mol of sebacic acid and 3.09 mol of decanediamine are weighed, 10% of deionized water based on the mass of sebacic acid and decanediamine, and 0.15% of sodium hypophosphite based on the mass of sebacic acid, decanediamine and deionized water are added. All the above raw materials are added to the polymerization kettle, and the temperature is raised at a rate of 5°C / min under nitrogen pressure of 0.2 MPa. The stirring is started at 100°C, and the stirring rate is controlled at 50 rpm. The stirring time is 0.5 h to promote the salt formation of diacid and diamine monomers in the solution.

[0085] The second stage continues to raise the temperature to 180°C at a rate of 5°C / min, the pressure rises to 1.0 MPa, and the pressure is kept stable by appropriate exhaust. After keeping the state for 1 h, the temperature is raised again to 240°C, and the pressure is adjusted to 1.7 MPa. After keeping the state for 1 h, the pressure is released to atmospheric pressure, and the reaction continues for 1 h. Then, the vacuum (vacuum pressure -80 kPa) reaction is carried out for 0.5 h. When the water output reaches 95% of the total water added, the discharge valve is opened to flash off the material. After crushing and drying, a bio-based polyamide prepolymer (denoted as Pre-PA1010) is obtained.

[0086] (2) 300 g of Pre-PA1010 and 700 g of PO3G are weighed, 15% of deionized water based on the mass of Pre-PA1010 and PO3G, and 0.25% of tetrabutyl titanate based on the mass of Pre-PA1010, PO3G and deionized water are added. They are added to the polymerization kettle, then the air in the reactor is purged, and the reactor is filled with 0.25 MPa of nitrogen. The temperature is raised to 210°C and maintained for 2 h. The high-pressure reactor is heated to 240°C after vacuumizing. The mixture is further reacted under vacuum for 2 h to discharge the material, and a bio-based polyamide elastomer is obtained.

[0087] (3) After drying, the bio-based polyamide elastomer is mixed with nanocellulose (the mass of nanocellulose is 0.5% of the mass of nanocellulose and bio-based polyamide elastomer), antioxidant 1098 (the mass of antioxidant 1098 is 1% of the mass of nanocellulose and bio-based polyamide elastomer), and then added to a twin-screw extruder. The settings are pre-melt conveying 200°C, dynamic crosslinking reaction zone 210°C, micro-phase homogenization zone 230°C, steady-state rheological control zone 240°C, and spinning temperature 250°C. The extruded melt stream is cooled by a cooling system to obtain the primary fiber.

[0088] (6) The primary fiber is drawn through the first winding hot roller, the jet stretching ratio is 30-50 times, the first collection roller temperature is 100℃, and the rotating speed is 500 m / min, to obtain the undrawn yarn.

[0089] (7) The undrawn yarn is drawn by the first and second stages, the first stage drawing temperature is 80℃, the drawing multiple is 3.0 times, the second stage drawing temperature is 180℃, the drawing multiple is 1.5 times, the heat setting temperature is 190℃, the second heat setting temperature is 200℃, and the final winding speed is 2500 m / min.

[0090] Example 3

[0091] (1) 3.36 mol of sebacic acid and 3.01 mol of decanediamine are weighed, 10% of deionized water based on the mass of sebacic acid and decanediamine, and 0.15% of sodium hypophosphite based on the mass of sebacic acid, decanediamine and deionized water are added. All the above raw materials are added to the polymerization kettle, and the temperature is raised at a rate of 5℃ / min under nitrogen pressure of 0.2 MPa. The stirring is started at 100℃, and the stirring rate is controlled at 50 rpm. The stirring time is 0.5 h to promote the salt formation of diacid and diamine monomers in the solution.

