Self-repairing nylon elastomer material as well as preparation method and application thereof

Abstract

The invention discloses a self-repairing nylon elastomer material as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, polymerizing a nylon monomer in the presence of an amine end-capping reagent to prepare a double-amino-terminated nylon hard segment; s2, adding the double-amino-terminated nylon hard segment, the double-carboxyl-terminated polyether and / or polyester soft segment and a disulfide bond-containing chain extender into a reactor, adjusting the proportion of the raw materials, and polymerizing under an optional auxiliary A to obtain a double-amino-terminated pre-polymerized nylon elastomer; and S3, adding the double-amino-terminated pre-polymerized nylon elastomer and a dialdehyde chain extender into the reactor, and carrying out a reaction in the presence of an optional auxiliary agent B to obtain the self-repairing nylon elastomer material. According to the self-repairing nylon elastomer material provided by the invention, the nylon elastomer can be self-repaired in various environments through the synergistic effect of various dynamic covalent bonds, and the polymerization efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of special nylon materials, and particularly to a self-healing nylon elastomer material, a preparation method thereof, and an application thereof. Background Art

[0002] Nylon elastomers are a type of block copolymer, combining the characteristics of rubber and thermoplastic resin. They exhibit rubber characteristics at room temperature and can be melted and plasticized at high temperatures. Different blocks provide different properties, with the hard segments acting as physical crosslinking points to provide the strength required for the material, and the soft segments providing the toughness of the material. Thermoplastic nylon elastomers have the characteristics of high tensile strength, high resilience rate, high low-temperature impact strength, excellent flex resistance, good wear resistance, and easy processing and molding, and are currently widely used in fields such as sports shoes, outdoor clothing, medical supplies, and electronic devices.

[0003] Traditional nylon elastomer materials are usually polymerized by the dibasic acid method. Dibasic acid is used as the nylon hard segment capping agent, and then esterification reaction is carried out with the hydroxyl polyether / polyester soft segment. The prepared nylon elastomer has stable covalent bonds in the molecular chain, and once damage or cracks occur, it cannot be repaired, thus affecting the service life of the overall material. Therefore, it is necessary to study the structural design and process route of nylon elastomers with self-healing functions.

[0004] Some researchers have tried to introduce reversible covalent bonds, such as imine bonds, borate bonds, disulfide bonds, diselenide bonds, "Schiff base" bonds, ester bonds, etc. during the synthesis of nylon elastomers. These dynamic covalent bonds can undergo reversible cleavage and recombination under specific conditions, thereby endowing the nylon elastomer with self-healing ability and restoring its original structural properties.

[0005] However, in the existing technology, introducing a single type of dynamic covalent bond often fails to meet the various requirements of self-healing materials. A single type of dynamic covalent bond may not achieve efficient self-healing in all usage environments. Therefore, it is necessary to develop new nylon elastomer materials with self-healing ability.

[0006] In summary, conventional nylon elastomers cannot achieve self-healing functions, and the introduction of a single type of dynamic covalent bond also fails to meet the various requirements of self-healing materials. Therefore, developing a new type of nylon elastomer with self-healing functions, through the cooperation of multiple dynamic covalent bonds, to achieve efficient self-healing while maintaining other excellent properties, has important theoretical significance and application value.

[0007] CN111690132A discloses a polyamide elastomer with self-healing function and its preparation method. In this invention, under the action of a solvent, a polyamide hard segment containing disulfide bonds and a polyether and / or polyester soft segment are used to prepare a self-healing polyamide elastomer by melt polymerization. The dynamic interaction of hydrogen bonds and disulfide bonds endows the material with self-healing function, reduces the restriction of segment movement, and improves the self-healing efficiency. However, the binary acyl chloride compound used in the preparation process has high toxicity, and the preparation cycle is long, requiring a large amount of solvent.

[0008] CN115286787B discloses a polyamide elastomer with self-healing function and its preparation method. This invention uses a diamine or dicarboxylic acid containing disulfide bonds to endow the nylon elastomer with self-healing function through melt polymerization. However, the reaction monomers in this patent are diamines or dicarboxylic acids containing disulfide bonds. Due to their structural complexity, the reaction activity is reduced, the reaction is relatively slow, and only one kind of reversible covalent bond is introduced into the segment structure, resulting in limited self-healing effect.

