Hydrophobic nylon elastomer and preparation method thereof

Abstract

The invention provides a hydrophobic nylon elastomer and a preparation method thereof. The method comprises the following steps: preparing a dicarboxyl-terminated nylon hard segment; carrying out esterification reaction on the dicarboxyl-terminated nylon hard segment, polyether polyol and a single-acid end-capping reagent to prepare a nylon elastomer of which the tail end is monocarboxyl; and reacting the monocarboxyl terminated nylon elastomer with epoxidized vegetable oil to generate a multi-arm nylon elastomer and epoxidized vegetable oil copolymer, namely the hydrophobic nylon elastomer. The hydrophobic nylon elastomer prepared by the invention has higher molecular weight, and meanwhile, a flexible hydrophobic chain segment is introduced, so that a high-toughness material is kept, the water absorption rate is very low, and the hydrophobic nylon elastomer has better dimensional stability.

Description

Technical Field

[0001] The present invention relates to the field of nylon materials, and in particular to a hydrophobic nylon elastomer and a preparation method thereof. Background Art

[0002] Thermoplastic elastomer is a polymer material between resin and rubber, which takes into account the characteristics of both and has been widely used in various industries. Nylon elastomer is the material at the top of the pyramid of thermoplastic elastomers. It is a block copolymer synthesized from highly crystalline nylon as the hard segment and flexible polyether polyol or polyester polyol as the soft segment. It is a regular AB type block copolymer with high resilience, low temperature resistance, and anti-aging properties. It is widely used in footwear, sports equipment, antistatic agents, medical catheters, industrial parts and other fields. However, since its soft segment is made of polyether polyol or polyester polyol, which is a hydrophilic group, the polymerized nylon elastomer has a high water absorption rate and poor dimensional stability, which limits its scope of application.

[0003] CN113024802B discloses a thermoplastic nylon elastomer containing an amorphous nylon segment with a pyrrolidone structure, which replaces the polyether polyol or polyester polyol of the soft segment of the conventional nylon elastomer with an amorphous nylon segment containing a pyrrolidone structure to improve the high water absorption of the nylon elastomer. The nylon elastomer of this patent is essentially different from the conventional nylon elastomer. The soft segment is changed from a polyether straight chain to an amorphous nylon segment containing a heterocycle, and its performance is inevitably affected, such as rebound and compression distortion will become worse, thereby limiting its application range.

[0004] In summary, the nylon elastomers currently prepared from polyether polyols or polyester polyols still have the problem of high water absorption, and after switching to other soft segments, the performance is greatly affected, thus limiting its scope of application. This problem needs to be solved urgently. Summary of the invention

[0005] In order to overcome the problems of the prior art, one of the objects of the present invention is to provide a method for preparing a hydrophobic nylon elastomer. The material prepared by the method has a very low water absorption rate and good dimensional stability while maintaining a high molecular weight and good toughness.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A method for preparing a hydrophobic nylon elastomer, the method comprising the following steps:

[0008] S1: Preparation of dicarboxyl terminated nylon hard segment;

[0009] S2: esterification of a dicarboxyl-terminated nylon hard segment, a polyether polyol and a monoacid end-capping agent to prepare a nylon elastomer with a monocarboxyl terminal;

[0010] S3: The monocarboxyl-terminated nylon elastomer and the epoxidized vegetable oil react to form a multi-arm nylon elastomer-epoxidized vegetable oil copolymer, namely, a hydrophobic nylon elastomer.

[0011] The method of the present invention can effectively reduce the water absorption rate of the material by introducing hydrophobic multi-arm epoxy vegetable oil, while increasing its polymerization degree and reducing the polymerization difficulty of nylon elastomer. In addition, the epoxy vegetable oil itself has a flexible chain break and does not change the characteristics of the nylon elastomer as a high-toughness material.

[0012] In one embodiment of the present invention, the dicarboxyl-terminated nylon in S1 is prepared by reacting a nylon hard segment and a dibasic acid; preferably, the number average molecular weight of the dicarboxyl-terminated nylon is 500-5000; preferably, the nylon hard segment is nylon prepared from C4-C24 raw materials, preferably one or more of nylon 6, nylon 66, nylon 56, nylon 610, nylon 510, nylon 612, nylon 614, nylon 512, nylon 1010, nylon 1012, nylon 1212, nylon 11, and nylon 12; preferably, the dibasic acid is a C4-C20 acid, preferably one or more of adipic acid, sebacic acid, undecane dioic acid, dodecanedioic acid, tridecanedioic acid, and tetradecanedioic acid.