[0092] The second stage continues to raise the temperature at a rate of 5℃ / min to 180℃, the pressure rises to 1.0 MPa, and the pressure is kept stable by appropriate exhaust. After keeping the state for 1 h, the temperature is raised again to 240℃, and the pressure is adjusted to 1.7 MPa. After keeping the state for 1 h, the pressure is released to atmospheric pressure, and the reaction continues for 1 h. Then the vacuum (vacuum pressure-80 kPa) reaction is carried out for 0.5 h. When the water output reaches 95% of the theoretical mass of water (water added+generated by reaction), the discharge valve is opened to flash the material. After crushing and drying, the bio-based polyamide prepolymer (denoted as Pre-PA1010) is obtained.

[0093] (2) 500 g of Pre-PA1010 and 500 g of PO3G are weighed, 15% of deionized water based on the mass of Pre-PA1010 and PO3G, and 0.25% of tetrabutyl titanate based on the mass of Pre-PA1010, PO3G and deionized water are added. They are added to the polymerization kettle, then the air in the reactor is purged, and the reactor is filled with 0.25 MPa of nitrogen. The temperature is raised to 210℃ and maintained for 2 h. The high-pressure reactor is heated to 240℃ after vacuumizing. The mixture is further reacted under vacuum for 2 h, and then discharged to obtain the bio-based polyamide elastomer.

[0094] (3) After the bio-based polyamide elastomer is dried, nanocellulose (the mass of the nanocellulose is 0.5% of the mass sum of the nanocellulose and the bio-based polyamide elastomer), and antioxidant 1098 (addition amount: 1 wt%) are mixed, and then added into a twin-screw extruder, and pre-melt conveying is set to 200°C; dynamic crosslinking reaction is set to 210°C; micro-phase homogenization is set to 230°C; steady-state rheological regulation is set to 240°C, and the spinning temperature is 250°C. The melt stream extruded through the spinneret is cooled through a cooling system to obtain a primary fiber.

[0095] (6) The primary fiber is drawn through a first winding hot roller of the spinneret, the spinneret draw ratio is 30-50 times, the first collection roller temperature is 100°C, and the rotation speed is 500 m / min to obtain an undrawn yarn.

[0096] (7) The undrawn yarn is drawn in a first stage and a second stage, the first-stage drawing temperature is 80°C, the drawing multiple is 3.0 times, the second-stage drawing temperature is 180°C, the drawing multiple is 1.5 times, the heat setting temperature is 190°C, the second heat setting temperature is 200°C, and the final winding speed is 2500 m / min.

[0097] Example 4

[0098] (1) 3.36 mol of sebacic acid and 3.01 mol of decanediamine are weighed, 10% of deionized water based on the mass sum of the sebacic acid and the decanediamine, and 0.15% of sodium hypophosphite based on the mass sum of the sebacic acid, the decanediamine, and the deionized water are added. All the above raw materials are added into a polymerization kettle, and the temperature is raised at a temperature raising rate of 5°C / min under nitrogen pressure of 0.2 MPa. When the temperature reaches 100°C, the stirring is started, the stirring rate is controlled to be 50 rpm, and the stirring time is 0.5 h to promote the salt formation of the diacid and diamine monomers in the solution.

[0099] In the second stage, the temperature is continuously raised at a temperature raising rate of 5°C / min to 180°C, the pressure is raised to 1.0 MPa, the pressure is appropriately released to keep the pressure stable, and the temperature is kept constant at this state for 1 h. Then, the temperature is raised again to 240°C, the pressure is adjusted to 1.7 MPa, and the temperature is kept constant at this state for 1 h. Then, the pressure is released to the atmospheric pressure, the reaction is continued for 1 h, and the vacuum (vacuum pressure -80 kPa) reaction is performed for 0.5 h. When the water output reaches 95% of the theoretical mass of water (water addition amount + reaction generation), the discharge valve is opened to flash the material, and the material is crushed and dried to obtain a bio-based polyamide prepolymer (denoted as Pre-PA1010).

[0100] (2) Take 300 g of bio-based PA1010 prepolymer and 700 g of PO3G, add 15% of deionized water based on the mass of Pre-PA1010 and PO3G, and 0.25% of tetrabutyl titanate based on the mass of Pre-PA1010, PO3G and deionized water. Add it to the polymerization kettle, then purge the air in the reactor, and fill it with 0.25 MPa of nitrogen, and raise the temperature to 210°C for 2 h. Vacuumize, heat the high-pressure reactor to 240°C. After the mixture is further reacted under vacuum for 2 h, it is discharged to obtain a bio-based polyamide elastomer.

