阅读说明：本技术 一种具有抗菌功能的交联烯烃热缩膜及其制备方法 (Crosslinked olefin heat-shrinkable film with antibacterial function and preparation method thereof ) 是由 吴安理 苏阳 吴淑芬 李小涛 于 2020-05-20 设计创作，主要内容包括：本发明涉及塑料薄膜领域,具体涉一种具有抗菌功能的交联烯烃热缩膜及其制备方法,包括以下步骤：S1.将DMAE和氯化苄回流反应5～10h；S2.步骤S1反应结束后冷却结晶,然后纯化得到DMAE-BC；S3.将细菌纤维素接枝原卟啉得到BC-PpIX；S4.按照重量份数计,将包括LDPE,HDPE,BC-PpIX,DMAE-BC,硫酸铜,乙烯-辛烯共聚物,Fe<Sub>3</Sub>O<Sub>4</Sub>@SiO<Sub>2</Sub>纳米粒子,二苯酮,TAIC的原料混合,在130～180℃条件下,采用紫外线高压汞灯辐照3～5h；S5.将步骤S3反应之后的混合熔融,再吹胀膜管加工形成收缩薄膜。本发明获得的交联烯烃热缩膜具有更好的抗菌效果以及良好的机械性能。(The invention relates to the field of plastic films, in particular to a cross-linked olefin heat-shrinkable film with an antibacterial function and a preparation method thereof, wherein the preparation method comprises the following steps: s1, carrying out reflux reaction on DMAE and benzyl chloride for 5-10 h; s2, after the reaction in the step S1 is finished, cooling and crystallizing, and then purifying to obtain DMAE-BC; s3, grafting protoporphyrin to the bacterial cellulose to obtain BC-PpIX; s4, according to parts by weight, mixing LDPE, HDPE, BC-PpIX, DMAE-BC, copper sulfate, ethylene-octene copolymer and Fe 3 O 4 @SiO 2 Mixing raw materials of nano particles, benzophenone and TAIC, and irradiating for 3-5 hours by adopting an ultraviolet high-pressure mercury lamp at the temperature of 130-180 ℃; s5, melting the mixture after the reaction in the step S3, and then blowing the film tube to form a shrink film. The cross-linked olefin heat-shrinkable film obtained by the invention has better antibacterial effect and good mechanical property.)

1. A preparation method of a cross-linked olefin heat-shrinkable film with an antibacterial function is characterized by comprising the following steps:

s1, DMAE and benzyl chloride are mixed according to a molar ratio of 1: (0.5-2) mixing and dissolving in an organic solvent, adding hydroquinone according to 1-5% of the molar weight of DMAE, and carrying out reflux reaction for 5-10 h;

s2, after the reaction in the step S1 is finished, cooling and crystallizing, and then purifying to obtain DMAE-BC;

s3, grafting protoporphyrin to the bacterial cellulose to obtain BC-PpIX;

s4, according to the parts by weight, the composite material comprises 40-50 parts of LDPE, 10-15 parts of HDPE, and 1-5 parts of BC-PpIX,

12-18 parts of DMAE-BC, 0.5-3 parts of copper sulfate, 30-55 parts of ethylene-octene copolymer and Fe₃O₄@SiO₂1-5 parts of nano particles, 8-15 parts of benzophenone and 7-15 parts of TAIC, and irradiating for 3-5 hours by adopting an ultraviolet high-pressure mercury lamp at the temperature of 130-180 ℃;

s5, melting the mixture after the reaction in the step S3, and processing the mixture by using an inflation film tube to form a shrinkage film.

2. The method for preparing a crosslinked olefin heat-shrinkable film having an antibacterial function according to claim 1, wherein the molar ratio of DMAE to benzyl chloride in step S1 is 1:1, and hydroquinone is added in an amount of 2% of the molar ratio of DMAE.

3. The method of claim 1, wherein in step S3, the raw materials include 42-47 parts of LDPE, 11-13 parts of HDPE, 2-4 parts of BC-PpIX, 26-17 parts of DMAE-BC14, 1-2 parts of copper sulfate, 35-50 parts of ethylene-octene copolymer, Fe₃O₄@SiO₂2-3 parts of nano particles, 9-12 parts of benzophenone and 9-12 parts of TAIC.