[0009] Therefore, a new type of nylon elastomer structure is needed, which not only requires a high degree of polymerization reaction, but also can introduce multiple dynamic covalent bonds to cooperate, so as to achieve stronger self-healing performance, enhance environmental adaptability and extend service life. Summary of the Invention

[0010] In order to solve the above technical problems, the present invention proposes a self-healing nylon elastomer material, its preparation method and application.

[0011] The present invention uses bis-amino-terminated nylon as the hard segment, bis-carboxyl-terminated polyether and / or polyester as the soft segment, and then adds a chain extender containing disulfide bonds for polymerization reaction. First, a bis-amino-terminated prepolymerized nylon elastomer is prepared, and then it is reacted with a dialdehyde chain extender to obtain a nylon elastomer with disulfide bonds and imine bonds in the main chain. It can not only make the nylon elastomer self-heal in various environments through the synergistic effect of multiple dynamic covalent bonds, but also has a significantly improved polymerization efficiency.

[0012] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0013] A preparation method of a self-healing nylon elastomer material, comprising the following steps:

[0014] S1. Polymerize nylon monomers in the presence of an amine-terminated agent to obtain a bis-amino-terminated nylon hard segment;

[0015] S2. Add the bis-amino-terminated nylon hard segment, bis-carboxyl-terminated polyether and / or polyester soft segment, and a chain extender containing disulfide bonds into a reactor, adjust the raw material ratio and polymerize under the optional aid A to obtain a bis-amino-terminated prepolymerized nylon elastomer;

[0016] S3. Add the diamine-terminated prepolymerized nylon elastomer and the dialdehyde chain extender into a reactor, and react under optional auxiliary agent B to obtain the self-healing nylon elastomer material.

[0017] In some examples, the nylon monomer is selected from the polymerization monomers of at least one of PA46, PA6, PA610, PA612, PA1010, PA1012, PA11, PA12, PA1212, PA1313, PA1414;

[0018] Preferably, the amine-terminated agent is one or more of pentamethylenediamine, hexamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine.

[0019] In some examples, the molecular weight of the diamine-terminated nylon hard segment obtained in step S1 is 500 - 4000 g / mol, preferably 1000 - 3000 g / mol;

[0020] Preferably, the reaction conditions in step S1 are: polymerization temperature 220 - 320 °C, preferably 240 - 280 °C, polymerization pressure 2 - 4 MpaG, reaction time 2 - 8 h, preferably 3 - 7 h.

[0021] Preferably, in step S1, the reaction can conventionally select a water-containing reagent as the solvent.

[0022] In some examples, the dicarboxyl-terminated polyether and / or polyester soft segment is selected from one or more of carboxyl-terminated polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene adipate, polybutylene adipate, polyhexylene adipate; preferably, the molecular weight of the dicarboxyl-terminated polyether and / or polyester soft segment is 500 - 3000 g / mol, more preferably 1000 - 2000 g / mol; the dicarboxyl-terminated polyether and / or polyester soft segment meeting the above requirements can be conventionally selected or customized from commercially available products, and the customization method can refer to the general method in patent CN113861412B for example.

[0023] Preferably, the molar ratio of the hard segment to the soft segment in step S2 is (1 - 1.1):(0.9 - 1), preferably (1 - 1.05):(0.95 - 1).

[0024] In some examples, the chain extender containing a disulfide bond is an aliphatic and / or aromatic disulfide compound having at least two amino groups, preferably one or more of 3,3'-dithiobis(propionyl hydrazide), 2,2'-diaminodiphenyl disulfide, 3,3'-diaminodiphenyl disulfide, 4,4'-diaminodiphenyl disulfide;

[0025] Preferably, the addition amount of the chain extender containing a disulfide bond is 0.1 - 15% of the total mass of the hard segment and the soft segment, preferably 0.5 - 10%.

[0026] In some examples, the auxiliary agent A includes catalyst A; the catalyst A is selected from one or more of antimony-based, titanium-based, and phosphorus-based catalysts, preferably one or more of antimony glycolate, tetrabutyl titanate, and phosphoric acid;

[0027] Preferably, the addition amount of the catalyst A is 0.5-3‰ of the total mass of the hard segment and the soft segment.