[0101] (3) After drying the bio-based polyamide elastomer, mix it with nanocellulose (the mass of nanocellulose is 0.5% of the mass sum of nanocellulose and bio-based polyamide elastomer), antioxidant 1098 (the mass of antioxidant 1098 is 1% of the mass sum of nanocellulose and bio-based polyamide elastomer), and then add it to a twin-screw extruder, set the pre-melt conveying temperature to 190°C; the dynamic crosslinking reaction zone to 210°C; the micro-phase homogenization zone to 230°C; the steady-state rheological control zone to 240°C, and the spinning temperature to 240°C. The melt stream extruded through the spinneret passes through the cooling system to obtain the nascent fiber.

[0102] (6) The nascent fiber is drawn through the spinneret at a draw ratio of 30-50 times, the first collection roller temperature is 100°C, and the rotation speed is 500 m / min to obtain the undrawn yarn.

[0103] (7) The undrawn yarn is drawn at a first-stage draw ratio of 3.2 times at a temperature of 80°C and a second-stage draw ratio of 1.8 times at a temperature of 180°C, heat-set at a temperature of 190°C, and heat-set again at a temperature of 200°C, and finally wound at a speed of 2550 m / min.

[0104] Comparative Example 1

[0105] (1) Take 3.36 mol of sebacic acid and 3.01 mol of decanediamine, add 10% of deionized water based on the mass of sebacic acid and decanediamine, and 0.15% of sodium hypophosphite based on the mass of sebacic acid, decanediamine and deionized water. Add all the above raw materials to the polymerization kettle, pressurize to 0.2 MPa with nitrogen, heat at a rate of 5°C / min, start stirring at 100°C, control the stirring speed at 50 rpm, and stir for 0.5 h to promote the salt formation of diacid and diamine monomers in the solution.

[0106] The second stage continues to increase the temperature to 180°C at a temperature increasing rate of 5°C / min, the pressure increases to 1.0 MPa, the pressure is kept stable by appropriate exhaust, and the pressure is kept stable at this state for 1 h. Then, the temperature is increased to 240°C again, the pressure is adjusted to 1.7 MPa, and the pressure is kept stable at this state for 1 h. Then, the pressure is released to the atmospheric pressure, and the reaction is continued for 1 h. Then, the vacuum reaction is performed for 0.5 h. When the water output reaches 95 wt% of the total water added, the discharge valve is opened to flash off the material, and the material is crushed and dried to obtain the bio-based PA1010 prepolymer.

[0107] (2) 300 g of the bio-based PA1010 prepolymer and 700 g of PTMEG were weighed, 15% of deionized water based on the mass of the bio-based PA1010 prepolymer and PTMEG, and 0.25% of tetrabutyl titanate based on the mass of the bio-based PA1010 prepolymer, PTMEG and deionized water were added. The mixture was added to a polymerization kettle, and then the air in the reactor was purged, and the reactor was filled with 0.25 MPa of nitrogen, and the temperature was increased to 210°C and maintained for 2 h. The vacuum was extracted, and the high-pressure reactor was heated to 240°C. The mixture was further reacted under vacuum for 2 h, and then discharged and dried.

[0108] (3) After the bio-based polyamide elastomer was dried, it was mixed with nanocellulose (the mass of the nanocellulose was 0.5% of the mass sum of the nanocellulose and the bio-based polyamide elastomer), and antioxidant 1098 (the mass of the antioxidant 1098 was 1% of the mass sum of the nanocellulose and the bio-based polyamide elastomer), and then added to a twin-screw extruder. The spinning temperature was set to 240°C, the melt stream extruded through the spinneret was cooled by a cooling system, and the nascent fiber was obtained.

