Anti-fracture polyester yarn and preparation method thereof

Abstract

The invention relates to the technical field related to polyester yarn structures, and discloses an anti-fracture polyester yarn and a preparation method thereof.The anti-fracture polyester yarn is prepared from, by weight, 60-80 parts of polyethylene glycol terephthalate, 3-5 parts of tributyl citrate and 5-8 parts of pyromellitic dianhydride. According to the invention, pyridine coordination is used for mainly strengthening the acting force between molecules, and the adhesive force of a contact surface caused by mutual diffusion generated by molecular chain sliding in the friction process of polyester is reduced, so that the friction resistance of the polyester industrial yarn is improved, and the influence caused by wear aggravation due to temperature rise caused by friction heat is reduced; by grafting the polyethylene glycol terephthalate and the cellulose diacetate, the tensile property and the wear resistance of the polyethylene glycol terephthalate are improved, and meanwhile, the tributyl citrate and the pyromellitic dianhydride are used for increasing the roll elasticity of the polyester yarn, so that the spinnability of the polyester yarn is enhanced, and the phenomenon that the polyester yarn is easy to break is reduced.

Description

Technical Field

[0001] The invention relates to the technical field related to polyester yarn structure, in particular to a break-resistant polyester yarn and a preparation method thereof. Background Art

[0002] Polyester fiber is a synthetic fiber obtained by spinning polyester formed by the condensation of organic dibasic acid and diol, referred to as PET fiber. It has good strength, drape and wrinkle resistance, has the appearance of bamboo fiber, and has a certain softness, and is very popular among consumers.

[0003] However, the conventional polyester yarns on the market now have poor tensile properties. During processing and use, the polyester yarns are prone to breakage and fracture, and the polyester yarns have poor elasticity, which shortens the service life of the finished polyester fabrics and accelerates the damage of the polyester fabrics. In order to solve such problems, an anti-fracture polyester yarn and a preparation method thereof are proposed. Summary of the invention

[0004] The present invention provides a breakage-resistant polyester yarn and a preparation method thereof, which solves the problems in the above-mentioned background technology.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] A break-resistant polyester yarn comprises the following raw materials in parts by weight: 60-80 parts of polyethylene terephthalate, 3-5 parts of tributyl citrate, 5-8 parts of pyromellitic anhydride, 10-15 parts of polylactic acid fiber, 3-5 parts of coupling agent, 1-3 parts of antibacterial agent, 10-20 parts of wear-resistant coating material, terephthalic acid chain segment and 2,2-bipyridine-4,4-dicarboxylic acid chain segment;

[0007] The polyethylene terephthalate is grafted with cellulose diacetate in advance to form a polyethylene terephthalate-cellulose diacetate graft copolymer;

[0008] The molar ratio of the terephthalic acid segment to the 2,2-bipyridine-4,4-dicarboxylic acid segment is 1:0.03-0.05.

[0009] Preferably, the wear-resistant coating material includes polyurethane resin and polyvinyl alcohol.

[0010] Preferably, the method for grafting polyethylene terephthalate with cellulose diacetate comprises the following specific steps:

[0011] Polyethylene terephthalate is heated and dissolved in advance, a grafting agent and a catalytic aid are added, heated for reaction, and then cellulose diacetate is added at a constant temperature. Finally, the product is centrifuged and dried to obtain a polyethylene terephthalate-cellulose diacetate graft copolymer.

[0012] Preferably, the grafting agent is isophorone diisocyanate, the antibacterial agent is chitin and tea polyphenols, and the polyester yarn raw material further includes 3 to 5 parts of bacterial cellulose.

[0013] Preferably, the bacterial cellulose is grafted onto polylactic acid fiber, and the grafting method comprises the following specific steps:

[0014] The bacterial cellulose, L-lactide and a catalyst are mixed in advance, and then heated in a vacuum to react to form a bacterial cellulose polymer. Then, the polylactic acid fiber and the bacterial cellulose polymer are dissolved in a solvent, and then heated to react to form a bacterial cellulose grafted polylactic acid fiber composite.

[0015] A break-resistant polyester yarn and a preparation method thereof, comprising the following specific steps:

[0016] Polyethylene terephthalate-cellulose diacetate graft copolymer, tributyl citrate, pyromellitic anhydride, polylactic acid fiber, coupling agent and antibacterial agent are mixed and melted to form a molten mixture, and then the molten mixture is directly spun and extruded to obtain polyester mother yarn. Then, during the cooling stage of the polyester mother yarn, a wear-resistant coating material is evenly coated on the outside of the mother yarn. Then, the polyester mother yarn is stretched into fully stretched filament yarn. The filament yarn is then pulled, mutated, and high-temperature twisted, and finally dried and packaged to obtain breakage-resistant polyester yarn.

