阅读说明：本技术 一种聚酰胺弹性体的制备方法 (Preparation method of polyamide elastomer ) 是由 唐成华 于哲 钟勇良 肖国文 肖朝晖 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种聚酰胺弹性体的制备方法,该方法是将生成聚酰胺的单体与二酸类单体进行预聚,得到双端羧基聚酰胺预聚体；将双端羧基聚酰胺预聚体依次通过脱盐水萃取、干燥及熔融处理,得到熔融态双端羧基聚酰胺预聚体；熔融态双端羧基聚酰胺预聚体与聚四氢呋喃醚和/或聚醚胺及催化剂混合后,送入卧式高粘自洁反应器进行反应,得到聚酰胺弹性体。该方法制备的聚酰胺弹性体具有良好的力学性能,且成本低廉,有利于大规模工业化生产。(The invention discloses a preparation method of polyamide elastomer, which comprises the steps of carrying out prepolymerization on a monomer for generating polyamide and a diacid monomer to obtain a polyamide prepolymer with double carboxyl groups; sequentially carrying out desalted water extraction, drying and melting treatment on the double-end carboxyl polyamide prepolymer to obtain a molten double-end carboxyl polyamide prepolymer; and mixing the molten double-end carboxyl polyamide prepolymer with polytetrahydrofuran ether and/or polyether amine and a catalyst, and feeding the mixture into a horizontal high-viscosity self-cleaning reactor for reaction to obtain the polyamide elastomer. The polyamide elastomer prepared by the method has good mechanical properties and low cost, and is beneficial to large-scale industrial production.)

1. A method for preparing a polyamide elastomer, which is characterized by comprising the following steps: the method comprises the following steps:

1) carrying out prepolymerization on a monomer for generating polyamide and a diacid monomer to obtain a double-end carboxyl polyamide prepolymer;

2) sequentially carrying out desalted water extraction, drying and melting treatment on the double-end carboxyl polyamide prepolymer to obtain a molten double-end carboxyl polyamide prepolymer;

3) and mixing the molten double-end carboxyl polyamide prepolymer with polytetrahydrofuran ether and/or polyether amine and a catalyst, and feeding the mixture into a horizontal high-viscosity self-cleaning reactor for reaction to obtain the polyamide elastomer.

2. The method for producing a polyamide elastomer according to claim 1, wherein: the polyamide-forming monomer comprises at least one of caprolactam, diamine dibasic acid salt and amino carboxylic acid monomer.

3. The method for producing a polyamide elastomer according to claim 2, wherein:

the diamine dibasic acid salt comprises at least one of hexamethylene diamine adipate, sebacic acid sebacic diamine salt and hexamethylene diamine dodecadiacid salt;

the amino carboxylic acid monomer comprises at least one of undecyl amino undecanoic acid and dodecyl amino dodecanoic acid.

4. The method for producing a polyamide elastomer according to any one of claims 1 to 3, characterized in that: the prepolymerization conditions are as follows: the pressure is 0.1-2.0 MPa, and the temperature is 240-280 ℃.

5. The method for producing a polyamide elastomer according to claim 1, wherein: the number average molecular weight of the polyamide prepolymer is 500-3000.

6. The method for producing a polyamide elastomer according to claim 1, wherein: the extraction conditions are as follows: the temperature is 90-150 ℃, and the extraction time is 3-12 hours.

7. The method for producing a polyamide elastomer according to claim 1, wherein: the number average molecular weight of the polytetrahydrofuran ether or the polyether amine is 500-3000.

8. The process for producing a polyamide elastomer according to claim 1 or 7, characterized in that: the polyether amine is polyether containing double-end amino; the polyether structure in the polyether containing double-end amino groups is polyethylene glycol, polypropylene glycol or polytetrahydrofuran, or a copolymerization structure of at least two of the polyethylene glycol, the polypropylene glycol and the polytetrahydrofuran.

