Preparation and performance of phenolic resin-based friction material modified with cardanol-graft-LNBR

Cardanol-graft-liquid nitrile rubber(LNBR) was prepared by solution grafting method firstly, and then phenolic resin (PF) was modified with LNBR and C-g-LNBR via in-situ polymerization, finally, the friction materials were fabricated using modified PF as matrix resins by compression-moulding. C-g-LNBR was characterized by FT-IR and weighting method. The dispersion of rubber phase in the matrixes was observed by optical microscope(OM), thermal properties of matrixes were analyzed by DSC and TG, mechanical and tribological properties of friction materials were also studied, and worn surfaces were observed by SEM. The results show that grafting reaction takes place between cardanol and LNBR, the extent of grafting is 4.22%. The dispersion of 2% C-g-LNBR in the matrix is better than 2% LNBR, Tcure of 2%-C-g-LNBR/PF decreases by 3.3℃ and 2.6℃, respectively, compared with pure PF and 2%-LNBR/PF. Besides, the impact strength of 2%-C-g-LNBR/PF based friction material increases by 14.8% and 7.3%, and its specific wear rate reduces by 13.6% and 15.4%, separately. In addition, the observation of SEM micrographs indicates that the pits of worn surface of 2%-C-g-LNBR/PF based friction material reduce obviously and the continuity of its worn surface is better than that of other friction materials. © 2016, Editorial Board of Polymer Materials Science & Engineering. All right reserved.