Non-isothermal Crystallization of Poly(ethylene-co-glycidyl methacrylate)/Silica Nanocomposites

Nano-sized silica particles were modified by γ-aminopropyltriethoxysilane and the modified and unmodified silica particles were then respectively compounded with poly(ethylene-co-glycidyl methacrylate) (PEGMA) in a twin-screw extruder. Non-isothermal crystallization behaviors of neat PEGMA, PEGMA/unmodified silica (Silica), and PEGMA/modified silica (A-Silica) were studied by differential scanning calorimeter at various cooling rates. Modified Avrami model, Ozawa model, and Liu model all successfully described the non-isothermal crystallization processes of the samples. All these models predicted correctly that the crystallization rate follows the order: PEGMA/Silica > PEGMA/A-Silica > PEGMA. Calculated activation energies for the non-isothermal crystallization processes also indicated that the addition of silica accelerated the crystallization process of PEGMA, whereas the silica particles also retarded the crystallization process if well dispersed.