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

Abstract

The present invention discloses a cationic dyeable bio-based spandex fiber, which is mainly composed of a bio-based polyester diol, a diisocyanate compound, a chain extender amino acid and a capping agent amino acid. The present invention also discloses a preparation method of a cationic dyeable bio-based spandex fiber, which comprises the steps of prepolymerization, chain extension, capping, aging, spinning and the like, to prepare the spandex fiber. The present invention selects a polyester diol from biological sources as a raw material, reacts with a diisocyanate to prepare an isocyanate-capped bio-based polyester, then uses biologically derived lysine for chain extension, and finally uses biologically derived amino acids for capping to prepare the spandex fiber. The prepared spandex fiber has an affinity for cationic dyes because the carboxylic acid or sulfonic acid group in the amino acid is introduced during the chain extension and capping process, and the spandex fiber can be dyed with cationic dyes.

Description

Technical Field

[0001] The invention belongs to the field of chemical materials and relates to bio-based spandex fiber and a preparation method thereof. Technical Background

[0002] Spandex, commonly known as Spandex internationally, is also known as polyurethane elastic fiber. It is a highly elastic fiber that was industrially produced in the 1950s. With the improvement of production technology and the promotion of application technology, the production and consumption of spandex have been strongly promoted, especially in recent years, which has ushered in the rapid development of spandex fiber production and consumption.

[0003] Spandex has been widely used in various elastic fabrics, such as sportswear, fashion and other elastic thin fabrics. It is an indispensable special fiber for the development of high-end elastic textiles and has a very wide range of application value and development prospects. Spandex fiber has excellent high elasticity and elastic recovery rate, with an elastic elongation of up to 400-800%. When the elongation is 500%, it still has an elastic recovery rate of more than 95%, which is unmatched by other fibers.

[0004] The elasticity of spandex fiber comes from the soft and hard segments in the fiber molecular chain. In the microscopic structure of a single spandex macromolecule, the spandex macromolecule chain is a linear block copolymer composed of polyether (soft segment) and urethane, isocyanate, and urea bonds (hard segment) alternating. The soft segment can be stretched and connected to each other by the hard segment, and the alternation of soft and hard segments is equivalent to forming a series of small springs.

[0005] In the aggregate structure of multiple spandex molecules, the hard segment is an easily crystallized urethane and urea structure, and the imino and carbonyl groups between the molecular chains can form strong hydrogen bonds. The soft segment can move freely after being stressed at room temperature, and the force between the molecular chains is very weak. After the hard segment is stretched and oriented, a crystal entanglement and cross-linking are formed, and the soft segment can move like a spring, which is equivalent to weaving many small springs into a fishing net. It has both elasticity and can use the hard segment crystal nodes for pullback and contraction.

[0006] The "soft segment" in the molecular structure of spandex mainly comes from polyethers, such as poly-1,4-butylene glycol (PTMEG), poly-1,2-propylene glycol, and even polyethylene glycol, and aliphatic polyesters, such as polybutylene succinate, polycaprolactone, etc.

[0007] For example, patent documents US5962130 and US6096252 introduce a method for preparing durable spandex fibers by dry spinning, which uses polytetramethylene ether (PTMG) with a molecular weight of 2000 as a diol, diphenylmethane diisocyanate (MDI) and other diisocyanate compounds as raw materials to prepare spandex fibers in a DMAc (N,N-dimethylacetamide) solution.

[0008] Patent document US5000899 introduces a method for preparing spandex fiber by using polytetrahydrofuran or poly-(3-methyltetrahydrofuran) as diol raw material, and the chain extender used is diamine. The prepared fiber has good thermal creep and heat setting efficiency.

[0009] Patent document US6063892 introduces a method for preparing spandex fibers using polyether, such as polytetrahydrofuran, as a diol raw material and bis-(4-isocyanate phenyl) propane or 1,4-bis(4-isocyanate-α,α-dimethylbenzyl) benzene as a diisocyanate raw material.

