Preparation process and application of crosslinkable polyamide elastomer

Abstract

The invention discloses a preparation process and application of a crosslinkable polyamide elastomer, and belongs to the technical field of nylon elastomer preparation. The process comprises the following steps: S1, by taking butadiene as a raw material, carrying out dimerization reaction to prepare vinyl cyclohexene; s2, carrying out selective epoxidation reaction on vinyl cyclohexene in the presence of an oxidizing agent to obtain a product of single epoxidation on intracyclic double bonds; s3, carrying out hydrogenation on vinyl cyclohexene to obtain cyclohexanol with an ethyl side chain; s4, further dehydrogenating the cyclohexanol with the ethyl side chain in the previous step to obtain ethyl substituted cyclohexanone; the density of the prepared nylon elastomer with the side chain is lower than that of a conventional nylon elastomer with the same carbon number, and the nylon elastomer is more suitable for preparing a low-density foaming material; the chain segment of the prepared nylon elastomer contains crosslinkable sites, and the nylon elastomer can be formed through chemical foaming, so that the application range of the nylon elastomer is greatly expanded, and the problem of low tearing strength is also solved.

Description

Technical Field

[0001] The invention specifically relates to a preparation process and application of a cross-linkable polyamide elastomer, and belongs to the technical field of nylon elastomer preparation. Background Art

[0002] Nylon elastomer is one of the main raw materials for foaming midsoles of high-end sports shoes. It has the characteristics of low density and good rebound, and is favored by major domestic and foreign brand sports shoe manufacturers. Existing nylon elastomers such as Chinese patent publication number: CN116444847A disclose nylon elastomer foam beads and their preparation method and application. The raw materials for forming the nylon elastomer foam beads include: nylon elastomer, tackifier, nucleating agent, antioxidant, homogenizing agent and physical foaming agent; the nylon elastomer foam beads have stable performance and high processing efficiency, and there is no problem of chemical degradation and yellowing of the nylon elastomer caused by long-term boiling water treatment; conventional nylon elastomers are linear molecules and cannot be cross-linked. Beads are mainly prepared by supercritical foaming and then steam-formed. They are rarely used for chemical foaming, which greatly limits their application; the non-cross-linkable characteristic also leads to low tear strength of nylon elastomer beads, and the midsole after molding is prone to bead shedding. Summary of the invention

[0003] To solve the above problems, the present invention proposes a preparation process and application of a cross-linkable polyamide elastomer, designs and synthesizes a lactam with a side chain, prepares a polyamide segment with a side chain by ring-opening polymerization, and then reacts with a soft segment to prepare a polyamide elastomer with a side chain. During chemical foaming, the side chain serves as a cross-linking site.

[0004] The process for preparing the crosslinkable polyamide elastomer of the present invention is as follows: S1: Using butadiene as raw material, vinyl cyclohexene is prepared through dimerization reaction; S2: selectively epoxidizing vinylcyclohexene in the presence of an oxidant to obtain a product monoepoxidized on the double bond in the ring; S3: hydrogenating the product obtained in the second step to obtain cyclohexanol with an ethyl side chain; S4: further dehydrogenating the cyclohexanol with an ethyl side chain obtained in the previous step to obtain ethyl-substituted cyclohexanone; S5: subjecting the ethyl-substituted cyclohexanone to an oximation-rearrangement reaction to obtain an ethyl-substituted caprolactam; S6: Ethyl-substituted caprolactam is subjected to ring-opening polymerization and carboxyl end-capping to prepare a nylon segment with ethyl side chains and carboxyl groups at both ends; S7: The nylon segment is subjected to polycondensation reaction with a diol or a diamine to prepare a nylon elastomer.

[0005] Furthermore, the reactant in S2 is vinylcyclohexene; the oxidant in S2 is an organic peroxide, preferably one or more of EBHP, TBHP or CHP; the reaction temperature in S2 is 70-100° C.; and the reaction pressure in S2 is 1-4 bar.

