Remarkable enhancement of thermal stability of epoxy resin through the incorporation of mesoporous silica micro-filler

For the first time, we incorporated mesoporous micro-silica (5 mu m, pore size = 50 nm) as a filler in epoxy resin aiming to enter polymer into the pore of the silica. As expected, the thermal stability of the composite increased remarkably, followed by noteworthy thermal degradation kinetics when compared to the controlled cured epoxy resin. Composites were prepared by the direct dispersion of modified nano-silica, modified mesoporous micro-silica, unmodified mesoporous micro-silica, non-porous micro-silica, and irregular micro-silica of various pore sizes as fillers in diglycidyl ether of bisphenol-A epoxy resin via ultra-sonication and shear mixing, followed by oven-curing with 4,4-diaminodiphenyl sulfone. DSC and TGA analyses demonstrated a higher glass transition temperature (increased by 3.65-5.75 degrees C) and very high activation energy for thermal degradation (average increase= 46.2%) was obtained for the same unmodified silica composite compared to pure epoxy, respectively.

Automated summary

In this study, mesoporous micro-silica was incorporated as a filler in epoxy resin for the first time, resulting in significantly improved thermal stability and higher glass transition temperature in the composite materials. DSC and TGA analyses showed that the silica composite had a higher activation energy for thermal degradation compared to pure epoxy resin.