[0028] In addition, the auxiliary agent A also optionally includes antioxidants, etc., to inhibit the possible yellowing of the prepared nylon elastomer material to a certain extent. It is well known in the art that the antioxidant can be selected from one or more of 1076, 626, 168, 1010, and 1098. The dosage of the antioxidant can be added according to the conventional method.

[0029] In some examples, the reaction conditions in step S2 are as follows: the polymerization temperature is 220-280°C, preferably 240-260°C, the polymerization time is 3-8 h, preferably 4-6 h, and the polymerization vacuum degree is 50-500 PaA, preferably 50-400 PaA.

[0030] In some examples, the dialdehyde chain extender is selected from one or more of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and terephthalaldehyde;

[0031] Preferably, the addition amount of the dialdehyde chain extender is 0.5-15‰, preferably 0.5-10‰ of the mass of the double amino-terminated prepolymerized nylon elastomer.

[0032] In some examples, the auxiliary agent B contains catalyst B; the catalyst B is a basic catalyst, preferably selected from one or more of sodium carbonate, sodium hydroxide, potassium hydroxide, and triethylamine;

[0033] Preferably, the addition amount of the catalyst B is 0.5-5‰, preferably 0.5-3‰ of the total mass of the double amino-terminated prepolymerized nylon elastomer and the dialdehyde chain extender;

[0034] Preferably, the reaction conditions in step S3 are as follows: the polymerization temperature is 230-270°C, preferably 240-260°C, the polymerization time is 3-8 h, preferably 4-6 h, and the polymerization vacuum degree is 50-200 PaA, preferably 50-100 PaA.

[0035] The present invention also provides an application of the self-healing nylon elastomer material prepared by the method as described above in foamed shoe materials, sports apparel, or medical device products.

[0036] The present invention has the following advantages over the prior art:

[0037] 1. Through the structural design of nylon elastomer, multiple dynamic covalent bonds are introduced to collaboratively solve the aforementioned problems existing in the existing technology. Not only the mechanical properties of nylon elastomer are improved, but also the self-healing properties of nylon elastomer are given, its environmental adaptability is enhanced, and the early failure of the material due to damage and the shortened service life are reduced.

[0038] 2. By optimizing the reaction process, the diamino-terminated nylon hard segment and the dicarboxyl-terminated polyether and / or polyester soft segment are subjected to chain extension reaction to prepare a diamino-terminated prepolymerized nylon elastomer. The amidation reaction process is faster and more efficient than the conventional polyesterification reaction process. Disulfide bonds can be introduced while accelerating the reaction efficiency, and then the self-healing nylon elastomer can be obtained by reacting with a dialdehyde chain extender, thereby more efficiently introducing disulfide bonds and imine bonds and improving the synergistic repair function of the material. DETAILED DESCRIPTION

[0039] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0040] Unless otherwise specified, the raw materials used in the following examples of the present invention are all common commercially available products, and other raw materials are prepared as follows:

[0041] Carboxyl-terminated polybutylene glycol: 500.0 g of polybutylene glycol (PTMG-2000, Aladdin) and 51.3 g of succinic anhydride were added to a reaction flask, heated to 110° C., reacted for 4 h, and then vacuumed to obtain carboxyl-terminated polybutylene glycol.

[0042] Carboxyl-terminated polyethylene glycol A: 500.0 g of polyethylene glycol (PEG-1000, Aladdin) and 102.6 g of succinic anhydride were added to a reaction flask, heated to 110° C., reacted for 4 h, and then vacuumed to obtain carboxyl-terminated polyethylene glycol A.

[0043] Carboxyl-terminated polyethylene glycol B: 500.0 g of polyethylene glycol (PEG-2000, Aladdin) and 51.3 g of succinic anhydride were added to a reaction flask, heated to 110° C., reacted for 4 h, and then vacuumed to obtain carboxyl-terminated polyethylene glycol B.

[0044] Carboxyl-terminated polybutylene adipate A: 500.0 g of polybutylene adipate (PBA-1500, Aladdin) and 68.4 g of succinic anhydride were added to a reaction flask, heated to 110° C., reacted for 4 hours, and then vacuumed to obtain carboxyl-terminated polybutylene adipate A.

[0045] Carboxyl-terminated polybutylene adipate B: 500.0 g of polybutylene adipate (PBA-1000, Aladdin) and 102.6 g of succinic anhydride were added to a reaction flask, heated to 110° C., reacted for 4 hours, and then vacuumed to obtain carboxyl-terminated polybutylene adipate B.

