Avaliação da biodegradação de composições de poliéster e amido com pigmentos/corantes naturais e sintéticos

Abstract

Due to their versatility, polymeric materials have been used in different industrial sectors and with this, their consumption and disposal have grown over the years. Because it is a material of difficult degradation, its accumulation has caused great environmental problems. In order to solve this environmental problem, researchers and industries have developed biodegradable polymers, which can be degraded by the action of microorganisms. As an example may be mentioned the biodegradable polymer, formed by poly (adipate-co-terephthalate of butylene) - PBAT and corn starch. The main applications of this polymer composition are: bag making, plant seed bags, reforestation tubes, pots and vases. The presence of pigments and dyes in this and other polymeric materials is quite common and necessary for the final presentation of the artifact. The pigments and dyes can be natural or synthetic and their use aims make it more attractive the plastic artifact, making it more attractive to the consumer or even to differentiate it through the most varied colors. The present work has the objective to elaborate PBAT / starch polymer compositions with pigments and dyes and to evaluate the influence of the presence of these in the polymer matrix and in the biodegradation process. The chosen pigments and dyes are natural and synthetic and have the colors that are commonly used in the manufacture of polymeric artifacts (red, yellow, white and blue): synthetic pigments red and yellow iron oxide, titanium dioxide, copper phthalocyanine And the natural dyes turmeric and urucum. Fourier transform infrared (FTIR), Thermogravimetric (TGA), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) spectroscopy techniques were used to characterize and evaluate the properties of the colored polymer compositions. The evaluation of the biodegradability was carried out using the burial method in simulated soil, according to ASTM G 160-03, for a period of 2 to 17 weeks. After each burial period, the loss of mass and morphology of the specimens were determined, as well as FTIR and TGA analyzes. In the biodegradability test, all colored polymer compositions retained the biodegradability of the pure polymer, although an increase in the degradation of the colored polymer compositions with the yellow and red iron oxides was observed, as expected