[0006] Furthermore, the hydrogenation in S3 is completed by a hydrogenation reactor, which is a fixed bed reactor; the reaction pressure in S3 is 12-16 MPa; the cyclohexanol with ethyl side chains in S3 needs to be purified by distillation; the purity range of the cyclohexanol with ethyl side chains in S3 is 90-100%, and the preferred purity range is 95-99.5%.

[0007] Furthermore, the dehydrogenation reaction temperature in S4 is 200-240° C.; the dehydrogenation reaction pressure in S4 is 2-3 bar; the ethyl-substituted cyclohexanone in S4 needs to be purified by distillation; the purity range of the ethyl-substituted cyclohexanone in S4 is 90-100%, preferably 95-99.5%.

[0008] Furthermore, the oximation reaction temperature of S5 is 60-100°C; the oximation reaction pressure of S5 is 1-10 bar; the oximation reaction product ketoxime of S5 needs to be purified by distillation; the purity range of the oximation reaction product ketoxime of S5 is 90-100%, and the preferred purity range is 95-99.5%; the rearrangement reaction of S5 is a normal pressure reaction, and the neutralization pH value is 6~7 after the reaction is completed; the catalyst used in the rearrangement reaction of S5 is an acidic catalyst, preferably one of concentrated sulfuric acid, concentrated hydrochloric acid, phosphoric acid, and concentrated nitric acid; the rearrangement reaction product ethyl-substituted caprolactam of S5 needs to be purified by distillation; the purity range of the rearrangement reaction product ethyl-substituted caprolactam of S5 is 90-100%, and the preferred purity range is 95-99.5%.

[0009] Furthermore, the ring-opening polymerization reaction temperature of S6 is 220-280°C; the ring-opening polymerization reaction pressure of S6 is 15-30bar; the end-capping agent of S6 is one or more of succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid; the ratio of the end-capping agent to the gram weight of ethyl-substituted caprolactam is 1~3:10.

[0010] Furthermore, the diol described in S7 is polytetrahydrofuran diol, polyether polyol, polyester polyol, or polycarbonate polyol; the diamine described in S7 is polyether amine; the ratio of the gram weight of the diol or diamine described in S7 to the nylon segment is 0.3~3:1, the polycondensation reaction temperature described in S7 is 200-250°C; the polycondensation reaction pressure described in S7 is from normal pressure to an absolute pressure of 500Pa; the polycondensation reaction catalyst described in S7 is one or more mixtures of an organic titanium series, an organic tin series, or an organic cobalt series; and the catalyst addition amount is 0.01-3wt% based on the total mass of the diol or diamine and the nylon segment.

[0011] An application of a cross-linkable polyamide elastomer, a nylon elastomer prepared by a cross-linkable polyamide elastomer preparation process, characterized in that the nylon elastomer is used as a base polymer to prepare a foaming material.

[0012] Furthermore, the preparation process of the foaming material is as follows: nylon elastomer, cross-linking agent, foaming agent, auxiliary agent and filler are mixed and foamed, wherein the cross-linking agent is a peroxide cross-linking agent, and the weight ratio of the cross-linking agent to the nylon elastomer is 1~5:100; the foaming agent is one or more of sodium bicarbonate, azo compounds, semicarbazide compounds and nitroso compounds, and the weight ratio of the foaming agent to the nylon elastomer is 1~5:100; the cross-linking foaming temperature is equal to or higher than the melting point of the nylon elastomer.

[0013] Furthermore, the foaming material is applied to the foaming material of sports shoes.

[0014] Compared with the prior art, the preparation process and application of the cross-linkable polyamide elastomer of the present invention have the following advantages: 1. The prepared nylon elastomer with side chains has a lower density than conventional nylon elastomers with the same carbon number, which can reach 1.03-1.05g / cm 3 , more suitable for preparing low-density foaming materials; the hardness is adjustable between 25D-70D, and the melting point is adjustable between 120-190℃.

