Polyethylene conductive composite material with graphene grafted on surface and preparation method thereof

文档序号：674271 发布日期：2021-04-30 浏览：24次中文

阅读说明：本技术 一种表面接枝石墨烯的聚乙烯导电复合材料及制备方法 (Polyethylene conductive composite material with graphene grafted on surface and preparation method thereof ) 是由黄燕于 2020-12-30 设计创作，主要内容包括：本发明涉及聚乙烯材料技术领域,且公开了一种表面接枝石墨烯的聚乙烯导电复合材料,由于羧基化石墨烯表面含有大量的羧基,可以加快与炔丙醇的酯化反应速率,从而引入更丰富的炔基,得到炔基化石墨烯,同时通过炔基化石墨烯与端叠氮基聚乙烯,进行准确高效的炔-点击化反应,得到了表面接枝多孔氧化石墨烯的聚乙烯导电聚合物,通过化学接枝的方式引入了石墨烯,使石墨烯在聚乙烯基体中具有良好的分散性,解决了纳米石墨烯的团聚问题,并且高度分散的石墨烯在聚乙烯膜中形成三维导电网络,提高了材料的导电性能和抗静电性,同时机械性能优异的石墨烯对聚乙烯的拉伸强度等力学性能有很大的提升。(The invention relates to the technical field of polyethylene materials, and discloses a polyethylene conductive composite material with a surface grafted with graphene, because the surface of the carboxylated graphene contains a large amount of carboxyl, the esterification reaction rate with the propargyl alcohol can be accelerated, thereby introducing richer alkynyl to obtain alkynyl graphene, simultaneously carrying out accurate and efficient alkyne-click reaction through the alkynyl graphene and terminal azido polyethylene to obtain the polyethylene conducting polymer with the surface grafted with the porous graphene oxide, the graphene is introduced in a chemical grafting mode, so that the graphene has good dispersibility in a polyethylene matrix, the problem of agglomeration of the nano graphene is solved, and the highly dispersed graphene forms a three-dimensional conductive network in the polyethylene film, so that the conductivity and the antistatic property of the material are improved, meanwhile, the mechanical properties of the graphene with excellent mechanical properties, such as tensile strength and the like, of the polyethylene are greatly improved.)

1. A surface graft graphene polyethylene conductive composite material is characterized in that: the preparation method of the polyethylene conductive composite material with the surface grafted with the graphene comprises the following steps:

(1) treating graphene oxide with hydrochloric acid, and then rapidly heating and stripping to obtain carboxylated graphene;

(2) adding carboxylated graphene into N, N-dimethyl amide, performing ultrasonic dispersion, adding propiolic alcohol, uniformly stirring, adding N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine, performing water bath reaction at 25-35 ℃ for 20-30h, performing centrifugal washing, and performing vacuum drying to obtain alkynyl graphene;

(3) reacting ethylene gas and diethyl zinc as reactants, iron pyridine diimine as a catalyst and methylaluminoxane as a cocatalyst in a polymerization reaction kettle to prepare hydroxyl-terminated polyethylene;

(4) hydroxyl-terminated polyethylene, p-toluenesulfonyl chloride and sodium azide are used as reactants, n-butyl lithium is used as a catalyst, and the reaction is carried out to prepare azido-terminated polyethylene;

(5) adding alkynyl graphene and azido-terminated polyethylene into an N, N-dimethyl amide solvent, adding cuprous sulfate and sodium ascorbate, heating for reaction, centrifugally separating and purifying, pouring a product into a polytetrafluoroethylene mold, defoaming in vacuum and curing to obtain the polyethylene conductive composite material with the surface grafted with graphene.

2. The polyethylene conductive composite material with the surface grafted with graphene as claimed in claim 1, wherein: in the step (2), the mass ratio of the carboxylated graphene, the propiolic alcohol, the N, N' -dicyclohexylcarbodiimide to the 4-dimethylaminopyridine is 10:15-25:500-600: 25-50.

