Poly(2,6-dimethyl-1,4-phenylene oxide)-poly(methyl methacrylate) interpenetrating polymer networks

Two-component simultaneous interpenetrating polymer networks (SINs)of brominated poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) cross-linked with ethylenediamine (EDA) and poly(methyl methacrylate) (PMMA) cross-linked with ethylene glycol dimethacrylate (EGDMA) were prepared. The estimated molecular weights between cross-links (M sub e ) from the stoichiometry of the PPO and PMMA networks were 6000 and 7900, respectively. Differential scanning calorimetry (DSC) measurements show that the IPNs have a single glass transition (T sub g ) intermediate in temperature to the T sub g s of the component networks. Transmission electron micrographs also are consistent with a single-phase morphology. A maximum in tensile strength significantly higher than the tensile strengths of a component network occurred at an intermediate composition, just as has been observed for the PPO/polystyrene IPNs. . 8 ref.--AA