Thermal characteristics of poly(ethylene oxide)/poly(methyl methacrylate) interpenetrating polymer networks

Poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) interpenetrating polymer networks (IPNs) were synthesized by radical polymerization of methyl methacrylate in the presence of PEO. Thermal properties were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dielectric analysis (DEA) and Fourier transform infrared (FT-IR) spectroscopy. The DEA was employed to ascertain the glass transition temperature (T-g) and melting temperature (T-m) of IPN. T-m for the IPNs was observed at 206 degreesC. The IPNs exhibited two TgS, indicating the presence of phase separation in the IPN at -46.8 and 78.2 degreesC. The thermal decomposition of the IPNs occurred near 250 degreesC. The IPNs exhibited a higher weight retention at elevated temperature than the cross-linked homopolymer.