阅读说明：本技术 一种pei复合材料的制备方法 (Preparation method of PEI (polyetherimide) composite material ) 是由 童光辉 付绪兵 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种PEI复合材料的制备方法,其特点是包括以下步骤：将石墨烯和纳米碳化硅微粉混合后,加入表面活性剂经研磨得纳米碳材料复配体的步骤；将纳米碳材料复配体超声震荡分散在N,N-二甲基甲酰胺中,然后加入对苯二胺和双酚A型二醚二酐进行高速搅拌,经原位聚合反应制得粘稠的预聚体聚酰胺酸,然后加入乙酸酐通过亚胺化作用得到PEI复合材料的步骤,各原料及其重量份数比如下：石墨烯0.5-2.5份、纳米碳化硅0.5-2.5份、表面活性剂3份、N,N-二甲基甲酰胺100份、对苯二胺15.5-17.5份、双酚A型二醚二酐73.5-82.5份和乙酸酐100份,优点是具有耐磨性能好、轻量化、高强度和高抗冲。(The invention discloses a preparation method of a PEI composite material, which is characterized by comprising the following steps: mixing graphene and nano silicon carbide micro powder, adding a surfactant, and grinding to obtain a nano carbon material complex; dispersing a nano carbon material complex ligand in N, N-dimethylformamide by ultrasonic oscillation, then adding p-phenylenediamine and bisphenol A type diether dianhydride for high-speed stirring, preparing viscous prepolymer polyamic acid by in-situ polymerization, then adding acetic anhydride for imidization to obtain the PEI composite material, wherein the raw materials and the weight parts thereof are as follows: 0.5-2.5 parts of graphene, 0.5-2.5 parts of nano silicon carbide, 3 parts of surfactant, 100 parts of N, N-dimethylformamide, 15.5-17.5 parts of p-phenylenediamine, 73.5-82.5 parts of bisphenol A type diether dianhydride and 100 parts of acetic anhydride.)

1. The preparation method of the PEI composite material is characterized by comprising the following steps:

(1) mixing graphene and nano silicon carbide micro powder, adding a surfactant, and grinding to obtain a nano carbon material complex;

(2) dispersing the carbon nanomaterial complex ligand in N, N-dimethylformamide by ultrasonic oscillation, adding p-phenylenediamine and bisphenol A type diether dianhydride, stirring at high speed, and carrying out in-situ polymerization to obtain viscous prepolymer polyamic acid;

(3) and adding acetic anhydride into the performed polymer polyamic acid to perform imidization, and stirring, separating out, filtering and drying to obtain the PEI composite material.

2. The method for preparing a PEI composite material as claimed in claim 1, wherein the raw materials in the steps (1) to (3) and the weight portion ratio thereof are as follows: 0.5-2.5 parts of graphene, 0.5-2.5 parts of nano silicon carbide, 3 parts of surfactant, 100 parts of N, N-dimethylformamide, 15.5-17.5 parts of p-phenylenediamine, 73.5-82.5 parts of bisphenol A type diether dianhydride and 100 parts of acetic anhydride.

3. The method of making a PEI composite according to claim 2, wherein: the graphene in the step (1) is pure graphene powder or slurry, the number of layers is 1-10, and the specific surface area is 100-²(ii)/g; the nano silicon carbide is green silicon carbide, and the SiC content is more than 97%; the surfactant is one or more of dimethylacetamide, N-dimethylformamide, ethylene bis-stearamide, zinc stearate, industrial white oil, methanol, ethanol and styrene.

4. The method of making a PEI composite according to claim 2, wherein: the ultrasonic vibration dispersion in the step (2) is specifically a combination mode of high-power ultrasonic and high-speed stirring, wherein the ultrasonic power is 1000-.

5. The method for preparing a PEI composite material as claimed in claim 2, wherein the step (3) comprises the following steps: adding acetic anhydride into performed polymer polyamic acid to dehydrate and form a ring, reacting for 5 hours at 90 ℃, stopping, stirring and cooling to room temperature, adding a mixed solvent which is equal in mass to acetic anhydride and is prepared by mixing methanol and water in equal volume, precipitating and separating out a polymer, and performing suction filtration and drying at 120 ℃ to obtain the PEI composite material.

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a preparation method of a PEI composite material.

Background

The Polyetherimide (PEI) resin is thermoplastic special engineering plastic with excellent comprehensive performance, has good flame retardance and low smoke degree, and has a combustion grade of UL 94-V0. It has strong high-temp stability, high-temp resistance, high thermal deformation temp up to 220 deg.C, and can be used for a long period at 160-180 deg.C. The hydrolysis stability is good, and the ultraviolet ray and Y ray resistance is good. Therefore, the metal alloy is effectively applied to the industrial departments of electronics, motors, aviation and the like and is used as a metal substitute material for traditional products and cultural living goods. If PEI is used instead of metal to make fiber optic connectors, the component structure can be optimized, simplifying its manufacturing and assembly steps, and maintaining more precise dimensions. In the automotive field, such as to make high-temperature connectors, high-power vehicle lights and indicator lights, sensors to control the temperature outside the cabin of an automobile, and sensors to control the temperature of air and fuel mixtures. It can also be used as a reflector of a non-illuminated anti-fog lamp, a ground glass receiving port of a distiller operated at 180 ℃, and the like.

