AvaliaÃÃo da Capacidade Biodegradora de Fungos em Filmes PolÃmÃricos / Evaluation of the Capacity Biodegradora de Fungos in PolÃmÃricos Films

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The current work to assess the capacity of a wild strain of Talaromyces wortmannii (Klocker) C.R. Bejamim 1955, which was isolated from the landfill of Muribeca (JaboatÃo dos Guararapes â PE), and the strain of Phanerochaete chrysosporium, in biodegradation of three kinds of polymeric films, i.e.: pure LDPE (low-density polyethylene), LDPE/starch (80/20%) (mixture of low-density polyethylene and starch) and biopolymer obtained from the fermentation of molasses by the strain Zoogloea Itzigsohn 1868, 30. The films of LDPE and of the mixture LDPE/starch, 0.6 mm of thickness, were formulated in a rheometer Haake 90, at the temperature of 130 ÂC. The biodegration levels of films were characterized before and after the spores inoculation by the following analyses: weight loss analyse; infrared spectroscopy with Fourier transformed â FTIR; scanning differential calorimetry â DSC; measurement of the fluidity index â MFI and determination of the resistance to tension at rupture and elogation. The analysis of the weight loss showed that there was a significant effect with LDPE/starch whilst for LDPE the was little change; following thirty days of inoculation with Talaromyces wortmannii fungus and Phanerochaete chrysosporium one. The experiments with the biopolimer showed that biodegradation was complete after 14 days with Talaromyces wortmannii and 7 days with Phanerochaete chrysosporium.The infrared spectroscopy with Fourier Transformed analysis showed that there was no increase in the carbonil and vynil groups at the absorbance bands of 1720 cm-1 and 910 cm-1. The results of the MFI and DSC analysis suggested that the biodegradation mechanism, begins with the amorphous part of the starch due to the penetration of the microorganism that can carry on attacking the LDPE in a slow and gradual way. The results of the mechanics analysis showed that no significant changes in the film resistance to tension at rupture were found. The changeless of the mechanics properties are justified by the short period of exposition of the films by fungi. In a general way, it was observed that Phanerochaete chrysosporium fungus has greater ability to biodegrate the material studied than the Talaromyces wortmannii one.

ASSUNTO(S)

polyethylene amido biopolymer biodegradation biopolÃmero engenharia quimica biodegradaÃÃo polietileno, phanerochaete chrysosporium zoogloea sp starch talaromyces wortmannii zoogloea sp phanerochaete chrysosporium talaromyces wortmannii

ACESSO AO ARTIGO

Documentos Relacionados