Biodegradable Hybrid Polymeric Materials Based on Lignin and Synthetic Polymers

摘要

Hybrid polymeric materials containing PVAc, PVA, and PCL as synthetic component and lignin, a cheap by-product of paper, pulp, and tannery industry, as natural component were prepared. In particular, lignin- PVAc graft copolymers were prepared by free radical polymerization in the presence of H_2O_2/CaCl_2 redox initiator, whereas PCL was grafted onto lignin by anionic bulk polymerization. Lignin-PVA copolymers were obtained by methanolysis of the corresponding lignin-PVAc graft copolymers In any case, the synthetic polymer chains are covalently bound to lignin, as indicated by both spectroscopic and SEC characterizations. The biodegradation behaviour of the analyzed polymeric hybrid materials clearly indicates the positive effect of lignin when chemically bound to vinyl alcohol polymer chains, whereas in the case of the lignin-PCL copolymer only a delay in the biodegradation process was observed. In spite of the preliminary character of the reported investigation, the results so far obtained evidence the possibility to synthesize in a relatively simple way, low cost, potentially biodegradable polymeric hybrid materials containing a significant amount of lignin, with obvious beneficial economic and environmental effects.