Polyester amide and preparation method thereof and fiber
阅读说明：本技术 一种聚酯酰胺及其制备方法和纤维 (Polyester amide and preparation method thereof and fiber ) 是由 杜宇鎏 郑毅 刘修才 于 2019-04-16 设计创作，主要内容包括：本发明提供一种聚酯酰胺及其制备方法和纤维。其中该聚酯酰胺的制备方法,包括如下步骤：惰性氛围下,使对苯二甲酸和/或其衍生物与二元醇在催化剂的存在下,于酯化反应釜中进行酯化反应；酯化反应结束后,向酯化反应釜中加入二元酸胺盐水溶液进行酰胺化反应,其中二元酸胺盐水溶液的质量浓度为20～80％；酰胺化反应结束后,将酰胺化产物转移至缩聚反应釜中进行缩聚反应,待缩聚产物的特性粘度达到0.3～1.8dL/g,结束缩聚反应,收集缩聚产物,得到聚酯酰胺。本发明提供的制备方法,能够解决现阶段聚酯酰胺合成过程中易发生的黄变问题,使得到的聚酯酰胺具有较低的黄色指数。(The invention provides a polyesteramide, a preparation method thereof and a fiber. The preparation method of the polyesteramide comprises the following steps: under the inert atmosphere, enabling terephthalic acid and/or derivatives thereof and dihydric alcohol to carry out esterification reaction in an esterification reaction kettle in the presence of a catalyst; after the esterification reaction is finished, adding a diamine salt aqueous solution into an esterification reaction kettle for amidation reaction, wherein the mass concentration of the diamine salt aqueous solution is 20-80%; and after the amidation reaction is finished, transferring the amidation product into a polycondensation reaction kettle for polycondensation reaction, finishing the polycondensation reaction when the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g, and collecting the polycondensation product to obtain the polyesteramide. The preparation method provided by the invention can solve the problem of yellowing easily caused in the synthesis process of the polyesteramide at the present stage, so that the obtained polyesteramide has a lower yellow index.)
1. A preparation method of polyesteramide is characterized by comprising the following steps:
under the inert atmosphere, enabling terephthalic acid and/or derivatives thereof and dihydric alcohol to carry out esterification reaction in an esterification reaction kettle in the presence of a catalyst;
after the esterification reaction is finished, adding a diamine salt aqueous solution into the esterification reaction kettle to perform amidation reaction, wherein the mass concentration of the diamine salt aqueous solution is 20-80%;
and after the amidation reaction is finished, transferring the amidation product into a polycondensation reaction kettle for polycondensation reaction, finishing the polycondensation reaction when the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g, and collecting the polycondensation product to obtain the polyesteramide.
2. The method according to claim 1, wherein the molar ratio of the diamine salt, the diol, the terephthalic acid and/or the derivative thereof is (0.002 to 99): (1-3): 1, preferably (0.005-3): (1.1-2.6): 1, more preferably (0.01 to 0.3): (1.2-2.0): 1.
3. the preparation method according to claim 1, wherein the temperature of the esterification reaction is 230 to 280 ℃, preferably 240 to 270 ℃, and more preferably 250 to 265 ℃; stopping the esterification reaction when more than 90 percent of the terephthalic acid and/or the derivatives thereof have the esterification reaction.
4. The process according to claim 1, wherein the temperature of the amidation reaction is 255 to 265 ℃ and the time is 10min or more.
5. The method according to claim 1, wherein the polycondensation reaction comprises: under the condition of maintaining the temperature at 230-310 ℃, firstly reducing the pressure in the polycondensation reaction kettle to 0.5-2 kpa, and after 40-90 min, reducing the pressure in the polycondensation reaction kettle to below 30Pa until the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g.
6. The method of claim 1, further comprising the step of adding an additive to the esterification reaction tank.
7. The method according to claim 6, wherein the additive comprises at least a heat stabilizer selected from one or more of phosphoric acid, phosphorous acid, a phosphinic acid compound, a phosphate compound, a phosphite compound, a phosphine compound and a derivative thereof.
