高导热石墨用聚酰亚胺薄膜的制备及其性能研究
采用BPDA为二酐，mPDA、ODA为二胺，控制mPDA与ODA的配比，通过两步法制备BPDA-mPDA-ODA型聚酰亚胺（PI）薄膜，利用红外光谱(FTIR)、热失重分析(TG)、万能电子拉伸机研究了不同二胺配比下PI薄膜的热学性能和力学性能。然后对PI薄膜进行碳化、石墨化热处理，制备PI基碳膜和石墨膜。通过X射线衍射、拉曼、扫描电镜、导电性测试等研究碳膜的结构与性能。通过导热仪测定最终石墨膜的导热性。32591
结果表明：PI薄膜拉伸强度随mPDA比重的增加而增大。随着碳化温度的升高或碳化时间的加长，所得碳膜碳结构有序性增加，石墨化程度提高。随着二胺中mPDA比重的增多，碳结构有序性增加，碳层致密性也更好。PI膜原始厚度对其碳化后碳膜的有序度影响非常明显，初始PI薄膜越薄，则碳膜的有序度越高。当碳化温度从700℃升到900℃，碳膜的电阻率呈数量级的降低，碳膜导电性变高。不同配方PI膜在相同碳化温度下碳化所得碳膜的电阻率基本相似，随着配方中mPDA比重的增加，碳膜导电性有微小的提高。石墨膜的规律与碳膜相似。
关键词：聚酰亚胺; 碳化; 石墨化; 热导率
毕业论文设计说明书外文摘要
Title Preparation of Polyimide Films Producing Carbon Materials with High Thermal Conductivity and Study of Their Properties
Abstract
Polyimide is the mainly commercial aromatic heterocyclic polymer.It has been widely used in aviation, aerospace, electrical, microelectronics, mechanical, chemical and other fields.
The raw materials are BPDA for dianhydride and mPDA, ODA for diamine. Polyimide(PI) film is prepared by two-step approach. And the ratio of mPDA and ODA was controled. By the test of infrared spectroscopy (FTIR), thermal graity analysis (TG) and universal electronic tensile machine，thermal properties and mechanical properties of PI film which have different ratio of diamineare were studied. And then through carbonization and graphitization heat treatment for PI film, the preparation of carbon and graphite membranes are completed. By the test of X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM) and electrical conductivity，structure and performance of carbon membrane are researched. Through thermal conductivity meter，the thermal conductivity of the graphite film finally is measured.
The results show that the tensile strength of PI film increases with the increasing of the content of mPDA. With the increase of carbonization temperature or the length of carbonization time,the order of carbon structure and the graphitization degree of carbon membrane improve. With the increase of content of mPDA in diamine, the order of carbon structure increases, and the carbon layer is more closely. The effect of original thickness of PI film on the carbide carbon membrane is obvious. The initial PI film is thinner, the degree of order of the carbide film is higher. When the carbonization temperature raised from 700℃ to 900℃, the electrical resistivity of carbon membranes show decrease trend with order of magnitude.Conductivity of carbon film become higher. The electrical resistivity of different formula carbide films at the same carbonization temperature is basically similar. With the increase of content of PDA in the materials, conductivity of carbon film has minor improvement.Laws of the graphite film are similar to carbon film.
Keywords: Polyimide;carbonization;Graphitization;Thermal conductivity
目录
1 绪论 1
1.1 聚酰亚胺概述 1
1.2 高导热石墨碳膜概述 3
1.3 聚酰亚胺基石墨膜概述 5
1.4本课题的研究目标与内容 6