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Single‐Phase blends of polycarbonate and poly(phenyl methacrylate)
Author(s) -
Kyu Thein,
Park Dongkyu,
Cho Wookap
Publication year - 1992
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1992.070441220
Subject(s) - miscibility , differential scanning calorimetry , materials science , polycarbonate , glass transition , polymer chemistry , methacrylate , polymer blend , phase (matter) , birefringence , polymer , analytical chemistry (journal) , composite material , polymerization , copolymer , organic chemistry , thermodynamics , chemistry , optics , physics
Miscibility studies on blends of polycarbonate (PC) and poly(phenyl methacrylate) (PPMA) were undertaken by means of differential scanning calorimetry (DSC), dynamic mechanical, and dielectric relaxation methods. PC and PPMA were mixed by dissolving in tetrahydrofuran (THE) and subsequently coprecipitated in methanol. DSC studies showed a single glass transition ( T g ) that shifts systematically with composition. These T g s are reproducible in repeated DSC heating cycles, suggesting true miscibility of the pair. The dry PC and PPMA pellets were melt mixed in a Mini‐Mixer/Molder. The extrudates were compression molded. These melt‐mixed PC/PPMA blends exhibited glass like transparency and also showed a single T g in the DSC scans. The true miscibility of PC and PPMA was further confirmed by dynamic mechnaical and dielectric relaxation methods. The net birefringence has been reduced substantially because of the opposite sign of the itrinsic birefringence of PC and PPMA molecules. At the 12/88 PC/PPMA, the birefringence remains zero at all draw ratios, indicating the achievement of birefringence free polymer alloys.