Development of green materials from ENR-25/PHBV blends: Curing characteristics and mechanical performance

Abstract

The objective of this work was to develop green materials from epoxidized natural rubber (25% epoxidation), (ENR-25), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), (PHBV), and polybutadiene adducted with maleic anhydride, (PB-g-MA) as compatibilizer. The ENR-25/PHBV blends were prepared at the ratio of 100/0, 90/10, and 80/20 with 0 and 10 %wt. PB-g-MA. The blends were prepared using an internal mixer, where PHBV was first melted at a temperature of 175 °C before mixing with ENR-25 and the incorporation of a compatibilizer. The mixing of ENR-25 and PHBV was continued at a temperature of 175 °C and mixing speed of 50 rpm until it reaches the complete blending time. All ENR-25/PHBV blends were then mixed with curing agents in an internal mixer at a temperature of 50 °C. The cure characteristics were determined using a moving die rheometer (MDR). Then vulcanization proceeded in a compression molding machine. The result shows that the addition of PHBV enhanced the modulus of ENR-25 for every blend ratio with and without compatibilizer owing to the mechanical properties of PHBV. Significantly, the PB-g-MA compatibilizer successfully improved the interface adhesion between ENR-25 and PHBV and the decrease in phase size was clearly seen in the SEM images.