[0046] The test methods used in the following embodiments of the present invention are as follows:

[0047] (1) Self-repair rate: The initial tensile strength of the nylon elastomer injection molded specimen was tested, and then the nylon elastomer injection molded specimen was cut in the middle and reassembled, and placed in a 60°C environment for self-repair. After 24 hours of repair, the tensile strength of the repaired nylon elastomer injection molded specimen was tested. The self-repair rate is the ratio of the tensile strength of the repaired nylon elastomer injection molded specimen to the initial tensile strength.

[0048] (2) Tensile strength: According to ISO 527 standard, the test was conducted using Shimadzu ATX-OV. The sample specifications were nylon elastomer pellets injection molded into standard dumbbell specimens with a length of 170 mm, a gauge width of 10 mm, and a thickness of 4 mm. The test conditions were a tensile rate of 500 mm / min.

[0049] Example 1

[0050] (1) 459.9 g of laurolactam, 40.1 g of dodecanediamine, and 100 g of water were added to a polymerization kettle, respectively. After replacing the air in the kettle with nitrogen for 4 times, the temperature was raised to 275° C., and the reaction was carried out at a pressure of 3.8 MPaG for 6 h. The pressure was then slowly released to normal pressure, and vacuum was drawn to obtain a diamino-terminated nylon hard segment with a number average molecular weight of 2500 g / mol.

[0051] (2) 8.8 g of antioxidant 1010, 2.7 g of tetrabutyl titanate, 384.6 g of terminal carboxyl polybutylene glycol, and 88.5 g of 3,3'-dithiobis(propionyl hydrazide) were added to the nylon hard segment obtained in step (1), and the air in the reactor was replaced with nitrogen for 4 times. The temperature was raised to 245° C. and polymerized for 5 h under a vacuum degree of 100 PaA to obtain a diamino-terminated prepolymerized nylon elastomer;

[0052] (3) 1.9 g of sodium hydroxide and 9.7 g of glyoxal were respectively added to the diamino-terminated prepolymerized nylon elastomer obtained in step (2), the temperature was raised to 245° C., and the polymerized reaction was performed for 5 h under a vacuum degree of 50 PaA to obtain the target self-healing nylon elastomer material 1.

[0053] Example 2

[0054] (1) 199.8 g of sebac diamine, 266.8 g of dodecanedioic acid, 33.4 g of dodecane diamine, and 100 g of water were respectively added to the polymerization kettle. After replacing the air in the kettle with nitrogen for 4 times, the temperature was raised to 260 °C, and the reaction was carried out at a pressure of 3.2 MPaG for 6 h. Then, the pressure was slowly released to atmospheric pressure, and vacuum was applied to obtain a nylon hard segment capped with double amino groups, with a number average molecular weight of 3000 g / mol;

[0055] (2) 0.8 g of antioxidant 1010, 0.8 g of tetrabutyl titanate, 301.6 g of carboxyl-terminated polybutylene glycol, and 40.1 g of 2,2'-diaminodiphenyl disulfide were respectively added to the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen for 4 times, the temperature was raised to 250 °C, and polymerization was carried out at a vacuum of 200 PaA for 5 h to obtain a double amino group-capped prepolymerized nylon elastomer;

[0056] (3) 1.7 g of sodium hydroxide and 4.2 g of butanedial were respectively added to the double amino group-capped prepolymerized nylon elastomer obtained in step (2). The temperature was raised to 240 °C, and polymerization was carried out at a vacuum of 80 PaA for 5 h to obtain the target self-healing nylon elastomer material 2.

