OBSERVATION OF 2-STAGE CRYSTALLIZATION OF POLY(ETHER ETHER KETONE) BYTHERMAL-MECHANICAL ANALYSIS

We report the application of thermal mechanical analysis (t.m.a.) to s tudying the crystallization behaviour of poly(ether ether ketone) (PEE K). We are able to show that the two crystallization stages of PEEK ar e clearly distinguished by measuring the variation of film thickness w ith time during isothermal crystallization. These two crystallization stages cannot be readily distinguished by d.s.c. The distinction by t. m.a. becomes less clear with increasing crystallization temperature du e to overlap of the two crystallization stages.