WO2019062675A1

WO2019062675A1 - Non-migrating high-efficiency antibacterial composite material and manufacturing method therefor

Info

Publication number: WO2019062675A1
Application number: PCT/CN2018/107078
Authority: WO
Inventors: 马丕明; 吕培; 冯永奇; 陈明清; 东为富
Original assignee: 江南大学
Priority date: 2017-09-27
Filing date: 2018-09-21
Publication date: 2019-04-04
Also published as: CN109553939B; CN109553939A

Abstract

The present invention relates to the field of materialogy, and provides a non-migrating high-efficiency antibacterial composite material and a manufacturing method therefor. The non-migrating high-efficiency antibacterial composite material consists of the following raw materials in parts by weight: 80-120 parts of polylactic acid A, 0.1-5 parts of nano-zinc oxide grafted polylactic acid B, 0.5-5 parts of chain extender, 0.2-2 parts of antioxidant, 0.1-2 parts of anti-hydrolysis agent, and 0-5 parts of nucleating agent (the polylactic acid A and the polylactic acid B are optical isomers). The non-migrating high-efficiency antibacterial composite material of the present invention has excellent antibacterial performance, is non-migrating antibacterial, is an environment-friendly antibacterial composite material, and can be used for manufacturing an antibacterial fiber and fabric, a plastic packaging material, an interior trim part of an automobile, or a medical consumable.

Description

Non-migration type high-efficiency antibacterial composite material and preparation method thereof

Technical field

The invention relates to a non-migratory high-efficiency antibacterial composite material and a preparation method thereof, and belongs to the field of materials science.

Background technique

In order to solve the problem of shortage of petroleum resources and serious environmental pollution, the development and utilization of environmentally friendly materials with low energy consumption has become a research hotspot in the field of materials. Polylactic acid (PLA) is a polymer obtained by polymerizing lactic acid as a main raw material. The raw material source is sufficient and renewable. In addition, polylactic acid has good biocompatibility, transparency, processability and gas barrier properties, and is ideal green. Polymer Materials.

Polylactic acid (PLA) includes L-polylactic acid (PLLA), D-polylactic acid (PDLA), and racemic polylactic acid (PDLLA). PLLA and PDLA have different optical rotations and can be selectively paired. When the two are blended, structural complementation occurs between the PLLA and PDLA molecular chains, and the methyl (CH ₃ ) and carbonyl groups (C=0) in the polylactic acid are rearranged in preference to the ether group (COC), and then A stable hydrogen bond CH···O=C is formed between the methyl group and the carbonyl group, so the interaction between the molecules is enhanced, and finally a polylactic acid stereocomplex is formed, which has a melting point of 210 to 230 ° C, which is more than L-polylactic acid or The melting point of D-polylactic acid is about 50 ° C higher.

With the rapid development of modern economy and society, people have put forward higher and higher requirements for antibacterial products. Nano ZnO is safe, non-toxic, odorless, inexpensive, and has excellent antibacterial properties. It can be widely used in fiber and fabric, plastic packaging materials, automotive interior parts, and medical consumables. It is an ideal material for developing green antibacterial products. However, in ordinary PLA/ZnO nanocomposites, ZnO migrates from the matrix to the environment, and there is a problem of short antibacterial life and environmental pollution of the composite.

Patent CN104116592A discloses a dressing having a nano zinc oxide composite antibacterial layer, wherein the nano zinc oxide particles are fixed on the polymer substrate by bonding or heat fixing, and the antibacterial dressing obtained by the method releases the nano zinc oxide into the environment, thereby The dressing has short antibacterial life and environmental pollution. Patent CN106917157A discloses a degradable antibacterial polylactic acid elastic fiber and a preparation method thereof, and the nano zinc oxide in the antibacterial polylactic acid elastic fiber obtained by the method also migrates to the environment. The patent CN106884226A discloses a colored degradable antibacterial polylactic acid elastic fiber and a preparation method thereof, and the elastic fiber obtained by the method has high inhibition rate against Escherichia coli and Staphylococcus aureus, but the inhibition zone experiment shows nano oxidation. The migration of zinc from the polylactic acid matrix to the environment also has the problems of short antibacterial life and environmental pollution.

In addition, the above patents mostly use polylactic acid and nano-zinc oxide to directly blend the method to obtain antibacterial materials, while the unmodified nano-zinc oxide is very easy to agglomerate, reducing the specific surface area, thereby making the material bacteriostatic rate low, and The antibacterial materials obtained by these methods, the nano zinc oxide will gradually migrate from the polylactic acid matrix to the environment, so that the composite material has a short antibacterial life and environmental pollution problems, which limits its application range. Therefore, it is highly desirable to invent a non-migratory high-efficiency antibacterial composite material.