8. The production method according to any one of claims 1 to 7, wherein the catalyst comprises at least one of a transesterification catalyst, an esterification catalyst and a polymerization catalyst;
preferably, the polymerization catalyst is selected from at least one of a germanium-containing catalyst, an antimony-containing catalyst, a titanium-containing catalyst, and an aluminum-containing catalyst, wherein:
the germanium-containing catalyst is at least one of germanium dioxide, germanium chloride, tetraethoxy germanium and tetra-n-butoxy germane; the mass ratio of germanium atoms in the germanium-containing catalyst to the theoretical yield of the polyesteramide is 5-150 ppm, preferably 10-100 ppm, and more preferably 20-70 ppm;
the antimony-containing catalyst is at least one selected from antimony trioxide, antimony pentoxide, antimony oxychloride, antimony acetate, antimony tartrate, antimony potassium tartrate, ethylene glycol antimony and triphenyl antimony; the mass ratio of antimony atoms in the antimony-containing catalyst to the theoretical yield of the polyesteramide is 10-400 ppm, preferably 20-300 ppm, and more preferably 30-250 ppm;
the titanium-containing catalyst is selected from at least one of tetraalkyl titanate and partial hydrolysate thereof, titanium oxalate salt, titanium trimellitate, titanium sulfate and titanium tetrachloride; in the titanium-containing catalyst, the mass ratio of titanium atoms to the theoretical yield of polyesteramide is 0.5-300 ppm, preferably 1-150 ppm, and more preferably 3-100 ppm;
the aluminum-containing catalyst is selected from at least one of an organoaluminum compound selected from at least one of aluminum carboxylates, aluminum alkoxides, aluminum acetylacetonate, aluminum acetoacetate, trimethylaluminum, and triethylaluminum, a partial hydrolysate of the organoaluminum compound, and an inorganic aluminum compound selected from at least one of aluminum oxide, aluminum hydroxide, aluminum chloride, and aluminum carbonate; the mass ratio of the aluminum atoms in the aluminum-containing catalyst to the theoretical yield of the polyesteramide is 1-400 ppm, preferably 3-300 ppm, and more preferably 5-500 ppm.
9. A polyesteramide obtained by the method according to any one of claims 1 to 8.
10. A fiber produced from the polyesteramide of claim 9.
Technical Field
The invention belongs to the field of high polymer materials, particularly relates to polyesteramide, a preparation method thereof and fibers, and particularly relates to a yellowing-resistant polyesteramide resin material, a preparation process thereof and fibers prepared from the polyesteramide.
Background
Polyesteramides are a class of copolymers containing ester and amide linkages in the main chain of the molecule. Due to the structural particularity, the polyester amide has the advantages of both polyester and polyamide to a certain extent. In addition, because the cost is low, the polyester amide is widely applied to the fields of fibers, biodegradable materials, plastic films and the like.
In the fiber field at the present stage, polyesteramide is generally obtained by firstly reacting diamine and dibasic acid to generate an intermediate containing amido bond, and then polycondensing the intermediate with dihydric alcohol; or the compound is obtained by esterification and acylation reaction of dihydric alcohol, terephthalic acid and/or derivatives thereof and dibasic acid amine salt and polycondensation reaction. However, the polyester amide slices synthesized by the method have serious yellowing, and the service performance of subsequent fibers is influenced.
Therefore, how to develop a preparation process of polyesteramide to inhibit the yellowing problem generated in the reaction process and obtain the yellowing-resistant polyesteramide material is a difficult problem to be solved by technical personnel in the field of fibers.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a preparation method of polyesteramide, which can avoid the yellowing problem in the synthesis process of polyesteramide and obtain the yellowing-resistant polyesteramide.
The invention also provides a polyesteramide which has a low yellow index because of being prepared by the preparation method.
The invention also provides a fiber which is prepared by taking the polyester amide as a raw material and has good performance.
