Filmes nanocompósitos de poli(butileno adipato co-tereftalato)/ argila organofílica.

Abstract

The improper disposal of polymers is responsible for their indiscriminate accumulation in nature, generating major environmental impacts, as polymers from non-renewable sources takes a long time to degrade. A viable alternative to minimize this problem is the total or partial substitution of synthetic polymers (petroleum derivatives highly resistant to degradation) by biodegradable polymers. Poly (butylene terephthalate-co-adipate) (PBAT) is considered to be one of the most promising polymers for the production of biodegradable film packaging. The present study deals with the production, characterization and properties of nanocomposite films of a biodegradable matrix (PBAT) and an organoclay (C20A). The effect of accelerated aging (by exposure to UV radiation and Temperature) on permeability, biodegradation, mechanical properties and colorimetry of the systems developed was ascertained. Nanocomposites containing 1.3 and 5% of clay were processed in a laboratory internal mixer and torque rheometry curves were analyzed. The compositions obtained were pelletized and extruded as flat films, which were characterized by XRD, DSC, FTIR and SEM. Tensile properties and gas permeability(O2 and CO2) of these films as a function of filler content and exposure times to UV radiation at 58oC were determined. Results show that the addition of small amounts of organoclay to PBAT did not increase the degradation of polymeric matrix during processing, nor affected its crystallization. Clay incorporation to the polymer matrix led to decreases in permeability to oxygen and carbon dioxide gases of the films manufactured. Biodegradation, colour, permeability and mechanical properties of the films were strongly affected by accelerated aging (UV/T) and depended on aging time and clay content of the systems.