Thermal properties of biocomposites

Thermal properties of new biocomposites prepared from modified starch matrix reinforced with natural vegetable fibres were studied. DSC and TG methods were applied to study thermal behaviour of biocomposites. Biocomposites were obtained in the laboratory twin-screw extruder. Two kinds of natural fibres were used, i.e. flax and cellulose in the amount of 0-40 mass%. DSC curves of biocomposites reveal glass transition temperature, attributed to the amorphous nature of the plasticized starch matrix. In general, incorporating natural fibres into modified starch matrix leads to an increase in glass transition temperature. Thermal degradation of modified starch matrix and cellulose reinforced biocomposites proceeds in three steps, whereas the degradation process of flax reinforced biocomposites occurs in two steps. For unreinforced matrix as well as for all biocomposites, regardless of type and amount of reinforcement, the major mass loss is observed at the temperature above 300 degrees C. The increase in thermal stability with introduction of natural fibre is observed for both flax and cellulose reinforced biocomposites.