[0017] Preferably, the performance indicators of the break-resistant polyester yarn are: multifilament fineness is 1100-3300 dtex, breaking strength is ≥8.1 cN / dtex, breaking strength CV value is ≤3.0%, breaking elongation is 13.0-16.5%, breaking elongation CV value is ≤8.0%, elongation at 4.0 cN / dtex load is 5.5-6.0%, and dry heat shrinkage under the conditions of 177°C×10min×0.05 cN / dtex is 5.5-9.0%.

[0018] Preferably, the fully drawn filaments are stretched during the variation process, the variation interval is 0.5 to 0.7 seconds, and the variation efficiency is 25 to 27 m / min.

[0019] The advantages and positive effects of the present invention are as follows: the intermolecular forces are mainly strengthened by pyridine coordination, the mutual diffusion caused by the sliding of the molecular chains of polyester during the friction process and the resulting adhesion of the contact surface are reduced, thereby improving the friction resistance of the polyester industrial yarn, and reducing the influence of the temperature increase caused by the friction heat on the aggravated wear, and the tensile strength and wear resistance of the polyethylene terephthalate are improved by grafting polyethylene terephthalate with cellulose diacetate, and at the same time, tributyl citrate and pyromellitic anhydride are used to increase the coil elasticity of the polyester yarn, thereby enhancing the spinnability of the polyester yarn and reducing the phenomenon that the polyester yarn is easy to break. DETAILED DESCRIPTION

[0020] The present invention will now be described in further detail.

[0021] The embodiments of the present invention are further described below:

[0022] Polyester yarn is a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic acid and diol, referred to as PET fiber, which has good strength, drape and wrinkle resistance, has the appearance of bamboo yarn, and has a certain degree of softness, and is very popular among consumers. However, conventional polyester yarns on the market now have poor tensile resistance. During processing and use, the polyester yarns are prone to breakage and fracture, and the elasticity of the polyester yarns is poor, thereby shortening the service life of the finished polyester fabrics and accelerating the damage of the polyester fabrics. In order to solve such problems, a break-resistant polyester yarn and a preparation method thereof are proposed, comprising the following raw materials in parts by weight: 60 to 80 parts of polyethylene terephthalate, 3 to 5 parts of tributyl citrate, 5 to 8 parts of pyromellitic anhydride, 10 to 15 parts of polylactic acid fiber, 3 to 5 parts of coupling agent, 1 to 3 parts of antibacterial agent, 10 to 20 parts of wear-resistant coating material, terephthalic acid segment and 2,2-bipyridine-4,4-dicarboxylic acid segment;

[0023] The polyethylene terephthalate is grafted with cellulose diacetate in advance to form a polyethylene terephthalate-cellulose diacetate graft copolymer;

[0024] The molar ratio of the terephthalic acid chain segment to the 2,2-bipyridine-4,4-dicarboxylic acid chain segment is 1:0.03-0.05; the intermolecular force is mainly strengthened by pyridine coordination, and the adhesion of the contact surface caused by the mutual diffusion of the sliding molecular chain of the polyester during the friction process is reduced, thereby improving the friction resistance of the polyester industrial yarn, and reducing the influence of the temperature increase caused by the friction heat on the aggravation of the wear, and the polyethylene terephthalate is grafted with cellulose diacetate to improve the tensile strength and wear resistance of the polyethylene terephthalate, and at the same time, tributyl citrate and pyromellitic anhydride are used to increase the coil elasticity of the polyester yarn, thereby enhancing the spinnability of the polyester yarn and reducing the phenomenon that the polyester yarn is easy to break.

[0025] It should be noted that the idea of ​​using pyridine coordination mentioned above is because the wear of polymer materials is caused by the force or chemical changes generated during the movement process. During the sliding process, there will be a lot of pressure on the contact point, which will cause the contact surface to produce micro-deformation and micro-convexity due to shear, and cause plastic deformation of the soft surface, macroscopic deformation of abrasive wear, and elastic hysteresis deformation of viscoelastic materials; in addition, frictional heat causes the temperature to rise, which intensifies the wear. The sliding wear of high molecular polymers mainly includes adhesive wear, abrasive wear and fatigue wear. The main reasons for adhesion are: (1) polymers are more easily deformed because they are soft; (2) the molecular chains of polymers will diffuse with each other during the sliding process, resulting in increased adhesion of the contact surface.