In order to achieve the above object, the present invention provides a method for preparing a polyesteramide, comprising the steps of:
under the inert atmosphere, enabling terephthalic acid and/or derivatives thereof and dihydric alcohol to carry out esterification reaction in an esterification reaction kettle in the presence of a catalyst;
after the esterification reaction is finished, adding a diamine salt aqueous solution into the esterification reaction kettle to perform amidation reaction, wherein the mass concentration of the diamine salt aqueous solution is 20-80%;
and after the amidation reaction is finished, transferring the amidation product into a polycondensation reaction kettle for polycondensation reaction, finishing the polycondensation reaction when the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g, and collecting the polycondensation product to obtain the polyesteramide.
According to the technical scheme provided by the invention, after the esterification reaction is finished, the dibasic acid amine salt aqueous solution with specific mass concentration is added for amidation reaction and then polycondensation is carried out, and the obtained polyesteramide has a very low yellow index. The inventors have carried out analyses based on this phenomenon, probably due to: compared with the modes of directly adding the diamine salt raw material at the initial stage of the esterification reaction, adding the glycol slurry of the diamine salt after the esterification reaction is finished and the like, the diamine salt is introduced in the mode of diamine salt aqueous solution after the esterification reaction is finished, and firstly, the reaction of by-products (such as aldehyde substances) of the esterification reaction and the diamine salt is avoided as much as possible to form colored impurities; secondly, the dispersity of the diamine salt in a reaction system is better, and the diamine salt is easier to perform amidation reaction and participate in the polycondensation reaction process; thirdly, the side reaction of converting the dihydric alcohol into the aldehyde compound is inhibited, and the imine compound which causes yellowing is avoided from being generated by further reaction of the aldehyde compound, thereby effectively avoiding the yellowing problem.
Through further research, the mass concentration of the diamine salt aqueous solution is reasonably controlled, so that the further yellowing inhibition problem is facilitated, and the obtained polyesteramide has a lower yellow index. In general, the higher the mass concentration of the diamine salt aqueous solution, the lower the yellow index of the obtained polyesteramide, and it is presumed that the higher the mass concentration of the diamine salt aqueous solution, the less the amount of solvent water is used, the less the influence on the temperature of the reaction system is, and the more favorable the reaction is, and the generation of imine compounds causing yellowing is further suppressed. However, if the mass concentration of the diamine salt aqueous solution is too high, precipitation of the diamine salt is likely to occur, and dispersion of the diamine salt is not facilitated, and the yellowness index of the polyester amide is increased, so that the mass concentration of the diamine salt aqueous solution is usually controlled to 30% to 70%, preferably 40% to 70%, and more preferably 50% to 70%.
The process conditions of the esterification reaction are not particularly limited in the present invention, and the esterification reaction may be a conventional process of the esterification reaction step in the synthesis of the polyesteramide in the prior art, and may be determined reasonably according to the kind of the raw material used. In the specific implementation process of the invention, under the protection of nitrogen or inert gas, dihydric alcohol, terephthalic acid and/or derivatives thereof and a catalyst are added into an esterification reaction kettle and are uniformly stirred, the temperature in the esterification reaction kettle is controlled to rise to 230-280 ℃, preferably 240-270 ℃, more preferably 250-265 ℃, and in the esterification reaction process, the esterification reaction product is fractionated through a fractionating tower, low-boiling components such as water and the like are continuously fractionated, so that the esterification reaction is promoted to be smoothly carried out, and the completion condition of the esterification reaction can be judged according to the amount of the fractionated water. The fractionation temperature is generally determined by the overhead temperature of the fractionation column, and is generally controlled to 145 to 155 ℃.