3. The polyethylene conductive composite material with the surface grafted with graphene as claimed in claim 1, wherein: polymerization cauldron includes the reation kettle body in step (3), reation kettle body fixedly connected with presss from both sides the cover, reation kettle body fixedly connected with zone of heating, the reation kettle body is provided with the connector, reation kettle body and air inlet fixed connection, air inlet fixedly connected with establishes the hole intake pipe, reation kettle body and feed inlet fixed connection, feed inlet fixedly connected with inlet pipe, reation kettle body fixedly connected with discharge gate, reation kettle body and gas outlet fixed connection, reation kettle body fixedly connected with motor, the motor passes through puddler fixedly connected with upper agitator and lower floor's agitator gear, lower floor's agitator gear swing joint has vertical agitator gear.

4. The polyethylene conductive composite material with the surface grafted with graphene as claimed in claim 1, wherein: in the step (5), the heating reaction temperature is 60-80 ℃, and the stirring reaction time is 24-48 h.

5. The polyethylene conductive composite material with the surface grafted with graphene as claimed in claim 1, wherein: in the step (5), the mass ratio of the terminal azido polyethylene to the alkynyl nano graphene to the cuprous sulfate to the sodium ascorbate is 100:2-5:0.1-0.25: 0.15-0.4.

Technical Field

The invention relates to the technical field of polyethylene materials, in particular to a polyethylene conductive composite material with a surface grafted with graphene and a preparation method thereof.

Background

Polyethylene, a thermoplastic resin prepared by ethylene polymerization, has the advantages of no toxicity, no odor, good chemical stability and the like, and is widely applied to daily life, such as: various waterproof breathable films, pipelines, electric wire wrapping layers, food boxes, engineering plastics and the like, but polyethylene and other high polymer materials are insulators and poor in conductivity and antistatic property, so that the application of the waterproof breathable films in partial fields is limited, and the requirements on materials are higher and higher along with social development, so that the materials are endowed with new functions by functionalizing the materials, and the original traditional materials can be applied to more fields.

The existing conductive polyethylene is generally a conductive composite material which is prepared by simply and physically compounding polyethylene serving as a base material and a conductive filler, and is generally compounded with carbon black due to good compatibility with the carbon black, but the mechanical property of the material is influenced by excessive simple physical mixing, the tensile strength of the material is reduced, graphene not only has better electrochemical property than the carbon black, but also has better mechanical property, so that one of the materials with the highest known strength at present has application capability far exceeding that of the carbon black in various fields, and the graphene is introduced in a surface grafting manner, so that the material has good dispersibility, has better conductive property, can greatly improve the mechanical property of the composite material, and is endowed with new performance.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a polyethylene conductive composite material with a surface grafted with graphene and a preparation method thereof, which solve the problems that the conductivity and antistatic property of polyethylene are poor, and the mechanical property of polyethylene is influenced by excessive conductive agent doping.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the preparation method of the polyethylene conductive composite material with the surface grafted with the graphene comprises the following steps:

(1) treating graphene oxide with hydrochloric acid, and then rapidly heating and stripping to obtain carboxylated graphene;

Preferably, the mass ratio of the carboxylated graphene, the propiolic alcohol, the N, N' -dicyclohexylcarbodiimide and the 4-dimethylaminopyridine in the step (2) is 10:15-25:500-600: 25-50.

Preferably, polymerization reaction kettle includes the reation kettle body in step (3), reation kettle body fixedly connected with presss from both sides the cover, reation kettle body fixedly connected with zone of heating, the reation kettle body is provided with the connector, reation kettle body and air inlet fixed connection, hole intake pipe is established to air inlet fixedly connected with, reation kettle body and feed inlet fixed connection, feed inlet fixedly connected with inlet pipe, reation kettle body fixedly connected with discharge gate, reation kettle body and gas outlet fixed connection, reation kettle body fixedly connected with motor, the motor passes through puddler fixedly connected with upper agitator and lower floor's agitator gear, lower floor's agitator gear swing joint has vertical agitator gear.

Preferably, in the step (5), the heating reaction temperature is 60-80 ℃, and the stirring reaction time is 24-48 h.

