Highly-transparent nylon elastomer polymer, preparation method, and polymer thin film

Abstract

A highly-transparent nylon elastomer polymer, a preparation method, and a polymer thin film. A component of the polymer is obtained by polymerizing a first monomer and a second monomer in one of the following modes: (1) self-polymerization of pure para-substituted caprolactam monomers; (2) copolymerization of a para-substituted caprolactam monomer and a caprolactam monomer at different molar ratios; (3) copolymerization of two different para-substituted caprolactam monomers at different molar ratios. By polymerizing a monomer having a structure similar to that of the caprolactam monomer with caprolactam, and using water-induced ring-opening polymerization which has less stringent requirements in industrial polymerization processes, problems such as a high residue rate and unstable molecular structures of copolymer products caused by thermodynamic miscibility and polymerization efficiency problems of common modified monomers are solved. Additionally, by restricting the interchain hydrogen bonding action of amide groups in a polyamide polymer material, aggregation between molecular chains is inhibited, thereby achieving the regulation of polymer crystallinity and crystal morphology and achieving the objective of preparing a transparent nylon elastomer.

Description

Highly transparent nylon elastomer polymer, preparation method and polymer film Technical Field

[0001] The invention belongs to the technical field of polymer material synthesis, and particularly relates to a highly transparent nylon elastomer polymer, a preparation method and a polymer film. Background Art

[0002] The chemical name of nylon 6 is polycaprolactam, and its structural formula is —[NH(CH2)5CO] n Nylon 6 is a translucent or milky white thermoplastic resin with excellent self-lubricity, wear resistance, and solvent resistance. These excellent properties are primarily derived from hydrogen bonding between adjacent amide bonds within the molecular chain. Therefore, nylon 6 is widely used as an engineering plastic in the manufacture of various high-load mechanical parts, electronic and electrical switches and equipment, building and structural materials, and transportation components. However, practical applications often require polymers to possess conflicting properties, such as heat resistance and ease of molding, high rigidity and impact resistance, which are often difficult to achieve with a single polymer. For example, nylon 6 has a poor structural toughness and can become brittle and fracture after prolonged use in dry, low-temperature environments. It is also susceptible to cracking or breaking when subjected to external forces. Therefore, nylon 6 is often toughened and modified.

[0003] The existing commonly used method to improve the toughness of nylon 6 matrix is ​​through copolymerization or blending modification. Blending modification is to prepare a polymer alloy by processing polyamide and elastomer, but most of the current elastomers are non-polar and have low surface energy, which leads to problems with its dyeability, hydrophilicity, antistatic properties and poor compatibility with nylon matrix or inorganic fillers, such as polyolefin elastomers and thermoplastic polyurethane elastomers (TPU). Therefore, the nylon alloy prepared by this method has a significant performance "ceiling". Copolymerization modification is to block polymerize a prepolymer obtained by polymerizing a dibasic acid with strong crystallinity and a diamine, or a prepolymer obtained by preliminary ring-opening polymerization of a cyclic lactam, as a hard segment and a polyester or polyether with a soft molecular chain as a soft segment to obtain a polyamide-type thermoplastic elastomer (TPAE). Polyamide-based thermoplastic elastomers obtained through copolymerization overcome the compatibility issues between polyamide and elastomers. Building on the inherent properties of polyamide, such as high-temperature resistance, friction resistance, and good dimensional stability, these elastomers, through modification with polyethers or polyesters, possess even more excellent properties, such as creep stability, low-temperature toughness, resilience, and impact resistance. However, this method requires solution polymerization, which places high demands on the polymerization process. Therefore, the development of polyamide elastomers that retain the excellent properties of polyamide while exhibiting even greater advantages, while also requiring a relatively simple polymerization process, has become a hot topic of research and holds significant significance.

