Effects of polyurethane-based coating agent compositions on their abrasion resistance and friction coefficient

Although polyurethane (PU)- and polysiloxane-based coating agents find wide applications in electronics and automotive industries (e.g., for sealing), their full potential can be realized only based on a deep understanding of property-determining factors. To contribute to this understanding, we synthesized PU resins from polycarbonate diol, poly(tetramethylene glycol), and 4,4-diphenylmethane diisocyanate. The abrasion resistance, modulus, and tensile strength of PU films increased with increasing hard segment content whereas the elongation at break of these films concomitantly decreased. PU-based coating agents were prepared by adding PE wax and other modifiers and their friction coefficients were investigated. A friction coefficient of coating agent was strongly affected by particle size and content of PE waxes.