Polymer blend of polyamide and high impact polystyrene

This research aims to study a polymer blend between polyamide 6 (PA6) and high impact polystyrene at a blend ratios of 20/80, 40/60, 60/40 and 80/20 PA6/HiPS respectively. Maleated styrene-ethylene/butylenes-styrene block copolymer (SEBS-g-MA) is added as a compatibilizer for the blend systems. The mechanical properties in terms of tensile properties, impact properties and the heat distortion temperature were investigated. The study shows that the addition of the SEBS-g-MA compatibilizer improves the toughness of almost all the polymer blends except the 40/60 PA6/HiPS. At such composition, the addition of the SEBS-g-MA shows an adverse effect in toughness. However, most of the mechanical properties of the polymer blends are still lower than both parent polymers. The thermal properties in terms of the glass transition and the melting point temperature were also studied. The results imply that uncompatibilized and compatibilized polymer blends are partially miscible. Microscopic study of the polymer blends shows that the addition of the compatibilizer improves the distribution and the dispersion of domain phase in the matrix. For 40/60 PA6/HiPS, the addition of the SEBS-f-MA compatibilizer changes from the fibril domain phase observed when SEBS-g-MA is not applied to a particle domain phase when SEBS-g-MA is applied. This change explains the reduction of the toughness at the 40/60 ratio. In addition, it shows the influence of the polymer blend morphology on the mechanical properties of the blends.