[0004] Summary of the Invention

[0005] In response to the above-mentioned problems, the present invention provides a highly transparent nylon elastomeric polymer and a method for preparing the same. By copolymerizing a novel caprolactam monomer substituted with a para-alkyl group, the introduction of the alkyl group introduces steric hindrance into the polyamide polymer chain, reduces the intermolecular forces between the chains, and enhances the toughness of the polymer. At the same time, the introduction of the alkyl chain can also reduce the grain size, thereby enhancing the transparency of traditional nylon materials. Ultimately, a method for preparing a copolymerized nylon 6 elastomeric polymer with both high elasticity and transparency is obtained.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A highly transparent nylon elastomeric polymer, wherein the polymer component is obtained by polymerizing a first monomer and a second monomer by one of the following methods:

[0008] (1) The first monomer and the second monomer are the same pure para-substituted caprolactam monomers, and the pure para-substituted caprolactam monomers are self-polymerized;

[0009] (2) the first monomer and the second monomer are a para-substituted caprolactam monomer and a caprolactam monomer, and the para-substituted caprolactam monomer and the caprolactam monomer are copolymerized in different molar ratios;

[0010] (3) The first monomer and the second monomer are two different para-substituted caprolactam monomers, and the two different para-substituted caprolactam monomers are copolymerized in different molar ratios.

[0011] Furthermore, the para-substituent is one of -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2OH, and -CH2CH2OH.

[0012] Furthermore, the different molar ratios of the two monomers in methods (2) and (3) are 5% to 85%.

[0013] Furthermore, the repeating unit of the polymer component is represented by the following formula:

[0014] Furthermore, in the polymer obtained by self-polymerization, R1=R2; in the polymer obtained by copolymerization, R1≠R2; wherein R1 or R2 is H, one of -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2OH, and -CH2CH2OH, and R1 and R2 are not H at the same time.

[0015] Furthermore, in the molecular structure shown in formula (1), m and n are both integers, and m+n is between 5 and 1000.

[0016] Furthermore, the tensile strain of the polymer can reach 100%-500%, and the crystallization temperature can be as low as 120-150 degrees Celsius.

[0017] The present invention also proposes a method for preparing the above-mentioned highly transparent nylon elastomeric polymer, comprising the following process: mixing a first monomer and a second monomer in a certain molar ratio and deionized water in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere, heating to 230-260°C and mechanically stirring; at the same time, increasing the pressure to 0.5-1.0 MPa; then, maintaining the polymerization of the monomers for 5 hours in the presence of water; then, maintaining the pressure constant, and continuing the reaction for 1 hour under a nitrogen atmosphere and atmospheric pressure respectively; finally, reducing the system pressure to 40-60 Pa and maintaining it for 1 hour; after the reaction is completed, the system is naturally cooled to room temperature.

[0018] The present invention also provides a polymer film made from the highly transparent nylon elastomer polymer.

[0019] Furthermore, the film has high elasticity and transparency and has a main chain structure consistent with nylon 6.

[0020] Furthermore, the polyamide component of the film contains both a homopolymer of para-substituted polyamide and a copolymer of para-substituted polyamide.

[0021] The present invention polymerizes caprolactam with a monomer having a structure similar to that of the caprolactam monomer and adopts water-initiated ring-opening polymerization with relatively low industrial polymerization process requirements, thereby overcoming the problems of high residual rate and unstable molecular structure of the copolymer product caused by thermodynamic miscibility and polymerization efficiency problems of common modified monomers. At the same time, by limiting the hydrogen bonding effect between amide chains on the polyamide polymer material, the aggregation between molecular chains is suppressed to achieve the regulation of polymer crystallinity and crystal morphology, thereby achieving the purpose of preparing a transparent nylon elastomer. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0023] The polymer composition of the present invention broadly relates to nylon self-polymers and copolymers. The polymer of the present invention relates to para-substituted caprolactam monomers which are not available from commercial sources but can be obtained by known preparation techniques with a purity of >98%. Caprolactam monomers can be directly obtained from commercial sources.

[0024] Para-substituted caprolactam, structural formula:

[0025] R=-CH3,-CH2CH3,-CH2CH2CH3,-CH2CH2CH2CH3,-CH2OH,-CH2CH2OH;