4. The antibacterial crosslinked olefin according to claim 1The preparation method of the heat-shrinkable film is characterized in that in the step S3, raw materials comprise 45 parts of LDPE, 12 parts of HDPE, 3 parts of BC-PpIX, 16 parts of DMAE-BC, 1.5 parts of copper sulfate, 40 parts of ethylene-octene copolymer and Fe₃O₄@SiO₂2.5 parts of nano particles, 9 parts of benzophenone and 10 parts of TAIC.

5. The preparation method of the crosslinked olefin heat-shrinkable film with the antibacterial function according to claim 1, wherein the melt index of the LDPE is 0.8-1.2 g/10min under the conditions of 2.16kg pressure and 190 ℃.

6. The method for preparing a crosslinked olefin heat-shrinkable film with an antibacterial function according to the pressure 1, wherein the preparation of BC-PpIX in the step S3 specifically comprises the following steps:

s31, activating the bacterial cellulose in a NaOH solution with the mass fraction of 4% -8% for 10-12 h;

s32, mixing and oxidizing the bacterial cellulose activated in the step S31 and sodium periodate to obtain BC-CHO;

s33, reacting the BC-CHO obtained in the step S22 with ethylenediamine to obtain ethylenediamine bacterial cellulose;

s34, reacting the quadrylated bacterial cellulose obtained in the step S33 with protoporphyrin to obtain BC-PpIX.

7. The crosslinked olefin heat-shrinkable film obtained by the method for producing a crosslinked olefin heat-shrinkable film having an antibacterial function according to any one of claims 1 to 6.

Technical Field

The invention relates to the field of plastic films, in particular to a cross-linked olefin heat-shrinkable film with an antibacterial function and a preparation method thereof.

Background

Among a plurality of packaging materials, the polyolefin heat shrinkable film is a packaging material with a very wide market prospect. With the economic prosperity of the commodity, the usage amount of the polyolefin heat shrinkable film is larger and larger. The application field of polyolefin shrink films is also becoming more and more extensive, especially in the field of packaging of foods and medicines. However, when used in food packaging, food is susceptible to bacterial growth and spoilage. Currently, an antibacterial agent is added in the preparation of the film, so that the antibacterial capability of the packaging film can be effectively improved. At present, inorganic antibacterial agents are mainly added into the thin film in a doping mode, but the inorganic antibacterial agents cannot be uniformly dispersed in the thin film, so that the mechanical property of the thin film is influenced. Further, the inorganic antibacterial agent may be lost during use to affect the antibacterial effect of the heat-shrinkable film. In addition, a single inorganic antibacterial agent has poor antibacterial effect, and cannot inhibit multiple bacteria generated during food transportation. In addition, in the prior art, the crosslinked olefin heat-shrinkable film mainly adopts a chemical polymerization method to cause crosslinking between macromolecules, and has long reaction time and large energy consumption.

Disclosure of Invention

The invention aims to overcome the problems that the addition of an inorganic antibacterial agent influences the mechanical performance of a heat-shrinkable film in the prior art, the antibacterial effect of a single anti-microbial agent is poor, the energy consumption of the existing preparation method of the cross-linked heat-shrinkable film is high, the reaction time is long and the like, and provides the cross-linked olefin heat-shrinkable film with the antibacterial function and the preparation method thereof.

In order to solve the problems, the invention is realized by the following technical scheme:

a preparation method of a cross-linked olefin heat-shrinkable film with an antibacterial function comprises the following steps:

s1, mixing 2- (N, N-dimethylamino) ethyl ester (DMAE) and benzyl chloride according to a molar ratio of 1: (0.5-2) mixing and dissolving in an organic solvent, adding hydroquinone according to 1-5% of the molar weight of DMAE, and carrying out reflux reaction for 5-10 h;

s2, after the reaction in the step S1 is finished, cooling and crystallizing, and then purifying to obtain DMAE-BC;

s3, grafting protoporphyrin to the bacterial cellulose to obtain BC-PpIX;

s4, according to parts by weight, the composite material comprises 40-50 parts of LDPE, 10-15 parts of HDPE, 1-5 parts of BC-PpIX, 12-18 parts of DMAE-BC, 0.5-3 parts of copper sulfate, 30-55 parts of ethylene-octene copolymer, and Fe₃O₄@SiO₂1-5 parts of nano particles, 8-15 parts of benzophenone and 7-15 parts of TAIC, and irradiating for 3-5 hours by adopting an ultraviolet high-pressure mercury lamp at the temperature of 130-180 ℃;

and S5, melting the mixture after the reaction in the step S3, and processing the mixture by using an inflation film tube to form a shrinkage film.

