Determination of the optimum polystyrene parameters using asphalt binder modified with poly(styrene-acrylated epoxidised soybean oil) through response surface modelling

This paper evaluated the modification effects of soybean oil-based block bio-advantaged copolymers, poly(styrene-block-acrylated epoxidised soybean oil) (PS-PAESO) using polymerised AESO (PAESO) married with various polystyrene molecular weights and polystyrene contents, in the base asphalt binder through performance grade testing. Best-fit prediction models were developed through response surface modelling (RSM) using the grading results to maximise the modification effects of PS-PAESO in the base binder by optimising the polystyrene parameters. The optimised formulation of PS-PAESO with 5% polystyrene content and 30 kg/mol polystyrene molecular weight was produced and blended with the base asphalt binder, which modified the base asphalt binder from PG 52-34 to PG 64-28 as estimated by the prediction models that could be used for warm climate regions pavement applications. This result verified the high accuracy of the prediction models, and showed that the optimised PS-PAESO formulation performed superior to the commercial poly(styrene-block-butadiene) (SB) in asphalt modification at the same dosage in terms of critical high temperature.