The correlation between crosslink density and thermal properties of high-density polyethylene/natural rubber/thermoplastic tapioca starch blends prepared via dynamic vulcanisation approach

Dynamically vulcanised NR phase with sulphur crosslinker was investigated on the thermal properties of high-density polyethylene/natural rubber/thermoplastic tapioca starch (HDPE/NR/TPS) blends. The effect of dynamic vulcanisation on the crosslink density of the NR phase was characterised by using the gel content method and Fourier transform infrared analysis. In this blend system, TPS acted as a biodegradation agent and the incorporation of TPS generally caused a decrease in thermal stability and the degree of crystallinity. However, through the comparison of thermal degradation, dynamic vulcanised HDPE/NR/TPS blends proved to be superior to unvulcanised HDPE/NR/TPS counterparts. The better dimensional stability and enhanced compatibility between phases were obtained in dynamic vulcanisation blends, as observed in the dynamic mechanical analysis. Moreover, the improvement observed in thermal degradation of dynamic vulcanisation of HDPE/NR/TPS was also correlated with the crosslink formation within the NR phase.