Summary of the invention

In view of the above problems existing in the prior art, the present invention provides a non-migrating high-efficiency antibacterial composite material comprising the following raw materials by weight: 80-120 parts of polylactic acid A, and polylactic acid B of nano-zinc oxide grafting 0.1-5 Parts, 0.5 to 5 parts of chain extender, 0.2 to 2 parts of antioxidant, 0.1 to 2 parts of anti-hydrolysis agent, and 0 to 5 parts of nucleating agent.

Wherein the polylactic acid A and the polylactic acid B are optical isomers, and the optical purity is greater than 96%;

The chain extender is at least one of a compound containing a plurality of epoxy groups and an isocyanate compound;

Optionally, the chain extender is at least one of BASF ADR-4368, BASF ADR-4370, BASF ADR-4300, BASF ADRE-4860, diphenylmethane diisocyanate and tolylene diisocyanate.

In the melt processing engineering, the chain extender can be chemically bonded to the polylactic acid A and/or the nano zinc oxide grafted polylactic acid B, and the melt viscosity of the composite material can be significantly improved, thereby facilitating the molding process.

The antioxidant is [β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester, tris[2,4-di-tert-butylphenyl]phosphite, bis ( At least one of 2,4-di-tert-butylphenol) pentaerythritol diphosphite; the anti-hydrolysis agent is N,N'-bis(2,6-diisopropylphenyl)carbodiimide and At least one of epoxy compounds;

The nucleating agent is at least one of talc, a hydrazide compound, an oxalic acid compound, and an amide compound.

The "non-migration" in the non-migratory high-efficiency antibacterial composite means that the composite material is immersed in deionized water at 37 ° C for 2 hours per square meter of surface area, and the concentration of zinc ions migrated is less than 1 mg.

The invention also discloses a preparation method of a non-migratory high-efficiency antibacterial composite material, which comprises the following two methods:

method one:

Polylactic acid A, nano zinc oxide grafted polylactic acid B, chain extender, antioxidant, anti-hydrolysis agent, nucleating agent are dissolved in dichloromethane or chloroform according to a certain weight ratio, to obtain uniform dispersion. a mixture, the solvent is removed to obtain a non-migratory high-efficiency antibacterial composite material;

Method Two:

Polylactic acid A, nano zinc oxide grafted polylactic acid B, chain extender, antioxidant, anti-hydrolysis agent, nucleating agent premixed uniformly at room temperature according to a certain weight ratio, and then passed through a screw extruder or dense The non-migratory high-efficiency antibacterial composite material can be obtained by melt blending at a certain temperature, wherein the melt blending temperature is 1 to 30 ° C above the melting point of the polylactic acid;

The polylactic acid A and the polylactic acid B are optical isomers; the polylactic acid A has a number average molecular weight of 50,000 to 300,000, and the optical purity is greater than 96%;

The preparation method of the nano zinc oxide grafted polylactic acid B is:

(1) the nano zinc oxide, the solvent and the aminated silane are blended according to a certain weight ratio, and the reaction is carried out for 0.5 to 12 hours, and after purification and drying, an aminated nano zinc oxide is obtained;

(2) Ammonia nano zinc oxide and polylactic acid B by reactive melt fusion blending through a screw extruder or an internal mixer to obtain a mixture A;

(3) The mixture A is dissolved in dichloromethane or chloroform, centrifuged, washed, and dried to obtain nano zinc oxide grafted polylactic acid B;

Wherein the solvent is at least one of water, methanol, ethanol, and toluene; the aminated silane is γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyl Methyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethyl (ethoxy) silane, N-β-aminoethyl- At least one of γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane, and aminoethylaminoethylaminopropyltrimethoxysilane The nano zinc oxide, the solvent and the aminated silane have a weight ratio of 5 to 15:65 to 85:10 to 30;

Or the preparation method of the nano zinc oxide grafted polylactic acid B is:

The nano zinc oxide, the aminated silane, and the polylactic acid B are directly reactively melt-blended by a screw extruder or an internal mixer to obtain a nano zinc oxide grafted polylactic acid B, wherein the melt blending temperature is higher than the melting point of the polylactic acid. 1 to 30 ° C.

The invention also relates to a method for inhibiting migration of nano zinc oxide in polylactic acid, comprising the steps of:

First, the poly(lactic acid B) is grafted on the surface of the nano zinc oxide to obtain the nano zinc oxide grafted polylactic acid B, and then the nano zinc oxide grafted polylactic acid B is added to the polylactic acid matrix A by solution or melt blending, thereby being effective. Inhibiting the migration of nano zinc oxide in a polylactic acid matrix;

Among them, polylactic acid B and polylactic acid matrix A are optical isomers, and the optical purity is greater than 96%.

The nano zinc oxide grafted polylactic acid B can be obtained by the following method:

method one:

(1) blending and reacting the nano zinc oxide and the aminated silane solution for 0.5 to 12 hours, and purifying and drying to obtain an aminated nano zinc oxide;

(2) Nano-zinc oxide grafted polylactic acid B can be obtained by reactively melt-blending aminated nano-zinc oxide and polylactic acid B.