[0010]

[0011] Patent documents US4871818 and US4767828 introduce methods for preparing spandex fibers using polyester as a diol principle. The polyester used is a polyester diol prepared by polycondensation of neopentyl glycol and 1,12-dodecanedioic acid, with a molecular weight between 2200 and 2700 and an acid value of less than 5 mg equivalent per kilogram. The diols and dibasic acids used are both petrochemical-based.

[0012] Patent document US4504612 introduces a method for preparing spandex fiber by adding polyester as an antifume. In this method, polyester is not used as a raw material for polymerization, but is only added as an auxiliary agent after the polymerization is completed.

[0013] Patent document US5118780 introduces a method for preparing polyester diols using 3-methyl-1,5-pentanediol and fatty acids and then preparing spandex fibers, wherein all dibasic acids are azelaic acid to dodecanedioic acid, and the molecular weight of the prepared polyester is 1000-3500.

[0014] Japanese Patent Document 101496 / 1973 also introduces a method for preparing polyester diol using 3-methyl-1,5-pentanediol and then melt-spinning to prepare spandex fibers; Japanese Patent Document 173117 / 1985 introduces a method for preparing polyester diol using 1,6-hexanediol and 1,10-decanediol and then preparing spandex, wherein the chain extender is a common diamine compound.

[0015] Patent document CN202110922180.9 introduces a method for preparing functional spandex fiber. Its preparation method is simply to add raw materials such as graphene and carbon nanotubes to the polymer raw materials; Patent document CN202110925027.1 introduces a method for preparing medium-high resilience chlorine-resistant spandex fiber, wherein the added chlorine-resistant stabilizer is 4,11-diamino-1H-naphtho[2,3-F]isoindole-1,3,5,10(2H)-tetraketone; Patent document CN202110943822.3 introduces a high-temperature resistant and alkali-resistant spandex and its preparation method, the main method of which is to introduce 3-methyl-2-butene caffeate into the polymer monomer; Patent document CN202110432982.1 introduces a spandex prepared by melt spinning and its method, the method of which is to irradiate the melt stream ejected from the spinneret end so that the cross-linking groups introduced in advance in the melt are cross-linked to prepare. Patent document CN201510304961.6 introduces a hyperdispersant and a method for preparing undyed polyurethane elastic fiber, the key point of which is to prepare the hyperdispersant in advance; Patent document CN201610204295.3 introduces an easily colored polyurethane elastic fiber and a method for preparing it, the main method of which is to add 4-amino-2,2,6,6-tetramethylpiperidine or 4-hydroxy-2,2,6,6-tetramethylpiperidine to the chain extender.

[0016] The main raw materials of existing spandex fibers are generally polyester diols, polyether diols and diisocyanate compounds, and the chain extender is a diamine compound. These raw materials are all petrochemical-based raw materials, and the biocarbon content in the prepared spandex fibers is almost zero. Summary of the invention

[0017] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and relates to a cationic dyeable bio-based spandex fiber and a preparation method thereof.

[0018] The bio-based spandex fiber prepared by the present invention is mainly composed of bio-based polyester diol, diisocyanate compound, chain extender amino acid and end-capping agent amino acid;

[0019] The bio-based polyester diol has the following structure:

[0020]

[0021] Wherein, R1 is: -(CH2)8- or -(CH2)9-, or a mixture of the two;

[0022] R2 is: -(CH2)6-, -(CH2) 10 or -(CH2) 11 -, or a mixture of both;

[0023] n is a natural number from 3 to 11.

[0024] A further preferred technical solution of the cationic dyeable bio-based spandex fiber of the present invention is that the molecular weight of the bio-based polyester diol is 1500-3000, and the amount used is 70-80% of the total mass of the bio-based spandex fiber.

[0025] A further preferred technical solution of the cationic dyeable bio-based spandex fiber of the present invention is that the chain extender amino acid is lysine.

[0026] A further preferred technical solution of the cationic dyeable bio-based spandex fiber of the present invention is that the amino acid of the end-capping agent is selected from the group consisting of glycine, glutamic acid, sodium taurine, aspartic acid or alanine.

[0027] A further preferred technical solution of the cationic dyeable bio-based spandex fiber of the present invention is that the diisocyanate compound is diphenylmethane diisocyanate or toluene diisocyanate.

