Preparation, characterization, and electrostatic dissipating properties ofpoly(oxyalkylene)-segmented polyureas

A family of poly(oxyalkylene)-segmented and urea-linkaged polymers were pre pared from the reaction of isophorone diisocyanate (IPDI) or toluene-2,4-di isocyanate (TDI) and poly(oxyalkylene)diamines at 1:1 or 1 :2 molar ratio. Their structures were characterized by using IR and GPC. The chemical struc tures with respect to oxyalkylene backbone, terminal -NH2, uriedo linkage, weight fraction, and crystallinity of the involved poly(oxyethylene) segmen ts were correlated to the measurement of surface resistivity. The oligomeri c polyureas prepared from poly(oxyethylene)diamine generally had a lower su rface resistivity than the starting amine due to the lowering crystallinity . The incorporation of poly(oxyethylene) segments proportionally increased hydrophilicity and consequently lowered surface resistivity as low as 10(7. 4) Omega sq(-1) in comparison with 10(9.8-10.0) Omega sq(-1) for the semi-c rystalline starting amines. Amine termination in oligomers also contributed to the lowering of surface resistivities. The comparisons between polyuret hanes and polyureas further revealed the importance of hydrogen bonding inv olving mechanism for the electron transfers.