Method Two:

Nano-zinc oxide, aminated silane, polylactic acid B can be directly reactively melt-blended by a screw extruder or an internal mixer to obtain nano zinc oxide grafted polylactic acid B, wherein the melt blending temperature is above the melting point of polylactic acid. ~30 ° C.

A non-migrating high-efficiency antibacterial composite material for use in the preparation of antimicrobial fibers and fabrics, plastic packaging materials, automotive interior parts or medical consumables.

The beneficial technical effect of the invention is that the non-migrating high-efficiency antibacterial composite material of the invention has excellent antibacterial property and is non-migratory antibacterial, which is due to (1) polylactic acid B grafted on the surface of the nano zinc oxide and having opposite optical rotation characteristics. The polylactic acid A of the matrix forms a polylactic acid stereocomplex structure (intrinsic strong interaction) during the blending process, so the nano zinc oxide grafted polylactic acid B is firmly fixed in the matrix polylactic acid A, and cannot be removed from the matrix. (2) The intermolecular force between the nano zinc oxide grafted polylactic acid B and the matrix polylactic acid A improves the compatibility of the two, so the nano zinc oxide is uniformly dispersed, and the antibacterial effect of the composite material is more remarkable.

DRAWINGS

1 is an infrared spectrum of nano zinc oxide, aminated nano zinc oxide, and nano zinc oxide grafted L-polylactic acid in Example 1 of the present invention.

2 is a polarizing microscope photograph of the polylactic acid composite material obtained in Example 1 of the present invention and Comparative Examples 1, 2, and 3 at 130 ° C for isothermal crystallization for 2 min.

Figure 3 is a graph showing the antibacterial rate test of the polylactic acid composite material obtained in Example 1 of the present invention and Comparative Examples 1, 2, and 3 against Escherichia coli and Staphylococcus aureus.

Figure 4 is a graph showing the inhibition zone of the polylactic acid composite material obtained in Example 1 of the present invention and Comparative Examples 1, 2, and 3 against Escherichia coli and Staphylococcus aureus.

Fig. 5 is a graph showing the amount of zinc ion precipitated per unit surface area of the polylactic acid composite material obtained in Example 1 of the present invention and Comparative Examples 1, 2, and 3, respectively, after being immersed in deionized water at 37 ° C and 70 ° C for two hours.

Detailed ways

DETAILED DESCRIPTION OF THE INVENTION The detailed embodiments of the present invention will be disclosed in conjunction with the drawings. The embodiments disclosed herein are examples of the invention, which may be embodied in different forms. Therefore, the details of the disclosure, including specific structural and functional details, are not intended to limit the invention, but only as the basis of the claims. The detailed description and drawings of the invention are intended to be The word "may" is used throughout the application in a permissible sense rather than a mandatory meaning. Similarly, the words "including", "comprising" and "comprising" are meant to include "including but not limited to" unless otherwise indicated. The word "a" or "an" means "at least one" and the word "a plurality" means more than one. When acronyms or technical terms are used, these terms mean the generally accepted meanings known in the art. The invention will now be described with reference to Figures 1-5.

Example 1:

A method for preparing a non-migratory high-efficiency antibacterial composite material, the method comprising the following steps:

96 parts of right-handed polylactic acid (number average molecular weight is 1.0×10 ⁵ , optical purity is 99%), nano zinc oxide grafted 3 parts of L-polylactic acid, 2 parts of BASF ADR-4368, [β-(3,5- 0.2 parts of di-tert-butyl-4-hydroxyphenyl)propanoic acid] pentaerythritol ester, 0.5 parts of N,N'-bis(2,6-diisopropylphenyl)carbodiimide dissolved in trichloromethane at room temperature In methane, a uniformly dispersed mixture is obtained, and after the mixture is removed at 60 ° C, a non-migrating high-efficiency antibacterial composite material is obtained.

The polarized photomicrograph of isothermal crystallization of the obtained non-migratory high-efficiency antibacterial composite at 130 ° C is shown in Fig. 2, and the bacteriostatic rate of the obtained non-migratory high-efficiency antibacterial composite against Escherichia coli and Staphylococcus aureus is shown in Fig. 3. The results of the inhibition zone of the obtained non-migrating high-efficiency antibacterial composite material are shown in Fig. 4. The zinc ion precipitation amount per unit surface area of the obtained non-migratory high-efficiency antibacterial composite material immersed in deionized water at 37 ° C and 70 ° C for two hours is shown in the figure. 5 is shown.

It can be seen from Fig. 1 that after nano-zinc oxide grafted L-polylactic acid, the absorption peak of nano zinc oxide hydroxyl group is obviously weakened, and a strong absorption peak of new left-handed polylactic acid carbonyl group appears, indicating that nano zinc oxide grafted L-polylactic acid is successfully produced. Got it.