[0028] The present invention also discloses a method for preparing a bio-based polyester diol in a cationic dyeable bio-based spandex fiber as described in the above technical solution: the dibasic acid in the synthetic raw material of the bio-based polyester diol is 1,10-decanedioic acid and 1,11-undecanedioic acid; the 1,10-decanedioic acid is derived from castor oil cracking; the 1,11-undecanedioic acid is prepared by biological fermentation; the diol in the synthetic raw material of the bio-based polyester diol is: 1,6-hexanediol, 1,10-decanedioic acid, 1,11-undecanedioic acid, and all are prepared by biological method. The biological method described in the present invention can be a biological method disclosed in the prior art.

[0029] The present invention also discloses a method for preparing the cationic dyeable bio-based spandex fiber as described in the above technical solution, and the steps are as follows:

[0030] (1) Prepolymerization: In a reaction kettle filled with a certain amount of organic solvent N,N-dimethylacetamide (DMAc), 1 mol of bio-based polyester diol is prepared into a solution with a concentration of 25% to 30%, and then 2.0 to 2.02 mol of diisocyanate compound is added while stirring, and prepolymerization is carried out at 40 to 45°C for 3 to 6 hours;

[0031] (2) Chain extension: 1 mol of chain extender lysine was added to the reaction kettle to carry out chain extension reaction on the prepolymer prepared in step (1) at 40-45° C. for 2-3 hours;

[0032] (3) End-capping: Add 0.1-0.15 mol of an amino acid as an end-capping agent to end-cap the polymer prepared in step (2) at 40-45° C. for 2-3 hours;

[0033] (4) aging: the bio-based polyurethane solution prepared in step (3) is aging by continuous stirring at 37-45° C. for 28-30 hours;

[0034] (5) Spinning: The spinning solution prepared in step (4) is spun through operations such as discharging, spraying, stretching, false twisting and oiling to produce spandex fibers.

[0035] In step (1), the bio-based polyester diol in the reaction raw material is preferably: polyhexanediol sebacate, polydecanediol sebacate, polyundecanedioic acid, polyhexanediol undecanedioic acid, polyhexanediol sebacate, polyhexanediol sebacate / undecanedioic acid, polydecanediol sebacate / undecanedioic acid, polydecanedioic acid / undecanedioic acid, and polydecanedioic acid / undecanedioic acid with a molecular weight of 1500-3000.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] 1. The raw material for preparing the polyester diol used in the preparation of the spandex fiber in the present invention is a bio-based raw material, that is, it is prepared by a bio-raw material chemical method or a bio-fermentation method. The bio-carbon content in the spandex fiber prepared by the present invention is higher than 70%.

[0038] 2. The chain extender and end-capping agent for preparing spandex fiber of the present invention are amino acids of biological origin, and the prepared fiber can be dyed with cationic dyes. DETAILED DESCRIPTION

[0039] The following examples are provided to further illustrate the present invention, but the present invention is not limited thereto.

[0040] The polyester diols used in the following examples are all bio-based polyester diols, and the raw materials for preparing the bio-based polyester diols, sebacic acid, undecanedioic acid, hexanediol, and undecanedioic acid are all biological products and can be obtained by biological fermentation or chemical treatment of ricinoleic acid.

[0041] Bio-sourced polyester diols are used as raw materials, reacted with diisocyanates to prepare isocyanate-terminated bio-based polyesters, then chain extended using bio-sourced lysine, and finally end-capped using bio-sourced amino acids to prepare spandex fibers. The prepared spandex fibers have an affinity for cationic dyes because carboxylic acid or sulfonic acid groups in amino acids are introduced during the chain extension and end-capping process, and spandex fibers can be dyed with cationic dyes.

