New linear polyurethaneureas based on polyoxytetramethylene, aliphatic diisocyanates, and aromatic diamines

摘要

AbstractNew polyurethaneureas have been synthesized with α‐ω hydroxylated polyoxytetramethylene, aliphatic diisocyanates and nonhalogenated aromatic diamines. Four series of PUR have been studied by varying the PTMO molecular weight, the stoichiometry, the nature of the aliphatic diisocyanate, and the steric hindrance of the aromatic diamine. Quantitative evaluation of the degree of phase separation was obtained by DSC. An estimation of the dispersed soft segments outside the soft phase could thus be made. In addition to DSC, dynamic mechanical properties, were obtained for the four series of PUR over a wide temperature range. The hard segments in the PUR chains are amorphous and their high temperature behavior depends only on the strength of interactions in the amorphous state. Finally, stress‐strain measurements were carried out on a few samples, and a wide range of tensile properties has been obs