Compatibiliser effects on properties of polyamide-6/acrylonitrile-butadiene-styrene and polyamide-6/acrylonitrile-butadiene-styrene/short glass fibrethermoplastic composite

Abstract

Polyamide-6 (PA6), acrylonitrile-butadiene-styrene (ABS) and their blends are an important class of engineering thermoplastics that are widely used in electronic and automotive industries. Many efforts have been taken to improve the properties of both pure components and the blends. It was for this reason that the dynamic mechanical and rheological properties of PA6/ABS blend systems compatibilised by acrylonitrile-butadiene-styrene–maleic anhydride (ABS-g-MAH) was studied. The compatibiliser levels were kept up to 5wt. % in the blends. Short glass fibre (SGF) was used to improve the stiffness of the compatibilised blends and the fibre contents were from 10 to 30 wt. %. Therefore, the reason behind blending the PA6/ABS blends with short glass fibre was to balance the toughness and stiffness. Both the blends and corresponding composites were compounded using a counter-rotating twin screw extruder. Tensile, flexural and impact properties were determined using the injection moulded test samples according to ASTM standards. The mechanical properties of the blends and the composites were investigated in both static and dynamic modes. Rheological properties were investigated using rotational and capillary rheometer. In general, the mechanical strength either dynamic (refer to dynamic mechanical properties) or static conditions improved by incorporation of compatibiliser to the PA6/ABS blends. The incorporation of SGF into the PA6/ABS blends enhanced the mechanical strength but reduced the toughness of the composites. The rheological measurements confirmed the interaction between the blend components with the incorporation of compatibiliser has been improved. However, the compatibiliser has no favourable effect on the mechanical properties of the composites although it has significant effect on the blends of PA6/ABS. The compatibiliser increased the melt viscosity of the blends. The SGF increased the rheological properties especially viscosity and flowability of the composites. The optimum ratio of compatibiliser and SGF concentration were determined using power law, n and consistency index, K analyses. From the analysis, the optimum ratio obtained was 1.5 wt. % for 50/50 and 60/40 PA6/ABS blends and 3 wt. % for 70/30 PA6/ABS blends. The n values drastically decreased, when concentration of the SGF was about 20 wt % indicating more pseudoplastic nature for the composites and suggesting that, 20 wt % is the optimum SGF concentration