Preparation method of high-elasticity nylon fiber for tennis racket string

Abstract

The invention relates to the technical field of fibers, and discloses a preparation method of a high-elasticity nylon fiber for a tennis racket string, nylon 6 and polyether modified polyimide with the mass ratio of 100: (10-30) are subjected to melt blending spinning in a spinning machine, then drafting and sizing are performed through a hot roller drafting machine, and the high-elasticity nylon fiber for the tennis racket string is obtained. The polyether modified polyimide contains the same amido bond structural unit as nylon 6, so that the polyether modified polyimide has good compatibility with nylon 6, the polyether modified polyimide can be uniformly dispersed in a nylon fiber matrix, and a flexible polyethylene glycol molecular chain is introduced into a polyimide molecular chain, so that the polyether modified polyimide improves the toughness and elasticity of the nylon fiber; therefore, the high elongation at break and the high elastic recovery rate are shown. The nylon fiber disclosed by the invention has good practical application in the aspects of tennis racket lines and the like.

Description

Technical Field

[0001] The invention relates to the technical field of fibers, in particular to a method for preparing high-elastic nylon fibers for tennis racket strings. Background Art

[0002] Nylon fiber is easy to prepare, the raw materials are cheap and easy to obtain, and it has good moisture resistance and heat resistance. It is widely used in tennis racket strings, ropes, wire mesh, fabrics, etc. Improving the tensile and rebound properties of nylon fibers is a research hotspot. Polyimide has high mechanical strength, large modulus, high temperature resistance, and good wear resistance. It can be made into plastics, fibers and other products and has a wide range of applications.

[0003] Combining polyimide with nylon products can produce high-performance composite materials. The patent with announcement number CN106188551B discloses a semi-aromatic polyimide modified nylon and its preparation method and a semi-aromatic polyimide preparation method. The semi-aromatic polyimide and nylon material are blended and extruded to prepare a polyimide modified nylon material with good hardness, mechanical properties and water resistance. Compared with the patent, the present invention significantly improves the resilience and tensile properties of nylon fibers by using modified polyimide. Summary of the invention

[0004] (I) Technical problem to be solved: The present invention provides a nylon fiber with high tensile properties and high elasticity for tennis racket strings.

[0005] (II) Technical solution: A method for preparing high elastic nylon fiber for tennis racket strings, comprising the following steps:

[0006] Step A, adding dianhydride monomer, p-phenylenediamine and aniline polyethylene glycol in a molar ratio of 1: (0.6-0.9): (0.1-0.4) to a solvent, reacting for 6-10 hours in a nitrogen atmosphere, then pouring the solution onto a clean glass plate surface, heat treating at 100-270° C. for 6-7 hours, and cooling to obtain a polyether-modified polyimide.

[0007] Step B, melt-blending and spinning nylon 6 and polyether-modified polyimide in a mass ratio of 100:(10-30) in a spinning machine at a spinning temperature of 240-250° C., then stretching through a hot roller stretching machine at a stretching temperature of 120-130° C. and a stretching ratio of 3-4 times, and shaping to obtain a high-elastic nylon fiber for tennis racket strings.

[0008] Preferably, the solvent in step A is N,N-dimethylformamide or N,N-dimethylacetamide.

[0009] Preferably, the dianhydride monomer is pyromellitic dianhydride or 3,3',4,4'-biphenyltetracarboxylic dianhydride.

[0010] Preferably, the preparation method of aniline polyethylene glycol comprises the following steps:

[0011] Step (1), in an ice bath, add double-terminated amino polyethylene glycol, triethylamine, and 4-nitrobenzoyl chloride in a molar ratio of 1: (2.6-3.2): (2.8-3.6) to dichloromethane, then react at room temperature for 18-24 hours, filter and rotary evaporate the filtrate, add the product to ether for precipitation, filter, and dry to obtain nitrophenyl polyethylene glycol.

