1987 Volume 44 Issue 12 Pages 867-876
The phase separated structures of crosslinked polyurethane ionenes with different lengths of ionene segments were studied. The contributions of ionic bonds in the concentration of effective network chains, νc/V, which were estimated from stress-strain measurements, were separated from those of covalent bonds. The ionene segment consists of N, N, N′, N′-tetramethylhexanediamine and 1, 6-dibromohexane (DBH series) or p-xylylenedichloride (XDC series). Small angle X-ray scattering patterns showed the existence of a superstructure with a long period; this results suggests that the polyurethane ionenes have hard ionene domains. The ionic bonds greatly contributed to the total νc/V. As the ionene segment length increased, the primary νc/V due to ionic bond decreased but the secondary νc/V markedly increased. A relation between the primary νc/V and the degree of phase separation estimated from dynamic mechanical measurements was noticed. As the degree of phase separation increased, the primary νc/V decreased in DBH series and increased in XDC series. These different trends in the primary νc/V arise from the different sizes of ionic domains in the two series of polyurethane ionenes.