9. The method for producing a polyamide elastomer according to claim 1, wherein: the double-end carboxyl polyamide prepolymer accounts for 20-50% of the weight of the polyamide elastomer.

10. The method for producing a polyamide elastomer according to claim 1, wherein: the reaction conditions are as follows: the temperature is 180-280 ℃, and the pressure is 0-60 KPa.

Technical Field

The invention relates to a preparation method of a polyamide elastomer, in particular to a method for producing a high-performance polyamide elastomer by removing impurities from a polyamide prepolymer and utilizing a high-viscosity self-cleaning reactor, belonging to the technical field of elastomers.

Background

Thermoplastic polyamide elastomer (TPAE) is a segmented block copolymer. It is composed of a plurality of blocks which are alternated, and the repeated blocks are composed of monomer units with completely different chemical structures. One block is a hard segment whose homopolymer has a relatively high glass transition temperature (Tg) or melting point (Tm); the other is a soft segment, which can be either a crystalline polymer or an amorphous polymer. The thermoplastic polyamide elastomer has soft segments alternating with hard segments to form alternating block copolymers.

TPAE can be classified into nylon 6 series, nylon 66 series, nylon 12 series, and the like according to the type of polyamide constituting the hard segment. The nylon 12 series is most common among products already commercialized.

In the elastomer synthesized by Chinese patent (CN200780022484), the polyether prepolymer is selected from commercial X-Y-X triblock polyether diamine, and a typical product is XTJ-542 (amino-terminated polytetrahydrofuran ether glycol-polypropylene glycol copolymer) of HUNTSMAN company. The synthesis process of the embodiment comprises a method for feeding polyamide monomers and polyether prepolymers at one time and a two-step method for synthesizing the polyamide prepolymers and then adding polyether.

The process introduced by the Chinese patent (CN200910200343) is as follows: a block copolymer of caprolactam and diisocyanate is first prepared by hydrolytic ring-opening polymerization, which is composed of two polyamide 6 segments and one diisocyanate segment. Then the polyamide 6-diisocyanate copolymer is used as a prepolymer to be subjected to esterification reaction with a polyether prepolymer to form the polyamide elastomer.

Chinese patent (CN201110301764) describes a solution polymerization method, which comprises first carrying out a polycondensation reaction on an amino-terminated polyamide prepolymer and an isocyanate-terminated polyether prepolymer, and then forming a solution system with dimethyl sulfoxide or dimethylacetamide as a solvent to prepare a polyamide elastomer. The solution reaction proceeds more sufficiently than the bulk reaction and is also easy to carry out.

Chinese patent (CN201410667956) describes a method for preparing polyamide elastomer by a hydrolysis ring-opening one-step method. Directly mixing the polyether prepolymer, caprolactam monomer, dicarboxylic acid and catalyst to initiate hydrolytic ring-opening polymerization and polycondensation reaction between the prepolymers.

Chinese patent (CN201510085070) introduces a two-step method of using copolyamide as a hard segment of polyamide elastomer, and adopts a process of preparing a copolyamide prepolymer by hydrolysis ring-opening and then adding a polyether prepolymer for polycondensation reaction.

Chinese patent (CN201410009966) adopts the reaction of heat-resistant modified polyurethane prepolymer and polyamide prepolymer to prepare polyamide elastomer. The heat-resistant modified polyurethane prepolymer is prepared by reacting polyether with isocyanate to generate a polyurethane prepolymer and then adding pyromellitic dianhydride for reaction. The isocyanate end groups of this prepolymer are then reacted with a carboxyl terminated polyamide prepolymer to form a block copolymer.

Chinese patent (CN200910200344) prepares active species by reacting amine-terminated polyether with an anionic initiator, and then adds caprolactam to initiate anionic polymerization to generate a polyamide elastomer. The anionic polymerization of caprolactam is fast and easier to perform than esterification.