As can be seen from Fig. 2, the present invention not only increases the crystal nucleus density of the polylactic acid crystal, but also significantly reduces the crystal size.

As can be seen from Fig. 3, the inhibitory effect against Escherichia coli and Staphylococcus aureus was more remarkable in the examples of the present invention than in Comparative Examples 1, 2 and 3 under the same amount of zinc oxide or zinc oxide grafted polylactic acid.

As can be seen from Fig. 4, in the examples of the present invention, compared with Comparative Examples 1, 2 and 3, no inhibition zone appeared in the E. coli inhibition zone experiment, indicating that the nano zinc oxide hardly migrated from the matrix.

As can be seen from Fig. 5, under the same conditions, the migration amount of zinc ions was significantly lower than that of Comparative Examples 2 and 3, and was less than 0.5 mg/dm ² .

The preparation method of the nano zinc oxide grafted L-polylactic acid is:

(1) The nano zinc oxide, methanol and aminoethylaminoethylaminopropyltrimethoxysilane are blended in a ratio of 8:72:20 parts by weight, reacted for 12 hours, washed with methanol and centrifuged to obtain an amination. Nano zinc oxide;

(2) The aminated nano zinc oxide and L-polylactic acid were melt-blended at 180 ° C for 10 minutes by an internal mixer to obtain a mixture A;

(3) The mixture A was dissolved in chloroform, centrifuged, washed, and dried to obtain nano zinc oxide grafted L-polylactic acid, wherein the graft ratio of L-polylactic acid was 20% by weight. The infrared spectrum of the obtained nano zinc oxide grafted L-polylactic acid is shown in Fig. 1.

The crystallization and melting behavior of non-migratory high-efficiency antibacterial composites were measured by DSC, and the inhibition rate of the composites and the migration behavior of nano-zinc oxide were tested by Escherichia coli and Staphylococcus aureus bacteriostatic test and inhibition zone experiment. The results are shown in Table 1.

Example 2

100 parts of right-handed polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted L-polylactic acid 0.6 parts, BASF ADR-4370 0.5 parts, three [2,4- two uncle 0.5 part of butylphenyl]phosphite, 0.5 part of epoxy compound, 3 parts of talc dissolved in dichloromethane at room temperature to obtain a uniformly dispersed mixture, and the mixture was removed at 70 ° C to obtain a Non-migratory high-efficiency antibacterial composite material.

The preparation method of the nano zinc oxide grafted L-polylactic acid is:

(1) The nano zinc oxide, ethanol and γ-aminopropyltriethoxysilane are blended according to a ratio of 15:60:25 parts by weight, reacted for 10 hours, washed with ethanol and centrifuged to obtain an aminated nano zinc oxide. ;

(2) The aminated nano zinc oxide and L-polylactic acid were melt-blended by an internal mixer at 175 ° C for 10 minutes to obtain a mixture A;

(3) The mixture A was dissolved in dichloromethane, centrifuged, washed, and dried to obtain nano zinc oxide grafted L-polylactic acid, wherein the graft ratio of L-polylactic acid was 18 wt%.

The crystallization and melting behavior of the non-migratory high-efficiency antibacterial composites were measured by DSC, and the inhibition rate of the composites and the migration behavior of nano-zinc oxide were measured by the antibacterial and antibacterial experiments of Escherichia coli and Staphylococcus aureus. The test results are shown in Table 1.

Example 3:

85 parts of L-polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted 5 parts of right-handed polylactic acid, 1.5 parts of BASF ADR-4300, double (2,4-two uncle Butylphenol) 2 parts of pentaerythritol diphosphite, 1 part of N,N'-bis(2,6-diisopropylphenyl)carbodiimide, 1 part of hydrazide compound dissolved in chloroform at room temperature In the case, a uniformly dispersed mixture is obtained, and the mixture is removed at 65 ° C to obtain a non-migrating high-efficiency antibacterial composite material.

The preparation method of the nano zinc oxide grafted right-handed polylactic acid is:

(1) The nano zinc oxide, toluene and N-β-aminoethyl-γ-aminopropyltrimethoxysilane are blended in a ratio of 5:85:10 parts by weight, reacted for 5 hours, washed with toluene and dried by centrifugation. Obtaining aminated nano zinc oxide;

(2) The aminated nano zinc oxide and the right-handed polylactic acid were melt-blended by an internal mixer at 175 ° C for 10 minutes to obtain a mixture A;

(3) The mixture A was dissolved in chloroform, centrifuged, washed, and dried to obtain nano zinc oxide grafted right-handed polylactic acid, wherein the graft ratio of the right-handed polylactic acid was 10% by weight.

Example 4

110 parts of L-polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted 2 parts of D-polylactic acid, 1.5 parts of diphenylmethane diisocyanate, [β-(3,5 -1 -di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester 0.1 part, 0.2 part of epoxy compound was dissolved in dichloromethane at room temperature to obtain a uniformly dispersed mixture, and the mixture was removed at 50 ° C after solvent removal. A non-migrating high-efficiency antibacterial composite material can be obtained.