At present, most manufacturers in the market modify PEI by adopting the traditional glass fiber, the impact strength of the modified PEI can be improved to a certain extent, and the requirements of good wear resistance, high impact resistance and high strength required in the fields of automobiles, electronic appliances and the like can not be met. Therefore, the search for a new material which can improve the performance of PEI materials and is added with a small amount of easily processed PEI materials is a target of continuous pursuit and research of various enterprises.

Graphene is a polymer made of carbon atoms in sp²The hybrid tracks form a hexagonal honeycomb lattice two-dimensional carbon nanomaterial. Has excellent optical, electrical and mechanical properties and is considered to be a revolutionary material in the future. The silicon carbide is a hexagonal crystal semiconductor material and has the advantages of good wear resistance, high chemical property temperature, high heat conductivity coefficient and the like. The problems of uneven dispersion and nanoparticle agglomeration are a big problem when nano carbon materials such as graphene and nano silicon carbide are applied to polymers, the problem of agglomeration cannot be effectively controlled because the nano carbon materials are difficult to be uniformly dispersed in the polymers by a common melt blending extrusion method, and Chinese patent CN107151443A mentions that the graphene, a coupling agent and a lubricant are blended and extruded with a dried PEI matrix, the graphene is not modified by modification such as modification coating, and only simple blending is carried out, so that an obvious effect is difficult to obtain. Chinese patents CN107454544A and CN107213796A mention that PEI composite materials are prepared by a solution blending method, and generally a mechanical stirring method is adopted to basically realize uniform mixing, but the solution blending method is adopted to obtain PEI composite materials due to the agglomeration of nano material particlesThe nano carbon material in the composite material has poor dispersibility, and even if the ultrasonic-assisted dispersion method is adopted, the dispersion of the nano carbon material can be improved to a certain extent, the nano carbon material structure is easy to damage through ultrasonic treatment, and the application is not facilitated.

Disclosure of Invention

The invention aims to provide a preparation method of a PEI composite material with enhanced wear resistance, toughness and impact strength.

The technical scheme adopted by the invention for solving the technical problems is as follows: a preparation method of a PEI composite material comprises the following steps:

(1) mixing graphene and nano silicon carbide micro powder, adding a surfactant, and grinding to obtain a nano carbon material complex;

(2) dispersing a nano carbon material complex ligand in N, N-Dimethylformamide (DMF) by ultrasonic oscillation, adding p-phenylenediamine and bisphenol A type diether dianhydride, stirring at a high speed, and carrying out in-situ polymerization to obtain viscous prepolymer polyamic acid;

(3) and adding acetic anhydride into the performed polymer polyamic acid to perform imidization, and stirring, separating out, filtering and drying to obtain the PEI composite material.

The raw materials in the steps (1) to (3) and the weight part ratio thereof are as follows: 0.5-2.5 parts of graphene, 0.5-2.5 parts of nano silicon carbide, 3 parts of surfactant, 100 parts of N, N-Dimethylformamide (DMF), 15.5-17.5 parts of p-phenylenediamine, 73.5-82.5 parts of bisphenol A type diether dianhydride and 100 parts of acetic anhydride.

The graphene in the step (1) is pure graphene powder or slurry, the number of layers is 1-10, and the specific surface area is 100-²(ii)/g; the nano silicon carbide is green silicon carbide, and the SiC content is more than 97%; the surfactant is one or more of Dimethylacetamide (DMA), N-Dimethylformamide (DMF), Ethylene Bis Stearamide (EBS), zinc stearate, industrial white oil, methanol, ethanol and styrene.

The ultrasonic vibration dispersion in the step (2) is specifically a combination mode of high-power ultrasonic and high-speed stirring, wherein the ultrasonic power is 1000-.

The specific process of the step (3) is as follows: adding acetic anhydride into performed polymer polyamic acid to dehydrate and form a ring, reacting for 5 hours at 90 ℃, stopping, stirring and cooling to room temperature, adding a mixed solvent which is equal in mass to acetic anhydride and is prepared by mixing methanol and water in equal volume, precipitating and separating out a polymer, and performing suction filtration and drying at 120 ℃ to obtain the PEI composite material.

Compared with the prior art, the invention has the advantages that: according to the preparation method of the PEI composite material, the graphene and the nano silicon carbide are compounded and are ground with a proper amount of the surfactant, so that the graphene and the nano silicon carbide achieve a good compounding effect, the graphene and the nano silicon carbide are not simply blended, the graphene and the nano silicon carbide are more beneficial to being mutually inserted into a PEI complex to form a net structure, the performances of the graphene and the nano silicon carbide are complementary and exerted, and the toughness, the impact resistance and the wear resistance of the PEI complex are further enhanced. The graphene and the nano silicon carbide can be effectively dispersed in the polymer matrix by adopting an in-situ polymerization method, and the premise that the composite material with superior performance can be obtained is that the nano carbon material can be uniformly dispersed in the polymer matrix, which is difficult to achieve by a melt blending method and a solution mixing method, so that good physical and chemical bonding effects between the graphene and the nano silicon carbide and the polymer matrix PEI are realized, and the wear resistance, toughness and impact strength of the PEI composite are further enhanced.

In conclusion, the invention adopts the composite ligand of the nano carbon material, and the composite ligand is small in particle size distribution range and high in specific surface area, so that the composite ligand is mutually inserted into a PEI matrix to form a net structure, and plays an excellent role in dispersion and compatibility, thereby preparing the PEI composite material which is good in wear resistance, light in weight, high in strength and high in impact resistance and is suitable for industrial large-scale production.

Detailed Description

The present invention will be described in further detail with reference to examples.