The above patents all relate to the synthesis of polyamide prepolymers, the presence of residual monomers and oligomers in the prepolymers greatly interferes with the subsequent reaction for synthesizing elastomers, and the performance of the elastomers is affected, and in the prior art, most of the condensation reactions of the polyamide prepolymers and the polyether prepolymers adopt tank reactors, and the polyamide prepolymers, the polyether prepolymers and intermediates thereof have insufficient mixing effect and incomplete reaction due to high viscosity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for removing impurities from a polyamide prepolymer and condensing and synthesizing a polyamide elastomer by combining a high-viscosity self-cleaning reactor, the method eliminates the influence of residual polyamide monomers and oligomers in the polyamide prepolymer, the condensation reaction is carried out by utilizing the high-viscosity self-cleaning reactor to ensure that the reaction is thorough, and the generated elastomer has excellent comprehensive chemical properties.

In order to achieve the above technical object, the present invention provides a method for preparing a polyamide elastomer, comprising the steps of:

1) carrying out prepolymerization on a monomer for generating polyamide and a diacid monomer to obtain a double-end carboxyl polyamide prepolymer;

2) sequentially carrying out desalted water extraction, drying and melting treatment on the double-end carboxyl polyamide prepolymer to obtain a molten double-end carboxyl polyamide prepolymer;

3) and mixing the molten double-end carboxyl polyamide prepolymer with polytetrahydrofuran ether and/or polyether amine and a catalyst, and feeding the mixture into a horizontal high-viscosity self-cleaning reactor for reaction to obtain the polyamide elastomer.

In a preferred embodiment, the polyamide-forming monomers include at least one of caprolactam, diamine diacid salt, and aminocarboxylic acid monomers.

Preferably, the diamine dibasic acid salt comprises at least one of hexamethylene diamine adipate, sebacic acid diamine salt and hexamethylene diamine dodeca diacid salt.

In a preferred embodiment, the aminocarboxylic acid monomer includes at least one of undecylaminoundecanoic acid and dodecylaminododecanoic acid.

In a preferred embodiment, the prepolymerization conditions are as follows: the pressure is 0.1-2.0 MPa, and the temperature is 240-280 ℃.

In a preferred scheme, the number average molecular weight of the polyamide prepolymer is 500-3000.

In a preferred embodiment, the extraction conditions are: the temperature is 90-150 ℃, and the extraction time is 3-12 hours. The double-end carboxyl polyamide prepolymer can effectively remove unreacted monomers, residual acid, oligomers and the like after being subjected to desalted water extraction. The content of residual monomers and oligomers in the polyamide prepolymer can be reduced to less than 0.6% by mass by means of preferred extraction conditions.

The drying of the invention is carried out under the protection of vacuum or nitrogen, so that the water content is lower than 0.1 percent.

In a preferable scheme, the number average molecular weight of the polytetrahydrofuran ether or the polyether amine is 500-3000.

In a preferable scheme, the polyether amine is polyether containing double-end amino; the polyether structure in the polyether containing double-end amino groups is polyethylene glycol, polypropylene glycol or polytetrahydrofuran, or a copolymerization structure of at least two of the polyethylene glycol, the polypropylene glycol and the polytetrahydrofuran.

In a preferable scheme, the double-end carboxyl polyamide prepolymer accounts for 20-50% of the weight of the polyamide elastomer.

In a preferred embodiment, the reaction conditions are: the temperature is 180-280 ℃, and the pressure is 0-60 KPa.

The invention obtains the prepolymer by ring-opening polymerization of caprolactam monomer or polycondensation of diamine dibasic acid salt monomer or amino carboxylic acid monomer, and introduces a proper amount of diacid monomer in the process of preparing the prepolymer to ensure that two ends of the polyamide prepolymer are carboxyl groups. Diacid monomers such as adipic acid and the like which are common fatty diacids.

The double-end carboxyl polyamide prepolymer is melted by a screw extruder in the melting process.