[0026] The synthesis method of para-propyl caprolactam takes propylcyclohexanone as an example: ①: weigh 14.4g 4-n-propylcyclohexanone, 14.28g hydroxylamine hydrochloride, and 32.64g anhydrous sodium carbonate in a beaker, add 120ml methanol and 60ml deionized water to the beaker, stir magnetically for 2.5h, then evaporate the methanol solution at 70℃, cool to room temperature, add 120ml ethyl acetate and 80ml deionized water to the beaker, stir vigorously and shake, let it stand, take the upper solution and rotary evaporate at 60℃ for 30min to obtain a white oily substance - 4-n-propylcyclohexanone oxime; ②: take 5g 4-n-propylcyclohexanone oxime in a beaker, slowly add 5ml 85% H2SO4 (solution A), add 3ml in a three-necked flask 85% H2SO4, heat to 120℃, and slowly add solution A dropwise to the three-necked flask under magnetic stirring. After the addition is completed, continue heating for 5 minutes, then remove the heat source and cool naturally to 80℃. Then cool to 5-8℃ in an ice-water bath, and add 25% ammonia solution dropwise to the three-necked flask at a rate of 20ml / h until the pH is 8. Transfer the solution in the three-necked flask to a beaker, add 120ml of dichloromethane and 80ml of H2O, shake thoroughly, and let it stand. Remove the lower layer of solution and rotary evaporate at 60℃ to obtain a brown solid - propyl caprolactam;

[0027] The synthesis methods of other para-substituted caprolactam monomers can refer to the synthesis method of para-propyl caprolactam described above.

[0028] Caprolactam, structural formula:

[0029] The polymerization process equation of polymer:

[0030] R1≠R2, copolymerization; R1=R2, self-polymerization;

[0031] In a preferred embodiment of the copolymerization of the present invention, using the copolymerization of propyl-substituted caprolactam and caprolactam as an example, the polymer comprises approximately 0.5-85 mol% of the propyl-substituted caprolactam monomer, with the remainder being caprolactam. More preferably, the propyl-substituted caprolactam monomer comprises 5-45 mol%, and most preferably, the propyl-substituted caprolactam monomer mixture comprises 10-50 mol%. In a preferred embodiment of the present invention, a polymer comprising 20 mol% propyl-substituted caprolactam and 80 mol% caprolactam is used for strip extrusion and film synthesis.

[0032] The specific embodiments are as follows:

[0033] Example 1

[0034] 10.75 g (0.095 mol) of ε-caprolactam, 0.63 g (0.005 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0035] Example 2

[0036] 10.18 g (0.09 mol) of ε-caprolactam, 1.26 g (0.01 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0037] Example 3

[0038] 9.05 g (0.08 mol) of ε-caprolactam, 2.54 g (0.02 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0039] Example 4

[0040] 5.65 g (0.05 mol) of ε-caprolactam, 6.35 g (0.05 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0041] Example 5

[0042] 2.26 g (0.02 mol) of ε-caprolactam, 10.17 g (0.08 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0043] Example 6

[0044] 0.56 g (0.005 mol) of ε-caprolactam, 12.07 g (0.095 mol) of para-methyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0045] Example 7

[0046] 10.75 g (0.095 mol) of ε-caprolactam, 0.71 g (0.005 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0047] Example 8

[0048] 10.18 g (0.09 mol) of ε-caprolactam, 1.42 g (0.01 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0049] Example 9

[0050] 9.05 g (0.08 mol) of ε-caprolactam, 2.82 g (0.02 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0051] Example 10

[0052] 5.65 g (0.05 mol) of ε-caprolactam, 7.05 g (0.05 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0053] Example 11

[0054] 2.26 g (0.02 mol) of ε-caprolactam, 11.29 g (0.08 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0055] Example 12

[0056] 0.56 g (0.005 mol) of ε-caprolactam, 13.41 g (0.095 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0057] Example 13

[0058] 10.75 g (0.095 mol) of ε-caprolactam, 0.775 g (0.005 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0059] Example 14

[0060] 10.18 g (0.09 mol) of ε-caprolactam, 1.55 g (0.01 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0061] Example 15

[0062] 9.05 g (0.08 mol) of ε-caprolactam, 3.10 g (0.02 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0063] Example 16

[0064] 5.56 g (0.05 mol) of ε-caprolactam, 7.76 g (0.05 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0065] Example 17

[0066] 2.26 g (0.02 mol) of ε-caprolactam, 12.4 g (0.08 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0067] Example 18

[0068] 0.56 g (0.005 mol) of ε-caprolactam, 14.73 g (0.095 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0069] Example 19

[0070] 9.05 g (0.08 mol) of ε-caprolactam, 3.40 g (0.02 mol) of para-butyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0071] Example 20

