CN114196011B - Long-acting antibacterial bio-based nylon resin and preparation method thereof - Google Patents

Abstract

The invention discloses a long-acting antibacterial bio-based nylon resin and a preparation method thereof. The preparation method comprises the following steps: reacting the first or second dibasic acid with diamine to obtain nylon salt; carrying out a pre-polycondensation reaction on nylon salt, a reactive antibacterial auxiliary agent and a selected auxiliary agent to obtain a nylon prepolymer; carrying out polycondensation reaction or solid phase reaction on the nylon prepolymer to obtain the long-acting antibacterial bio-based nylon resin; the reactive antibacterial auxiliary agent is prepared by the following method: anhydrous and oxygen-free, and reacting a reaction system containing pentanediamine, eugenol, a first catalyst and an organic solvent to obtain an intermediate product; and carrying out Michael addition reaction on a reaction system containing an intermediate product, methyl-esterified itaconic acid, a first catalyst and an organic solvent to obtain the reactive antibacterial auxiliary agent. The preparation method provided by the invention is green and environment-friendly, and the nylon resin has lasting and efficient antibacterial effect, can still maintain extremely high antibacterial property under long-term high-temperature and high-humidity conditions, and has good yellowing resistance.

Description

Long-acting antibacterial bio-based nylon resin and preparation method thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a long-acting antibacterial bio-based nylon resin and a preparation method thereof.

Background

With the rapid development of the intelligent electronic industry and the increasingly higher living level and health consciousness of people, the research of the antibacterial plastic product with the self-cleaning function becomes a great development direction of the plastic product, and the product can be widely applied to the fields of electronic appliance shells, household appliance parts, plastic spectacle frame lenses, medical goggles and the like. The antibacterial material for plastics is required to have broad spectrum, high efficiency, environmental friendliness and good compatibility with plastic products, and can effectively prevent or inhibit the breeding of bacteria on the surfaces of the products. Polyamide (also called nylon) as one of five engineering plastics is widely applied to industries of various electronic and electric appliances, automobiles, textiles and the like by virtue of excellent comprehensive properties (outstanding mechanical properties, chemical resistance, environmental adaptability, wear resistance and the like), so that the research on nylon materials with long-acting antibacterial property has great development prospect.

Chinese patent CN106633829A discloses an antibacterial nylon using attapulgite-nano silver composite inorganic powder as an antibacterial agent additive and a preparation method thereof. Although the antibacterial agent has the advantages of small amount, high efficiency, low price and simple process, the problem that the long-acting antibacterial activity of the silver nanoparticle antibacterial agent is influenced because the silver nanoparticle antibacterial agent is insufficient in long-acting stability and is easy to agglomerate and oxidize to change color is not considered.

Chinese patent CN107541054A discloses an antibacterial nylon using a mixture of polyguanidine salt and sodium pyrithione as an antibacterial agent and a preparation method thereof, and the antibacterial nylon material is prepared by melt blending nylon, the antibacterial agent and a dispersing agent, extruding and granulating. However, the polyguanidine salt in the additive antibacterial agent has high water solubility, is easy to cause compatibility problems and yellowing phenomena with nylon materials after long-term use, and may influence the mechanical properties and chemical stability of the nylon materials.

In summary, currently, most of common antibacterial nylons adopt additive antibacterial agents, and the modified nylons are obtained by melt blending. However, the additive-type antibacterial auxiliary agent is easy to have the problems of compatibility with a nylon body material, precipitation failure under long-term use conditions, yellowing and the like, so that the research on the efficient and durable reactive antibacterial auxiliary agent is very important.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a long-acting antibacterial bio-based nylon resin and a preparation method thereof.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

in a first aspect, the present invention provides a method for preparing a long-acting antibacterial bio-based nylon resin, comprising:

(1) carrying out salt forming reaction on a first dibasic acid monomer or a second dibasic acid monomer and a diamine monomer in water to obtain a nylon salt;

(2) carrying out pre-polycondensation reaction on the nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a nylon prepolymer;

(3) performing polycondensation reaction or solid phase reaction on the nylon prepolymer to obtain long-acting antibacterial bio-based nylon resin;

the reactive antibacterial auxiliary agent is prepared by the following method:

under the anhydrous and anaerobic conditions, carrying out a first reaction on a first uniformly mixed reaction system containing pentanediamine, eugenol, a first catalyst and an organic solvent to obtain an intermediate product;

and carrying out Michael addition reaction on a second uniformly mixed reaction system containing the intermediate product, methyl-esterified itaconic acid, a first catalyst and an organic solvent to obtain the reactive antibacterial auxiliary agent.