[0015] 2. The prepared nylon elastomer chain segments contain cross-linkable sites and can be formed by chemical foaming, which greatly expands the application range of nylon elastomers and solves the problem of low tear strength.

[0016] 3. The prepared nylon elastomer has a special segment structure and is suitable for preparing high-performance foam materials in the chemical foaming process. The density of the prepared foam material after molding is 0.10-0.12g / cm 3 , rebound greater than 70%, extremely low compression deformation, excellent stretching, delamination and tearing properties, can improve the stability and balance of sports shoes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the synthesis principle of the nylon elastomer of the present invention.

[0018] Figure 2 The figure is a schematic diagram of the preparation process of the nylon elastomer of the present invention. DETAILED DESCRIPTION

[0019] like Figure 1 and Figure 2 As shown, the preparation process of the cross-linkable polyamide elastomer of the present invention is as follows: S1: Using butadiene as raw material, vinyl cyclohexene is prepared through dimerization reaction; S2: selectively epoxidizing vinylcyclohexene in the presence of an oxidant to obtain a product monoepoxidized on the double bond in the ring; S3: hydrogenating the product obtained in the second step to obtain cyclohexanol with an ethyl side chain; S4: further dehydrogenating the cyclohexanol with an ethyl side chain obtained in the previous step to obtain ethyl-substituted cyclohexanone; S5: subjecting the ethyl-substituted cyclohexanone to an oximation-rearrangement reaction to obtain an ethyl-substituted caprolactam; S6: Ethyl-substituted caprolactam is subjected to ring-opening polymerization and carboxyl end-capping to prepare a nylon segment with ethyl side chains and carboxyl groups at both ends; S7: The nylon segment is subjected to polycondensation reaction with a diol or a diamine to prepare a nylon elastomer.

[0020] The reactant in S2 is vinylcyclohexene; the oxidant in S2 is an organic peroxide, preferably one or more of EBHP, TBHP or CHP; the reaction temperature in S2 is 70-100° C.; the reaction pressure in S2 is 1-4 bar.

[0021] The hydrogenation in S3 is completed by a hydrogenation reactor, which is a fixed bed reactor; the reaction pressure in S3 is 12-16MPa; the cyclohexanol with ethyl side chains in S3 needs to be purified by distillation; the purity range of the cyclohexanol with ethyl side chains in S3 is 90-100%, and the preferred purity range is 95-99.5%.

[0022] The dehydrogenation reaction temperature in S4 is 200-240° C.; the dehydrogenation reaction pressure in S4 is 2-3 bar; the ethyl-substituted cyclohexanone in S4 needs to be purified by distillation; the purity range of the ethyl-substituted cyclohexanone in S4 is 90-100%, and the preferred purity range is 95-99.5%.

[0023] The oximation reaction temperature of S5 is 60-100°C; the oximation reaction pressure of S5 is 1-10bar; the oximation reaction product ketoxime of S5 needs to be purified by distillation; the purity range of the oximation reaction product ketoxime of S5 is 90-100%, and the preferred purity range is 95-99.5%; the rearrangement reaction of S5 is a normal pressure reaction, and the pH value is neutralized to 6~7 after the reaction; the catalyst used in the rearrangement reaction of S5 is an acidic catalyst, preferably one of concentrated sulfuric acid, concentrated hydrochloric acid, phosphoric acid, and concentrated nitric acid; the rearrangement reaction product ethyl-substituted caprolactam of S5 needs to be purified by distillation; the purity range of the rearrangement reaction product ethyl-substituted caprolactam of S5 is 90-100%, and the preferred purity range is 95-99.5%.

[0024] The ring-opening polymerization reaction temperature of S6 is 220-280°C; the ring-opening polymerization reaction pressure of S6 is 15-30bar; the end-capping agent of S6 is one or more of succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid; the ratio of the end-capping agent to the ethyl-substituted caprolactam by gram weight is 1~3:10.

