MORPHOLOGY DEVELOPMENT DURING SOLID-STATE ANNEALING OF POLY(ETHER-ESTER) MULTIBLOCK COPOLYMERS

Morphology development during isothermal annealing of poly(ether-ester ) multiblock copolymers with hard segments containing poly(tetramethyl ene isophthalate) is examined by differential scanning calorimetry (DS C) and small-angle x-ray scattering (SAXS). Reorganization in the soli d-state occurs by melting and recrystallization. At temperatures close to the melting point, glass transition measurements after quenching f rom the annealing temperature suggest microphase mixing follows meltin g. The temperature of maximum recrystallization rate is elevated relat ive to that of isothermal crystallization. SAXS experiments suggest th at a memory of the initial morphology is retained during annealing. As pects of the DSC scans related to crystallization on cooling and resca nning also suggest that the morphology at the annealing temperature pl ays a governing role in the determination of the degree of order possi ble on cooling. The crystalline regions stable at the annealing temper ature are envisioned to function in a dual role, acting as nucleation centers for recrystallization and as a form of ''constraint'' to order ing on cooling. (C) 1996 John Wiley & Sons, Inc.