Preferably, the mass ratio of the terminal azido polyethylene, the alkynyl nano graphene, the cuprous sulfate and the sodium ascorbate in the step (5) is 100:2-5:0.1-0.25: 0.15-0.4.

(III) advantageous technical effects

Compared with the prior art, the invention has the following experimental principles and beneficial technical effects:

according to the polyethylene conductive composite material with the surface grafted with the graphene, the surface of the carboxylated graphene contains a large number of carboxyl groups, so that the esterification reaction rate with propargyl alcohol can be accelerated, and richer alkynyl is introduced to obtain the alkynylated graphene.

According to the polyethylene conductive composite material with the surface grafted with the graphene, firstly, carboxyl on the surface of carboxylated graphene and propiolic alcohol are subjected to esterification reaction to obtain alkynyl graphene, then, hydroxylation polyethylene is subjected to azide reaction to obtain azido polyethylene, the alkynyl graphene and terminal azido polyethylene are subjected to accurate and efficient alkyne-azide click reaction to obtain the polyethylene conductive polymer with the surface grafted with the porous graphene oxide, the graphene is introduced in a chemical grafting mode, so that the graphene has good dispersibility in a polyethylene matrix, the problem of agglomeration of the nano graphene is solved, and the highly dispersed graphene forms a three-dimensional conductive network in the polyethylene film, so that the conductivity and the antistatic property of the material are improved, meanwhile, the mechanical properties of the graphene with excellent mechanical properties, such as tensile strength and the like, of the polyethylene are greatly improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a polymerization reactor.

1-a reaction kettle body; 2-a jacket; 3, heating a layer; 4-a connector; 5-an air inlet; 6-arranging a hole air inlet pipe; 7-a feed inlet; 8-feeding pipe; 9-a discharge hole; 10-air outlet; 11-a motor; 12-upper stirrer; 13-lower layer stirring gear; 14-longitudinal stirring gear.

Detailed Description

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a polyethylene conductive composite material with a surface grafted with graphene comprises the following steps:

(1) treating graphene oxide with hydrochloric acid, and then rapidly heating and stripping to obtain carboxylated graphene;

(2) adding carboxylated graphene into N, N-dimethyl amide, performing ultrasonic dispersion, adding propiolic alcohol, uniformly stirring, adding N, N' -dicyclohexylcarbodiimide and 4-dimethylaminopyridine in a mass ratio of 10:15-25: 500: 600:25-50, performing water bath reaction at 25-35 ℃ for 20-30h, performing centrifugal washing, and performing vacuum drying to obtain alkynyl graphene;

(3) ethylene gas and diethyl zinc are used as reactants, iron pyridine diimine is used as a catalyst, methylaluminoxane is used as a cocatalyst, the polymerization kettle comprises a reaction kettle body, the reaction kettle body is fixedly connected with a jacket, the reaction kettle body is fixedly connected with a heating layer, the reaction kettle body is provided with a connector, the reaction kettle body is fixedly connected with an air inlet, the air inlet is fixedly connected with a perforated air inlet pipe, the reaction kettle body is fixedly connected with a feed inlet, the feed inlet is fixedly connected with a feed pipe, the reaction kettle body is fixedly connected with a discharge outlet, the reaction kettle body is fixedly connected with an air outlet, the reaction kettle body is fixedly connected with a motor, the motor is fixedly connected with an upper stirrer and a lower stirring gear through a stirring rod, the lower stirring gear is movably connected with a longitudinal stirring gear, and the reaction is carried out to;

(5) adding alkynyl graphene and azido-terminated polyethylene into an N, N-dimethyl amide solvent, adding cuprous sulfate and sodium ascorbate at the mass ratio of 100:2-5:0.1-0.25:0.15-0.4, heating for reaction at the temperature of 60-80 ℃, stirring for 24-48h, centrifugally separating and purifying, pouring the product into a polytetrafluoroethylene mold, defoaming in vacuum and curing to obtain the polyethylene conductive composite material with the surface grafted with graphene.

Example 1