Synthesis and decomposition performance of a polymeric foaming agent containing a sulfonyl hydrazide moiety

A new monomer, methacryloyloxybis(benzenesulfonyl hydrazide) (MAOBSH) containing a foamable sulfonyl hydrazide functional group after decomposition by heating, was synthesized from 4,4′-oxybis(benzenesulfonyl hydrazide) (OBSH) with methacryloyl chloride, and used to obtain poly(MAOBSH) as a polymeric foaming agent (PFA) in dry tetrahydrofuran at 70 °C using azobisisobutyronitrile as an initiator. The structures of the synthesized MAOBSH and poly(MAOBSH) were identified using Fourier transform infrared and 1 H NMR spectroscopies. The decomposition temperature of poly(MAOBSH) was determined to be 245 °C and this temperature was decreased to around 160 °C by adding an activator such as surface-treated urea to the polymer. The exothermic temperature and heat determined by the decomposition of the polymer were 256 °C and 287 J g−1. The amount of gas evolution for poly(MAOBSH) measured at the decomposition temperature was 74 mL g−1. Furthermore, polymers incorporating the PFA showed better skin and finer cell structure as well as better mechanical properties such as elongation and compression set than polymers with added OBSH due to the better compatibility of the developed PFA with polymers. © 2012 Society of Chemical Industry