多面体低聚倍半硅氧烷对环氧树脂热性能影响分析

选用有机–无机纳米杂化材料乙烯环氧基多面体低聚倍半硅氧烷(EOVS)和环氧醚基多面体低聚倍半硅氧烷(GPOSS)为改性剂,与4,4′-二氨基二苯甲烷环氧树脂共混制得不同改性剂质量分数(树脂与改性剂总质量的百分数)的EOVS或GPOSS改性环氧树脂,考察了改性树脂的固化反应程度、玻璃化转变温度(Tg)和热稳定性。结果表明,当EOVS或GPOSS的质量分数为1%时,两种改性树脂的固化交联程度和Tg最高,Tg比未改性树脂分别提高了9.18℃和11.51℃;当EOVS质量分数为5%或GPOSS质量分数为1%时,改性树脂的热失重5%温度比未改性树脂提高6.24℃和8.1℃。在笼形结构的空间位阻和Si—O、Si—C等高键能化学键的综合作用下,多面体低聚倍半硅氧烷的引入可提高环氧树脂的热性能。

Analysis on Effects of Polyhedral Oligomeric Silsesquioxane on Thermal Properties of Epoxy Resin

Two kinds of organic-inorganic nano hybrid material—ethylene epoxy polyhedral oligomeric silsesquioxane(EOVS)and epoxy ether polyhedral oligomeric silsesquioxane(GPOSS)were used as modifiers,and they were blended with 4,4′-diaminodiphenylmethane epoxy resin(EP)to obtain EOVS or GPOSS modified EP with different modifier content(percentage of total mass of EP and modifier),and degree of curing reaction,glass-transition temperature(Tg)and thermal stability of the modified EP were investigated.When the content of EOVS or GPOSS is 1wt%,compared with the unmodified EP,Tg of the modified EP are increased by 9.18℃and 11.51℃respectively due to the highest crosslinking degree.When the content EOVS is 5wt%or GPOSS is 1wt%,compared with the unmodified EP,the 5%thermal decomposition temperature of the modified EP are increased by 6.24℃and 8.1℃respectively.Considering spatial resistance of cage structure,high-energy bonds such as Si—O and Si—C,bringing in polyhedral oligomeric silsesquioxane can improve the thermal properties of EP.