SYNTHESIS, CHARACTERIZATION AND THERMAL-DEGRADATION STUDIES OF POLY(ETHER ETHER KETONE) COPOLYMERS

Poly(ether ether ketone) copolymers (I-V) were prepared by the nucleophilic reaction of 4,4'-difluorobenzophenone with varying mole proportions of hydroquinone and resorcinol using sulpholane as solvent and in the presence of K2CO3. The polymers were characterized by different physico-chemical techniques. The glass transition temperature and crystallinity of the polymers was found to decrease with increase in concentration of the resorcinol units in the polymers. Thermogravimetric studies showed that all the polymers were stable up to 400-degrees-C with a char yield above 50% at 900-degrees-C in nitrogen atmosphere. The isomeric polymers (I and V) showed distinct differences in their thermal degradation behaviour and the pyrolysis-g.c. data indicated the random nature of the copolymers (II-IV). The amount of resorcinol evolved during pyrolysis at 800-degrees-C was correlated with the sequence distribution of the comonomers in the polymer.