Esterification of cellulose-enriched agricultural by-products and characterization of mechanical properties of cellulosic films

Two agricultural by-products, wheat bran and maize bran have been examined for their suitability to be transformed into biomaterials by esterification by lauroyl chloride. Influence of biochemical characteristic of cellulose (cellulose content, viscosity-average degree of polymerization, crystallini ty) was studied on eight samples enriched in cellulose after chemical remov al of heteroxylans and lignin. After an acidic pre-treatment, esterificatio n was carried out with lauroyl chloride and an optimized reaction time of 8 h was used. Chemical compositions were similar for all cellulose esters obtained, but c ellulose content of initial material had a marked influence on the amount o f esterified product. A film was easily obtained by casting and the mechani cal (tensile strength and elongation), thermomechanical and calorimetric pr operties were determined. The possible role of grafted fatty acid as intern al plasticizer was finally discussed. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.