The Influence of Polybutadiene-g-(Styrene-Acrylonitrile) Concentration on the Mechanical Properties and Flow Behavior of Acrylonitrile-Butadiene-Styrene Resin

Abstract

Acrylonitrile-butadiene-styrene (ABS) resin is a typical elastomer-toughening plastic, where the rubber component is polybutadiene (PB). In this paper, the influence of PB-g-Styrene-Acrylonitrile (SAN) concentration on the mechanical properties as well as the flow behavior of the ABS resin was studied. The notched impact strength of the ABS resin including 30 wt% PB-g-SAN was 18.7 kJ/m2, more than five times as high as that of neat SAN resin (3.8 kJ/m2). Scanning electron microscopy (SEM) examination confirmed that the primary reason of the improved toughness of the ABS resin was the shear yielding effect of the matrix. Additionally, a melt flow indexer, rotating rheometer, torque rheometer and dynamic mechanical analyzer (DMA) were utilized to analyze the influence of PB-g-SAN concentration on the ABS resin flow behavior. The results showed that the melt flow rate (MFR) of the ABS resin decreased linearly and the complex viscosity (η*) as well as the tensile plateau modulus (E’) values increased significantly with the growing concentration of PB-g-SAN. This indicated that the flow behavior of the ABS resin was negatively affected when excess PB-g-SAN concentration was added. The entanglement effect between the SAN copolymer on the PB particles surface and the matrix SAN molecular chains, as well as the PB particle volume effect, were suggested to be the main reasons of the negative effect. This research, we suggest, will provide profound scientific guidance for regulating the mechanical and processing characteristics of the ABS resin.