In a second aspect, the invention also provides a long-acting antibacterial bio-based nylon resin prepared by the method.

Based on the technical scheme, compared with the prior art, the invention has the beneficial effects that:

1. the prepared full-bio-based antibacterial compound is prepared from bio-based raw materials, is green and environment-friendly, and has sustainable development.

2. According to the preparation method provided by the invention, the reactive antibacterial auxiliary agent is directly chemically bonded into a bio-based nylon molecular chain, so that the problems of reduced antibacterial effect caused by long-term use and precipitation and complicated material formula caused by addition of a compatible auxiliary agent are avoided, the antibacterial effect is lasting and high-efficiency, and the problem of compatibility between the traditional additive antibacterial auxiliary agent and a nylon body material is solved.

3. The long-acting antibacterial bio-based nylon resin provided by the invention also has good yellowing resistance, and can still maintain extremely high antibacterial property under long-term high-temperature and high-humidity conditions.

The above description is only an outline of the technical solution of the present invention, and in order to enable those skilled in the art to more clearly understand the technical means of the present invention and to implement the technical solution according to the content of the description, the following description is given of the preferred embodiment of the present invention.

Detailed Description

In view of the deficiencies in the prior art, the inventors of the present invention have made extensive studies and extensive practices to provide technical solutions of the present invention. The technical solution, its implementation and principles, etc. will be further explained as follows.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as specifically described herein and, therefore, the scope of the present invention is not limited by the specific embodiments disclosed below.

Moreover, relational terms such as "first" and "second," and the like, may be used solely to distinguish one element or method step from another element or method step having the same name, without necessarily requiring or implying any actual such relationship or order between such elements or method steps.

The embodiment of the invention provides a preparation method of a long-acting antibacterial bio-based nylon resin, which comprises the following steps:

(1) carrying out salt forming reaction on a first dibasic acid monomer or a second dibasic acid monomer and a diamine monomer in water to obtain a nylon salt;

(2) carrying out pre-polycondensation reaction on the nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a nylon prepolymer;

(3) performing polycondensation reaction or solid phase reaction on the nylon prepolymer to obtain long-acting antibacterial bio-based nylon resin;

the reactive antibacterial auxiliary agent is prepared by the following method:

under the anhydrous and anaerobic conditions, a first uniform mixed reaction system containing pentanediamine, a double-bond-containing bio-based antibacterial substance, a first catalyst and an organic solvent is subjected to a first reaction to obtain an intermediate product;

and (3) carrying out Michael addition reaction on a second uniformly mixed reaction system containing the intermediate product, a bio-based reaction connector, a first catalyst and an organic solvent to obtain the reactive antibacterial auxiliary agent, wherein the bio-based reaction connector comprises a bio-based compound containing a double bond and at least two carboxyl groups.

Except for cleaning, the water used in each chemical reaction is the water with the purity grade of deionized water and above.

In a typical embodiment, the preparation scheme of the long-acting antibacterial bio-based nylon resin may be as follows:

step (1): one or two different dibasic acids and diamine are subjected to salt forming reaction in an aqueous solution according to a certain proportion. And carrying out suction filtration, washing and drying to obtain the nylon salt C or the nylon salt mixture D.

Step (2): and putting the prepared nylon salt C or nylon salt mixture D, water, the reactive antibacterial assistant B and other reaction assistants into a high-pressure polymerization reaction kettle according to a certain proportion, heating and boosting the pressure under the protection of nitrogen in a closed environment, and carrying out pre-polycondensation reaction to obtain the nylon prepolymer C or nylon prepolymer D.

And (3): slowly heating the nylon prepolymer C in the reaction kettle, continuously exhausting and reducing pressure, and carrying out further polycondensation reaction to obtain the antibacterial bio-based nylon; and carrying out solid-phase reaction on the discharged nylon prepolymer D in a tackifying kettle, and controlling the reaction conditions to prepare the antibacterial bio-based nylon.

