Mark F. Teasley, B. Hsiao
Sep 23, 1996
Citations
0
Influential Citations
38
Citations
Journal
Macromolecules
Abstract
The title composition, isoPEK, was prepared from 4-fluoro-3‘-hydroxybenzophenone in N-methylcaprolactam at 225 °C. Cyclomer formation interfered with polymerization at lower temperatures in alternative solvents and dominated in dilute solutions. The 50/50 to 70/30 copolymers of PEK and isoPEK were prepared using 4-fluoro-4‘-hydroxybenzophenone. An analogous composition, poly(oxy-1,3-phenylenecarbonyl-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) or isoPEKEK, was prepared from 4,4‘-difluorobenzophenone and 3,4‘-dihydroxybenzophenone using similar conditions. Thermal crystallization of the copolymers was successful, but isoPEK and isoPEKEK were only capable of solvent-induced crystallization. The semicrystalline materials were studied by thermal analysis and X-ray diffraction. The copolymers melted at 264−307 °C and possessed random microstructures with isomorphic crystallization of the PEK and isoPEK repeat units. IsoPEK and isoPEKEK melted, respectively, at the low temperatures of 180 and 193 °C. ...