Preparation and Characterization of Electroconductive Adhesives of NanoG/Polyurethane-Epoxy IPNs

摘要

Polyurethanes (PU) based on toluene diisocyanate (TDI) and polypropylene glycol 2000 (PPG) were reacted with an epoxy resin (EP) to prepare interpenetrating polymer networks (IPNs). Three kinds of electroconductive adhesives were prepared by dispersing nano-graphite (NanoG) into different matrices, i.e., pure PU, crosslinked PU/EP, and pure EP. The effects of epoxy content on morphological structure, conducting properties, thermal stability, and adhesive properties of the electroconductive adhesives were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, standard digital multimeter, dynamic mechanical thermal analysis, and lapshear tests. The results indicate that epoxy in the polyurethane-epoxy IPN adhesives plays an important role in clanging the morphological structure and improving conductivity properties, thermal stability, and adhesive properties of the electroconductive adhesives of PU.