Wherein, as a preferred embodiment, the nylon salt C can refer to 56 salt or 510 salt; nylon salt mixture D may refer to a 5T/56 salt mixture or a 5T/5I salt mixture; the nylon prepolymer C refers to a PA 56 prepolymer or a PA 510 prepolymer; nylon prepolymer D refers to PA 5T/56 prepolymer or PA 5T/5I prepolymer.

In some embodiments, in step (1), the first diacid monomer comprises any one of sebacic acid, adipic acid, and/or the second diacid monomer comprises a combination of any two of terephthalic acid, isophthalic acid, and adipic acid; and/or the diamine monomer comprises pentanediamine.

In some embodiments, the bio-based antimicrobial substance comprises eugenol.

In some embodiments, the bio-based reactive linker comprises methyl esterified itaconic acid.

In some embodiments, in step (1), the molar ratio of the first diacid monomer or the second diacid monomer to diamine monomer is from 1: 1 to 1: 1.05.

In some embodiments, in step (1), water is added in an amount of 50 to 200% of the total mass of the first diacid monomer or the second diacid monomer and the diamine monomer.

In some embodiments, in step (2), the reactive antimicrobial additive is added in an amount of 0.2 to 1% of the total mass of the first diacid monomer or the second diacid monomer and diamine monomer.

In some embodiments, in step (2), water is added in an amount of 50 to 200% of the total mass of the first diacid monomer or the second diacid monomer and diamine monomer.

In some embodiments, the first catalyst comprises sodium ethoxide; the organic solvent comprises ethanol.

In some embodiments, the molar ratio of the pentanediamine to the bio-based antibacterial substance is 4-6: 1, the reaction temperature of the first reaction is 75-85 ℃, and the reaction time is 2-6 h.

In some embodiments, the molar ratio of the intermediate product to the bio-based reaction linker is from 0.9 to 1.1: 1, the reaction temperature of the Michael addition reaction is from 75 to 85 ℃, and the reaction time is from 0.5 to 2 hours.

In a typical embodiment, the reactive antimicrobial assistant is prepared by the following steps: firstly, under the anhydrous and oxygen-free conditions, sodium ethoxide is used as a catalyst, ethanol is used as a solvent, and pentanediamine and eugenol react for 2-6 hours at 80 ℃ according to the molar ratio of 5: 1. And carrying out suction filtration, washing and drying to obtain a reactant A. And then feeding the reactant A and methyl-esterified itaconic acid in a molar ratio of 1: 1, taking ethanol as a solvent and sodium ethoxide as a catalyst, and carrying out Michael addition reaction at 80 ℃ for 0.5-2 hours. And carrying out suction filtration, washing and drying to obtain a reactant B, namely a full-bio-based antibacterial compound which can be used as the reactive antibacterial auxiliary agent.

In the above embodiment, the chemical formulas of eugenol, methyl esterified itaconic acid, reactant a, and reactant B are shown in the following formulas (a) to (d):

in some embodiments, the selected promoter comprises any one of a capping agent, a second catalyst, or a combination of both.

In some embodiments, the end-capping agent comprises one or a combination of two or more of benzoic acid, terephthalic acid, 2-naphthoic acid, phthalic anhydride.

In some embodiments, the second catalyst comprises one or a combination of two or more of sodium hypophosphite, phosphoric acid, phosphorous acid, metaphosphoric acid;

in some embodiments, the capping agent is added in an amount of 0.2 to 1% of the total moles of diacid monomers.

In some embodiments, the second catalyst is added in an amount of 0.1 to 1% of the total mass of the first diacid monomer or the second diacid monomer and diamine monomer.

In some embodiments, in step (2), the reaction temperature of the pre-polycondensation reaction is 200 ℃ to 220 ℃, and the reaction time is 0.5 to 2 hours.

In some embodiments, the method of making comprises:

carrying out salt forming reaction on a first diacid monomer and a diamine monomer in water to obtain a first nylon salt;

carrying out pre-polycondensation reaction on the first nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a first nylon prepolymer;

and (3) performing pressure relief operation on the first nylon prepolymer system, relieving the pressure to normal pressure within 50-90 minutes, automatically raising the temperature of the system to 240-260 ℃ in the pressure relief operation process, and then vacuumizing to gauge pressure of-0.06 to-0.08 MPa for reaction for 0.5-2 hours to obtain the long-acting antibacterial bio-based nylon resin. In a typical embodiment, the reaction conditions of the nylon prepolymer C can be slowly increased to 240-260 ℃, and the vapor in the kettle is gradually released to reduce the pressure in the kettle to the normal pressure, and then the kettle is evacuated to-0.06-0.08 MPa for 0.5-2 hours.

