A new approach to blending starch with natural rubber

Abstract

Thermoplastic starch (TPS) is the most widely used renewable and biodegradable polymer in applications such as packaging and disposable materials due to its properties, abundance and low cost. Research aimed at widening its range of applications includes the improvement of its mechanical properties by mixing it with other polymers. In this study, TPS was blended with oxidized natural rubber (ONR) in order to enhance its plasticity through higher interface compatibility. The oxidation of natural rubber was carried out to promote chemical interactions between the hydroxyl groups of ONR with those of TPS through hydrogen bonding. The blends were prepared by extrusion and characterized using dynamic mechanical analysis, tensile tests, contact angle measurements, water absorption and scanning electron microscopy. The results showed that these new materials displayed the expected improvements, as well as better water resistance and decreased brittleness.