[0057] Example 3

[0058] (1) 456.9 g of 11-aminoundecanoic acid, 43.1 g of sebac diamine, and 100 g of water were respectively added to the polymerization kettle. After replacing the air in the kettle with nitrogen for 4 times, the temperature was raised to 280 °C, and the reaction was carried out at a pressure of 4 MPaG for 5.5 h. Then, the pressure was slowly released to atmospheric pressure, and vacuum was applied to obtain a nylon hard segment capped with double amino groups, with a number average molecular weight of 2000 g / mol;

[0059] (2) 1.7 g of antioxidant 1098, 1.7 g of phosphoric acid, 356.4 g of carboxyl-terminated poly(butylene adipate) A, and 68.5 g of 4,4'-diaminodiphenyl disulfide were respectively added to the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen for 4 times, the temperature was raised to 245 °C, and polymerization was carried out at a vacuum of 180 PaA for 5 h to obtain a double amino group-capped prepolymerized nylon elastomer;

[0060] (3) 2.8 g of potassium hydroxide and 7.4 g of terephthalaldehyde were respectively added to the double amino group-capped prepolymerized nylon elastomer obtained in step (2). The temperature was raised to 255 °C, and polymerization was carried out at a vacuum of 60 PaA for 4.5 h to obtain the target self-healing nylon elastomer material 3.

[0061] Example 4

[0062] (1) 441.9 g of caprolactam, 58.1 g of hexamethylenediamine, and 100 g of water were respectively added to the polymerization kettle. After replacing the air in the kettle with nitrogen 4 times, the temperature was raised to 240 °C, and the reaction was carried out at a pressure of 2 MPaG for 3 h. Then, the pressure was slowly released to atmospheric pressure, and vacuum was applied to obtain a nylon hard segment capped with double amino groups, with a number-average molecular weight of 1000 g / mol;

[0063] (2) 0.5 g of antioxidant 1076, 0.5 g of antimony glycolate, 490.2 g of carboxyl-terminated polyethylene glycol A, and 5 g of 3,3'-dithiobis(propionylhydrazide) were respectively added to the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen 4 times, the temperature was raised to 240 °C, and polymerization was carried out at a vacuum of 400 PaA for 4 h to obtain a double amino group-terminated prepolymerized nylon elastomer;

[0064] (3) 0.5 g of sodium carbonate and 0.5 g of glyoxal were respectively added to the double amino group-terminated prepolymerized nylon elastomer obtained in step (2). The temperature was raised to 240 °C, and polymerization was carried out at a vacuum of 100 PaA for 4 h to obtain the target self-healing nylon elastomer material 4.

[0065] Example 5

[0066] (1) 467.7 g of 11-aminoundecanoic acid, 32.3 g of hexamethylenediamine, and 100 g of water were respectively added to the polymerization kettle. After replacing the air in the kettle with nitrogen 4 times, the temperature was raised to 255 °C, and the reaction was carried out at a pressure of 2.9 MPaG for 5 h. Then, the pressure was slowly released to atmospheric pressure, and vacuum was applied to obtain a nylon hard segment capped with double amino groups, with a number-average molecular weight of 1800 g / mol;

[0067] (2) 3.1 g of antioxidant 1076, 3.1 g of phosphoric acid, 545.0 g of carboxyl-terminated polyethylene glycol B, and 62.7 g of 4,4'-diaminodiphenyl disulfide were respectively added to the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen 4 times, the temperature was raised to 260 °C, and polymerization was carried out at a vacuum of 100 PaA for 4.5 h to obtain a double amino group-terminated prepolymerized nylon elastomer;

[0068] (3) 2.1 g of sodium carbonate and 6.27 g of glyoxal were respectively added to the double amino group-terminated prepolymerized nylon elastomer obtained in step (2). The temperature was raised to 250 °C, and polymerization was carried out at a vacuum of 60 PaA for 5.5 h to obtain the target self-healing nylon elastomer material 5.

[0069] Example 6

[0070] (1) Add 469.2 g of dodecanolactam, 30.8 g of decanediamine, and 100 g of water into the polymerization kettle respectively. After purging the air in the kettle with nitrogen for 4 times, raise the temperature to 270 °C and react at a pressure of 3.7 MPaG for 7 h. Then slowly release the pressure to atmospheric pressure and evacuate to obtain a nylon hard segment capped with double amino groups, with a number-average molecular weight of 2800 g / mol;

[0071] (2) Add 1.0 g of antioxidant 1098, 1.0 g of tetrabutyl titanate, 173.4 g of carboxyl-terminated polybutylene adipate B, and 28.7 g of 3,3'-dithiobis(propionyl hydrazide) into the nylon hard segment obtained in step (1) respectively. After purging the air in the kettle with nitrogen for 4 times, raise the temperature to 260 °C and polymerize for 6 h under a vacuum of 50 PaA to obtain a double amino-capped prepolymerized nylon elastomer;

[0072] (3) Add 2.0 g of sodium hydroxide and 4.0 g of butanedial into the double amino-capped prepolymerized nylon elastomer obtained in step (2) respectively. Raise the temperature to 260 °C and polymerize for 6 h under a vacuum of 50 PaA to obtain the target self-healing nylon elastomer material 6.