In some embodiments, the method of making comprises:

carrying out salt forming reaction on a second diacid monomer and a diamine monomer in water to obtain a second nylon salt;

carrying out pre-polycondensation reaction on the second nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a second nylon prepolymer;

and in the nitrogen atmosphere, raising the temperature of the second nylon prepolymer to 220-260 ℃ for solid-phase reaction for 4-8h to obtain the long-acting antibacterial bio-based nylon resin.

In a typical embodiment, the solid phase reaction conditions may be: and (4) purging with nitrogen, and raising the solid-phase reaction temperature to 220-260 ℃ for 4-8 hours.

The embodiment of the invention also provides the long-acting antibacterial bio-based nylon resin prepared by the preparation method.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced otherwise than as specifically described herein and, therefore, the scope of the present application is not limited by the specific embodiments disclosed below.

Example 1

The embodiment 1 of the invention provides a preparation method of long-acting antibacterial bio-based nylon 56 resin, and the specific synthetic route is as follows:

(1) and (3) performing salt forming reaction. . 146 parts of adipic acid are dissolved in 160 parts of water. Under the continuous stirring action at 60 ℃, slowly dripping the pentamethylene diamine into the mixed system solution, controlling the dripping time of the system to be about 60min, and strictly controlling the pH value of the reaction end point of the system to be within the range of 7.5-7.9 in the process. And finally, carrying out suction filtration washing operation on the obtained nylon salt solution, respectively washing the nylon salt solution with water and ethanol for three times, and then placing the nylon salt solution in a vacuum drying oven at the temperature of 80 ℃ for 12 hours for drying to obtain the PA 56 salt.

(2) And (4) performing prepolymerization. 100 parts of the prepared PA 56 salt, 0.2 part of the reaction type antibacterial auxiliary B prepared in the above embodiment, 0.2 part of benzoic acid, 0.4 part of sodium hypophosphite and 160 parts of water are put into a 10L high-pressure polymerization reaction kettle, high-purity nitrogen is introduced, vacuum pumping is carried out, and the steps are repeated for more than three times to fully replace the air in the kettle. Starting stirring, controlling the stirring speed at 100rpm, raising the temperature in the kettle to 210 ℃, and maintaining the pressure (keeping the pressure in the kettle at 1.6-1.9 MPa) for 1 hour to perform the pre-polycondensation reaction.

(3) And (3) performing post polymerization. And raising the temperature in the kettle to 260 ℃, slowly opening a pressure relief valve in the temperature raising process, and gradually releasing steam in the kettle within 90 minutes to reduce the pressure in the kettle to the normal pressure. Vacuumizing to-0.06-0.08 MPa, and reacting for 2 hours to complete the polycondensation reaction. And finally, filling high-purity nitrogen until the pressure in the kettle is positive, standing for a period of time, opening a discharge valve at the bottom of the reaction kettle, and allowing the material to pass through a cooling water tank, drawing, granulating and vacuum drying to obtain the PA 56 long-acting antibacterial bio-nylon resin.

The raw material composition components of this example are listed in table 1. The long-acting antibacterial bio-based nylon resin is tested for the properties such as melting point, viscosity, mechanical property, heat resistance, yellowing resistance, antibacterial property and the like, and the test results of various properties are listed in table 2 and the test results of antibacterial property are listed in table 3.

Example 2

The embodiment 2 of the invention provides a preparation method of long-acting antibacterial bio-based nylon 510 resin, the component proportion and the preparation process are basically the same as those of the embodiment 1, and the difference is that the diacid monomer in the embodiment is sebacic acid, the addition amount of the reactive antibacterial auxiliary agent B is 0.5 percent of the total mass of the monomer diacid and the diamine, and the PA 510 long-acting antibacterial bio-based nylon resin is prepared. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Example 3