[0042] Taking toluene diisocyanate as the diisocyanate compound and sodium taurate as the end-capping agent as an example, the synthetic route of spandex fiber is as follows:

[0043]

[0044] Example 1, a preparation experiment of a cationic dyeable bio-based spandex fiber:

[0045] (1) Prepolymerization: In a reactor containing 500 kg of N,N-dimethylacetamide (DMAc), 214 kg of bio-based polyester diol was added. (polyhexanediol sebacate, hydroxyl value 74.8, molecular weight 1500. Produced by Nanjing Advanced Biomaterials and Process Equipment Research Institute Co., Ltd.), then 71.4 kg of diphenylmethane diisocyanate (produced by BASF Chemical) was added while stirring, and prepolymerized at 40°C for 3 hours;

[0046] (2) Chain extension: 20.86 kg of chain extender lysine (produced by Shandong Ruiyuan Biotechnology Co., Ltd.) was added to the reactor to carry out chain extension reaction on the prepolymer prepared in step (1) at 40° C. for 2 hours;

[0047] (3) Capping: 1.89 kg of aspartic acid (produced by Shandong Ruiyuan Biotechnology Co., Ltd.), a capping agent, was added to cap the polymer prepared in step (2) at 40° C. for 2 hours.

[0048] (4) Ripening: The bio-based polyurethane solution prepared in step (3) was matured by continuous stirring at 45° C. for 28 hours, and the system viscosity was measured to be 3550 poise.

[0049] (5) Spinning: The spinning solution prepared in step (4) is spun through operations such as discharging, spraying, stretching, false twisting and oiling to produce spandex fibers, numbered 1#.

[0050] Example 2, a preparation experiment of a cationic dyeable bio-based spandex fiber:

[0051] (1) Prepolymerization: In a reactor containing 700 kg of N,N-dimethylacetamide (DMAc), 300 kg of bio-based polyester diol 116 (poly(hexanediol undecanoate), hydroxyl value 56.1, molecular weight 2000. Produced by Nanjing Advanced Biomaterials and Process Equipment Research Institute Co., Ltd.), then 75.45 kg of diphenylmethane diisocyanate (produced by BASF Chemical) was added while stirring, and prepolymerized at 45°C for 6 hours;

[0052] (2) Chain extension: 21.93 kg of chain extender lysine (produced by Shandong Ruiyuan Biotechnology Co., Ltd.) was added to the reactor to carry out chain extension reaction on the prepolymer prepared in step (1) at 40° C. for 3 hours;

[0053] (3) End-capping: 2.82 kg of taurine (produced by Shandong Ruiyuan Biotechnology Co., Ltd.), a capping agent, was added to cap the polymer prepared in step (2) at 40° C. for 3 hours.

[0054] (4) Ripening: The bio-based polyurethane solution prepared in step (3) was matured by continuous stirring at 45° C. for 30 hours, and the system viscosity was measured to be 3700 poise.

[0055] (5) Spinning: The spinning solution prepared in step (4) is spun through operations such as discharging, spraying, stretching, false twisting and oiling to produce spandex fibers, numbered 2#.

[0056] Example 3, a preparation experiment of a cationic dyeable bio-based spandex fiber:

[0057] (1) Prepolymerization: In a reactor containing 1000 kg DMAc, 428 kg of bio-based polyester diol 1011 (polyundecyl sebacate, hydroxyl value 37.4, molecular weight 3000. Produced by Nanjing Advanced Biomaterials and Process Equipment Research Institute Co., Ltd.), then add toluene diisocyanate while stirring T65N (a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, produced by Covestro) 50.2 kg, prepolymerized at 44 ° C for 6 hours;

[0058] (2) Chain extension: 43086 kg of chain extender lysine was added to the reactor to carry out chain extension reaction on the prepolymer prepared in step (1) at 45° C. for 2 hours;

[0059] (3) Capping: 1.61 kg of glycine, a capping agent, was added to cap the polymer prepared in step (2) at 45° C. for 2 hours.

[0060] (4) Ripening: The bio-based polyurethane solution prepared in step (3) was matured by continuous stirring at 40° C. for 28 hours. The system viscosity was measured to be 4200 poise.

[0061] (5) Spinning: The spinning solution prepared in step (4) is spun through operations such as discharging, spraying, stretching, false twisting and oiling to produce spandex fibers, numbered 3#.

[0062] Example 4, a preparation experiment of a cationic dyeable bio-based spandex fiber:

[0063] The experimental method is the same as in Example 3, except that the bio-based polyester polyol used is bio-based polyester diol 2106 (polyundecanediol / sebacic acid hexanediol ester, hydroxyl value 44.9, molecular weight 2500), the end-capping agent is alanine. Step (4) The viscosity of the spinning solution after aging is 3800 poise.