The horizontal high-viscosity self-cleaning reactor disclosed by the invention is a LIST-CRP type high-viscosity self-cleaning reactor manufactured by LIST company of Switzerland or an STC type high-viscosity self-cleaning reactor manufactured by Hangzhou original science and technology. An exemplary highly viscous self-cleaning reactor configuration, such as a horizontal arrangement, has a cylindrical configuration. The feed inlet and the discharge outlet are arranged at two ends of the cylinder body, and a vacuum suction port communicated with the inner cavity of the cylinder body is arranged on the shell of the cylinder body. The cylinder body is internally provided with a single-shaft or double-shaft rotor structure, which pushes the polyamide melt to move forwards and simultaneously forms a mass transfer interface, so that the micromolecular substances are pumped and discharged in vacuum. The design of the rotor and the inner cavity of the cylinder body has the function of self-cleaning, and can avoid melt retention. The outlet of the reactor is provided with a three-way valve, wherein one way is the discharging of the reactor, and the other way returns the melt to the inlet of the reactor through a conveying screw or a melt pump. The reactor adopts an intermittent operation mode, the reaction materials move from an inlet to an outlet and then return to the inlet for circulating operation, and after the reaction is finished, the three-way valve is switched to the discharging direction to extrude the elastomer product. The invention realizes the polycondensation between the double-end carboxyl polyamide prepolymer and polytetrahydrofuran ether or polyether amine by using the horizontal high-viscosity self-cleaning reactor for the first time, so that the reaction is thorough and the high-performance polyamide elastomer is obtained.

The catalyst of the present invention is a conventional polycondensation catalyst such as tetrabutyl titanate or triphenyl phosphite. The addition amount thereof is 0.1 to 3% by mass, preferably 0.4 to 2% by mass of the system.

Compared with the prior art, the technical scheme of the invention has the beneficial technical effects that:

the extraction method is used for extracting the polyamide prepolymer, so that residual monomers, oligomers, residual acid and the like can be effectively and deeply removed, and the influence of small molecules on the subsequent condensation reaction is reduced.

The invention adopts the high-viscosity self-cleaning reactor to carry out the condensation reaction of the polyamide and the polyether, has strong stirring, dispersing and mixing effects on high-viscosity materials, and has thorough condensation reaction, and the generated elastomer has excellent performance.

The polyamide elastomer prepared by the invention has excellent comprehensive mechanical properties such as hardness, tensile strength, elasticity and the like.

Detailed Description

The following examples are intended to further illustrate the present disclosure, but not to limit the scope of the claims.

Example 1

Adding 400g of caprolactam, 87.6g of adipic acid and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to normal pressure, continuing to react for 2 hours, vacuumizing to the absolute pressure of 70KPa, and reacting for 2 hours to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 96 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The extractable matter content of the nylon 6 prepolymer after extraction was 0.4%. The nylon 6 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 812.6.

The nylon 6 prepolymer was melt-plasticized by a single-screw extruder, and 600g of polytetrahydrofuran ether glycol (number average molecular weight 1000) and 7g of tetrabutyl titanate catalyst were mixed and then fed into the extruder by a metering pump. The mixed materials are sent into a LIST-CRP type high-viscosity self-cleaning reactor of LIST company of Switzerland, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is tested to be 190 ℃, the tensile strength is 11.53MPa, and the elongation at break is 381.3%.

Example 2

350g of caprolactam, 94.9g of adipic acid and 6g of desalted water are added into a polymerization kettle, polymerization is carried out for 2 hours at 260 ℃ and under the pressure of 0.6MPa, the pressure is slowly reduced to the normal pressure, the reaction is continued for 2 hours, the vacuum pumping is carried out until the absolute pressure reaches 70KPa, and the reaction is carried out for 2 hours, so as to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 105 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The extractable matter content of the nylon 6 prepolymer after extraction was 0.32%. The nylon 6 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 684.4.

