Interpenetrating polymer networks of polyaniline and maleimide-terminated polyurethanes

A series of novel conducting interpenetrating polymer networks (IPNs) was prepared by sequential polymerization of maleimide-terminated Polyurethane (UBMI) and polyaniline (PANI) which was doped with dodecylbenzenesulfonic acid (PANIDB). From the differential scanning calorimetry (DSC) analysis of the IPNs, the compatibility of the polyether-type UBMI with PANIDB was better than that of the polyester-type UBMI with PANIDB. The IPNs exhibited higher conductivity and better mechanical properties when the polyether-type UBMIs were used in the composition. The scanning electron microscopy (SEM) of the IPNs illustrated heterogeneous structure of the cured resins when the polyester-type UBMI was incorporated in the UBMI/PANIDB IPNs. Scanning tunneling microscopy (STM) images of the compatible polyether-type PANIDB /UBMI IPNs indicated that the conducting region of the PANIDB was distributed as continuous conducting networks in the matrix, which resulted in higher conductivity and very low threshold concentration of the PANIDB for the conducting IPNs.