[0025] The diol described in S7 is polytetrahydrofuran diol, polyether polyol, polyester polyol, polycarbonate polyol; the diamine described in S7 is polyether amine; the ratio of the gram weight of the diol or diamine described in S7 to the nylon segment is 0.3~3:1, the polycondensation reaction temperature described in S7 is 200-250℃; the polycondensation reaction pressure described in S7 is normal pressure to absolute pressure 500Pa; the polycondensation reaction catalyst described in S7 is one or more mixtures of organic titanium series, organic tin series, and organic cobalt series; the catalyst addition amount is 0.01-3wt% based on the total weight of the diol or diamine and the nylon segment.

[0026] An application of a cross-linkable polyamide elastomer, a nylon elastomer prepared by a cross-linkable polyamide elastomer preparation process, and a foaming material prepared by using the nylon elastomer as a base polymer.

[0027] The foaming material preparation process is as follows: nylon elastomer, crosslinking agent, foaming agent, auxiliary agent and filler are mixed and foamed, wherein the crosslinking agent is a peroxide crosslinking agent, and the weight ratio of the crosslinking agent to the nylon elastomer is 1-5:100; the foaming agent is one or more of sodium bicarbonate, azo compounds, semicarbazide compounds and nitroso compounds, and the weight ratio of the foaming agent to the nylon elastomer is 1-5:100; the crosslinking foaming temperature is equal to or higher than the melting point of the nylon elastomer.

[0028] The foaming material is used in footwear, cushions, seats, mattresses and the like.

[0029] Embodiment 1: The process for preparing the crosslinkable polyamide elastomer of the present invention is as follows: S1: Using butadiene as raw material, vinyl cyclohexene is prepared through dimerization reaction; S2: subjecting vinylcyclohexene to a selective epoxidation reaction in the presence of an oxidant to obtain a product monoepoxidized on the double bond within the ring, i.e., monoepoxidized vinylcyclohexene; S3: hydrogenating the product obtained in S2 to obtain cyclohexanol with an ethyl side chain; S4: further dehydrogenating the cyclohexanol with an ethyl side chain obtained in the previous step to obtain ethyl-substituted cyclohexanone; S5: subjecting the ethyl-substituted cyclohexanone to an oximation-rearrangement reaction to obtain an ethyl-substituted caprolactam; S6: Ethyl-substituted caprolactam was subjected to ring-opening polymerization to prepare nylon segments with ethyl side chains and carboxyl groups at both ends; S7: The nylon segment is subjected to polycondensation reaction with a diol or a diamine to prepare a nylon elastomer.