(1) The nano zinc oxide, water and N-β-aminoethyl-γ-aminopropyltrimethoxysilane are blended in a ratio of 10:75:15 parts by weight, reacted for 3 hours, washed with toluene and dried by centrifugation. Obtaining aminated nano zinc oxide;

(2) Ammonia nano-zinc oxide and D-polylactic acid were melt-mixed by an internal mixer at 175 ° C for 10 minutes to obtain a mixture A;

(3) The mixture A was dissolved in dichloromethane, centrifuged, washed, and dried to obtain nano zinc oxide grafted right-handed polylactic acid, wherein the graft ratio of the right-handed polylactic acid was 15% by weight.

Example 5

115 parts of right-handed polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted L-polylactic acid 1 part, toluene diisocyanate 2.0 parts, double (2,4-di-tert-butyl) Phenol) pentaerythritol diphosphite 0.8 parts, N,N'-bis(2,6-diisopropylphenyl)carbodiimide 1.1 parts, 4 parts of talc powder premixed uniformly at room temperature, then passed through double A non-migrating high-efficiency antibacterial composite material can be obtained by melt blending at 185 ° C (screw speed 160 rpm, L=20, L/D=40).

The preparation method of the nano zinc oxide grafted L-polylactic acid is:

(1) The nano zinc oxide, methanol and N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane were blended in a ratio of 11:64:25 parts by weight, reacted for 3 hours, and washed with methanol. After centrifugal drying, an aminated nano zinc oxide is obtained;

(2) Ammonia nano zinc oxide and L-polylactic acid by reactive blending melt at 185 ° C to obtain a mixture A;

(3) The mixture A was dissolved in chloroform, centrifuged, washed, and dried to obtain nano zinc oxide grafted L-polylactic acid, wherein the graft ratio of L-polylactic acid was 16 wt%.

Example 6

95 parts of right-handed polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted L-polylactic acid 2.5 parts, BASF ADRE-4860 1.2 parts, three [2,4- two uncle 1.5 parts of butylphenyl]phosphite, 0.5 parts of N,N'-bis(2,6-diisopropylphenyl)carbodiimide, 0.5 parts of hydrazide compound, premixed uniformly at room temperature, and then passed The non-migratory high-efficiency antibacterial composite material was obtained by melt blending at 175 ° C for 5 minutes.

The preparation method of the nano zinc oxide grafted L-polylactic acid is:

(1) The nano zinc oxide, toluene and γ-aminopropylmethyldiethoxysilane are blended in a ratio of 7:83:10 parts by weight, reacted for 1 hour, washed with toluene and centrifuged to obtain an aminated nanometer. Zinc oxide;

(2) The aminated nano zinc oxide and L-polylactic acid were melt-blended by an internal mixer at 175 ° C for 8 minutes to obtain a mixture A;

(3) The mixture A was dissolved in dichloromethane, centrifuged, washed, and dried to obtain nano zinc oxide grafted L-polylactic acid, wherein the graft ratio of L-polylactic acid was 16 wt%.

Example 7

105 parts of L-polylactic acid (number average molecular weight is 1.5×10 ⁵ , optical purity is 97%), nano zinc oxide grafted 4 parts of right-handed polylactic acid, BASF ADR-4370 2.5 parts, double (2,4-two uncle Butylphenol) 1.8 parts of pentaerythritol diphosphite, 1 part of epoxy compound, 3.5 parts of talc powder premixed uniformly at room temperature, and then melt blended at 190 ° C through an internal mixer to obtain a non-migratory type Antibacterial composites.

(1) The nano zinc oxide, ethanol and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane are blended in a ratio of 12:70:18 parts by weight, reacted for 0.5 hour, and washed with toluene. After centrifugal drying, an aminated nano zinc oxide is obtained;

(2) Ammonia nano zinc oxide and D-polylactic acid were melt-blended at 190 ° C for 5 minutes by an internal mixer to obtain a mixture A;

(3) The mixture A was dissolved in dichloromethane, centrifuged, washed, and dried to obtain nano zinc oxide grafted right-handed polylactic acid, wherein the graft ratio of the right-handed polylactic acid was 13% by weight.

Example 8

80 parts of L-polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted 5 parts of D-polylactic acid, 1.5 parts of toluene diisocyanate, three [2,4-di-tert-butyl 1.5 parts of phenyl]phosphite, 1.0 part of epoxy compound, 0.5 parts of amide compound premixed uniformly at room temperature, and then melt blended at 170 ° C through an internal mixer to obtain a non-migratory high-efficiency antibacterial Composite material.