[0013] In one embodiment of the present invention, the polyether polyol described in S2 is a polyether polyol having a repeating unit of C2-C8, preferably one or more of polyethylene glycol, polypropylene glycol, and polybutylene glycol.

[0014] In one embodiment of the present invention, the monoacid capping agent in S2 is C x H 2x O2 monocarboxylic acid, wherein x is an integer from 1 to 16, preferably an integer from 2 to 6.

[0015] In one embodiment of the present invention, the molecular weight of the nylon elastomer with a single carboxyl terminal described in S2 is 5000-30,000.

[0016] In one embodiment of the present invention, the S2 esterification reaction is carried out at a vacuum absolute pressure of ≤500 PaA for 2-10 h.

[0017] In one embodiment of the present invention, a catalyst is added in S2; preferably the catalyst is a metal alkoxide M(OR) n , wherein M is a transition metal element, preferably one or more of Sb, Ti, Zr, and Ge, R is a C1-C10 alkyl group, and n is an integer of 1-4, preferably an integer of 2-4; preferably, the amount of catalyst added is 0.01wt%-0.3wt% of the total of the carboxyl-terminated nylon hard segment, the polyether polyol, and the monoacid end-capping agent.

[0018] In the present invention, various common additives can be added, for example, antioxidants, ultraviolet absorbers and other additives can be added to S2; based on the total mass of the dicarboxyl-terminated nylon hard segment, polyether polyol and monoacid end-capping group as 100%, the amount of the additive added is 0.01wt%-0.3wt%. The addition of additives is well known in the art.

[0019] In one embodiment of the present invention, the epoxidized vegetable oil in S3 is an epoxidized oil compound, preferably one or more of epoxidized soybean oil, epoxidized castor oil, and epoxidized corn oil.

[0020] In one embodiment of the present invention, the ratio of the molar number of carboxyl groups of the monocarboxyl-terminated nylon elastomer in S3 to the molar number of epoxy groups of the epoxidized vegetable oil is (0.95-1.05):1.

[0021] In one embodiment of the present invention, the reaction conditions of S3 are 160-260° C. and the reaction time is 1-6 h.

[0022] In one embodiment of the present invention, a catalyst is added in S3; preferably, the catalyst is a nitrogen-containing heterocyclic compound, preferably an imidazole catalyst; preferably, the amount of catalyst added is 0.01wt%-0.1wt% of the total of the monocarboxyl-terminated nylon elastomer and the epoxidized vegetable oil.

[0023] Another object of the present invention is to provide a hydrophobic nylon elastomer.

[0024] A hydrophobic nylon elastomer, the elastomer is prepared by the above method, and the hydrophobic nylon elastomer is a multi-arm nylon elastomer epoxy vegetable oil copolymer. This polymer structure is also expressed as ABz, wherein A represents epoxy vegetable oil, B represents nylon elastomer, and z represents the number of nylon elastomers in a segment, that is, the number of multi-arms, and z is ≥2. Taking epoxy soybean oil, nylon 12 elastomer and their products as examples, the structural formula is shown as follows:

[0025] Epoxidized soybean oil

[0026]

[0027] The monocarboxyl-terminated nylon elastomer is produced by the reaction of dicarboxyl-terminated nylon, polyethylene glycol, and acetic acid, as shown below:

[0028]

[0029] The structural formula of the multi-arm nylon elastomer epoxy soybean oil copolymer generated by the reaction of epoxy soybean oil and monocarboxyl terminated nylon elastomer is shown in FIG.

[0030] As shown below:

[0031]

[0032] Another object of the present invention is to provide a use of a hydrophobic nylon elastomer.

[0033] A use of a hydrophobic nylon elastomer, the elastomer is prepared by the above method, or is the above elastomer, and the elastomer is used for waterproof shoes, food packaging, cable sheaths, and sports goods.