[0073] Comparative Example 1

[0074] (1) Add 459.9 g of dodecanolactam, 40.1 g of dodecanediamine, and 100 g of water into the polymerization kettle respectively. After purging the air in the kettle with nitrogen for 4 times, raise the temperature to 275 °C and react at a pressure of 3.8 MPaG for 6 h. Then slowly release the pressure to atmospheric pressure and evacuate to obtain a nylon hard segment capped with double amino groups, with a number-average molecular weight of 2500 g / mol;

[0075] (2) Add 8.8 g of antioxidant 1010, 2.7 g of tetrabutyl titanate, and 384.6 g of carboxyl-terminated polybutanediol into the nylon hard segment obtained in step (1) respectively. After purging the air in the kettle with nitrogen for 4 times, raise the temperature to 245 °C and polymerize for 5 h under a vacuum of 100 PaA to obtain nylon elastomer material 1-1.

[0076] Comparative Example 2

[0077] (1) Add 199.8 g of decanediamine, 266.8 g of dodecanedioic acid, 33.4 g of dodecanediamine, and 100 g of water into the polymerization kettle respectively. After purging the air in the kettle with nitrogen for 4 times, raise the temperature to 260 °C and react at a pressure of 3.2 MPaG for 6 h. Then slowly release the pressure to atmospheric pressure and evacuate to obtain a nylon hard segment capped with double amino groups, with a number-average molecular weight of 3000 g / mol;

[0078] (2) Respectively add 0.8 g of antioxidant 1010, 0.8 g of tetrabutyl titanate, 301.6 g of carboxyl-terminated polybutylene glycol, and 40.1 g of 2,2'-diaminodiphenyl disulfide into the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen 4 times, raise the temperature to 250 °C, and polymerize for 5 h under a vacuum of 200 PaA to obtain nylon elastomer 2-2.

[0079] Comparative Example 3

[0080] (1) Add 456.9 g of 11-aminoundecanoic acid, 43.1 g of decanediamine, and 100 g of water into the polymerization kettle respectively. After replacing the air in the kettle with nitrogen 4 times, raise the temperature to 280 °C and react for 5.5 h under a pressure of 4 MPaG. Then slowly release the pressure to atmospheric pressure and evacuate to obtain a nylon hard segment terminated with double amino groups, with a number average molecular weight of 2000 g / mol;

[0081] (2) Respectively add 1.7 g of antioxidant 1098, 1.7 g of phosphoric acid, and 356.4 g of carboxyl-terminated poly(butylene adipate) A into the nylon hard segment obtained in step (1). After replacing the air in the kettle with nitrogen 4 times, raise the temperature to 245 °C, and polymerize for 5 h under a vacuum of 180 PaA to obtain a prepolymerized nylon elastomer terminated with double amino groups;

[0082] (3) Respectively add 2.8 g of potassium hydroxide and 7.4 g of terephthalaldehyde into the prepolymerized nylon elastomer obtained in step (2). Raise the temperature to 255 °C, and polymerize for 4.5 h under a vacuum of 60 PaA to obtain nylon elastomer 3-3.

[0083] The initial tensile strength and the tensile strength after self-repair of the above-prepared elastomers were tested, and the results are summarized in Table 1 below.

[0084] Table 1. Experimental data of samples

[0085]

[0086] It can be seen from the above test results that the self-repair rate of the nylon elastomer material prepared by the present invention can reach 70%-87%, and it has excellent self-repair performance. Comparative Example 1 was not designed for results compared with Example 1. It not only does not have self-repair ability, but also the mechanical properties of the synthesized elastomer are significantly poor; Comparative Example 2 compared with Example 2 and Comparative Example 3 compared with Example 3 only contain single reversible covalent bonds, and the self-repair ability is insufficient.

