Effect of chemical treatment on the mechanical properties of starch-based blends reinforced with sisal fibre

Biocomposites were produced using polycaprolactone (PCL) and starch as the matrix, and washed and treated sisal fibres as reinforcement. The matrix consists of a biodegradable product commercially known as MaterBi-Z(R), which is based on a PCL, starch and additive. Alkaline and acetylation treatments were performed on the fibre in order to enhance the adhesion degree and the compatibility between the fibre and the matrix. The effect of chemical treatment on morphology, physical and chemical properties and tensile properties of fibres and composites were determined. Tensile properties of the biodegradable composite were improved by the presence of the fibre. However, the untreated fibres behaved as better reinforcement than the acetylated and alkali-treated fibres. This was attributed to an impairment of the mechanical properties of the acetylated fibres and incompatibility of the alkali-treated fibres. The results observed are supported by SEM analysis of fibres and the composite materials.