氨基-环氧基新型有机硅固化体系

Amino-epoxy Group for Silicone Curing System

以六甲基二硅氧烷、四甲氧基硅烷为原料合成了MQ树脂,然后与带环氧基的硅氧烷反应,合成了环氧基改性硅树脂;用γ-氨丙基三乙氧基硅烷合成氨基笼形倍半硅氧烷(氨基POSS)。并用红外光谱仪和X射线衍射仪表征了二者。将氨基POSS作为环氧基改性硅树脂的固化剂,利用多氨基和环氧基的开环加成反应组成一种新型有机硅固化体系。考察了环氧基改性硅树脂与氨基POSS的质量比对固化体系表干时间及固化物硬度的影响、固化物的耐热性。结果表明,环氧基改性硅树脂与氨基POSS的质量比为100∶1～150∶1时,表干时间较快,固化物表面光滑平整、硬度较好;环氧基改性硅树脂与氨基POSS的最佳质量比为100∶1;此固化体系室温下的操作时间较长,放置4周后黏度上升不超过15%;差热分析结果显示,固化物在40～300℃时的质量损失率为5%左右,分解温度在450℃左右,在681.28℃时的残留率仍有53%。

MQ resin was prepared from tetramethoxyl silane and hexamethyldisiloxane;then reacting with epoxy-containing silane to get epoxy modified silicone resin.γ-aminopropyl triethoxysilane was used to synthesis amino-cage POSS（polyhedral oligomeric silsesquioxane）,both were characterized by IR and XRD.A new type of silicone curing system was developed via the ring-opening addition reaction between amino and epoxy groups with epoxy modified silicone resin as the curing agent for amino-POSS.The weight ratio of epoxy modified silicone resin and amino POSS had an effect on the surface dry time of curing system,the hardness and curing thermal stability of the cured films.The results showed that when the weight ratio of epoxy modified silicone resin and amino POSS was 100∶1～150∶1,the short surface drying time and smooth curing surface could be obtained with good hardness.When the weight ratio of epoxy modified silicone resin and amino POSS was 100∶1,the system had good storage stability,whose viscosity increased 15% even after 4 weeks at room temperature.DSC analysis showed that the weight% decreased about 5% when temperature increased from 40 ℃ to 300 ℃,decomposition temperature was 450 ℃,and residual mass fraction was 53% at 681.28 ℃ with good heat-resistance.