[0012] Step (2), add nitrophenyl polyethylene glycol to ethanol, heat to 75-80°C, add palladium carbon catalyst, dropwise add hydrazine hydrate solution, condense and reflux for 5-8h, filter and rotary evaporate the filtrate, add the product to ether for precipitation, filter and dry to obtain anilino polyethylene glycol. The reaction formula is:

[0013]

[0014] Preferably, in step (2), the mass ratio of nitrophenyl polyethylene glycol, palladium carbon catalyst and hydrazine hydrate solution is 100:(3.4-4):(16-22).

[0015] (III) Technical effect of the present invention: The dianhydride monomer is polymerized with p-phenylenediamine and aniline polyethylene glycol to obtain a polyether-modified polyimide whose molecular chain contains polyethylene glycol and amide bond structural units, and then melt-spun with nylon 6. The polyether-modified polyimide contains the same amide bond structural units as nylon 6, so that the polyether-modified polyimide has good compatibility with nylon 6 and can be evenly dispersed in the nylon fiber matrix. The polyimide itself has high mechanical strength and can improve the breaking strength of the fiber. In addition, a flexible polyethylene glycol molecular chain is introduced into the polyimide molecular chain, so that the polyether-modified polyimide improves the toughness and elasticity of the nylon fiber, thereby showing higher elongation at break and elastic recovery rate. The nylon fiber of the present invention has good practical applications in tennis racket strings and the like. DETAILED DESCRIPTION

[0016] The double-terminated amino polyethylene glycol was prepared according to the method described in the journal "Synthesis of Double-Terminated Amino Polyethylene Glycol".

[0017] Example 1

[0018] (1) In an ice bath, add 3 mmol of double-terminated amino polyethylene glycol, 9.6 mmol of triethylamine, and 10.8 mmol of 4-nitrobenzoyl chloride to 50 mL of dichloromethane, and then react at room temperature for 18 hours. After filtering, the filtrate is rotary evaporated, and the product is added to diethyl ether for precipitation, filtered, and dried to obtain nitrophenyl polyethylene glycol.

[0019] (2) Add 5 g of nitrophenyl polyethylene glycol to 60 mL of ethanol, heat to 80° C., add 0.2 g of palladium carbon catalyst, dropwise add 0.8 g of hydrazine hydrate solution (mass fraction 80%), condense and reflux for 5 h, filter and rotary evaporate the filtrate, add the product to ether for precipitation, filter and dry to obtain anilino polyethylene glycol.

[0020] (3) Add 10 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9 mmol of p-phenylenediamine and 1 mmol of aniline polyethylene glycol to 100 mL of N,N-dimethylformamide, and react for 6 h in a nitrogen atmosphere. Then pour the solution onto a clean glass plate and heat treat the solution at 100°C for 1 h, 150°C for 1 h, 200°C for 2 h, 240°C for 2 h and 270°C for 2 h in sequence, and cool to obtain a polyether-modified polyimide.

[0021] (4) 50 g of nylon 6 and 5 g of polyether modified polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 240°C, and then stretched by a hot roller stretching machine at a stretching temperature of 130°C and a stretching ratio of 4 times, and shaped to obtain high-elastic nylon fiber for tennis racket strings.

[0022] Example 2

[0023] (1) In an ice bath, add 3 mmol of double-terminated amino polyethylene glycol, 7.8 mmol of triethylamine, and 8.4 mmol of 4-nitrobenzoyl chloride to 40 mL of dichloromethane, and then react at room temperature for 24 hours. After filtering, the filtrate is rotary evaporated, and the product is added to diethyl ether for precipitation, filtered, and dried to obtain nitrophenyl polyethylene glycol.

[0024] (2) Add 5 g of nitrophenyl polyethylene glycol to 70 mL of ethanol, heat to 75° C., add 0.17 g of palladium carbon catalyst, dropwise add 1.1 g of hydrazine hydrate solution (mass fraction 80%), condense and reflux to react for 8 h, filter and rotary evaporate the filtrate, add the product to ether for precipitation, filter and dry to obtain anilino polyethylene glycol.

[0025] (3) Add 10 mmol of pyromellitic anhydride, 8 mmol of p-phenylenediamine and 2 mmol of aniline polyethylene glycol to 120 mL of N,N-dimethylformamide, and react for 8 h in a nitrogen atmosphere. Then pour the solution onto a clean glass plate and heat treat the solution at 100 ° C for 1 h, 150 ° C for 1 h, 200 ° C for 2 h, 240 ° C for 2 h and 270 ° C for 2 h in sequence, and cool to obtain a polyether modified polyimide.