The judgment of the end of the esterification reaction in the invention follows the general standard in the polyester synthesis process in the field, namely, when more than 90 percent of terephthalic acid and/or derivatives thereof are subjected to the esterification reaction, the esterification reaction can be considered to be ended. In the process of the present invention, the reaction completion rate of terephthalic acid and/or its derivatives in the esterification stage is generally controlled to be above 95%, for example, the amount of distilled water reaches 95% to 98% of the theoretical amount, which means the esterification reaction is completed. It is understood that the higher the proportion of esterification, the more advantageous the subsequent polycondensation reaction proceeds.
The dihydric alcohol is not particularly limited, and can be a commonly used dihydric alcohol raw material for synthesizing polyesteramide at present, such as aliphatic dihydric alcohol with a carbon chain length of 2-18, and the molecular structural formula of the dihydric alcohol can be represented as follows:
wherein x is an integer of 2 to 18. Preferably, x is an integer of 2 to 4, for example, x is 2, i.e., Ethylene Glycol (EG).
The terephthalic acid and/or its derivatives are not particularly limited in the present invention, and may be one or more of the terephthalic acids and/or its derivatives commonly used in the synthesis of polyesteramides, such as terephthalic acid, or compounds in which all or part of the hydrogen on the benzene ring of terephthalic acid is substituted by alkane having 1 to 4 carbon atoms. The molecular structural formula of terephthalic acid and/or its derivatives can be represented as follows:
wherein R is1～R4Independently selected from H, C1～C4One of the alkyl radicals, e.g. R1～R4Are all H, i.e. terephthalic acid (PTA).
After the esterification reaction is finished, adding the diamine salt aqueous solution into the esterification reaction kettle and carrying out amidation reaction. Specifically, the aqueous solution of the amine salt of dibasic acid can be added into the esterification reaction kettle through a charging tank under the protection of nitrogen or inert gas and continuously stirred. And controlling the temperature in the esterification reaction kettle to be 255-265 ℃ in the amidation reaction process, and observing that the newly distilled water amount is more than 60% of the theoretical water amount generated by amidation and the total amount of solvent water in the diamine salt aqueous solution, namely finishing the amidation reaction. Generally, after the diamine salt aqueous solution is added, the amount of water evaporated again is 60 to 70 percent of the sum of the water generated by theoretical amidation and the solvent water in the diamine salt aqueous solution after about 10min or more, for example, 10 to 20 min. And (4) after the amidation reaction is finished, transferring the amidation reaction product to a polycondensation reaction kettle for further polycondensation.
It should be noted that the esterification reaction kettle and the polycondensation reaction kettle are reaction vessels commonly used in the synthesis process of the polyester amide at present, and the invention is not particularly limited. In the laboratory stage, because small-sized reaction equipment is adopted and only a single kettle is adopted, esterification, amidation and polycondensation can be completed in one reaction kettle; in the pilot plant or the industrial production, because a larger production device is adopted, for example, the pilot plant usually adopts the configuration of one esterification reaction kettle and one polycondensation reaction kettle, and the industrial production usually adopts a four-kettle system of two esterification reaction kettles and two polycondensation reaction kettles, the esterification reaction kettle and the amidation reaction can be completed in the esterification reaction kettle, and then the esterification reaction kettle and the amidation reaction kettle are transferred to the polycondensation reaction kettle for the polycondensation reaction.
The diamine salt is used as raw material in the process of synthesizing polyesteramide, in order to ensure that the mole ratio of the dibasic acid and the diamine participating in the reaction is basically equal. The diamine can be aliphatic diamine with a carbon chain length of 2-18, and the molecular structural formula of the diamine can be represented as follows:
wherein y is an integer of 2 to 18, preferably an integer of 4 to 12, such as pentamethylenediamine, hexamethylenediamine, etc.;
the dibasic acid can be aliphatic dibasic acid with a carbon chain length of 2-18, and the molecular structural formula of the dibasic acid can be represented as follows:
wherein z is an integer of 2 to 18, preferably an integer of 4 to 6, such as glutaric acid and adipic acid.
