Effect of blending lignin biopolymer on the biodegradability of polyolefinplastics

The ability of the lignin-degrading microorganism Phanerochaete chrysospori um to attack polyethylene and polypropylene was investigated using a series of polymer blends containing 10, 20 and 30% lignin obtained from the waste product of pulp and paper industry. In the cultivation medium, lignin pero xidase and Mn(II)peroxidase activities were detected. Degradation was verif ied by quantitative u.v. spectrophotometric analysis of the cultivation med ium and by liberation of CO2 from the blends. Measurement of the tensile st rength after 30-days cultivation showed that the mechanical properties of t he polymer blends were decreased during the biodegradation process. The iso lation of oligomer fractions by tetrahydrofuran (THF) extraction of biodegr aded polymers and their characterization by gel permeation chromatography ( GPC), u.v. and Fourier transmission infrared (FTIR) spectroscopy indicates that biotransformation of the lignin component during the cultivation proce ss initiates partial biodegradation of the synthetic polymer matrix.