The nylon 6 prepolymer was melt-plasticized by a single-screw extruder, and 650g of polytetrahydrofuran ether glycol (number average molecular weight 1000) and 5g of tetrabutyl titanate catalyst were mixed and then fed into the extruder by a metering pump. The mixed materials are sent into a LIST-CRP type high-viscosity self-cleaning reactor of LIST company of Switzerland, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The test melting point is 189 ℃, the tensile strength is 10.5MPa, and the breaking elongation is 531.1%.

Example 3

350g of caprolactam, 47.5g of adipic acid and 6g of desalted water are added into a polymerization kettle, polymerization is carried out for 2 hours at 260 ℃ and under the pressure of 0.6MPa, the pressure is slowly reduced to the normal pressure, the reaction is continued for 2 hours, the vacuum pumping is carried out until the absolute pressure reaches 70KPa, and the reaction is carried out for 2 hours, so as to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 105 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The content of extractables in the extracted nylon 6 prepolymer was 0.36%. The nylon 6 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 1369.

The nylon 6 prepolymer was melt-plasticized by a single-screw extruder, and 650g of polytetrahydrofuran ether glycol (number average molecular weight 2000) and 10g of tetrabutyl titanate catalyst were mixed and then fed into the extruder by a metering pump. The mixed materials are sent into a LIST-CRP type high-viscosity self-cleaning reactor of LIST company of Switzerland, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is measured to be 197 ℃, the tensile strength is 15.7MPa, and the breaking elongation is 311.1 percent.

Example 4

Adding 280g of caprolactam, 70g of adipic acid adipate, 94.9g of adipic acid and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to normal pressure, continuously reacting for 2 hours, vacuumizing to the absolute pressure of 70KPa, and reacting for 2 hours to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 105 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The extractable content of the nylon 6/66 prepolymer after extraction was 0.28%. The nylon 6/66 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 684.4.

The nylon 6/66 prepolymer was melt-plasticized by a single-screw extruder, and 650g of polytetrahydrofuran ether glycol (number average molecular weight 1000) and 5g of triphenyl phosphite catalyst were mixed and fed into the extruder via a metering pump. The mixed materials are sent into an original Hangzhou science and technology STC type high-viscosity self-cleaning reactor, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is tested to be 165 ℃, the tensile strength is 7.6MPa, and the elongation at break is 468.3%.

Example 5

Adding 280g of caprolactam, 70g of adipic acid adipate, 94.9g of adipic acid and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to normal pressure, continuously reacting for 2 hours, vacuumizing to the absolute pressure of 70KPa, and reacting for 2 hours to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 105 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The extractable content of the nylon 6/66 prepolymer after extraction was 0.28%. The nylon 6/66 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 684.4.

The nylon 6/66 prepolymer was melt-plasticized by a single-screw extruder, and 650g of polyetheramine (Huntsman XTJ-542, number average molecular weight 1000) and 8g of triphenyl phosphite catalyst were mixed and fed into the extruder via a metering pump. The mixed materials are sent into an original Hangzhou science and technology STC type high-viscosity self-cleaning reactor, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is 158 ℃, the tensile strength is 6.7MPa, and the breaking elongation is 502.3 percent.

Comparative example 1

Adding 400g of caprolactam, 87.6g of adipic acid, 600g of polytetrahydrofuran ether glycol (number average molecular weight is 1000), 7g of tetrabutyl titanate catalyst and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to the normal pressure, continuing to react for 2 hours, vacuumizing to the absolute pressure of 70KPa, reacting for 2 hours, vacuumizing to 1KPa, reacting for 6 hours, and extruding and granulating a melt to obtain the polyamide elastomer. The test shows that the melting point is 188 ℃, the tensile strength is 10.3MPa, and the elongation at break is 221.3%.