[0030] The S2 is specifically as follows: using vinyl cyclohexene as a substrate and an organic peroxide as an oxidant, controlling the reaction temperature at 75°C with a temperature fluctuation range of 5°C, controlling the pressure at 1.5 bar with a pressure fluctuation range of 0.5 bar, selectively oxidizing the double bond on the ring to obtain a product of monocyclic oxidation on the double bond in the ring, namely vinyl cyclohexane oxide; Specifically, S3 comprises: performing fixed-bed hydrogenation of vinyl cyclohexene oxide under the condition of 14 MPa and a pressure fluctuation value range of 2 MPa to obtain cyclohexanol with an ethyl side chain, namely, ethyl cyclohexanol, and performing distillation separation and purification; the hydrogenation in S3 is completed by a hydrogenation reactor, and the hydrogenation reactor is a fixed-bed reactor; the purity range of the cyclohexanol with an ethyl side chain in S3 is 95%, and the purity fluctuation value is 4%; The dehydrogenation reaction temperature in S4 is 235°C, the temperature fluctuation range is 5°C, the dehydrogenation reaction pressure is 2.5 bar, the pressure fluctuation range is 0.5 bar, the ethyl-substituted cyclohexanone in S4 needs to be purified by distillation; the purity range of the ethyl-substituted cyclohexanone in S4 is 95%, and the purity fluctuation value is 4%; The oximation reaction temperature of S5 is 70°C, the temperature fluctuation range is 10°C, the oximation reaction pressure is 2.5 bar, the pressure fluctuation range is 0.5 bar, and the oximation reaction product ketoxime needs to be purified by distillation; the purity range of the oximation reaction product ketoxime of S5 is 95%, and the purity fluctuation value is 4%; the rearrangement reaction of S5 is a normal pressure reaction, and the neutralization pH value after the reaction is 6.5, and the pH fluctuation value is 0.5; the catalyst used in the rearrangement reaction of S5 is concentrated sulfuric acid; the rearrangement reaction product ethyl substituted caprolactam of S5 needs to be purified by distillation; the purity range of the rearrangement reaction product ethyl substituted caprolactam of S5 is 95%, and the purity fluctuation value is 4%; The S6 and S7 are as follows: ethyl-substituted caprolactam reacts in the presence of water and adipic acid to obtain a nylon segment with a side chain and carboxyl end-capping, the reaction temperature is 250°C, the temperature fluctuation range is 30°C, the pressure is 22 bar, the pressure fluctuation range is 7 bar, polytetrahydrofuran polyol is continuously added, and under the action of a catalyst, a nylon elastomer with a side chain is obtained by polycondensation; the end-capping agent in S6 is adipic acid; the weight ratio of the end-capping agent to the ethyl-substituted caprolactam is 2:10; the diol in S7 is polytetrahydrofuran diol; the diamine in S7 is polyetheramine; the weight ratio of the diol or diamine in S7 to the nylon segment is 1.6:1, the polycondensation reaction temperature in S7 is 225°C, and the temperature fluctuation range is 25°C; the polycondensation reaction pressure in S7 is from normal pressure to an absolute pressure of 500Pa; The polycondensation reaction catalyst in S7 is an organic titanium series; the catalyst addition amount is 0.1wt% based on the total mass of the added diol or diamine and the nylon segment.

[0031] An application of a cross-linkable polyamide elastomer, a nylon elastomer prepared by a cross-linkable polyamide elastomer preparation process, and a foaming material prepared by using the nylon elastomer as a base polymer.

[0032] The foaming material preparation process is as follows: nylon elastomer, crosslinking agent, foaming agent, auxiliary agent and filler are mixed and foamed, wherein the crosslinking agent is a peroxide crosslinking agent, and the weight ratio of the crosslinking agent to the nylon elastomer is 3:100; the foaming agent is one or more of sodium bicarbonate, azo compounds, semicarbazide compounds and nitroso compounds, and the weight ratio of the foaming agent to the nylon elastomer is 3:100; the crosslinking foaming temperature is equal to or higher than the melting point of the nylon elastomer.

[0033] Embodiment 2: The process for preparing the crosslinkable polyamide elastomer of the present invention is as follows: S1. Using butadiene as a raw material, vinyl cyclohexene is prepared through dimerization reaction; The second step is to selectively epoxidize vinylcyclohexene in the presence of an oxidant to obtain a product that is monoepoxidized on the double bond in the ring; The third step is to hydrogenate vinyl cyclohexene to obtain cyclohexanol with an ethyl side chain; Step 4: further dehydrogenate the cyclohexanol with an ethyl side chain obtained in the previous step to obtain ethyl-substituted cyclohexanone; Step 5, subjecting the ethyl-substituted cyclohexanone to an oximation-rearrangement reaction to obtain an ethyl-substituted caprolactam; Step 6: The ethyl-substituted caprolactam is subjected to ring-opening polymerization to prepare a nylon fragment with ethyl side chains and carboxyl groups at both ends; Step 7: react the nylon fragment with diol to prepare a nylon elastomer.