[0026] (4) 50 g of nylon 6 and 8 g of polyether modified polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 240°C, and then stretched by a hot roller stretching machine at a stretching temperature of 130°C and a stretching ratio of 4 times, and shaped to obtain high-elastic nylon fiber for tennis racket strings.

[0027] Example 3

[0028] (1) Add 10 mmol of pyromellitic dianhydride, 7 mmol of p-phenylenediamine, and 3 mmol of anilino polyethylene glycol (prepared in Example 1) to 120 mL of N,N-dimethylacetamide, and react for 10 h in a nitrogen atmosphere. Then pour the solution onto a clean glass plate surface, heat treat the solution at 100° C. for 1 h, 150° C. for 1 h, 200° C. for 2 h, 240° C. for 2 h, and 270° C. for 1 h, and cool the solution to obtain a polyether-modified polyimide.

[0029] (2) 50 g of nylon 6 and 12 g of polyether modified polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 250°C, and then stretched by a hot roller stretching machine at a stretching temperature of 120°C and a stretching ratio of 4 times, and shaped to obtain high-elastic nylon fiber for tennis racket strings.

[0030] Example 4

[0031] (1) Add 10 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 6 mmol of p-phenylenediamine and 4 mmol of anilino polyethylene glycol (prepared in Example 1) to 120 mL of N,N-dimethylformamide, and react for 10 h in a nitrogen atmosphere. Then pour the solution onto a clean glass plate, heat-treat the solution at 100° C. for 1 h, 150° C. for 1 h, 200° C. for 2 h, 240° C. for 2 h and 270° C. for 1 h, and cool the solution to obtain a polyether-modified polyimide.

[0032] (2) 50 g of nylon 6 and 15 g of polyether modified polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 250°C, and then stretched by a hot roller stretching machine at a stretching temperature of 130°C and a stretching ratio of 3 times, and shaped to obtain high-elastic nylon fiber for tennis racket strings.

[0033] Comparative Example 1

[0034] (1) 50 g of nylon 6 was melt-blended and spun in a spinning machine at a spinning temperature of 240° C., and then stretched by a hot roller stretching machine at a stretching temperature of 130° C. and a stretching ratio of 4 times, and shaped to obtain a high-elastic nylon fiber for tennis racket strings.

[0035] Comparative Example 2

[0036] (1) Add 10 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride and 10 mmol of p-phenylenediamine to 100 mL of N,N-dimethylformamide, react for 6 h in a nitrogen atmosphere, then pour the solution onto a clean glass plate, heat treat the solution at 100°C for 1 h, 150°C for 1 h, 200°C for 2 h, 240°C for 2 h, and 270°C for 2 h, and cool to obtain a polyimide.

[0037] (2) 50 g of nylon 6 and 5 g of polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 240°C, and then stretched by a hot roller stretching machine at a stretching temperature of 130°C and a stretching ratio of 4 times, and shaped to obtain high-elastic nylon fibers for tennis racket strings.

[0038] Comparative Example 3

[0039] (1) Add 10 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9 mmol of p-phenylenediamine and 1 mmol of double-terminated amino polyethylene glycol to 100 mL of N,N-dimethylformamide, react for 6 h in a nitrogen atmosphere, then pour the solution onto a clean glass plate, heat treat at 100°C for 1 h, 150°C for 1 h, 200°C for 2 h, 240°C for 2 h and 270°C for 2 h, and cool to obtain a polyether-modified polyimide.

[0040] (2) 50 g of nylon 6 and 5 g of polyether modified polyimide are melt-blended and spun in a spinning machine at a spinning temperature of 240°C, and then stretched by a hot roller stretching machine at a stretching temperature of 130°C and a stretching ratio of 4 times, and shaped to obtain high-elastic nylon fiber for tennis racket strings.

[0041] The tensile breaking properties of nylon fibers were tested by an electronic single fiber strength tester. The clamping distance was 10 mm and the tensile speed was 10 mm / min.