In the invention, the molar ratio of the diamine diacid salt, the dihydric alcohol, the terephthalic acid and/or the derivatives thereof can be controlled to be (0.002-99): (1-3): 1.
the proportion of the dihydric alcohol to the terephthalic acid and/or the derivatives thereof is reasonably controlled, the complete esterification reaction is favorably ensured, in addition, the proportion of flexible groups and rigid groups in a polyester amide molecular chain is directly influenced, and the performance of the polyester amide is further influenced, and in the invention, the molar ratio of the dihydric alcohol to the terephthalic acid and/or the derivatives thereof is generally controlled to be (1.1-2.6): 1, preferably (1.2-2.0): 1.
the inventors have further investigated that the amount of amine salt of dibasic acid added also affects the yellowness index of the polyesteramide, and roughly speaking, within a certain range, the yellowness index of the polyesteramide increases with increasing amount of amine salt of dibasic acid. In the specific implementation process of the invention, the molar ratio of the diamine salt to the terephthalic acid and/or the derivative thereof is generally controlled to be (0.005-3): 1, preferably (0.01-0.3): 1, more preferably (0.015 to 0.25): 1.
the source of the used diamine salt raw material is not particularly limited, and the diamine salt raw material can be purchased or prepared by self, for example, the diamine salt raw material can be prepared by acid-base neutralization reaction of diacid and diamine in solvents such as ethanol, deionized water and the like. In the process of the invention, the technology in patent CN105777553A is referred to, and the pentanediamine-adipic acid crystal salt with the purity of more than 99 percent is obtained.
It is understood that the preparation of the aqueous solution of the amine salt of a dibasic acid is preferably carried out under an inert atmosphere. In the specific implementation process of the invention, the diamine salt is dissolved in water under the protection of nitrogen, and then the diamine salt aqueous solution is obtained. Of course, in order to obtain a relatively high mass concentration of the aqueous solution of the amine salt of a dibasic acid, heating may be appropriate. For example, when the mass concentration of the aqueous solution of the pentanediamine-adipic acid is lower than 50%, the pentanediamine-adipic acid crystal salt can be fully dissolved by stirring at normal temperature, when the required mass concentration is 50% -80%, the aqueous solution of the diamine dibasic acid salt is heated to 60 ℃ and stirred to be dissolved, and the prepared aqueous solution of the amine salt of the dibasic acid is added into an esterification reaction kettle for reaction while the aqueous solution is hot.
After the amidation reaction is finished, transferring the amidation product into a polycondensation reaction kettle under the protection of nitrogen or inert gas for polycondensation reaction, wherein the intrinsic viscosity [ eta ] (intrinsic viscosity) of the polycondensation product to be detected reaches 0.3-1.8 dL/g, for example, 0.4-1.5 dL/g, and finishing the polycondensation reaction.
In some embodiments of the present invention, the polycondensation reaction is performed at a temperature of 230 to 310 ℃, preferably 240 to 280 ℃, more preferably 255 to 270 ℃.
Further, the polycondensation reaction can be carried out in two stages, specifically, the pressure in the polycondensation reaction kettle is reduced to 0.5-2 kpa, after about 40-90 min of pre-polycondensation, the pressure in the polycondensation reaction kettle is reduced to below 30Pa, preferably below 10Pa, until the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g.
In the specific implementation process of the present invention, the initial pressure in the polycondensation reaction kettle is generally controlled to be about 1kPa, and the pre-polycondensation can be completed after about 1 hour.
Before the polycondensation reaction, an additive can be added into the esterification reaction kettle. Specifically, the additive can be added into the esterification reaction kettle before the esterification reaction starts; and/or, adding an additive to the esterification reaction kettle prior to transferring the amidation product to the polycondensation reaction kettle.
The selection of the additive is not particularly limited, and suitable additives including, but not limited to, at least one of an antioxidant, a weather resistant agent, an anti-sticking agent, a lubricant, a crystal nucleating agent, a plasticizer, an antistatic agent, a flame retardant, a filler, a heat stabilizer, a light stabilizer, and the like can be selected and added according to the actual requirements on the properties of the polyesteramide product. In addition, conductive materials and the like can be added to further improve the application performance of the polyesteramide product.
