PLA-PHB BLENDS: THE EFFECT OF DIFFERENT COMPATIBILIZERS ON MECHANICAL AND RHEOLOGICAL PROPERTIES

In recent years, there has been an increase in the use of biodegradable polymers derived from renewable resources. Polylactic acid (PLA) is one of the most widely used and studied biopolymers. It is a highly transparent, amorphous and rigid material, with a glass transition temperature of around 60°C. It can been processed as a conventional thermoplastic polymer. The main drawbacks of PLA are its high brittleness and low thermal stability. The ways of overcoming these problems are to use plasticizer, copolymerization with others components, making composites and blending with other polymers. In this work, in order to obtain a biodegradable and biocompatible material, a blend with Polyhydroxybutyrate (PHB) was chosen. This is a semicrystalline biopolymer made by controlled bacterial fermentation. Specifically, we have studied different compatibilizer systems with different chemical structure to improve the miscibility between PLA and PHB; furthermore the thermal and mechanical properties of formulated blends were investigated.