[0042] Fix the nylon fiber in a strength meter, measure the fiber length as L0, stretch at a speed of 10 mm / min, stretch to an elongation of 10% or 20% (length L1), hold for 1 min, then stop stretching and relax to a tensile stress of 0, test the length L, and calculate the elastic recovery rate W.

[0043] W = (L1 - L) / L0 x 100%.

[0044] Table 1 Nylon fiber performance test

[0045]

[0046]

[0047] Compared with Comparative Examples 1-3, the nylon fibers of Examples 1-4 have higher elongation at break, higher elongation at break and higher elastic recovery rate. This is because the added polyether-modified polyimide contains the same amide bond structural unit as nylon 6, so that the polyether-modified polyimide has good compatibility with nylon 6 and can be evenly dispersed in the nylon fiber matrix. The polyimide itself has high mechanical strength and can improve the breaking strength of the fiber. In addition, a flexible polyethylene glycol molecular chain is introduced into the polyimide molecular chain, so that the polyether-modified polyimide improves the toughness and elasticity of the nylon fiber, thereby showing higher elongation at break and elastic recovery rate.

Claims

1. A method for preparing a high elastic nylon fiber for tennis racket strings, characterized in that: The preparation method comprises the following steps: Step A, adding dianhydride monomer, p-phenylenediamine, and aniline polyethylene glycol to a solvent, reacting for 6-10 hours in a nitrogen atmosphere, then pouring the solution onto a clean glass plate surface, heat treating at 100-270° C. for 6-7 hours, and cooling to obtain a polyether-modified polyimide; Step B: melt-blending and spinning nylon 6 and polyether-modified polyimide in a mass ratio of 100:(10-30) in a spinning machine, and then drawing and shaping through a hot roller drawing machine to obtain high-elastic nylon fibers for tennis racket strings.

2. The method for preparing a high elastic nylon fiber for tennis racket strings according to claim 1, characterized in that: The solvent in step A is N,N-dimethylformamide or N,N-dimethylacetamide.

3. The method for preparing the high elastic nylon fiber for tennis racket string according to claim 1, characterized in that: In the step A, the molar ratio of the dianhydride monomer, p-phenylenediamine, and anilino polyethylene glycol is 1:(0.6-0.9):(0.1-0.4).

4. The method for preparing a high elastic nylon fiber for tennis racket strings according to claim 2, characterized in that: The dianhydride monomer is pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride.

5. The method for preparing high elastic nylon fiber for tennis racket string according to claim 2, characterized in that: The preparation method of the anilino polyethylene glycol comprises the following steps: Step (1), in an ice bath, adding double-terminated amino polyethylene glycol, triethylamine, and 4-nitrobenzoyl chloride to dichloromethane, and then reacting at room temperature for 18-24 hours, filtering and rotary evaporating the filtrate, adding the product to ether for precipitation, filtering, and drying to obtain nitrophenyl polyethylene glycol; Step (2), add nitrophenyl polyethylene glycol to ethanol, heat to 75-80°C, add palladium carbon catalyst, dropwise add hydrazine hydrate solution, condense and reflux for 5-8h, filter and rotary evaporate the filtrate, add the product to ether for precipitation, filter and dry to obtain anilino polyethylene glycol.

6. The method for preparing high elastic nylon fiber for tennis racket string according to claim 5, characterized in that: In the step (1), the molar ratio of double-terminated amino polyethylene glycol, triethylamine and 4-nitrobenzoyl chloride is 1:(2.6-3.2):(2.8-3.6).

7. The method for preparing high elastic nylon fiber for tennis racket string according to claim 5, characterized in that: In the step (2), the mass ratio of nitrophenyl polyethylene glycol, palladium carbon catalyst and hydrazine hydrate solution is 100:(3.4-4):(16-22).

8. The method for preparing high elastic nylon fiber for tennis racket string according to claim 1, characterized in that: The temperature during the melt blending spinning in step B is 240-250°C.

9. The method for preparing high elastic nylon fiber for tennis racket string according to claim 1, characterized in that: The temperature of the hot roller drawing machine is 120-130° C., and the drawing ratio is 3-4 times.

Images