(1) The nano zinc oxide, water and γ-aminopropyltrimethoxysilane are blended in a ratio of 5:65:30 parts by weight, reacted for 9 hours, washed with water and centrifuged to obtain an aminated nano zinc oxide;

(2) The aminated nano zinc oxide and the right-handed polylactic acid were melt-blended by a twin-screw extruder at 180 ° C to obtain a mixture A;

(3) Dissolving the mixture A in chloroform, centrifuging, washing and drying to obtain nano zinc oxide grafted right-handed polylactic acid.

The nano zinc oxide, γ-aminopropyltrimethoxysilane and the right-handed polylactic acid are directly reactively melt-blended by an internal mixer according to a ratio of 1:0.1:30 parts by weight (the blending temperature and time are respectively 180 ° C and 10 minutes), nano-zinc oxide grafted right-handed polylactic acid was obtained, and the grafting ratio of the right-handed polylactic acid was 12% by weight after purification.

Example 9

90 parts of right-handed polylactic acid (number average molecular weight 2 × 10 ⁵ , optical purity 98%), nano zinc oxide grafted L-polylactic acid 4 parts, BASF ADR-4368 3 parts, double (2,4-two uncle Butylphenol) pentaerythritol diphosphite 1.0 part, N,N'-bis(2,6-diisopropylphenyl)carbodiimide 1.2 parts, 0.3 parts of oxalic acid compound dissolved in trichloromethane at room temperature In methane, a uniformly dispersed mixture is obtained, and after the mixture is removed at 65 ° C, a non-migrating high-efficiency antibacterial composite material is obtained.

The preparation method of the nano zinc oxide grafted L-polylactic acid is:

The nanometer zinc oxide, γ-aminopropylmethyldiethoxysilane and L-polylactic acid were reactively melt-blended at 175 ° C through an internal mixer at a ratio of 1:0.2:30 by weight (mixing temperature and time respectively) The nano zinc oxide grafted L-polylactic acid was obtained at 180 ° C and 10 minutes, wherein the graft ratio of L-polylactic acid was 15% by weight.

Comparative Example 1

96 parts of right-handed polylactic acid (number average molecular weight of 1.0 × 10 ⁵ , optical purity of 99%), 2 parts of BASF ADR-4368, [β-(3,5-di-tert-butyl-4-hydroxyphenyl) 0.2 parts of propionic acid] pentaerythritol ester, 0.5 parts of N,N'-bis(2,6-diisopropylphenyl)carbodiimide dissolved in chloroform at room temperature to obtain a uniformly dispersed mixture, After the mixture was removed at 60 ° C, a composite material was obtained. The crystallization and melting behavior of the composites were measured by DSC, and the inhibition rate and migration behavior of nano zinc oxide were measured by Escherichia coli and Staphylococcus aureus bacteriostasis experiments and inhibition zone experiments. The test results are shown in Table 1. The polarized photomicrograph of isothermal crystallization of the obtained composite at 130 °C is shown in Fig. 2. The bacteriostatic rate of the composite material against Escherichia coli and Staphylococcus aureus is shown in Fig. 3. The experimental results of the composite inhibition zone are shown in Fig. 4. Show.

Comparative Example 2

96 parts of right-handed polylactic acid (number average molecular weight of 1.0 × 10 ⁵ , optical purity of 99%), 3 parts of nano zinc oxide, 2 parts of BASF ADR-4368, [β-(3,5-di-tert-butyl- 4-hydroxyphenyl)propionic acid] pentaerythritol ester 0.2 parts, N,N'-bis(2,6-diisopropylphenyl)carbodiimide 0.5 parts dissolved in chloroform at room temperature to obtain dispersion A homogeneous mixture was obtained by removing the solvent at 60 ° C to obtain a composite. The crystallization and melting behavior of the composites were measured by DSC, and the inhibition rate and migration behavior of nano zinc oxide were measured by Escherichia coli and Staphylococcus aureus bacteriostasis experiments and inhibition zone experiments. The test results are shown in Table 1. The polarized photomicrograph of isothermal crystallization of the obtained composite at 130 °C is shown in Fig. 2. The bacteriostatic rate of the composite material against Escherichia coli and Staphylococcus aureus is shown in Fig. 3. The experimental results of the composite inhibition zone are shown in Fig. 4. The amount of zinc ion precipitated per unit surface area of the obtained composite material immersed in deionized water at 37 ° C and 70 ° C for two hours is shown in FIG. 5 .

Comparative Example 3

96 parts of right-handed polylactic acid (number average molecular weight is 1.0×10 ⁵ , optical purity is 99%), aminated nano zinc oxide 3 parts, BASF ADR-4368 2 parts, [β-(3,5-di-tert-butyl) 0.2 parts of pentaerythritol ester of benzyl-4-hydroxyphenyl)propanoic acid, 0.5 parts of N,N'-bis(2,6-diisopropylphenyl)carbodiimide dissolved in chloroform at room temperature, A uniformly dispersed mixture was obtained, and the mixture was removed at 60 ° C to obtain a composite material. The polarized photomicrograph of isothermal crystallization of the obtained composite at 130 °C is shown in Fig. 2. The bacteriostatic rate of the composite material against Escherichia coli and Staphylococcus aureus is shown in Fig. 3. The experimental results of the composite inhibition zone are shown in Fig. 4. The amount of zinc ion precipitated per unit surface area of the obtained composite material immersed in deionized water at 37 ° C and 70 ° C for two hours is shown in FIG. 5 .

