Biodegradable composites made from thermoplastic starch and ash wood particles

Abstract

The number of studies to develop biodegradable products from natural polymers has increased, among which starch is outstanding because it is a promising material for this purpose. The present work describes the production and characterization of biocomposites of corn starch reinforced with wood particles of ash-tree, for the method of thermo-compression. The biocomposites was prepared with particle sizes, 425 μm, 600 μm and 1.4 mm, as well as, in different ratios (5, 10 and 20 %) and a thermoplastic matrix (0 % particles) was used as reference. The obtained results demonstrated that it is possible to elaborate thermoplastic starch by the thermo-compression method. The ash wood particles incorporated into the thermoplastic matrix contributed to improve the tensile strength and elongation modulus, showing a good interface (matrix-particle) observed in the SEM images. The thermal treatment (annealing) applied to the specimens had a great effect in the results of tensile strength. The composites with 10 and 20 % wood particles and of 600 μm particle size presented the major values of mechanical resistance. The biocomposites are flammable but tend to auto-extinguish. During the process of plastification occurs a slight thermal degradation which causes the formation of carbonyl groups. Incorporating wood particles to the thermoplastic matrix decreased moisture absorption.