[0026] In addition, abrasive wear refers to the behavior in which some hard particles or hard rough surfaces move relative to the surface of a soft material during sliding, causing deformation or tearing damage. The abrasive wear between two materials causes damage such as plowing or fracture of the hard material on the surface of the soft material during sliding.

[0027] Furthermore, from the perspective of molecular motion, the three mechanical states of polyester crystalline polymers that appear with temperature changes are closely related to the different motion states of internal molecules at different temperatures. In the glass state, due to the low temperature, the energy of molecular motion is very low, which is not enough to overcome the barrier of internal rotation of the main chain, so the movement of the chain segment cannot be stimulated, and the chain segment is in a frozen state. Only those smaller units with lower activation energy can move. At this time, the mechanical properties of the polymer are very small after being subjected to force; as the temperature rises, the molecular thermal motion energy gradually increases. When it reaches Tg, it is enough to overcome the barrier of internal rotation, and the coordinated movement of dozens of adjacent single bonds is stimulated. The chain segment can begin to move to change the conformation of the chain, and the polymer enters a highly elastic state; if the polymer chain undergoes a large deformation when subjected to force, the temperature continues to rise, and the movement of the entire chain is stimulated. Under the action of external force, the chains slip against each other, and the polymer enters a viscous flow state, which will produce irreversible deformation when subjected to force.

[0028] It should also be noted that Example 1: This embodiment provides a break-resistant polyester yarn, comprising the following raw materials in parts by weight: polyethylene terephthalate, 70 kg, tributyl citrate 4 kg, pyromellitic anhydride 7 kg, polylactic acid fiber 13 kg, coupling agent 4 kg, antibacterial agent 2 kg, wear-resistant coating material 15 kg; wherein polyethylene terephthalate is pre-grafted with cellulose diacetate, the wear-resistant plate coating material is polyvinyl alcohol, the coupling agent is silane coupling agent KH570, the antibacterial agent is chitin, and the molar ratio of terephthalic acid segment to 2,2-bipyridine-4,4-dicarboxylic acid segment is 1:0.03-0.05; the preparation method of the break-resistant polyester yarn comprises the following specific steps:

[0029] S1: Polyethylene terephthalate is preheated in tetrachloroethane until it is dissolved to form a PET solution, and then a grafting agent isophorone diisocyanate and a catalyst aid dibutyltin dilaurate are added to the PET solution, the mass ratio of polyethylene terephthalate, the grafting agent and the catalyst aid is 1:1.1:0.3, and the mixture is reacted at 70°C for 5 hours to form a polyethylene terephthalate-isocyanate composite liquid; then cellulose diacetate is dissolved in tetrachloroethane to form a cellulose diacetate solution, and the cellulose diacetate solution is added to the polyethylene terephthalate-isocyanate composite liquid at a constant temperature of 70°C, and the reaction is performed for 8 hours. Then, the product is precipitated with acetone, centrifuged, and dried to obtain a polyethylene terephthalate-cellulose diacetate graft copolymer.

[0030] S2: After the polyethylene terephthalate-cellulose diacetate graft copolymer and polylactic acid fiber are dried, they are mixed with tributyl citrate, isomellitic anhydride, a coupling agent and an antibacterial agent, and melted at 240°C to form a molten mixture. The molten mixture is then directly spun and extruded to obtain a polyester mother yarn. During the cooling stage of the polyester mother yarn, a wear-resistant coating material is evenly coated on the outside of the mother yarn to form a polyester mother yarn with an average fineness of 150D.

[0031] S3: Put the polyester mother yarn into the upper wire rack, pull and stretch it into fully stretched filament, and then put the filament into the fancy twisting machine and perform variable stretching when passing through the roller rod of the machine, once every 0.6 seconds, each time lasting 0.5 seconds, frequency 16.64Hz, efficiency 26m / min, then the mutated filament comes out of the roller rod, and then is twisted at 270℃, and finally dried and packaged to obtain the breakage-resistant polyester yarn.