[0034] Compared with the prior art, the present invention has the following positive effects:

[0035] By introducing hydrophobic multi-arm epoxy vegetable oil, the water absorption rate of the material can be effectively reduced, and a hydrophobic nylon elastomer can be prepared. At the same time, the multi-arm structure increases its degree of polymerization and reduces the difficulty of polymerization of the nylon elastomer. In addition, the epoxy vegetable oil itself is a flexible chain and does not change the characteristics of the nylon elastomer as a high-toughness material. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a contact angle test diagram of the nylon elastomer resin prepared in Example 1;

[0037] Figure 2 This is a contact angle test diagram of the nylon elastomer resin prepared in Comparative Example 1;

[0038] Figure 3 The infrared spectra of epoxidized soybean oil, monocarboxyl terminated nylon elastomer and hydrophobic nylon elastomer resin 1 are shown in FIG. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present invention, the content of the present invention is further described below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments;

[0040] The following test methods are used in each example of the present invention:

[0041] (1) Contact angle test method: GB / T 30693-2014 standard is adopted, and the equipment is an optical contact angle measuring instrument;

[0042] (2) Water absorption test method: ISO62 standard, immersion conditions: 23°C, 24h;

[0043] (3) Elongation at break test method: ISO527 standard, universal testing machine, tensile rate 500 mm / min;

[0044] (4) Infrared test method: GB / T 6040 standard is adopted, the test instrument is Fourier total reflection infrared spectrometer, and the scanning parameter wavelength is set to 500~4000cm -1 Measure its absorption curve below.

[0045] The raw materials used in the following examples and comparative examples are all commercial chemicals with industrial grade purity, wherein the epoxy equivalent of epoxidized soybean oil is 267, the epoxy equivalent of epoxidized corn oil is 271, and the epoxy equivalent of epoxidized castor oil is 284.

[0046] Product Name factory Specification Epoxy equivalent Epoxidized soybean oil Zibo Kailian Chemical Co., Ltd. Industrial Grade 267 Epoxidized corn oil Zibo Kailian Chemical Co., Ltd. Industrial Grade 271 Epoxy castor oil Zibo Kailian Chemical Co., Ltd. Industrial Grade 284 Polyether polyols BASF SE Industrial Grade / Monoacid Shandong Unite Industrial Grade / Dibasic Acid Shenma Shares Industrial Grade / Imidazole Jiangsu Kanglejia Industrial Grade / Esterification catalyst Shandong Oriental Sunrise Industrial Grade /

[0047] Example 1

[0048] (1) 5.55 kg of laurolactam, 1.65 kg of dodecanedioic acid, and 6 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 290° C. and a pressure of 4.2 MPaG for 2 h to obtain a dicarboxyl-terminated nylon 12 hard segment with a number average molecular weight of 1000;

[0049] (2) 5 kg of the dicarboxyl-terminated nylon 12 hard segment prepared in step (1), 5 kg of polyethylene glycol (PEG-1000), 60 g of acetic acid, 10 g of ethylene glycol antimony and 10 g of antioxidant (1098) were placed in a polymerization reactor and replaced with nitrogen three times. The temperature was then raised to 270° C. and the absolute pressure was controlled at 100 PaA for 6 h to prepare a monocarboxyl-terminated nylon elastomer having a number average molecular weight of 10,000.

[0050] (3) 20 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 534 g of epoxy soybean oil, and 10.267 g of N,N-carbonyldiimidazole were added into a reactor, and the polymerization reactor was purged with nitrogen for 3 times. Then, stirring was started and the temperature was raised to 220° C. After reacting for 3 hours, a hydrophobic nylon elastomer resin 1 was obtained through the discharge port.

[0051] Example 2

[0052] (1) 7.4 kg of laurolactam, 2.7 kg of adipic acid, and 8 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 300° C. and a pressure of 4.5 MPaG for 6 h to obtain a dicarboxyl-terminated nylon 12 hard segment with a number average molecular weight of 500;

[0053] (2) 5 kg of the dicarboxyl-terminated nylon 12 hard segment prepared in step (1), 5 kg of polybutylene glycol (PTMG-500), 46 g of formic acid, 1 g of zirconium n-propoxide, and 20 g of antioxidant (1010) were placed in a polymerization reactor and replaced with nitrogen three times. After nitrogen replaced the polymerization reactor three times, stirring was started and the temperature was raised to 280° C., and the vacuum was evacuated to an absolute pressure of 50 PaA. The reaction was reacted for 2 h to prepare a monocarboxyl-terminated nylon elastomer with a molecular weight of 5000;

[0054] (3) 10 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 542 g of epoxy corn oil, and 10.542 g of 1-methylimidazole were put into a reactor, and the polymerization reactor was substituted with nitrogen for 3 times. Then, stirring was started and the temperature was raised to 160° C. After reacting for 6 hours, a hydrophobic nylon elastomer resin 2 was obtained through the discharge port.

