多面体硅倍半氧烷锂盐在环氧树脂中的纳米分散与力学增强效应

Incompletely condensed hepta-phenyl silsesquioxane trisilanol (T₇-Ph-POSS) and hepta-phenyl silsesquioxane lithium salt (Li-Ph-POSS) were selected as functional additive. Two epoxy resin (EP) composites were prepared by adding 1% of polyhedral oligomeric silsesquioxane (POSS). The thermal stability, optical properties, mechanical properties and flame retardant properties were investigated. The results show that three-dimensional submicron spherical particles of T₇-Ph-POSS are dispersed in the EP matrix, the dispersion particle size is 0.1~1 μm. While Li-Ph-POSS displays the dispersion of zero-dimensional spherical nanoparticles, and the dispersion particle size is about 40 nm. The thermal stability of the EP composites is improved. EP/Li-Ph-POSS has the property of absorbing blue-violet light and endows with the excellent transparency, and the transmittance in the purple light region is close to 0. Compared with pure EP, the tensile strength, flexural strength and impact strength of EP/Li-Ph-POSS are increased by 40.2%, 40.8%, and 3.8%, respectively, and the peaks of heat release rate and smoke release rate are significantly reduced. Therefore, the mechanical properties and flame retardancy of EP/Li-Ph-POSS are obviously enhanced.