COMPATIBILITY OF PEO POLY(ISO-BUTYL METHACRYLATE) AND PEO/POLY(TERT-BUTYL METHACRYLATE) BLENDS BY DTA/

Melting temperatures and crystallization rates of poly(ethylene oxide) /poly(iso-butyl methacrylate) and poly(ethylene oxide)/poly(tert-butyl methacrylate) blends of different compositions were studied by differ ential thermal analysis (DTA). The equilibrium melting temperatures we re found to decrease, for a given T-C or Delta T-m, as the poly(iso-bu tyl methacrylate) (PIBMA) and poly(tert-butyl methacrylate) (PTBMA) co ntents decrease. For a given blend composition, the higher the crystal lization temperature, the higher the observed melting point. Negative values of the binary Flory-Huggins interaction parameter, chi(12), wer e obtained by studying the dependence of the equilibrium melting tempe rature depression, Delta T-m, upon composition for both systems. Such observations are interpreted by assuming that PIBMA and PTBMA are comp atible with poly(ethylene oxide) (PEG) in the range of crystallization temperatures and compositions investigated. Crystallization rates wer e found to follow the Avrami equation.