Processing, properties and stability of biodegradable composites based on Mater-Bi-(R) and cellulose fibres

In this work, the behaviour of biocomposites obtained by the addition of flax cellulose pulp to Mater-Bi(R) a commercial thermoplastic matrix based on starch, has been studied in comparison with traditional glass fibre composites. The composites were produced by compounding with a twin-screw extruder. Depending on the kind of fibre, reinforcement contents of 10-40% were obtained. The mechanical behaviour, both in normal conditions and after water absorption, was analysed. It has been noted that the addition of cellulose pulp increases the composite modulus more than glass fibre: in fact, a poor adhesion of the interface between the glass fibre and Mater-Bi(R) has been observed. The thermal degradation behaviour of the composite has been studied by thermogravimetric analysis (TGA). Different degradation peaks have been observed and the activation energies, related to the main peak, have been calculated. The addition of cellulose pulp produces better mechanical properties and higher thermal stability. Copyright (C) 2003 John Wiley Sons, Ltd.