SYNTHESIS AND PROPERTIES OF POLY(ETHER ETHER KETONE) 4,4'-DIHYDROXYDIPHENYL SULFONE MULTIBLOCK COPOLYMERS

Poly(ether ether ketone) (PEEK)/4,4'-dihydroxydiphenyl sulfone (DHDPS) multiblock copolymers with a content of the diphenoxysulfone (DPOS) m oiety between 4.9 and 36.6 wt.-% were synthesized by the reaction of D HDPS and fluorine-terminated PEEK oligomers. The number-average molecu lar weight of PEEK oligomers (M-n) was varied from 470 to 4900. The ef fect of the compositional variation on the properties was investigated . Microphase separation was not observed. The copolymers formed a homo geneous system having good compatibility. The copolymers whose DPOS co ntents are not exceeding 23.1 wt.-% (M-n of PEEK segment greater than or equal to 865) have crystalline structure. From the measurements of wide- and small-angle X-ray scatterings it was revealed that the cryst al structure of the copolymers is rhombic, equal to PEEK, and the dist ribution of the thickness of the crystalline and amorphous regions is very broad. The degree of crystallinity and the melting point of the c opolymers decreased and the glass transition temperature (T-g) gradual ly rose with the increase of the DPOS content (or the decrease of M-n of the PEEK segment).