Poly‐cardanol as plasticizer and compatibilizer on styrene butadiene rubber with improved processability and silica dispersion

Abstract Natural products used as plasticizer can inhibit its migration in rubber and improve the dispersion of inorganic power. Herein, styrene butadiene rubber (SBR) was plasticized by poly‐cardanol (PCA) originated from the Friedel–Crafts alkylation without solvent of cardanol which was extracted from abandoned cashew nut shell. Results show that the Mooney viscosity of SBR/PCA compounds decreases from 45.8 to 34.7 and T g from −52°C to −56.3°C when PCA is added from 0 to 30 phr. Moreover, the elongation at break of SBR contained 30 phr PCA increases by 515% compared with SBR. PCA also shows amphiphilic, which is verified by the improved dispersion of SiO 2 in SBR/PCA compounds. The swelling ratio of SBR/PCA/SiO 2 vulcanized rubber decreases and the crosslinking density increases. Meanwhile, the elongation at break of SBR 70 ‐40 vulcanized rubber is 17.3%, which is higher than that of SBR 100 ‐40 vulcanized rubber. PCA, acted as plasticizer and compatibilizer, provides a simple and green way for the application of natural products in the rubber industry.