[0087] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a self-healing nylon elastomer material, characterized in that, It includes the following steps: S1. Polymerize nylon monomers in the presence of an amine-terminated agent to obtain a bis-amino-terminated nylon hard segment. S2. Add the bis-amino-terminated nylon hard segment, a bis-carboxyl-terminated polyether and / or polyester soft segment, and a chain extender containing a disulfide bond into a reactor, adjust the raw material ratio, and polymerize in the presence of optional additive A to obtain a bis-amino-terminated prepolymerized nylon elastomer. S3. Add the bis-amino-terminated prepolymerized nylon elastomer and a dialdehyde chain extender into the reactor, and react in the presence of optional additive B to obtain a self-healing nylon elastomer material.

2. The preparation method of the self-healing nylon elastomer material according to claim 1, characterized in that The nylon monomers are selected from polymerization monomers of at least one of PA46, PA6, PA610, PA612, PA1010, PA1012, PA11, PA12, PA1212, PA1313, PA1414. Preferably, the amine-terminated agent is one or more of pentanediamine, hexanediamine, octanediamine, nonanediamine, decanediamine, dodecanediamine.

3. The preparation method of the self-healing nylon elastomer material according to claim 1, wherein The molecular weight of the bis-amino-terminated nylon hard segment obtained in step S1 is 500 - 4000 g / mol, preferably 1000 - 3000 g / mol. Preferably, the reaction conditions in step S1 are: polymerization temperature 220 - 320 °C, preferably 240 - 280 °C, polymerization pressure 2 - 4 MpaG, reaction time 2 - 8 h, preferably 3 - 7 h.

4. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-3, characterized in that, The bis-carboxyl-terminated polyether and / or polyester soft segment is selected from one or more of carboxyl-terminated polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene adipate, polybutylene adipate, polyhexylene adipate; preferably, the molecular weight of the bis-carboxyl-terminated polyether and / or polyester soft segment is 500 - 3000 g / mol, more preferably 1000 - 2000 g / mol. Preferably, the molar ratio of the hard segment to the soft segment in step S2 is (1 - 1.1):(0.9 - 1), preferably (1 - 1.05):(0.95 - 1).

5. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-4, characterized in that, The chain extender containing a disulfide bond is an aliphatic and / or aromatic dithio compound having at least two amino groups, preferably one or more of 3,3'-dithiobis(propionyl hydrazide), 2,2'-diaminodiphenyl disulfide, 3,3'-diaminodiphenyl disulfide, 4,4'-diaminodiphenyl disulfide. Preferably, the addition amount of the chain extender containing a disulfide bond is 0.1 - 15% of the total mass of the hard segment and the soft segment, preferably 0.5 - 10%.

6. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-5, characterized in that, The additive A includes catalyst A; catalyst A is selected from one or more of antimony-based, titanium-based, and phosphorus-based catalysts, preferably one or more of antimony glycolate, tetrabutyl titanate, phosphoric acid. Preferably, the addition amount of catalyst A is 0.5 - 3‰ of the total mass of the hard segment and the soft segment.

7. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-6, characterized in that, The reaction conditions in step S2 are: polymerization temperature 220 - 280 °C, preferably 240 - 260 °C, polymerization time 3 - 8 h, preferably 4 - 6 h, polymerization vacuum degree 50 - 500 PaA, preferably 50 - 400 PaA.

8. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-7, characterized in that, The dialdehyde chain extender is selected from one or more of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipic aldehyde, terephthalaldehyde. Preferably, the addition amount of the dialdehyde chain extender is 0.5-15‰, preferably 0.5-10‰ of the mass of the double-amino-terminated prepolymerized nylon elastomer.

9. The preparation method of the self-healing nylon elastomer material according to any one of claims 1-8, characterized in that, The auxiliary agent B contains a catalyst B; the catalyst B is a basic catalyst, preferably selected from one or more of sodium carbonate, sodium hydroxide, potassium hydroxide, and triethylamine; Preferably, the addition amount of the catalyst B is 0.5-5‰, preferably 0.5-3‰ of the total mass of the double-amino-terminated prepolymerized nylon elastomer and the dialdehyde chain extender; Preferably, in step S3, the reaction conditions are a polymerization temperature of 230-270°C, preferably 240-260°C, a polymerization time of 3-8 h, preferably 4-6 h, and a polymerization vacuum degree of 50-200 PaA, preferably 50-100 PaA.

10. Application of a self-healing nylon elastomer material prepared by the method according to any one of claims 1-9 in foamed shoe materials, sportswear or medical device products.

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