BLENDS OF POLYACRYLONITRILE WITH POLYURETHANE IONOMERS

Solution blends of a modified polyacrylonitrile (PAN) with polyurethan e (PU) ionomers were prepared in N,N-dimethylformamide. PU anionomer ( PUAn20) blends showed phase separation of up to several micrometers, w hereas almost homogeneous morphology was obtained with PU cationomer b lends. In PU cationomer blends, the tan delta peaks of the soft segmen ts of PU and PAN moved toward lower and higher temperature, respective ly. Notably, the tensile strength of PU cationomer blend at 30/70 (PU/ PAN by weight) increased to over 2.5 times that of PAN; for this blend the concentration of PU cation approximately matched that of the sulf onate anion of the modified PAN. The synergistic effect was interprete d in terms of ionic interactions between the main chains of the polyme rs.