[0109] (6) The nascent fiber was drawn by the spinneret at a draw ratio of 30-50 times through the first winding hot roller, and the first collection roller had a temperature of 100°C and a speed of 500 m / min, and the undrawn yarn was obtained.

[0110] (7) The undrawn yarn was drawn by a primary and secondary drawing process. The primary drawing temperature was 80°C, and the draw ratio was 3.0 times. The secondary drawing temperature was 180°C, and the draw ratio was 1.5 times. The heat setting temperature was 190°C, and the second heat setting temperature was 200°C. The final winding speed was 2500 m / min.

[0111] Comparative Example 2

[0112] (1) Take 3.36 mols of dodecanedioic acid and 3.01 mol of 1,12-dodecanediamine, add 10% of deionized water based on the mass of dodecanedioic acid and 1,12-dodecanediamine, and 0.15% of sodium hypophosphite based on the mass of dodecanedioic acid, 1,12-dodecanediamine and deionized water. Add all the above raw materials to the polymerization kettle, heat at a rate of 5°C / min under nitrogen pressure of 0.2 MPa, start stirring at 100°C, control the stirring rate at 50 rpm, and stir for 0.5 h to promote the salt formation of diacid and diamine monomers in the solution.

[0113] The second stage continues to heat at a rate of 5°C / min to 180°C, the pressure rises to 1.0 MPa, and the pressure is stabilized by appropriate exhaust. After keeping the pressure for 1 h, it is heated again to 240°C, and the pressure is adjusted to 1.7 MPa. After keeping the pressure for 1 h, it is depressurized to atmospheric pressure, and the reaction continues for 1 h, and then vacuum reaction for 0.5 h. When the water output reaches 95 wt% of the total water added, open the discharge valve to flash off the material, and after drying by crushing, the bio-based PA1010 prepolymer is obtained.

[0114] (2) Take 300 g of bio-based PA1010 prepolymer and 700 g of PTMEG, add 15% of deionized water based on the mass of bio-based PA1010 prepolymer and PTMEG, and 0.25% of tetrabutyl titanate based on the mass of bio-based PA1010 prepolymer, PTMEG and deionized water. Add it to the polymerization kettle, then purge the air in the reactor and fill it with 0.25 MPa of nitrogen, and raise the temperature to 210°C for 2 h. Vacuumize, and heat the high-pressure reactor to 240°C. After further reaction of the mixture under vacuum for 2 h, discharge and dry.

[0115] (3) After drying the bio-based polyamide elastomer, mix it with nanocellulose (the mass of nanocellulose is 0.5% of the mass of nanocellulose and bio-based polyamide elastomer), antioxidant 1098 (the mass of antioxidant 1098 is 1% of the mass of nanocellulose and bio-based polyamide elastomer), and add it to a twin-screw extruder. Set the spinning temperature to 240°C, and the melt stream extruded through the spinneret passes through the cooling system to obtain the nascent fiber.

[0116] (6) The nascent fiber is drawn through the first winding hot roller, the spinneret draw ratio is 30-50 times, the first collection roller temperature is 100°C, and the speed is 500 m / min to obtain the undrawn yarn.

[0117] (7) The undrafted yarn is drafted in one stage and two stages, the one-stage drafting temperature is 80°C, the drafting multiple is 3.0, the two-stage drafting temperature is 180°C, the drafting multiple is 1.5, the heat setting temperature is 190°C, the second heat setting temperature is 200°C, and the final winding speed is 2500 m / min.

[0118] Table 1 Comparison of performance indexes of Examples 1-4 and Comparative Examples 1-2

[0119] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Elastomer tensile strength (MPa) 38.2 41.5 42.6 38.2 39.7 33.5 Elastomer Tg (°C) -25 -27 -29 -26 -19 -18 Elastomer intrinsic viscosity (dL / g) 1.27 1.30 1.34 1.29 1.20 1.18 Elastomer elastic retention (°) 86.2 87.6 88.4 87.1 80.1 81.5 Fiber breaking strength (cN / dtex) 2.91 3.23 3.47 3.05 3.15 2.40 Fiber breaking elongation (%) 561 513 476 492 439 464 Bio-based content (%) ＞90 ＞90 ＞90 ＞90 ＜30 ＜30

[0120] Although the above embodiments have made a detailed description of the present application, it is only a part of the embodiments of the present application, not all the embodiments, and other embodiments can be obtained according to the present embodiments without creativity, which all belong to the protection scope of the present application.