The embodiment 3 of the present invention provides a preparation method of a long-acting antibacterial bio-based nylon 5T/56 resin, and the salt formation reaction and the prepolymerization reaction are substantially the same as those in embodiment 1, except that in this embodiment, the diacid monomer is selected from terephthalic acid and adipic acid, the mass ratio of 5T salt to 56 salt is 50: 50, and the addition amount of the reactive antibacterial assistant B is 1% of the total mass of the monomer diacid and diamine. The polymerization was then as follows: and (3) putting the PA 5T/56 prepolymer into a tackifying kettle, gradually heating to 260 ℃ under nitrogen purging, and reacting for 6 hours to obtain the PA 5T/56 long-acting antibacterial bio-based nylon resin. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Example 4

Embodiment 4 of the present invention provides a preparation method of a long-acting antibacterial bio-based nylon 5T/5I resin, wherein the component ratios and preparation methods of the salt formation reaction and the prepolymerization reaction are substantially the same as those in embodiment 1, and the differences are that the dibasic acid monomer in this embodiment is selected from terephthalic acid and isophthalic acid, the mass ratio of the 5T salt to the 5I salt is 60: 40, and the addition amount of the reactive antibacterial auxiliary agent B is 0.5% of the total mass of the monomer dibasic acid and diamine. The polymerization reaction was then as follows: and (3) putting the PA 5T/5I prepolymer into a tackifying kettle, gradually heating to 260 ℃ under the nitrogen purging, and reacting for 6 hours to obtain the PA 5T/5I long-acting antibacterial bio-nylon resin. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Comparative example 1

The invention provides a preparation method of antibacterial bio-based nylon 56 resin according to comparative example 1, the component proportion and the preparation method are basically the same as those of example 1, and the difference is that eugenol is selected as the antibacterial auxiliary agent of the comparative example to replace a reactive antibacterial auxiliary agent B, and the addition amount is 0.2%. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Comparative example 2

The comparative example 2 of the invention provides a preparation method of antibacterial bio-based nylon 510 resin, the component ratio and the preparation method are basically the same as those of the example 2, and the difference is that silver chloride is selected as the antibacterial assistant in the comparative example to replace the reactive antibacterial assistant B, and the addition amount is 1%. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Comparative example 3

Comparative example 3 of the present invention provides a method for preparing an antibacterial bio-based nylon 5T/56 resin, wherein the salt formation reaction and the prepolymerization reaction are substantially the same as those in example 3, except that the post-polymerization reaction is extrusion by twin-screw reaction, in the comparative example, the reactive antibacterial aid B is not added in the prepolymerization process of the base nylon resin, and eugenol is added as an additive antibacterial aid in the reactive extrusion process. The extrusion molding method comprises the following steps: 1 part of eugenol and 0.2 part of dispersant (ethylene bis stearamide) are subjected to full stirring treatment and post-treatment process, then the eugenol, 100 parts of PA 5T/56 prepolymer, 0.4 part of compatilizer, 0.1 part of antioxidant and 0.05 part of antistatic agent are uniformly mixed and then are put into an extruder, the extrusion temperature is 260-300 ℃, the retention time is controlled for 6 minutes, and the polycondensation reaction is completed, so that the PA 5T/56 antibacterial bio-based nylon resin is obtained. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

Comparative example 4

Comparative example 4 of the present invention provides a preparation method of an antibacterial bio-based nylon 5T/5I resin, the salt forming reaction and the prepolymerization reaction are substantially the same as those in example 4, and the difference is that the post polymerization reaction adopts twin-screw reactive extrusion, in the comparative example, the reactive antibacterial agent B is not added in the prepolymerization process of the basic nylon resin, and silver chloride is added as an additive antibacterial agent in the reactive extrusion process. The extrusion molding method comprises the following steps: 1 part of silver chloride and 0.2 part of dispersing agent (ethylene bis stearamide) are subjected to full stirring treatment and post-treatment process, then the silver chloride, 100 parts of PA 5T/56 prepolymer, 0.4 part of compatilizer, 0.1 part of antioxidant and 0.05 part of antistatic agent are uniformly mixed and then are put into an extruder, the extrusion temperature is controlled to be 200-250 ℃, the retention time is controlled to be 6 minutes, and the polycondensation reaction is completed, so that the PA 5T/5I antibacterial bio-based nylon resin is obtained. The composition of the raw materials of this example is shown in table 1, the results of the performance tests are shown in table 2, and the results of the antibacterial performance tests are shown in table 3.