Preferably, the molar ratio of DMAE to benzyl chloride in the step S1 is 1:1, and hydroquinone is added in an amount of 2% of the molar ratio of DMAE.

The preparation method of the cross-linked olefin heat-shrinkable film with the antibacterial function adopts benzophenone as a photoinitiator and triallyl isocyanurate (TAIC) as a photocrosslinking agent. Under the irradiation of ultraviolet high-pressure mercury lamp, the high polymers are crosslinked through photochemical reaction, the reaction speed is high, and the conversion rate is high. In the crosslinking process of low-density polyethylene (LDPE), high-density polyethylene (HDPE) and ethylene-octene copolymer under the action of photoinitiator, the double bond structure in methacryloyloxyethyl-benzyl-dimethylammonium chloride (DMAE-BC) reacts with the double bond structure ethyl LDPE in TAIC or HDPE ethyl ethylene-octene copolymer, so that DMAE-BC with quaternary ammonium salt structure is connected with the ethyl LDPE or HDPE ethyl ethylene-octene copolymerBranching into the composite. Thereby improving the antibacterial property of the composite material. In addition, an inorganic antibacterial agent Fe is also added into the composite material₃O₄@SiO₂Nanoparticles and protoporphyrin grafted bacterial cellulose (BC-PpIX). Fe₃O₄@SiO₂The nano particles are uniformly distributed among cross-linked molecular chains in the reaction process, and furthermore, a plurality of N atoms with lone pair electrons are contained in the grafted protoporphyrin molecules in BC-PpIX and can generate coordination with copper sulfate, so that inorganic metal ions and organic molecules form a stable homogeneous state. In this way, the obtained composite material contains the quaternary ammonium salt antibacterial agent grafted on the polymer chains and the inorganic Fe existing between the polymer chains₃O₄@SiO₂The nano-particle catalyst also comprises biological antibacterial cellulose of a biological antibacterial agent, in addition, the biological antibacterial cellulose is also coordinated with a metal ion antibacterial agent, and the antibacterial effect of the composite material is improved by the mutual cooperation of a plurality of catalysts.

In addition, the method adopts a photoinitiation method, and has the characteristics of higher reaction speed and higher conversion efficiency compared with the common chemical synthesis method.

Preferably, in the step S3, the raw materials include 42-47 parts of LDPE, 11-13 parts of HDPE, 2-4 parts of BC-PpIX, 14-17 parts of DMAE-BC, 1-2 parts of copper sulfate, 35-50 parts of ethylene-octene copolymer, and Fe₃O₄@SiO₂2-3 parts of nano particles, 9-12 parts of benzophenone and 9-12 parts of TAIC.

Preferably, in the step S3, the raw materials comprise 45 parts of LDPE, 12 parts of HDPE, 3 parts of BC-PpIX, 3 parts of DMAE-BC16 parts of copper sulfate, 1.5 parts of ethylene-octene copolymer and 40 parts of Fe₃O₄@SiO₂2.5 parts of nano particles, 9 parts of benzophenone and 10 parts of TAIC.

Preferably, the melt index of the LDPE is 0.8-1.2 g/10min under the conditions of 2.16kg pressure and 190 ℃.

Preferably, the preparation of BC-PpIX in the step S3 specifically comprises the following steps:

s31, activating the bacterial cellulose in a NaOH solution with the mass fraction of 4% -8% for 10-12 h;

s32, mixing and oxidizing the bacterial cellulose activated in the step S31 and sodium periodate to obtain BC-CHO;

s33, reacting the BC-CHO obtained in the step S22 with ethylenediamine to obtain ethylenediamine bacterial cellulose;

s34, reacting the quadrylated bacterial cellulose obtained in the step S33 with protoporphyrin to obtain BC-PpIX.

The cross-linked olefin heat-shrinkable film prepared by the preparation method of the cross-linked olefin heat-shrinkable film with the antibacterial function.

Compared with the prior art, the invention has the following technical effects:

compared with the common chemical synthesis method, the photo-initiation method has the characteristics of higher efficiency and higher conversion rate. And the antibacterial effect of the composite material is synergistically improved by adopting the quaternary ammonium salt antibacterial agent, the inorganic nano particle antibacterial agent, the biological antibacterial cellulose and the metal ion antibacterial agent. Various antibacterial agents can form stable homogeneous phase with the composite material, and the obtained composite material has good mechanical properties.

Detailed Description

The present invention will be further described in detail with reference to the following specific examples, which are provided for illustration only and are not intended to limit the scope of the present invention. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.