Claims

1. A bio-based polyamide elastomer fiber comprising an elastomer and nanocellulose; the elastomer comprises alternating hard segment polymers and soft segment polymers; the hard segment polymer is a bio-based polyamide prepolymer; the soft segment polymer is a bio-based polytrimethylene ether glycol; the elastomer and nanocellulose are dynamically cross-linked; The hard segment polymer has a structure shown in Formula I; The number average molecular weight of the hard segment polymer is 1000 to 5000 g / mol; The mass proportion of the hard segment polymer in the elastomer is 10% to 50%.

2. The bio-based polyamide elastomer fiber according to claim 1, characterized in that The mass proportion of the soft segment polymer in the elastomer is 50% to 90%; the number average molecular weight of the soft segment polymer is 2000 g / mol.

3. The bio-based polyamide elastomer fiber according to claim 1, characterized in that The mass content of the elastomer in the bio-based polyamide elastomer fiber is ≥90%; and the number average molecular weight of the elastomer is 20,000 to 30,000 g / mol.

4. The method for preparing the bio-based polyamide elastomer fiber according to any one of claims 1 to 3, comprising the following steps: (1) mixing decanediamine, sebacic acid, water and a polycondensation catalyst to carry out a polycondensation reaction to obtain a bio-based polyamide prepolymer; wherein the decanediamine and sebacic acid are derived from castor oil; (2) mixing a bio-based polyamide prepolymer, a bio-based polytrimethylene ether glycol, water, and a titanium-based catalyst, and performing block polymerization to obtain a copolymer having a block structure with alternating soft and hard segments; (3) The copolymer and nanocellulose are mixed and then extruded and spun in sequence, and the resulting spun fibers are drawn and heat-set in sequence to obtain the bio-based polyamide elastomer fibers.

5. The preparation method according to claim 4, wherein The polycondensation reaction is carried out in the presence of a polycondensation catalyst, wherein the polycondensation catalyst comprises sodium hypophosphite and / or sodium hypophosphite; The molar ratio of decanediamine to sebacic acid is 0.7-0.95:1.

0.

6. The preparation method according to claim 4, wherein The extrusion area is divided into a pre-melting conveying area, a dynamic cross-linking reaction area, a micro-phase homogenization area and a steady-state rheology control area; the temperature of the pre-melting conveying area is 180-200°C; the temperature of the dynamic cross-linking reaction area is 200-210°C; the temperature of the micro-phase homogenization area is 210-230°C; the temperature of the steady-state rheology control area is 230-250°C; The spinning temperature is 230-250°C.

7. The preparation method according to claim 4, wherein The drawing includes primary drawing and secondary drawing performed sequentially; the temperature of the primary drawing is 80-100° C., the drawing ratio of the primary drawing is 2.8-3.2 times, the temperature of the secondary drawing is 160-180° C., and the drawing ratio of the secondary drawing is 1.2-1.5 times.

8. The preparation method according to claim 4, wherein The temperature of the heat setting is 180-200°C.

9. The preparation method according to claim 4, wherein The block polymerization is to carry out preliminary block polymerization and final block polymerization in sequence; The temperature of the preliminary block polymerization is 210-230° C., the pressure is 0.1-0.3 MPa, and the time is 1.5-3.0 h; The final block polymerization is carried out under vacuum conditions, the temperature of the final block polymerization is 240-250° C., and the time is 1.5-3.0 hours.

10. Use of the bio-based polyamide elastomer fiber according to any one of claims 1 to 3 or the bio-based polyamide elastomer fiber prepared by the preparation method according to any one of claims 4 to 9 in biomedicine, smart sensing or sportswear.

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