TABLE 1 examples and comparative examples each raw material composition component

Detection method

In the above examples and comparative examples, the test methods and standards for each performance parameter are as follows:

(1) melting point: measured using a DSC tester, under nitrogen atmosphere, at a temperature rise rate of 10 deg.C/min.

(2) Relative viscosity: the relative viscosity of the product at a concentration of 0.5g/dL was measured in a 98% concentrated sulfuric acid solution at (25. + -. 0.01). degree.C.using an Ubbelohde viscometer.

(3) Mechanical properties: the tensile strength is tested with reference to standard ISO 527-1/-2, the flexural strength and flexural modulus are tested with reference to standard ISO 178, and the impact strength of a simple beam is tested with reference to standard ISO 179/1 eA.

(4) Flexural strength 1 and flexural modulus 1: the samples were placed in an environment at 120 ℃ and tested for flexural strength and flexural modulus with reference to standard ISO 178.

(5) Heat distortion temperature: the heat distortion temperature was measured under a load of 1.8MPa, with reference to the ISO standard 75-1/-2.

(6) Yellow index: the yellowness index of the sample of 2mm standard measurement thickness was evaluated using CLE lab color difference using a calorimeter 3600D with reference to astm D1925.

(7) Antibacterial property: escherichia coli (Escherichia coli) ATCC 25922 and Staphylococcus aureus (Staphylococcus aureus) ATCC 6538 were used for the tests with respect to QB/T2591-2003A, "antimicrobial Plastic antimicrobial Performance test method and antimicrobial Effect".

Analysis of results

TABLE 2 results of various property tests of bio-based nylon resins of examples and comparative examples

TABLE 3 antibacterial property test results of bio-based nylon resins of examples and comparative examples

Based on the above detection results, it is clear that:

from the test results in table 2, the comprehensive properties (including mechanical properties, heat resistance, etc.) of the examples are better than those of the comparative examples as a whole, and the reaction type auxiliary agent B participates in the composition of the polymer molecular chain and introduces a rigid structure. And the yellow index YI of the examples is generally lower than that of the comparative examples, which shows that the reaction type auxiliary agent B can play a role in resisting yellowing to a certain extent.

The antibacterial test results (table 3) of the bio-based nylons of the examples show that the antibacterial rate of the examples can reach more than 99% within the test time range of 24h and 48h, which indicates that the bio-based nylon added with the reactive antibacterial auxiliary B has strong antibacterial effect, and the antibacterial rate of the bio-based nylon still keeps more than 99% along with the increase of the test time range. While the bio-based nylon resins of comparative examples 1-4 maintained appreciable antimicrobial efficacy at 24 hours, the decrease was greater after 48 hours. Under the condition of double 85 (that is, the sample is placed under the condition of 85% relative humidity and 85 ℃ temperature), the antibacterial rate of each sample of the examples is still kept at a high level (more than 98%) after 1000h, while the antibacterial rate of the sample of the comparative example is less than half of the original antibacterial rate, namely the antibacterial effect of the sample under the condition of long-term use is extremely poor.

In summary, the bio-based nylon resin prepared by the reaction of the full bio-based antibacterial nylon compound composed of the reactive antibacterial auxiliary B has the advantages of less addition of the antibacterial auxiliary, high antibacterial efficiency, high mechanical property of the material, good yellowing resistance, and excellent comprehensive performance, so that the bio-based nylon resin has wide application prospect.

It should be understood that the above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and therefore, the protection scope of the present invention is not limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims (16)

1. A preparation method of a long-acting antibacterial bio-based nylon resin is characterized by comprising the following steps:

(1) carrying out salt forming reaction on a first dibasic acid monomer or a second dibasic acid monomer and a diamine monomer in water to obtain a nylon salt; wherein the first diacid monomer is selected from any one of sebacic acid and adipic acid, the second diacid monomer is selected from the combination of any two of terephthalic acid, isophthalic acid and adipic acid, and the diamine monomer is selected from pentanediamine;

(2) carrying out pre-polycondensation reaction on the nylon salt, a reactive antibacterial auxiliary agent and a selected auxiliary agent in water to obtain a nylon prepolymer, wherein the selected auxiliary agent is selected from any one or a combination of two of a capping agent and a second catalyst, and the addition amount of the reactive antibacterial auxiliary agent is 0.2-1% of the total mass of the first dibasic acid monomer or the second dibasic acid monomer and the diamine monomer;

