Differential Scanning Calorimetry Analysis of Silicon-Containing and Phosphorus-Containing Segmented Polyurethane. I-Thermal Behaviors and Morphology

摘要

This article investigated thermal transition and morphology utilizing differential scanning calorimetry (DSC), which was performed on silicon-containing and phosphorus-containing segmented polyurethane (si-PU and P-PU). The hard segments of those Si-PU and P-PU polymers investigated consisted of 4,4'-diephenylmethane diisocyanate(MDI) and diphenylsianediol (DSiD), and methylphosponic (MPA), respectively. The soft segment of those polymers comprised polytetramethylene ether glycol, with an average molecular weight of 1000 or 2000 (PTMG 1000 and PTMG 2000, respectively). Several thermal transitions appeared for on the Si-PU and P-PU polymers, reflecting both the soft-segment and hard-segment phases. The Si-PU and P-PU polymers with a lower hard-segment content exhibited a high degree of phase separating as indicated by the constancy of both the soft-segment glass transition temperature (T_gs) and the breadth of transition size (#DELTA#B). The polymers in which PTMG 2000 was used as the soft segment generally exhibited a crystalline melting endotherm about 10 deg C, while crystallization usually disappeared upon melt quenching. The hard segments of the Si-PU and P-PU polymers displayed multiple endotherms. The first endotherm was related to a short-range ordering of the hard segment domain (Region I), and the second endotherm was ascribed to a long-range ordering of the domain (Region II). The wide-angle X-ray demonstrated that the structure in Region I and Region II was almost completely amorphous.