[0064] The prepared spandex fiber is numbered 4#.

[0065] Example 5, a preparation experiment of a cationic dyeable bio-based spandex fiber:

[0066] The experimental method is the same as in Example 3, except that the bio-based polyester polyol used is bio-based polyester diol 1111 (polyundecanediol undecanediol ester, hydroxyl value 41.6, molecular weight 2700), the end-capping agent is glutamic acid. Step (4) The viscosity of the spinning solution after aging is 4100 poise.

[0067] The prepared spandex fiber is numbered 5#.

[0068] Example 6, Preparation experiment of a cationic dyeable bio-based spandex fiber

[0069] The experimental method is the same as in Example 3, except that the bio-based polyester polyol used is bio-based polyester diol 2111 (polyundecanediol / decanediol sebacate, hydroxyl value 38.7, molecular weight 2900), the end-capping agent is sodium taurate. Step (4) The viscosity of the spinning solution after aging is 4000 poise.

[0070] The prepared spandex fiber is numbered 6#.

[0071] The comparative example is as follows:

[0072] Comparison sample 1#

[0073] This example is a comparative example of spandex fiber prepared from non-bio-based raw materials. The experimental method is the same as that of Example 3, except that PTMEG2000 (polytetrahydrofuran, produced by Dow Chemical) is used, the chain extender is ethylenediamine, and the end-capping agent is ethanolamine. Step (4) The viscosity of the spinning solution after aging is 4700 poise.

[0074] The prepared spandex fiber number: comparison sample 1#.

[0075] Comparison sample 2#

[0076] This example is a comparative example of spandex fiber prepared from non-bio-based raw materials. The experimental method is the same as that of Example 3, except that PTMEG1500 (polytetrahydrofuran, produced by Dow Chemical) is used, the chain extender is ethylenediamine, and the end-capping agent is ethylamine. Step (4) The viscosity of the spinning solution after aging is 4300 poise.

[0077] The prepared spandex fiber number: comparison sample 2#.

[0078] Bio-Spandex Fiber Performance Test

[0079] The bio-based spandex fiber samples prepared in the examples were tested according to the standards FZ / T 50006-2013 (Test method for tensile properties of spandex fiber) and FZ / T 50007-2012 (Test method for elasticity of spandex yarn). The biocarbon content of the prepared spandex fiber was tested according to the method of the standard GB / T 39715.2-2021 (Determination of bio-based content of plastics). The relevant results are shown in Table 1.

[0080] Table 1. Mechanical properties and biochar content of spandex fibers

[0081]

[0082]

[0083] * In Table 1, TEN is the breaking strength; ELO (%) is the breaking elongation.

[0084] As can be seen from Table 1 above, bio-based spandex fibers not only have good tensile elongation, but also have greater breaking strength. Compared with ordinary polyether-based spandex fibers, the breaking elongation strength of 70D bio-based spandex fibers exceeds 100cN, and the strength at 300% elongation is greater than that of ordinary polyether-based spandex fibers, both exceeding 20cN.

[0085] In terms of biocarbon content, the biocarbon content of bio-based spandex fibers is greater than 70%, while the biocarbon content of ordinary spandex fibers is 0.

[0086] Cationic dye dyeing performance test

[0087] Three cationic dyes, namely cationic red X-GRL, cationic yellow SD-5GL and cationic blue X-BL (Yancheng Dongwu Dye Co., Ltd.), were selected to dye the prepared example fibers, and the dye uptake and K / S value after dyeing were measured.

[0088] Dyeing process: prepare 2% (owf) cationic dye, adjust the pH value of the dye solution with citric acid-sodium hydrogen phosphate buffer solution, the bath ratio is 1:30, and place it in an infrared dyeing machine. Dye at 40℃, heat to 90℃ at a rate of 1℃ / min, and keep warm for 60 minutes. After dyeing, cool down, take out the fiber, wash it with water, dry it, collect the dyeing residue, fix the volume, and test the dyeing percentage.