The addition amount of the above additives can be added according to actual requirements on the premise of not damaging the performance of the polyester amide product, and the addition mode can adopt the existing known method, and is not particularly limited.
Preferably, the additives used comprise at least a heat stabilizer, which may be chosen in particular from phosphoric acid and phosphorous acid (H)3PO3) One or more of phosphorus-containing compounds such as phosphinic acid compounds, phosphate ester compounds, phosphite ester compounds, phosphine compounds and derivatives thereof. The addition of the heat stabilizer into the esterification reaction kettle is beneficial to leading the obtained polyesteramide to have lower yellow index.
Wherein the phosphoric acid esterThe compounds belong to orthophosphoric acid derivatives, such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, dimethyl phosphate, dibutyl phosphate, etc. The hypophosphorous acid compound can be, for example, hypophosphorous acid (H)3PO2) And hypophosphites such as sodium hypophosphite. The phosphite ester compound may be, for example, triethyl phosphite, tributyl phosphite, or the like. The phosphine compound and its derivative may be, for example, methylphosphonic acid, dimethyl methylphosphonate, dimethyl ethylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, etc. In particular, when trimethyl phosphate is selected as the heat stabilizer, the resulting polyesteramide has a lower yellowness index.
In the present invention, the amount of the heat stabilizer is generally measured by the mass of the phosphorus atom contained therein, and specifically, the mass ratio of the phosphorus atom in the heat stabilizer to the theoretical yield of the polyesteramide is 1 to 200ppm, preferably 5 to 150ppm, and more preferably 10 to 100 ppm.
In the invention, the catalyst used in the preparation process of the polyesteramide can be reasonably selected according to factors such as actual reaction conditions, used raw materials and the like. Wherein, in the esterification reaction stage, an ester exchange catalyst and/or an esterification catalyst can be selectively added, and in addition, an etherification catalyst, an etherification inhibitor and the like can be added according to actual requirements. In the polycondensation stage, a polymerization catalyst, a polymerization regulator, and the like may be added.
The transesterification catalyst and the esterification catalyst may be those commonly used in the art for polyester synthesis, such as compounds containing manganese, cobalt, zinc, titanium, calcium, etc.
The etherification inhibitor may be an etherification inhibitor commonly used in the art, such as an amine compound.
The polymerization catalyst may specifically be at least one of a germanium-containing catalyst, an antimony-containing catalyst, a titanium-containing catalyst, an aluminum-containing catalyst, an alkali metal-containing catalyst, and an alkaline earth metal-containing catalyst, wherein:
germanium-containing catalysts include, but are not limited to, germanium dioxide (including amorphous germanium dioxide, crystalline germanium dioxide), germanium chloride, tetraethoxygermanium, tetra-n-butoxygermane, and the like. The mass ratio of the germanium-containing catalyst to the theoretical yield of the polyesteramide is 5-150 ppm, preferably 10-100 ppm, and more preferably 20-70 ppm, calculated by germanium atoms; or the ratio of the mass of germanium atoms in the germanium-containing catalyst to the theoretical yield of polyesteramide is 5-150 ppm, preferably 10-100 ppm, more preferably 20-70 ppm.
Antimony containing catalysts include, but are not limited to, one or more of antimony trioxide, antimony pentoxide, antimony oxychloride, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony glycol, antimony triphenyl, and the like. The amount of the antimony-containing catalyst is measured by mass of antimony atoms, and specifically, the mass ratio of the antimony atoms in the antimony-containing catalyst to the theoretical yield of the polyesteramide can be generally 10 to 400ppm, preferably 20 to 300ppm, and more preferably 30 to 250 ppm.