[0034] The second step is as follows: S2 is as follows: using vinyl cyclohexene as a substrate and an organic peroxide as an oxidant, controlling the reaction temperature at 95°C with a temperature fluctuation range of 5°C, controlling the pressure at 2.5 bar with a pressure fluctuation range of 0.5 bar, selectively oxidizing the double bond on the ring to obtain a product of monocyclic oxidation on the double bond in the ring, namely vinyl cyclohexane oxide; S3 specifically comprises: performing fixed bed hydrogenation of vinyl cyclohexene oxide under the condition of 14 MPa and a pressure fluctuation value range of 2 MPa to obtain cyclohexanol with an ethyl side chain, namely, ethyl cyclohexanol, and performing distillation separation and purification; the hydrogenation in S3 is completed by a hydrogenation reactor, and the hydrogenation reactor is a fixed bed reactor; the purity range of the cyclohexanol with an ethyl side chain in S3 is 95%, and the purity fluctuation value is 4%; The dehydrogenation reaction temperature in S4 is 225°C, the temperature fluctuation range is 5°C, the dehydrogenation reaction pressure is 1.5 bar, the pressure fluctuation range is 0.5 bar, the ethyl-substituted cyclohexanone in S4 needs to be purified by distillation; the purity range of the ethyl-substituted cyclohexanone in S4 is 95%, and the purity fluctuation value is 4%; The oximation reaction temperature of S5 is 90°C, the temperature fluctuation range is 10°C, the oximation reaction pressure is 8bar, the pressure fluctuation range is 2bar, and the oximation reaction product ketoxime needs to be purified by distillation; the purity range of the oximation reaction product ketoxime of S5 is 95%, and the purity fluctuation value is 4%; the rearrangement reaction of S5 is a normal pressure reaction, and the neutralization pH value after the reaction is 6.5, and the pH fluctuation value is 0.5; the catalyst used in the rearrangement reaction of S5 is concentrated sulfuric acid; the rearrangement reaction product ethyl substituted caprolactam of S5 needs to be purified by distillation; the purity range of the rearrangement reaction product ethyl substituted caprolactam of S5 is 95%, and the purity fluctuation value is 4%; The S6 and S7 are specifically as follows: ethyl-substituted caprolactam reacts in the presence of water and adipic acid to obtain nylon segments with side chains and carboxyl end-capping, the reaction temperature is 250°C, the temperature fluctuation range is 30°C, the pressure is 22 bar, the pressure fluctuation range is 7 bar, and polyetheramine is continuously added without using a catalyst to obtain a nylon elastomer with side chains by condensation.

[0035] The nylon elastomers prepared in Example 1 and Example 2 have side chains and a lower density than conventional nylon elastomers with the same carbon number, which can reach 1.03-1.05 g / cm 3 , more suitable for preparing low-density foaming materials; the hardness is adjustable between 25D-70D, and the melting point is adjustable between 120-190℃; the prepared nylon elastomer has a special segment structure and is suitable for preparing high-performance foam materials by chemical foaming process. The prepared foam material has a density of 0.10-0.12g / cm after molding 3 , the rebound is greater than 70%.

[0036] The above embodiments are only preferred implementations of the present invention, so any equivalent changes or modifications made according to the structures, features and principles described in the scope of application of the present invention are included in the scope of application of the present invention.

Claims

1. A process for preparing a cross-linkable polyamide elastomer, characterized in that: The process is as follows: S1: Using butadiene as raw material, vinyl cyclohexene is prepared through dimerization reaction; S2: selectively epoxidizing vinylcyclohexene in the presence of an oxidant to obtain a product monoepoxidized on the double bond in the ring; S3: hydrogenating the product obtained in the second step to obtain cyclohexanol with an ethyl side chain; S4: further dehydrogenating the cyclohexanol with an ethyl side chain obtained in the previous step to obtain ethyl-substituted cyclohexanone; S5: subjecting the ethyl-substituted cyclohexanone to an oximation-rearrangement reaction to obtain an ethyl-substituted caprolactam; S6: Ethyl-substituted caprolactam is subjected to ring-opening polymerization and carboxyl end-capping to prepare a nylon segment with ethyl side chains and carboxyl groups at both ends; S7: The nylon segment is subjected to polycondensation reaction with a diol or a diamine to prepare a nylon elastomer.

2. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The reactant in S2 is vinylcyclohexene; the oxidant in S2 is an organic peroxide, preferably one or more of EBHP, TBHP or CHP; the reaction temperature in S2 is 70-100° C.; the reaction pressure in S2 is 1-4 bar.

3. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The hydrogenation in S3 is completed by a hydrogenation reactor, which is a fixed bed reactor; the reaction pressure in S3 is 12-16MPa; the cyclohexanol with ethyl side chains in S3 needs to be purified by distillation; the purity range of the cyclohexanol with ethyl side chains in S3 is 90-100%, and the preferred purity range is 95-99.5%.

4. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The dehydrogenation reaction temperature in S4 is 200-240° C.; the dehydrogenation reaction pressure in S4 is 2-3 bar; the ethyl-substituted cyclohexanone in S4 needs to be purified by distillation; the purity range of the ethyl-substituted cyclohexanone in S4 is 90-100%, and the preferred purity range is 95-99.5%.

5. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The oximation reaction temperature of S5 is 60-100°C; the oximation reaction pressure of S5 is 1-10bar; the oximation reaction product ketoxime of S5 needs to be purified by distillation; the purity range of the oximation reaction product ketoxime of S5 is 90-100%, and the preferred purity range is 95-99.5%; the rearrangement reaction of S5 is a normal pressure reaction, and the pH value is neutralized to 6~7 after the reaction; the catalyst used in the rearrangement reaction of S5 is an acidic catalyst, preferably one of concentrated sulfuric acid, concentrated hydrochloric acid, phosphoric acid, and concentrated nitric acid; the rearrangement reaction product ethyl-substituted caprolactam of S5 needs to be purified by distillation; the purity range of the rearrangement reaction product ethyl-substituted caprolactam of S5 is 90-100%, and the preferred purity range is 95-99.5%.

6. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The ring-opening polymerization reaction temperature of S6 is 220-280°C; the ring-opening polymerization reaction pressure of S6 is 15-30bar; the end-capping agent of S6 is one or more of succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid; the ratio of the end-capping agent to the ethyl-substituted caprolactam by gram weight is 1~3:

10.

7. The process for preparing a cross-linkable polyamide elastomer according to claim 1, characterized in that: The diol described in S7 is polytetrahydrofuran diol, polyether polyol, polyester polyol, polycarbonate polyol; the diamine described in S7 is polyether amine; the ratio of the gram weight of the diol or diamine described in S7 to the nylon segment is 0.3~3:1, the polycondensation reaction temperature described in S7 is 200-250℃; the polycondensation reaction pressure described in S7 is normal pressure to absolute pressure 500Pa; the polycondensation reaction catalyst described in S7 is one or more mixtures of organic titanium series, organic tin series, and organic cobalt series; the catalyst addition amount is 0.01-3wt% based on the total weight of the diol or diamine and the nylon segment.

8. An application of a cross-linkable polyamide elastomer, a nylon elastomer prepared by the cross-linkable polyamide elastomer preparation process according to any one of claims 1 to 7, characterized in that: The nylon elastomer is used as a base polymer to prepare a foamed material.

9. The use of the cross-linkable polyamide elastomer according to claim 8, characterized in that: The foaming material preparation process is as follows: nylon elastomer, crosslinking agent, foaming agent, auxiliary agent and filler are mixed and foamed, wherein the crosslinking agent is a peroxide crosslinking agent, and the weight ratio of the crosslinking agent to the nylon elastomer is 1-5:100; the foaming agent is one or more of sodium bicarbonate, azo compounds, semicarbazide compounds and nitroso compounds, and the weight ratio of the foaming agent to the nylon elastomer is 1-5:100; the crosslinking foaming temperature is equal to or higher than the melting point of the nylon elastomer.

10. The use of the cross-linkable polyamide elastomer according to claim 8, characterized in that: The foaming material is applied to the foaming material of sports shoes.

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