[0032] Example 2: The difference between Example 2 and Example 1 is that the amount of polyethylene terephthalate used in the anti-break polyester yarn raw material is 60kg, the amount of tributyl citrate used is 3kg, the amount of isophthalic acid dianhydride used is 8kg, the amount of polylactic acid fiber used is 15kg, the amount of coupling agent used is 3kg, the amount of antibacterial agent used is 1kg, and the amount of wear-resistant coating material used is 10kg.

[0033] Example 3: The difference between Example 3 and Example 1 is that the amount of polyethylene terephthalate used in the anti-break polyester yarn raw material is 80 kg, the amount of tributyl citrate used is 5 kg, the amount of isophthalic acid dianhydride used is 5 kg, the amount of polylactic acid fiber used is 10 kg, the amount of coupling agent used is 5 kg, the amount of antibacterial agent used is 3 kg, and the amount of wear-resistant coating material used is 20 kg.

[0034] Example 4: The difference between Example 4 and Example 1 is that the wear-resistant coating material in the anti-break polyester yarn raw material is polyurethane.

[0035] Example 5: The difference between Example 5 and Example 1 is that the wear-resistant coating material in the anti-fracture polyester yarn raw material is a mixture of polyurethane and polyvinyl alcohol in a mass ratio of 1:1.

[0036] Example 6: The difference between Example 6 and Example 5 is that the antibacterial agent in the anti-break polyester yarn raw material is a mixture of chitosan and tea polyphenols in a mass ratio of 1:1.

[0037] Example 7: The difference between Example 7 and Example 6 is that the anti-break polyester yarn raw material also includes 4 kg of bacterial cellulose.

[0038] Example 8: The difference between Example 8 and Example 7 is that the amount of bacterial cellulose used in the anti-break polyester yarn raw material is 3 kg.

[0039] Example 9: The difference between Example 9 and Example 7 is that the amount of bacterial cellulose used in the anti-break polyester yarn raw material is 5 kg.

[0040] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that the polyethylene terephthalate in the break-resistant polyester yarn raw material is not grafted with cellulose diacetate.

[0041] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that tributyl citrate is not used in the raw material of the anti-break polyester yarn.

[0042] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that tributyl citrate and pyromellitic anhydride are not used in the raw materials of the anti-breaking polyester yarn.

[0043] And the above-mentioned embodiments and comparative examples were subjected to performance tests. The following performance tests were conducted on the anti-breakage polyester yarns provided by embodiments 1-9 and comparative examples 1-3 of the present application. The specific test results are shown in Table 1;

[0044]

[0045] Table 1

[0046] From the performance test results, it can be seen that the polyester yarn prepared in the present application has good elasticity and tensile strength. In Examples 1-3 of the present application, polyethylene terephthalate is pre-grafted with cellulose diacetate to improve the tensile strength and wear resistance of the polyester yarn, enhance the spinnability of the polyester yarn, and reduce the phenomenon of easy breakage of the polyester yarn. At the same time, tributyl citrate and pyromellitic anhydride are compounded to improve the elasticity and tensile recovery performance of the polyester yarn, and further reduce the phenomenon of easy breakage of the polyester yarn.

[0047] By comparing Comparative Example 1 with Example 1, it can be seen that the polyethylene terephthalate and cellulose diacetate are grafted in Comparative Example 1. From the performance test results, it can be seen that the tensile strength of the polyester yarn is significantly reduced, which further illustrates the promoting effect of cellulose diacetate on the tensile strength of polyethylene terephthalate.

[0048] By comparing Comparative Examples 2 and 3 with Example 1, it can be seen that tributyl citrate is not used in Comparative Example 2, and tributyl citrate and pyromellitic anhydride are not used in Comparative Example 3. From the performance test results, it can be seen that the elastic recovery performance and elastic elongation rate of the polyester yarn are significantly reduced; it further illustrates that the compounding of tributyl citrate and pyromellitic anhydride can better enhance the flexibility and elastic recovery performance of the polyester yarn.

[0049] By comparing Examples 4 and 5 with Example 1, it can be seen that the wear-resistant coating material in Example 4 is polyurethane, and the wear-resistant coating material in Example 5 is polyurethane and polyvinyl alcohol. From the performance test results, it can be seen that the wear resistance of the polyester yarn prepared in Example 5 is better than that of Examples 1 and 4; it further illustrates that polyurethane enhances the bonding force between polyvinyl alcohol and polyester yarn, polyvinyl alcohol is firmly bonded to the surface of the polyester yarn, performs film-forming protection on the polyester yarn, improves the wear resistance of the polyester yarn, and reduces the wear phenomenon of the polyester yarn.