[0055] Example 3

[0056] (1) 4.641 kg of decanediamine, 6.681 kg of dodecanedioic acid, and 8 kg of water were reacted in a polymerization reactor at a temperature of 210° C. and a pressure of 1.8 MPaG for 9 hours to obtain a dicarboxyl-terminated nylon 1012 hard segment with a number average molecular weight of 5000;

[0057] (2) 15 kg of the dicarboxyl-terminated nylon 1012 hard segment prepared in step (1), 6 kg of polypropylene glycol (PPG-2000), 256 g of hexadecanoic acid, 63.6 g of tetraethyl germanium, and 10 g of antioxidant (1098) and 10 g of antioxidant (168) were added into a polymerization reactor, and the polymerization reactor was replaced with nitrogen for 3 times, and then stirring was started and the temperature was raised to 220° C., and the absolute pressure was evacuated to 500 PaA, and the reaction was carried out for 10 hours to prepare a monocarboxyl-terminated nylon elastomer with a number average molecular weight of 30,000;

[0058] (3) 2.85 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 284 g of epoxy castor oil, and 0.33 g of 2-ethyl-4-methylimidazole were added to a reaction kettle, and the polymerization reaction kettle was purged with nitrogen for three times. Then, stirring was started and the temperature was raised to 260° C. After reacting for 1 hour, a hydrophobic nylon elastomer resin 3 was obtained through the discharge port.

[0059] Example 4

[0060] (1) 8.6 kg of decanediamine, 13.8 kg of dodecanedioic acid, and 18 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 255° C. and a pressure of 3.2 MPaG for 4 h to obtain a dicarboxyl-terminated nylon 1012 hard segment with a number average molecular weight of 2000;

[0061] (2) 6 kg of the dicarboxyl-terminated nylon 1012 hard segment prepared in step (1), 9 kg of polyethylene glycol (PEG-3000), 172 g of decanoic acid, 15 g of tetrabutyl titanate, 10 g of antioxidant (1098), and 5 g of antioxidant (168) were added into a polymerization reactor. After nitrogen was replaced in the polymerization reactor for 3 times, stirring was started and the temperature was raised to 180° C., and the absolute pressure was evacuated to 80 PaA. The reaction was carried out for 7 h to prepare a monocarboxyl-terminated nylon elastomer with a molecular weight of 15,000.

[0062] (3) 23.625 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 400.5 g of epoxy soybean oil, and 11.45 g of N,N-carbonyldiimidazole were added into a reactor, and the polymerization reactor was purged with nitrogen for 3 times. Then, stirring was started and the temperature was raised to 200° C. After reacting for 4 hours, a hydrophobic nylon elastomer resin 4 was obtained through the discharge port.

[0063] Example 5

[0064] (1) 9.25 kg of lauryl lactam, 2.55 kg of sebacic acid and 11 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 275° C. and a pressure of 3.6 MPaG for 3 h to obtain a dicarboxyl-terminated nylon 12 hard segment with a number average molecular weight of 1000;

[0065] (2) 8 kg of the dicarboxyl-terminated nylon 12 hard segment prepared in step (1), 16 kg of polyethylene glycol (PEG-2000), 88 g of butyric acid, 12 g of tetrabutyl titanate, and 12 g of antioxidant (1098) were added into a polymerization reactor. After nitrogen was replaced in the polymerization reactor for 3 times, stirring was started and the temperature was raised to 265° C., and the absolute pressure was evacuated to 250 PaA. After reacting for 4 hours, a monocarboxyl-terminated nylon elastomer with a number average molecular weight of 24,000 was prepared.