The preparation method of the aminated nano zinc oxide is:

The nano zinc oxide, methanol and aminoethylaminoethylaminopropyltrimethoxysilane are blended according to a ratio of 8:72:20 parts by weight, reacted for 12 hours, washed with methanol and centrifuged to obtain an aminated nano zinc oxide. ;

It can be seen from Fig. 1 that after the nano zinc oxide is modified by aminoethylaminoethylaminopropyltrimethoxysilane, the absorption peaks of primary and secondary amines appear, indicating that the aminated nano zinc oxide is successfully prepared.

The crystallization and melting behavior of the composites were measured by DSC, and the inhibition rate of the composites and the migration behavior of nano-zinc oxides were measured by Escherichia coli and Staphylococcus aureus bacteriostasis experiments and inhibition zone experiments. The test results are shown in the table. 1 is shown.

Table 1

Note: T _c is the crystallization temperature of polylactic acid homogeneous crystal (hc) during the first cooling; ΔH _c is the crystal enthalpy of polylactic acid homogeneous crystal (hc) during the first cooling; T _cc is the second The cold crystallization temperature of the polylactic acid homogeneous crystal (hc) during the second temperature rise; ΔH _cc is the cold crystallization enthalpy of the polylactic acid homogeneous crystal (hc) during the second heating; ΔH _m1 is the second heating process The melting enthalpy of the lactic acid homogeneous crystal (hc); ΔH _m2 is the melting enthalpy of the polylactic acid stereocomplex (sc) during the second heating.

The crystallization and melting behavior of the above composites were tested by differential scanning calorimeter (Perkin Elmer, DSC 8000): firstly, the temperature was raised from room temperature to 250 ° C (first temperature increase) at a rate of 20 ° C / min, and the temperature was maintained for 3 minutes, and then The speed of 10 ° C / min was reduced to 0 ° C (first cooling), held for 3 minutes, and then heated to 250 ° C at a rate of 10 ° C / min (second temperature rise).

The composite material inhibition zone experiment uses the Kirby-Bauer test method (such as Am. J. Clin. Pathol. 1966, 45, 493-496.), and the composite material inhibition rate experiment uses the plate counting method (J. Food Sci. 2012, 77, 280- 286).

It can be seen from the test results listed in Table 1 that the non-migratory high-efficiency antibacterial composite materials obtained in Examples 1 to 8 are in the process of cooling (10 ° C / min) compared with the polylactic acid composite material obtained in Comparative Example 2. The crystallization temperature (T _c ) of the polylactic acid homogeneous crystal (hc) increased by 12.2 to 16.7 ° C, the crystallization enthalpy (ΔH _c ) increased by 1.4 to 2.7 times, and no polylactic acid homogeneous crystal appeared during the second heating. (hc) cold crystallization process (T _cc ), polylactic acid stereocomplex (sc) melting enthalpy (ΔH _m2 ) is 0.2-3.4 J / g, high antibacterial rate, no inhibition zone, nano zinc oxide Did not migrate from the polylactic acid matrix.

It can be seen that the non-migrating high-efficiency antibacterial composite material obtained by the method of the present invention has a faster crystallization rate and crystallization during cooling by the molten state than the antibacterial material obtained by the prior art. High temperature and high antibacterial rate, the antibacterial agent nano zinc oxide does not migrate, is an environmentally friendly antibacterial composite material, which can be widely used in antibacterial fiber and fabric, plastic packaging materials, automotive interior parts, medical consumables.

The drawings and the preferred embodiments of the present invention are not intended to limit the invention to the specific forms disclosed. Modifications, equivalents and alternatives.

Claims

The non-migration type high-efficiency antibacterial composite material is characterized in that: the antibacterial composite material comprises: 80 to 120 parts of polylactic acid A and 0.1 to 5 parts of nano zinc oxide grafted polylactic acid B by weight;

Wherein the polylactic acid A and the polylactic acid B are optical isomers.
The non-migrating high-efficiency antibacterial composite material according to claim 1, wherein the polylactic acid A has a number average molecular weight of 50,000 to 300,000 and an optical purity of more than 96%.
A non-migrating high-efficiency antibacterial composite material according to claim 1, wherein said nano zinc oxide grafted polylactic acid B is obtained by the following method:

method one:

(1) blending nano zinc oxide, a solvent and an aminated silane, reacting for 0.5 to 12 hours, and purifying and drying to obtain an aminated nano zinc oxide;