The titanium-containing catalyst includes, but is not limited to, at least one of tetraalkyl titanates and partial hydrolyzates thereof, titanium oxalate salts, titanium sulfate, titanium tetrachloride, and the like. Wherein the tetraalkyl titanate can be, for example, tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate; the titanium oxalate salt may be, for example, ammonium titanium oxalate, sodium titanium oxalate, potassium titanium oxalate, calcium titanium oxalate, strontium titanium oxalate, or the like. The amount of the titanium-containing catalyst can be measured by the mass of titanium atoms, specifically, the mass ratio of the titanium atoms in the titanium-containing catalyst to the theoretical yield of the polyesteramide can be 0.5-300 ppm, preferably 1-150 ppm, and more preferably 3-100 ppm.
The aluminum-containing catalyst may be at least one of an organoaluminum compound such as at least one of aluminum carboxylate, aluminum alkoxide, aluminum acetylacetonate, aluminum acetoacetate, trimethylaluminum, triethylaluminum, and the like, a partial hydrolysate of the organoaluminum compound, and an inorganic aluminum compound. The aforementioned aluminum carboxylate compound may be, for example, aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, or the like; the inorganic aluminum compound may be, for example, alumina, aluminum hydroxide, aluminum chloride, aluminum carbonate; the aluminum alkoxide may be, for example, aluminum methoxide, aluminum ethoxide, or the like. The aluminum-containing catalyst may be a complex such as aluminum acetylacetonate or aluminum acetoacetate, or an organoaluminum compound such as trimethylaluminum or triethylaluminum or a partial hydrolysate thereof. The amount of the aluminum-containing catalyst may be measured by the mass of aluminum, and specifically, the mass ratio of aluminum atoms in the aluminum-containing catalyst to the theoretical yield of the polyesteramide may be 1 to 400ppm, preferably 3 to 300ppm, and more preferably 5 to 500 ppm.
In contrast, when an antimony-containing catalyst is used, particularly when ethylene glycol antimony is used as the polymerization catalyst, the polycondensation reaction can proceed more stably, and the performance of the polyesteramide is better, particularly the yellowness index is lower.
After the polycondensation reaction is finished, discharging, cooling the polycondensation product by pure water at 10 ℃, carrying out washing treatment, and then carrying out wire drawing and grain cutting to obtain the polyesteramide product.
The invention also provides a polyester amide which is prepared by the preparation method. As mentioned above, the diamine salt is introduced in the form of diamine salt aqueous solution after the esterification reaction, so that the serious yellowing problem which often occurs in the polyester amide synthesis process at the present stage can be solved, and the obtained polyester amide has a low yellow index.
The invention also provides a fiber which is prepared by taking the polyester amide as a raw material.
The fiber product can be polyester amide nascent fiber, polyester amide filament, polyester amide POY fiber, polyester amide elastic filament, polyester amide FDY, polyester fiber short fiber, etc.
The invention does not specially limit the specific processing technique of the fiber, and can be prepared by the fiber processing technique at the present stage.
According to the preparation method of the polyesteramide, the diamine salt is introduced in the form of diamine salt aqueous solution after the esterification reaction is finished, so that the yellowing problem in the synthesis process of the polyesteramide at the present stage can be effectively solved, the yellow index of the polyesteramide is obviously reduced, the thermal stability of the polyesteramide is improved, and other performances of the polyesteramide are ensured.
In addition, the preparation method is simple in process, and can be put into use by simply modifying the existing polyester production device.
The polyesteramide provided by the invention is prepared by the preparation method, so compared with polyesteramide obtained by directly adding diamine salt and the like at the present stage, the polyesteramide provided by the invention has relatively lower yellow index and relatively higher thermal stability, and can be better used for manufacturing fiber products.
The fiber provided by the invention is prepared by taking the polyesteramide as a raw material. Compared with the fiber product prepared from the polyester amide obtained by the prior art, the fiber product provided by the invention has higher breaking strength and good elongation at break, so that the fiber product has more outstanding service performance. In addition, the fiber product provided by the invention also has higher dye uptake, thereby improving the processing performance of the fiber product. Thus, the present invention provides a fiber product having improved overall performance.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.