[0072] 9.05 g (0.08 mol) of ε-caprolactam, 2.86 g (0.02 mol) of para-hydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0073] Example 21

[0074] 9.05 g (0.08 mol) of ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0075] Example 22

[0076] 10.17 g (0.08 mol) of para-methyl-substituted ε-caprolactam, 2.82 g (0.02 mol) of para-ethyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0077] Example 23

[0078] 10.17 g (0.08 mol) of para-methyl-substituted ε-caprolactam, 3.10 g (0.02 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0079] Example 24

[0080] 10.17 g (0.08 mol) of para-methyl-substituted ε-caprolactam, 3.40 g (0.02 mol) of para-butyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was naturally cooled to room temperature.

[0081] Example 25

[0082] 10.17 g (0.08 mol) of para-methyl-substituted ε-caprolactam, 2.86 g (0.02 mol) of para-ethylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was naturally cooled to room temperature.

[0083] Example 26

[0084] 10.18 g (0.08 mol) of para-methyl-substituted ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0085] Example 27

[0086] 11.29 g (0.08 mol) of para-ethyl-substituted ε-caprolactam, 3.10 g (0.02 mol) of para-propyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0087] Example 28

[0088] 11.29 g (0.08 mol) of para-ethyl-substituted ε-caprolactam, 3.40 g (0.02 mol) of para-butyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under a nitrogen atmosphere and atmospheric pressure, respectively. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was naturally cooled to room temperature.

[0089] Example 29

[0090] 11.28 g (0.08 mol) of para-ethyl-substituted ε-caprolactam, 2.86 g (0.02 mol) of para-hydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0091] Example 30

[0092] 11.28 g (0.08 mol) of para-ethyl-substituted ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0093] Example 31

[0094] 12.41 g (0.08 mol) of para-propyl-substituted ε-caprolactam, 3.40 g (0.02 mol) of para-butyl-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0095] Example 32

[0096] 12.41 g (0.08 mol) of para-propyl-substituted ε-caprolactam, 2.86 g (0.02 mol) of para-ethylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0097] Example 33

[0098] 12.14 g (0.08 mol) of para-propyl-substituted ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0099] Example 34

[0100] 13.60 g (0.08 mol) of para-butyl-substituted ε-caprolactam, 2.86 g (0.02 mol) of para-ethylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0101] Example 35

[0102] 13.60 g (0.08 mol) of para-butyl-substituted ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0103] Example 36

[0104] 11.44 g (0.08 mol) of para-ethylhydroxy-substituted ε-caprolactam, 3.14 g (0.02 mol) of para-propylhydroxy-substituted ε-caprolactam, and 12 ml of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under a nitrogen atmosphere and atmospheric pressure, respectively. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was naturally cooled to room temperature.

[0105] Comparative Example 1

[0106] 22.6 g (0.2 mol) of caprolactam and 2.2 g of deionized water were mixed in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere and heated to 230-260°C with mechanical stirring. Simultaneously, the pressure was increased to 0.5-1.0 MPa. The reaction was then maintained in the presence of water for 5 hours to allow polymerization of the monomers. The pressure then stabilized, and the reaction continued for 1 hour under both a nitrogen atmosphere and atmospheric pressure. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was complete, the system was allowed to cool naturally to room temperature.

[0107] Comparative Example 2

[0108] 23.2 g (0.2 mol) of hexamethylenediamine and 29.2 g (0.2 mol) of adipic acid were placed in a polymerization reactor, 50 g of deionized water was added, and the mixture was heated under nitrogen with continuous stirring to produce a salt solution. The nylon salt was then cooled, crystallized, filtered, and dried. The above-mentioned nylon 66 salt, catalyst, and deionized water were added to the reactor in proportion. After the pressure began to stabilize, the reaction was continued for 1 hour under nitrogen atmosphere and atmospheric pressure, respectively. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was completed, the system was naturally cooled to room temperature.