(2) Ammonia nano zinc oxide and polylactic acid B by reactive melt fusion blending through a screw extruder or an internal mixer to obtain a mixture A;

(3) removing unreacted polylactic acid B in the mixture A to obtain nano zinc oxide grafted polylactic acid B; or

Method Two:

The nano zinc oxide, the aminated silane, and the polylactic acid B are directly reactively melt-blended by a screw extruder or an internal mixer to obtain a nano zinc oxide grafted polylactic acid B, wherein the melt blending temperature is higher than the melting point of the polylactic acid. 1 to 30 ° C.
The non-migrating high-efficiency antibacterial composite material according to any one of claims 1 to 3, wherein the crystal structure of the nano zinc oxide is a hexagonal wurtzite structure, a cubic sphalerite structure, and a chlorination. At least one of a sodium octahedral structure; 0.5 to 5 parts of a chain extender, 0.2 to 2 parts of an antioxidant, 0.1 to 2 parts of a hydrolysis inhibitor, and 0 to 5 parts of a nucleating agent may be added to the composite material. The chain extender is at least one of a compound containing a plurality of epoxy groups and an isocyanate compound; the antioxidant is [β-(3,5-di-tert-butyl-4-hydroxyphenyl) At least one of propionic acid] pentaerythritol ester, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenol)pentaerythritol diphosphite; said hydrolysis resistance The agent is at least one of N,N'-bis(2,6-diisopropylphenyl)carbodiimide and an epoxy compound; the nucleating agent is talc, hydrazide compound, oxalic acid amide At least one of a compound and an amide compound.
The non-migrating high-efficiency antibacterial composite material according to claim 3, wherein the nano zinc oxide, the solvent and the aminated silane in the step (1) are in a ratio by weight of 5 to 15:65 to 85 : 10 to 30 blends.
The non-migrating high-efficiency antibacterial composite material according to claim 3, wherein the solvent is at least one of water, methanol, ethanol, and toluene; and the aminated silane is γ-aminopropyl. Triethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-aminoethyl- Γ-aminopropyltrimethyl (ethoxy) silane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyl At least one of ethoxysilane and aminoethylaminoethylaminopropyltrimethoxysilane.
A non-migrating high-efficiency antibacterial composite material according to any one of claims 1 to 4, wherein the polylactic acid A and the polylactic acid B are L-polylactic acid and/or D-polylactic acid.
The method for preparing a non-migrating high-efficiency antibacterial composite material according to any one of claims 1 to 7, wherein the method is obtained by the following two methods.

method one:

Polylactic acid A, nano zinc oxide grafted polylactic acid B, chain extender, antioxidant, anti-hydrolysis agent, nucleating agent are dissolved in dichloromethane or chloroform according to the weight ratio, to obtain a uniformly dispersed mixture. Removing the solvent from the mixture to obtain a non-migrating high-efficiency antibacterial composite; or

Method Two:

Polylactic acid A, nano zinc oxide grafted polylactic acid B, chain extender, antioxidant, anti-hydrolysis agent, nucleating agent premixed uniformly at room temperature according to the weight ratio, and then passed through a screw extruder or a mixture The machine is melt blended at a certain temperature to obtain a non-migratory high-efficiency antibacterial composite material, wherein the melt blending temperature is 1 to 30 ° C above the melting point of the polylactic acid.
A method for inhibiting migration of nano zinc oxide in polylactic acid, characterized in that the method comprises the following steps:

First, the poly(lactic acid B) is grafted on the surface of the nano zinc oxide to obtain the nano zinc oxide grafted polylactic acid B, and then the nano zinc oxide grafted polylactic acid B is added to the polylactic acid matrix A by solution or melt blending, thereby being effective. Inhibiting the migration of nano zinc oxide in a polylactic acid matrix;

Among them, polylactic acid B and polylactic acid matrix A are optical isomers, and the optical purity is greater than 96%.
A method of inhibiting migration of nano zinc oxide in polylactic acid according to claim 9, wherein said nano zinc oxide grafted polylactic acid B can be obtained by the following method:

method one:

(1) blending and reacting the nano zinc oxide and the aminated silane solution for 0.5 to 12 hours, and purifying and drying to obtain an aminated nano zinc oxide;

(2) obtaining a nano zinc oxide grafted polylactic acid B by reactively melt-blending aminated nano zinc oxide and polylactic acid B, wherein the melt blending temperature is 1 to 30 ° C above the melting point of the polylactic acid;

Method Two:

Nano-zinc oxide, aminated silane, polylactic acid B can be directly reactively melt-blended by a screw extruder or an internal mixer to obtain nano zinc oxide grafted polylactic acid B, wherein the melt blending temperature is above the melting point of polylactic acid. ~30 ° C.
The use of a non-migrating high-efficiency antibacterial composite according to any one of claims 1 to 8, characterized in that the composite material can be used for preparing antibacterial fibers and fabrics, plastic packaging materials, automotive interior parts or medical Consumables.