The effect of silica nanoparticles on the morphology, mechanical propertiesudand thermal degradation kinetics of polycarbonate

摘要

Polycarbonate/silica nanocomposites with different silica quantities were prepared by a melt compoundingudmethod. The effect of silica amount, in the range 1–5 wt.%, on the morphology, mechanical propertiesudand thermal degradation kinetics of polycarbonate (PC) was investigated. Clusters of silica nanoparticlesudwere well dispersed in the polycarbonate whose structure remained amorphous. NMR results showedudintermolecular interactions involving the carbonyl groups of different polymeric chains which did notudaffect the intramolecular rotational motions. The presence of the lowest silica content showed a decreaseudin the storage and loss moduli below the glass transition temperature, probably due to a plasticizationudeffect. However, an increase in the amount of silica increased the moduli. The presence of silica in PCudslightly increased the thermal stability, except for the highest silica content which showed a decrease.udThe activation energies of thermal degradation for the nanocomposites depended on the amount of silicaudand on the degree of conversion.