New methods for acylation of pure and sawdust-extracted cellulose by fatty acid derivatives - Thermal and mechanical analyses of cellulose-based plastic films

This work deals with the synthesis of cellulosic plastic films obtained in homogeneous conditions by microwave-induced acylation of commercial or chestnut tree sawdust cellulose by fatty acids. The acylation reaction was studied according to N,N-dimethyl-4-aminopyridine (DMAP) amount, DMAP simultaneously playing the role of catalyst and proton trapping base. This study clearly showed that DMAP does not influence degrees of substitution (DS), massic, and molar yields. Plastic films synthesized in the absence of DMAP showed a decrease in mechanical behavior. Organic (tributylamine) or inorganic bases (CaCO3, Na2CO3) were then added to replace DMAP basic activity, and no changes were observed. Concerning thermal and mechanical properties of plastics obtained with various bases, glass transition temperatures (T-g) and degradation temperature (T-d) were found constant whatever the base, and the best mechanical properties were obtained for films synthesized in the presence of CaCO3. The same remarks were made concerning the valorization of chestnut tree sawdust cellulose. Microbial biodegradation of plastic films with DS = 2.2 led to a loss of their mechanical behaviors. (c) 2005 Wiley Periodicals, Inc.