Comparative example 2

350g of caprolactam, 47.5g of adipic acid and 6g of desalted water are added into a polymerization kettle, polymerization is carried out for 2 hours at 260 ℃ and under the pressure of 0.6MPa, the pressure is slowly reduced to normal pressure, reaction is continuously carried out for 2 hours, vacuum pumping is carried out until the absolute pressure reaches 70KPa, and the reaction is carried out for 2 hours, so as to obtain a nylon 6 prepolymer; 650g of polytetrahydrofuran ether glycol (number average molecular weight 2000) and 5g of tetrabutyl titanate catalyst were mixed and introduced into a polymerization vessel via a metering pump. The reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is tested to be 194 ℃, the tensile strength is 18.4MPa, and the elongation at break is 195.2%.

Comparative example 3

Adding 280g of caprolactam, 70g of adipic acid adipate, 94.9g of adipic acid and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to normal pressure, continuously reacting for 2 hours, vacuumizing to the absolute pressure of 70KPa, and reacting for 2 hours to obtain the nylon 6 prepolymer. 650g of polyetheramine (huntsman XTJ-542, number average molecular weight 1000) and 8g of triphenyl phosphite were mixed and fed into a polymerization vessel through a metering pump, the reaction temperature was 260 ℃, the vacuum degree was 1KPa, and the reaction time was 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is tested to be 161 ℃, the tensile strength is 7.7MPa, and the elongation at break is 242.3%.

Comparative example 4

350g of caprolactam, 47.5g of adipic acid and 6g of desalted water are added into a polymerization kettle, polymerization is carried out for 2 hours at 260 ℃ and under the pressure of 0.6MPa, the pressure is slowly reduced to the normal pressure, the reaction is continued for 2 hours, the vacuum pumping is carried out until the absolute pressure reaches 70KPa, and the reaction is carried out for 2 hours, so as to obtain the nylon 6 prepolymer. Mixing with 650g polytetrahydrofuran ether glycol (number average molecular weight 2000) and 5g tetrabutyl titanate catalyst, and feeding into an STC type high-viscosity self-cleaning reactor. The reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is tested to be 191 ℃, the tensile strength is tested to be 14.4MPa, and the elongation at break is tested to be 295.2%.

Comparative example 5

Adding 280g of caprolactam, 70g of adipic acid adipate, 94.9g of adipic acid and 6g of desalted water into a polymerization kettle, polymerizing for 2 hours at 260 ℃ under the pressure of 0.6MPa, slowly reducing the pressure to normal pressure, continuously reacting for 2 hours, vacuumizing to the absolute pressure of 70KPa, and reacting for 2 hours to obtain the nylon 6 prepolymer. Vacuum is eliminated by high-purity nitrogen, the nylon 6 prepolymer is pressed out of a polymerization kettle, the mixture is granulated and then extracted by desalted water, the extraction temperature is 105 ℃, the extraction water is replaced once after 2 hours of extraction, and extraction is carried out for three times. The extractable content of the nylon 6/66 prepolymer after extraction was 0.28%. The nylon 6/66 prepolymer was dried under nitrogen for 16 hours and had a water content of 0.06%. The number average molecular weight of the nylon 6 prepolymer was 684.4.

The nylon 6/66 prepolymer was melt-plasticized by a single-screw extruder, and 650g of polytetrahydrofuran ether glycol (number average molecular weight 1000) and 5g of triphenyl phosphite catalyst were mixed and fed into the extruder via a metering pump. The mixed materials are sent into a stirring polymerization reaction kettle with the volume of 3L, the reaction temperature is 260 ℃, the vacuum degree is 1KPa, and the reaction time is 6 hours. And extruding and granulating the melt to obtain the polyamide elastomer. The melting point is 169 ℃, the tensile strength is 9.6MPa, and the elongation at break is 262.5 percent.

Through the comparison, the performance of the polyamide elastomer produced by the process is obviously superior to that of the polyamide prepolymer and polyether which are directly reacted in a polymerization kettle.