ON THE CRYSTALLINE NATURE OF POLY(DI-ISOPROPYL FUMARATE)

Molecular order of poly(di-isopropylfumarate) (PDIPF), obtained by free-radical initiation, is investigated by calorimetric measurements and X-ray diffraction analysis. It is found that the polymer decomposes without melting at temperatures above 200°C while displaying two endothermic transitions, probably of the solid-solid type, at 65 and 126°C respectively. Further evidence of crystalline order and orientability is provided by the X-ray experiments which show one equatorial (11.16 angstrom) and two meridional stereoselective nature of the polymerization reaction is interpreted as resulting from the steric influence of the bulky isopropyl substituents of the monomer.