A New Synthesis Method of Hyperbranched Polyurethane Acrylate for Conductive Ink

Abstract

Hyperbranched polyester polyols (HBPE) of second, third and forth generation were synthesized by procedures involving one step (HBPE-2), step by step (HBPE-3, HBPE-4). Based on the hyperbranched polymer chain extension method, a new type of hyperbranched polyurethane acrylate (HPUA) was obtained by the end-capping of HBPE with the obtained UA which was synthesized isophorone diisocyanate (IPDI), hydroxyethyl methacrylate (HEMA) and dibutyltin dilaurate (DBTL) at the reaction temperature of 70 °C. The characterization of the polysters was done by fourier transform infrared spectroscopy (FTIR), acid value, differential scanning calorimeter (DSC), isocyanata on solution, thermogravimetry (TG) and nuclear magnetic resonance (NMR). The results of DSC and TG showed that the glass transition temperature (Tg) of HBPE-3 and HPUA-3 were respectively 56.13 and 35.56 °C. The cold crystallization temperature (Tc) of HPUA-3 was 110.92 °C and melting temperature (Tm) was 134.74 °C. Therefore, both of them can be achieved under low temperature melting. Moreover, the introduction of a large number of unsaturated units in the end of HPUA can provide new ideas to UV curing resin. Finally, it gained good conductivity (8405 S/m) when it was applied to conductive inks.