Compatibilizing and toughening blends of recycled acrylonitrile-butadiene-styrene/recycled high impact polystyrene blends via styrene-butadiene-glycidyl methacrylate terpolymer

To increase the effectiveness of recovered acrylonitrile-butadiene-styrene (rABS) and recycled high impact polystyrene (rHIPS), styrene-butadiene-glycidyl methacrylate (SBG) was incorporated to the rABS/rHIPS system by melt blending for the first time. Multiple epoxy groups in SBG can combine with the butadiene ageing groups in rABS/rHIPS to generate ester groups, repairing the broken molecular chains, improving the compatibility between the two phases, and enhancing the mechanical properties of the blends. The findings demonstrated that adding SBG greatly increased the blends' molecular weight, impact strength, tensile strength, flexural strength, storage modulus, loss modulus, and complex viscosity. When SBG content was 8 wt%, the notch impact strength of the blends reached 8.84 kJ/m2, which was 108% higher than that of rABS/rHIPS. In addition, the interface between polybutadiene (PB) phase and styrene-acrylonitrile copolymer (SAN) phase became more blurred, and the compatibility of the two phases was improved, which enabled the high-value recovery of rABS/rHIPS.

Automated summary

For the first time, styrene-butadiene-glycidyl methacrylate (SBG) was incorporated into the recovered acrylonitrile-butadiene-styrene (rABS) and recycled high impact polystyrene (rHIPS) system by melt blending to increase effectiveness. The epoxy groups in SBG react with the butadiene aging groups in rABS/rHIPS, resulting in the formation of ester groups, which repairs broken molecular chains, improves phase compatibility, and enhances mechanical properties of the blends. Adding SBG significantly improves the molecular weight, impact strength, tensile strength, flexural strength, storage modulus, loss modulus, and complex viscosity of the blends. When SBG content is 8 wt%, the notch impact strength of the blends increases by 108% compared to rABS/rHIPS. Furthermore, the interface between the polybutadiene (PB) phase and styrene-acrylonitrile copolymer (SAN) phase becomes less distinct, improving the compatibility and enabling high-value recovery of rABS/rHIPS.