[0050] By comparing Example 6 with Example 1, it can be seen that the antibacterial agent used in Example 6 is a mixture of chitosan and tea polyphenols. From the performance test results, it can be seen that Example 6 has a better antibacterial effect. This may be because the antibacterial agent in Example 6 has a broader spectrum of antibacterial properties and can better combine with polyester yarns, thereby improving the antibacterial properties of polyester yarns.

[0051] In Examples 7-9, a proper amount of bacterial cellulose was added to the polyester yarn raw material. From the performance test results, it can be seen that the tensile properties and wear resistance of the polyester yarn are improved, which further illustrates the promoting effect of bacterial cellulose on polyester yarn.

[0052] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the embodiments described in the specific implementation manners. Any other implementation manners derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. A break-resistant polyester yarn, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of polyethylene terephthalate, 3-5 parts of tributyl citrate, 5-8 parts of pyromellitic anhydride, 10-15 parts of polylactic acid fiber, 3-5 parts of coupling agent, 1-3 parts of antibacterial agent, 10-20 parts of wear-resistant coating material, terephthalic acid chain segment and 2,2-bipyridine-4,4-dicarboxylic acid chain segment; The polyethylene terephthalate is grafted with cellulose diacetate in advance to form a polyethylene terephthalate-cellulose diacetate graft copolymer; The molar ratio of the terephthalic acid segment to the 2,2-bipyridine-4,4-dicarboxylic acid segment is 1:0.03-0.

05.

2. The anti-break polyester yarn according to claim 1, characterized in that: The wear-resistant coating material comprises polyurethane resin and polyvinyl alcohol.

3. The anti-break polyester yarn according to claim 1, characterized in that: The grafting method of polyethylene terephthalate and cellulose diacetate comprises the following specific steps: Polyethylene terephthalate is heated and dissolved in advance, a grafting agent and a catalytic aid are added, heated for reaction, and then cellulose diacetate is added at a constant temperature. Finally, the product is centrifuged and dried to obtain a polyethylene terephthalate-cellulose diacetate graft copolymer.

4. The anti-break polyester yarn according to claim 3, characterized in that: The grafting agent is isophorone diisocyanate, the antibacterial agent is chitin and tea polyphenols, and the polyester yarn raw material also includes 3 to 5 parts of bacterial cellulose.

5. The anti-break polyester yarn according to claim 4, characterized in that: The bacterial cellulose is grafted onto the polylactic acid fiber, and the grafting method comprises the following specific steps: The bacterial cellulose, L-lactide and a catalyst are mixed in advance, and then heated in a vacuum to react to form a bacterial cellulose polymer. Then, the polylactic acid fiber and the bacterial cellulose polymer are dissolved in a solvent, and then heated to react to form a bacterial cellulose grafted polylactic acid fiber composite.

6. A break-resistant polyester yarn and a preparation method thereof according to any one of claims 1 to 5, characterized in that: The specific steps include: Polyethylene terephthalate-cellulose diacetate graft copolymer, tributyl citrate, pyromellitic anhydride, polylactic acid fiber, coupling agent and antibacterial agent are mixed and melted to form a molten mixture, and then the molten mixture is directly spun and extruded to obtain polyester mother yarn. Then, during the cooling stage of the polyester mother yarn, a wear-resistant coating material is evenly coated on the outside of the mother yarn. Then, the polyester mother yarn is stretched into fully stretched filament yarn. The filament yarn is then pulled, mutated, and high-temperature twisted, and finally dried and packaged to obtain breakage-resistant polyester yarn.

7. The method for preparing the break-resistant polyester yarn according to claim 6, characterized in that: The performance indicators of break-resistant polyester yarn are: multifilament fineness is 1100~3300dtex, breaking strength is ≥8.1cN / dtex, breaking strength CV value is ≤3.0%, breaking elongation is 13.0~16.5%, breaking elongation CV value is ≤8.0%, elongation at 4.0cN / dtex load is 5.5~6.0%, and dry heat shrinkage under the conditions of 177℃×10min×0.05cN / dtex is 5.5~9.0%.

8. The method for preparing the break-resistant polyester yarn according to claim 7, characterized in that: During the variation process, the fully drawn filaments are stretched, the variation interval is 0.5 to 0.7 seconds, and the variation efficiency is 25 to 27 meters per minute.

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