[0109] Comparative Example 3

[0110] 11.08 g (0.08 mol) of hexamethylenediamine, 3.76 g (0.02 mol) of 3-propylhexamethylenediamine, 9.29 g (0.08 mol) of adipic acid, and 3.16 g (0.02 mol) of 3-methyladipic acid were placed in a polymerization kettle. 30 g of deionized water was added, and the mixture was heated and stirred under nitrogen to obtain a salt solution. The nylon salt was then cooled, crystallized, filtered, and dried. The copolymerized nylon 66 salt, catalyst, and deionized water were added to the reactor in proportion. After the pressure began to stabilize, the reaction was continued under nitrogen atmosphere and atmospheric pressure for 1 hour. Finally, the system pressure was reduced to approximately 50 Pa and maintained for 1 hour. After the reaction was completed, the system was naturally cooled to room temperature.

[0111] Table 1. Composition and properties of nylon 6 matrix polymer

[0112] The following conclusions can be drawn from the polymer property data obtained from Examples 1-36 and compared with Comparative Examples 1-3:

[0113] (1) After the copolymerization of caprolactam (or para-substituted caprolactam) and para-substituted caprolactam, the resulting copolyamide 6 (copolynylon 6) has a significantly lower glass transition temperature and significantly improved toughness and transparency compared to polyamide 6 (nylon 6). In addition, as the proportion of para-substituted caprolactam in the copolymer component increases, its transparency, elasticity / toughness improve, and it possesses typical elastomer characteristics;

[0114] (2) According to the performance requirements of the elastomer, suitable monomers and proportions can be selected for copolymerization;

[0115] (3) The method of using para-substituted caprolactam copolymerization has obvious advantages over the multi-component binary monomer copolymerization method, and it is easier to obtain nylon elastomers / films with good transparency and high elasticity.

[0116] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A highly transparent nylon elastomeric polymer, characterized in that: The polymer component is obtained by polymerizing the first monomer and the second monomer in one of the following ways: (1) the first monomer and the second monomer are the same pure para-substituted caprolactam monomers, and the pure para-substituted caprolactam monomers are self-polymerized; (2) the first monomer and the second monomer are a para-substituted caprolactam monomer and a caprolactam monomer, and the para-substituted caprolactam monomer and the caprolactam monomer are copolymerized at different molar ratios; (3) The first monomer and the second monomer are two different para-substituted caprolactam monomers, and the two different para-substituted caprolactam monomers are copolymerized in different molar ratios.

2. A highly transparent nylon elastomeric polymer according to claim 1, characterized in that: The para-substituent is one of -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2OH, and -CH2CH2OH.

3. The highly transparent nylon elastomeric polymer according to claim 1, characterized in that: The different molar ratios of the two monomers in methods (2) and (3) are 5% to 85%.

4. The highly transparent nylon elastomeric polymer according to claim 2, characterized in that: The repeating unit of the polymer component is represented by the following formula:

5. The highly transparent nylon elastomeric polymer according to claim 4, characterized in that: In the polymer obtained by self-polymerization, R1=R2; in the polymer obtained by copolymerization, R1≠R2; wherein R1 or R2 is H, one of -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2OH, -CH2CH2OH, and R1 and R2 are not H at the same time.

6. The highly transparent nylon elastomeric polymer according to claim 4, characterized in that: In the molecular formula structure shown in formula (1), m and n are both integers, and m+n is between 5 and 1000.

7. A method for preparing a highly transparent nylon elastomeric polymer according to any one of claims 1 to 6, characterized in that: The method comprises the following process: mixing a first monomer and a second monomer in a certain molar ratio and deionized water in a steel reactor equipped with a nitrogen inlet under a nitrogen atmosphere, heating to 230-260° C. and mechanically stirring; at the same time, increasing the pressure to 0.5-1.0 MPa; then, maintaining the polymerization of the monomers for 5 hours in the presence of water; then, maintaining the pressure constant, and continuing the reaction for 1 hour in a nitrogen atmosphere and atmospheric pressure respectively; finally, reducing the system pressure to 40-60 Pa and maintaining it for 1 hour; after the reaction is completed, the system is naturally cooled to room temperature.

8. A polymer film made from the highly transparent nylon elastomeric polymer according to any one of claims 1 to 6.

9. A polymer film according to claim 8, characterized in that: The film has high elasticity and transparency and has a main chain structure consistent with nylon 6.

10. A polymer film according to claim 8, characterized in that: The polyamide component of the film contains both a homopolymer of a para-substituted polyamide and a copolymer of a para-substituted polyamide.

Images