[0066] (3) 24 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 267 g of epoxy soybean oil, and 7.28 g of N,N-carbonyldiimidazole were added into a reactor, and the polymerization reactor was purged with nitrogen for 3 times. Then, stirring was started and the temperature was raised to 240° C. After reacting for 2 h, a hydrophobic nylon elastomer resin 5 was obtained through the discharge port.

[0067] Example 6

[0068] (1) 9.28 kg of hexamethylenediamine, 23.25 kg of tetradecanedioic acid, and 10 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 255° C. and a pressure of 3.2 MPaG for 4 h to obtain a dicarboxyl-terminated nylon 614 hard segment with a number average molecular weight of 3000;

[0069] (2) 12 kg of the dicarboxyl-terminated nylon 614 hard segment prepared in step (1), 4 kg of polyethylene glycol (PEG-1000), 60 g of acetic acid, 32 g of ethylene glycol antimony, 16 g of antioxidant 1098 and 32 g of anti-ultraviolet additive UV312 were added into a polymerization reactor, and the polymerization reactor was replaced with nitrogen for 3 times, and then stirring was started and the temperature was raised to 265° C., and the absolute pressure was evacuated to 20 PaA. After reacting for 4 hours, a single carboxyl-terminated nylon elastomer was prepared, and the molecular weight was 16,000;

[0070] (3) 32 kg of the monocarboxyl-terminated nylon elastomer prepared in step (2), 534 g of epoxy soybean oil, and 22.78 g of N,N-carbonyldiimidazole were added into a reactor, and the polymerization reactor was purged with nitrogen three times. Then, stirring was started and the temperature was raised to 180° C. After reacting for 5 hours, a hydrophobic nylon elastomer resin 6 was obtained through the discharge port.

[0071] The hydrophobic nylon elastomer resins 2-6 prepared in the above examples have contact angles similar to that of the hydrophobic nylon elastomer resin 1. Figure 1 Shown is the contact angle spectrum of hydrophobic nylon elastomer resin 1. Figure 3 The infrared spectra of epoxidized soybean oil, monocarboxyl-terminated nylon elastomer and hydrophobic nylon elastomer resin 1 are shown in Figure 1. -1 The characteristic peak of epoxy group is 1640cm -1 The peak at the center is the characteristic peak of the amide bond. From the attached figure, it can be seen that the characteristic peak of the epoxy group at resin 1 has disappeared, indicating that the monocarboxyl-terminated nylon elastomer has reacted with the epoxy soybean oil to form the hydrophobic nylon elastomer resin 1. The contact angles and infrared spectra of other resins are not listed here one by one.

[0072] Comparative Example 1

[0073] Compared with Example 1, the only difference is that no hydrophobic segment is grafted.

[0074] (1) 5.55 kg of laurolactam, 1.65 kg of dodecanedioic acid, and 6 kg of water were added to a polymerization reactor, and the reaction conditions were a temperature of 290° C. and a pressure of 4.2 MPaG for 2 h to obtain a dicarboxyl-terminated nylon 12 hard segment with a number average molecular weight of 1000;

[0075] (2) 5 kg of the dicarboxyl-terminated nylon 12 hard segment prepared in step (1), 5 kg of polyethylene glycol (PEG-1000), 60 g of acetic acid, 10 g of ethylene glycol antimony and 10 g of antioxidant (1098) were placed in a polymerization reactor and replaced with nitrogen three times. The temperature was then raised to 270° C. and the absolute pressure was controlled at 100 PaA for reaction for 6 hours to obtain a monocarboxyl-terminated nylon elastomer 1-1 having a number average molecular weight of 10,000.

[0076] The contact angle spectrum of the obtained nylon elastomer resin 1-1 is as follows: Figure 2 as shown in .

[0077] The water absorption and elongation at break of the nylon elastomer resin prepared above were tested, and the results are shown in Table 1 below;

[0078] Table 1

[0079] Water absorption (%) Elongation at break (%) Nylon Elastomer Resin 1 1.2 ＞500 Nylon Elastomer Resin 2 0.4 ＞500 Nylon Elastomer Resin 3 0.72 ＞500 Nylon Elastomer Resin 4 1.1 ＞500 Nylon Elastomer Resin 5 1.21 ＞500 Nylon Elastomer Resin 6 0.7 ＞500 Nylon elastomer resin 1-1 35 ＞500

[0080] It can be seen from the data in Table 1 that the nylon elastomer prepared by this method can effectively reduce the water absorption rate of the material, and a hydrophobic nylon elastomer is prepared. At the same time, the multi-arm structure increases its degree of polymerization and reduces the difficulty of polymerization of the nylon elastomer. In addition, the epoxy vegetable oil itself is a flexible chain, which does not change the characteristics of the nylon elastomer as a high-toughness material.