(3) performing polycondensation reaction or solid phase reaction on the nylon prepolymer to obtain long-acting antibacterial bio-based nylon resin;

wherein the molecular formula of the reactive antibacterial auxiliary agent is shown as the following formula:

and is prepared by the following method:

under the anhydrous and anaerobic conditions, carrying out a first reaction on a first uniformly mixed reaction system containing pentanediamine, a double-bond-containing bio-based antibacterial substance, a first catalyst and an organic solvent to obtain an intermediate product, wherein the bio-based antibacterial substance is eugenol;

and carrying out Michael addition reaction on a second uniformly mixed reaction system containing the intermediate product, a bio-based reaction connector, a first catalyst and an organic solvent to obtain the reactive antibacterial auxiliary agent, wherein the bio-based reaction connector is methyl-esterified itaconic acid.

2. The method of claim 1, wherein in step (1), the molar ratio of the first diacid monomer or the second diacid monomer to diamine monomer is 1: 1 to 1: 1.05.

3. The method according to claim 1, wherein in the step (1), the amount of water added is 50 to 200% by mass of the total mass of the first dibasic acid monomer or the second dibasic acid monomer and the diamine monomer.

4. The production method according to claim 1, wherein in the step (1), the pH value of the reaction end point system of the salt-forming reaction is 7.5 to 7.9.

5. The method according to claim 1, wherein in the step (2), the amount of water added is 50 to 200% of the total mass of the first dibasic acid monomer or the second dibasic acid monomer and the diamine monomer.

6. The production method according to claim 1, wherein the first catalyst comprises sodium ethoxide; the organic solvent comprises ethanol.

7. The preparation method according to claim 1, wherein the molar ratio of the pentanediamine to the bio-based antibacterial material is 4-6: 1 when the reactive antibacterial auxiliary is prepared, the reaction temperature of the first reaction is 75-85 ℃, and the reaction time is 2-6 h.

8. The method of claim 1, wherein the molar ratio of the intermediate product to the bio-based reaction linker is 0.9-1.1: 1, the reaction temperature of the michael addition reaction is 75-85 ℃, and the reaction time is 0.5-2 h.

9. The production method according to claim 1, characterized in that; the end capping agent comprises one or the combination of more than two of benzoic acid, terephthalic acid, 2-naphthoic acid and phthalic anhydride.

10. The method according to claim 1, wherein the second catalyst comprises one or a combination of two or more of sodium hypophosphite, phosphoric acid, phosphorous acid, and metaphosphoric acid.

11. The method according to claim 1, wherein the end-capping reagent is added in an amount of 0.2 to 1% based on the total molar amount of the dibasic acid monomer.

12. The method according to claim 1, wherein the second catalyst is added in an amount of 0.1 to 1% by mass based on the total mass of the first dibasic acid monomer or the second dibasic acid monomer and the diamine monomer.

13. The preparation method as claimed in claim 1, wherein in the step (2), the reaction temperature of the pre-polycondensation reaction is 200-220 ℃, and the reaction time is 0.5-2 h.

14. The method of claim 1, comprising:

carrying out salt forming reaction on a first diacid monomer and a diamine monomer in water to obtain a first nylon salt;

carrying out pre-polycondensation reaction on the first nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a first nylon prepolymer;

and (3) carrying out pressure relief operation on the first nylon prepolymer system, unloading to normal pressure within 50-90 minutes, automatically raising the temperature of the system to 240-260 ℃ in the pressure relief operation process, and then vacuumizing to gauge pressure of-0.06 to-0.08 MPa for reaction for 0.5-2h to obtain the long-acting antibacterial bio-based nylon resin.

15. The method of claim 1, comprising:

carrying out salt forming reaction on a second diacid monomer and a diamine monomer in water to obtain a second nylon salt;

carrying out pre-polycondensation reaction on the second nylon salt, the reactive antibacterial auxiliary agent and the selected auxiliary agent in water to obtain a second nylon prepolymer;

and in the nitrogen atmosphere, raising the temperature of the second nylon prepolymer to 220-260 ℃ for solid-phase reaction for 4-8h to obtain the long-acting antibacterial bio-based nylon resin.

16. A long-acting antibacterial bio-based nylon resin prepared by the method of any one of claims 1-15.