Radiation crosslinking of styrene–butadiene rubber containing waste tire rubber and polyfunctional monomers

• The effect of γ radiation on SBR blended with waste tire rubber was studied.
• Two polyfunctional monomers were used to increase the crosslinking.
• Mechanical properties of the blends were increased with absorbed dose.
• TMPTA containing blend showed higher tensile strength and thermal stability.
• Comparison with sulfur crosslinking was also done.

The objective of this study was to investigate the influence of polyfunctional monomers (PFMs) and absorbed dose on the final characteristics of styrene–butadiene rubber (SBR) mixed with waste tire rubber (WTR). A series of SBR/WTR blends were prepared by varying the ratios of WTR in the presence of PFMs, namely trimethylolpropane trimethacrylate (TMPTMA) and trimethylolpropane triacrylate (TMPTA) and crosslinked using gamma rays. The physicochemical characteristics of the prepared blends were investigated. It was observed that tensile strength, hardness and gel content of the blends increased with absorbed dose while the blends containing TMPTA showed higher tensile strength, gel content and thermal stability as compared to the blends containing TMPTMA. Higher thermal stability was observed in the blends which were crosslinked by radiation as compared to the blends crosslinked by sulfur. These blends exhibited higher rate of swelling in organic solvents, whereas negligible swelling was observed in acidic and basic environment.