[0081] It is easy to understand that the above embodiments are only examples for clear explanation and do not mean that the present invention is limited thereto. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the present invention.

Claims

1. A method for preparing a hydrophobic nylon elastomer, characterized in that: The method comprises the following steps: S1: Preparation of dicarboxyl terminated nylon hard segment; S2: esterification of a dicarboxyl-terminated nylon hard segment, a polyether polyol and a monoacid end-capping agent to prepare a nylon elastomer with a monocarboxyl terminal; S3: The monocarboxyl-terminated nylon elastomer and the epoxidized vegetable oil react to form a multi-arm nylon elastomer-epoxidized vegetable oil copolymer, namely, a hydrophobic nylon elastomer.

2. The method according to claim 1, characterized in that The dicarboxyl-terminated nylon described in S1 is prepared by reacting a nylon hard segment with a dibasic acid; Preferably, the number average molecular weight of the dicarboxyl-terminated nylon is 500-5000; Preferably, the nylon hard segment is nylon prepared from C4-C24 raw materials, preferably one or more of nylon 6, nylon 66, nylon 56, nylon 610, nylon 510, nylon 612, nylon 614, nylon 512, nylon 1010, nylon 1012, nylon 1212, nylon 11, and nylon 12; Preferably, the dibasic acid is a C4-C20 acid, preferably one or more of adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, and tetradecanedioic acid.

3. The method according to claim 1, characterized in that The polyether polyol described in S2 is a polyether polyol with repeating units of C2-C8, preferably one or more of polyethylene glycol, polypropylene glycol, and polybutylene glycol; And / or, the monoacid end-capping agent in S2 is C x H 2x O2 monocarboxylic acid, wherein x is an integer from 1 to 16, preferably an integer from 2 to 6; and / or, the molecular weight of the nylon elastomer with a single carboxyl terminal in S2 is 5000-30,000; and / or, the S2 esterification reaction is carried out at a vacuum absolute pressure of ≤500 PaA for 2-10 h; And / or, a catalyst is added in S2; preferably the catalyst is a metal alkoxide M(OR) n , wherein M is a transition metal element, preferably one or more of Sb, Ti, Zr, and Ge, R is a C1-C10 alkyl group, and n is an integer of 1-4, preferably an integer of 2-4; Preferably, the catalyst is added in an amount of 0.01 wt% to 0.3 wt% of the total amount of the carboxyl-terminated nylon hard segment, the polyether polyol and the monoacid end-capping agent.

4. The method according to claim 1, characterized in that: The epoxidized vegetable oil in S3 is an epoxidized oil compound, preferably one or more of epoxidized soybean oil, epoxidized castor oil, and epoxidized corn oil; And / or, the ratio of the molar number of carboxyl groups of the monocarboxyl-terminated nylon elastomer to the molar number of epoxy groups of the epoxidized vegetable oil in S3 is (0.95-1.05):1; and / or, the reaction conditions of S3 are 160-260° C. and the reaction time is 1-6 h; and / or, adding a catalyst in S3; Preferably, the catalyst is a nitrogen-containing heterocyclic compound, preferably an imidazole catalyst; Preferably, the catalyst is added in an amount of 0.01 wt% to 0.1 wt% of the total amount of the monocarboxyl-terminated nylon elastomer and the epoxidized vegetable oil.

5. A hydrophobic nylon elastomer, which is prepared by the method according to any one of claims 1 to 4, characterized in that: The hydrophobic nylon elastomer is a multi-arm nylon elastomer epoxy vegetable oil copolymer.

6. Use of a hydrophobic nylon elastomer, wherein the elastomer is prepared by the method according to any one of claims 1 to 4, or is the elastomer according to claim 5, and the elastomer is used for waterproof shoes, food packaging, cable sheaths, and sporting goods.

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