Application of lignin-modified phenolic resins to brake friction material

摘要

Lignin-modified phenolic resin (LPF) is prepared from methanol-soluble lignin by polymer blend methods (solvent blend and in situ polymerization) for application to environment-friendly brake friction material. The chemical structure of LPF is characterized by ~(13)C NMR, and TMA and DSC analyses are conducted to evaluate the thermal behaviors. Flexural tests and brake dynamometer tests of samples prepared from LPF by compression molding are carried out, and the results are compared with those for the samples prepared from commercial phenolic resin (PF). Results of the flexural test show that the addition of methanol-soluble lignin by solvent blend polymerization decreases the flexural strength. In contrast, in situ polymerized LPF exhibits flexural strength equivalent to that of PF. Results of the brake dynamometer test show that replacement of PF with methanol-soluble lignin increases the fade resistance of the brake friction material at elevated temperatures.