THE EFFECT OF CHAIN-LENGTH AND SOFT OLIGO(OXYETHYLENE) SEGMENTS CONTENT ON SOME PROPERTIES OF COPOLY(ESTER-ETHERS) .1. THERMAL-PROPERTIES

Multiblock copoly(ester-ethers) (KPEE) comprising rigid oligo(tetramethylene terephthalate) segments and flexible oligo(oxyethylene) segments were prepared. In the synthesis of KPEEs, oligo(oxyethylene) diols with molecular weights ((M) over bar(n)) of 400, 1000, 2000, 4000 or 6000 were used and the mass content of the flexible segments was changed over the range of 10-90%. The resulting KPEEs were investigated by intrinsic viscosity, swelling in water and benzene, and in particular by the DSC and WAXS methods. Crystallization of rigid and, at lower temperatures, of soft segments took place. Effects were studied of the (M) over bar(n) and of the mass content of flexible segment on the melting point, crystallization temperature and degree of crystallization of either type of segments and on mutual miscibility of the segments.