[0089] Use a UV-visible spectrophotometer to measure the absorbance of the dyeing solution and the residual solution at the maximum absorption wavelength, and calculate the dyeing percentage E.

[0090]

[0091] Where: E——dyeing percentage

[0092] A0——Absorbance of original solution

[0093] A1——Absorbance of residual liquid

[0094] The fiber apparent color depth K / S value was tested using a D600 colorimeter (Data Color, USA). 。 Observation angle at D 65 Test 4 times under light source and take the average value

[0095] Table 2. Dyeing properties of spandex fibers

[0096]

[0097] As can be seen from Table 2, due to the introduction of carboxylic acid functional groups and sulfonic acid functional groups with affinity for cationic dyes into the fiber structure, the spandex fibers prepared by the present invention have good dyeing performance for cationic dyes, with dyeing rates reaching more than 90%, and the color depths (K / S values) of red, yellow and blue dyes are all high. However, ordinary polyether-based spandex fibers have only a very low dyeing rate for cationic dyes.

Claims

1. A cationic dyeable bio-based spandex fiber, characterized in that: The bio-based spandex fiber is mainly composed of bio-based polyester diol, diisocyanate compound, chain extender amino acid and end-capping agent amino acid; The structure of the bio-based polyester diol is as follows: Wherein, R1 is: -(CH2)8- or -(CH2)9-, or a mixture of the two; R2 is: -(CH2)6-, -(CH2)10 or -(CH2)11-, or a mixture of the two; n is a natural number of 3-11; the diisocyanate compound is diphenylmethane diisocyanate or toluene diisocyanate, the chain extender amino acid is lysine, and the capping agent amino acid is selected from at least one of glycine, glutamic acid, taurine, sodium taurate, aspartic acid or alanine.

2. The cationic dyeable bio-based spandex fiber according to claim 1, characterized in that: The molecular weight of the bio-based polyester diol is 1500-3000, and the usage is 70-80% of the total mass of the bio-based spandex fiber.

3. A method for preparing a bio-based polyester diol in a cationic dyeable bio-based spandex fiber as claimed in claim 1 or 2, characterized in that , including the following steps: (1) Prepolymerization: In a reaction kettle filled with a certain amount of organic solvent N,N-dimethylacetamide (DMAc), 1 mol of bio-based polyester diol is prepared into a solution with a concentration of 25% to 30%, and then 2.0 to 2.02 mol of diisocyanate compound is added while stirring, and prepolymerization is carried out at 40 to 45°C for 3 to 6 hours; (2) Chain extension: 1 mol of chain extender lysine is added to the reaction kettle to carry out chain extension reaction on the prepolymer prepared in step (1) at 40-45° C. for 2-3 hours; (3) End-capping: Add 0.1-0.15 mol of an amino acid as an end-capping agent to end-cap the polymer prepared in step (2) at 40-45° C. for 2-3 hours; (4) aging: the bio-based polyurethane solution prepared in step (3) is aging by continuous stirring at 37-45° C. for 28-30 hours; (5) Spinning: The spinning solution prepared in step (4) is spun through operations such as discharging, spraying, stretching, false twisting and oiling to produce spandex fibers.

4. The preparation method according to claim 3, characterized in that: The dibasic acids in the synthetic raw materials of the bio-based polyester diol described in step (1) are 1,10-decanedioic acid and 1,11-undecanedioic acid; the 1,10-decanedioic acid is derived from the cracking of castor oil; the 1,11-undecanedioic acid is prepared by biological fermentation; the diols in the synthetic raw materials of the bio-based polyester diol are: 1,6-hexanediol, 1,10-decanediol, 1,11-undecanedioic acid, and all of them are prepared by biological method.

5. The preparation method according to claim 3, characterized in that: In step (1), the bio-based polyester diol in the reaction raw material is selected from polyhexanediol sebacate, polydecanediol sebacate, polyundecanedioic acid, polyhexanediol undecanedioic acid, polyhexanediol sebacate / undecanedioic acid, polydecanediol sebacate / undecanedioic acid, and polydecanedioic acid / undecanedioic acid undecanedioic acid with a molecular weight of 1500-3000.

Images