Mechanical and Morphological Properties of Poly(Butylene Succinate)/Poly(Hydroxybutyrate-co-Hydroxyhexanoate) Polymer Blends: Effect of Blend Ratio and Maleated Compatibiliser

Abstract

Poly(butylene succinate)/Poly(hydroxybutyrate-co-hydroxyhexanoate) (PBS/PHBHH) blends were prepared using melt blending in an internal mixer at 160°C. Mechanical and morphological properties of the blends, with ratios of 10/90, 20/80, 30/70, 40/60 and 50/50, are studied by tensile test and microscopy analysis. The effects of maleated PHBHH (PHBHHgMA) compatibiliser on the blend’s mechanical and morphological properties are also investigated. The compatibiliser is prepared by melt grafting maleic anhydride (MA) onto PHBHH at 160°C, in the presence of dicumyl peroxide (DCP) initiator. In this study, the purified compatibiliser is added to the blends. The highest tensile strength was achieved by the 10/90 blend, with a value of 24.83MPa; which is slightly higher than the neat PBS. The tensile modulus of the blends decreased with increasing PBS ratio, and approximately followed the Rule of Mixtures. Meanwhile, the elongation at break achieved its optimum value at 10wt. % PBS loading. The addition of PHBHHgMA at 5wt. % improved the tensile properties of all blends; with the highest value being achieved by the 10/90 blend ratio. Morphological observation via SEM was conducted to observe phase morphology and compatibility between the blend’s components.