宇航材料工艺2024，Vol.54Issue(4)：117-125,9.DOI:10.12044/j.issn.1007-2330.2024.04.017
酚醛/硅改性环氧共混物空气环境降解残留物结构及组分研究
Study on Structure and Composition of Residual Compounds From Air Environment Thermolysis of Phenolic/Siloxane Modified Epoxy Blends
摘要
Abstract
The epoxy-polysiloxane copolymer(ES)was synthesized by condensation reaction of hydroxy-terminated polydimethylsiloxane(HTPDMS)and bisphenol A epoxy resin(CYD-128),and then blended with phenolic resin to modify and obtain polysiloxane modified epoxy/phenolic blend(ES/PF).Thermal properties of ES/PF blend and the chemical structure and composition of pyrolysis residues at different temperatures were investigated by thermogravimetry-differential scanning calorimetry(TGA-DSC),fourier transform infrared spectroscopy(FTIR),scanning electron microscopy with energy dispersive spectrometer(SEM-EDS),and X-ray photoelectron spectroscopy(XPS).The results show that,compared with pure phenolic resin,the residual yield of ES/PF blend increases by 438％at 800 ℃ in air atmosphere,and the maximum heat release rate decreases from 21.98 W/g to 14.93 W/g.However,under N2 atmosphere,the residual yield decreases slightly by 14.3％.In addition,the hybrid structure rich in Si-Ox in the pyrolysis condensed phase of ES/PF blend system within 430-600 ℃ plays a key role in the stable formation of carbon layer,effectively delaying and inhibiting the further degradation of resin,and thus improving the carbon residue rate.When the temperature exceeds 430 ℃,the existing form of silicon element in the residue changes significantly,from SiO2(accounting for more than 80％)at 430 ℃ to hydrated silica(SiO2·nH2O)at 600 ℃.These results fully indicate that the silicon element can significantly improve the carbon residue and thermal stability of phenolic resin under thermal oxygen condition,but its influence is suppressed to a certain extent under N2 conditions,which may be attributed to the oxygen absorption mechanism of siloxane groups during pyrolysis process.In addition,the structure and composition of pyrolysis residues of ES/PF blend system have a positive effect on improving the thermal residual strength and ablation resistance of the material.关键词
聚硅氧烷/环氧树脂/酚醛树脂/热解/结构Key words
Polysiloxane/Epoxy resin/Phenolic/Thermolysis/Structure分类
通用工业技术引用本文复制引用
冀运东,江艳艳,周睿,曹东风,李书欣..酚醛/硅改性环氧共混物空气环境降解残留物结构及组分研究[J].宇航材料工艺,2024,54(4):117-125,9.基金项目
先进能源科学与技术广东省实验室佛山分中心(佛山仙湖实验室)重点基金(No.XHT2020-002) （佛山仙湖实验室）
中央高校基本科研业务费专项资金(2020Ⅲ066GX) （2020Ⅲ066GX）
湖北省对外科技合作项目(2013BHE008) （2013BHE008）
