Jk. Cao et al., SYNTHESIS, PROPERTIES AND CRYSTALLIZATION BEHAVIOR OF POLY(ETHER ETHER KETONE) POLY(PHENOLPHTHALEIN ETHER SULFONE) BLOCK-COPOLYMERS/, Die Angewandte makromolekulare Chemie, 238, 1996, pp. 191-206
Poly(ether ether ketone) (PEEK)/poly(phenolphthalein ether sulfone) (P
PES) block copolymers were synthesized by a condensation reaction of f
luorine-terminated PEEK oligomers and hydroxy-terminated PPES oligomer
s. The content of PPES in the copolymers was varied from 12 to 44 wt.-
%, and the effect of the compositional variation on the properties was
investigated. Microphase separation was not observed and the copolyme
rs formed a homogeneous system having good compatibility. The crystal
structure of the copolymers is rhombic, equal to PEEK. The degree of c
rystallinity of the copolymers was low and decreased rapidly with the
increase of PPES content. Concerning the cell parameters of the crysta
lline unit, a- and b-axes are apparently longer and V is, thus, also l
arger compared with PEEK. Analyses of the isothermal crystallization k
inetics of the copolymers provided an Avrami exponent (n) of 2.0. The
glass transition temperature (T-g) of the copolymers greatly rose but
the thermal stability became much poorer with the increase of PPES con
tent. PEEK/PPES block copolymers possess good mechanical properties su
ch as high strength and modulus.