Synthesis and properties of ordered polyurethanes from p-isocyanato benzylisocyanate as a nonsymmetric diisocyanate, ethylene glycol and 1,3-benzenedimethanol

Ordered polyurethanes with totally head-to-head (H-H) or totally tail-to-ta il (T-T) structure were prepared by polyaddition reaction of a nonsymmetric monomer, p-isocyanatobenzyl isocyanate (PIBI) with a symmetric monomer, et hylene glycol (EG) and 1,3-benzenedimethanol (BM). The polymerization was c onducted under various conditions by changing the order in which the monome rs were introduced. The microstructure of the obtained polymer was investig ated by C-13 NMR spectroscopy, the polymer had the expected structural regu larity. The constitutional regularity of the polymers influenced the solubi lity, thermal properties, crystallinity and optical properties.