Síntese e Caracterização de Filmes Híbridos de Amido de Feijão Carioca (Phaseolus Vulgaris L.) e Tetraetilortossilicato (TEOS).

Abstract

The starch has been investigated to obtain biodegradable films, but has disadvantages such as hydrophilicity and poor mechanical properties. The addition of inorganic materials to these films can enhance mechanical properties by the synergism of the components. The aim of this study was to obtain hybrid films of bean starch and different tetraethylorthosilicate (TEOS) content 5, 20 and 40% (w/w) as well as evaluate the influence of inorganic precursor in the properties of films. The films were prepared by the casting method with hydrolysis and condensation of TEOS in situ under controlled pH. The films were subjected to extensive characterization for possible application as packaging. Some characterizations were performed after 3 and 15 days of storage to evaluate the influence of storage time on the properties. Overall the films were homogeneous and transparent, presenting higher value of Young’s modulus, higher resistance to degradation in the region 170-280 °C for the film containing 40% (w/w) starch, lower melting temperature. The relative crystallinity, optical properties and water vapor permeability were not affected by adding the precursor. The greatest film storage time leads to a decrease in solubility probably due to increased interaction between the components of the film, decreasing the availability for interaction with water.