Acidic activation of cellulose and its esterification by long-chain fatty acid

Cellulose-enriched residues from wheat bran can be transformed in bio-plast ics after esterification of the cellulose by lauroyl chloride. Before the e sterification reaction, an activation step with a swelling of the sample in dilute acid and subsequent drying was required. This activation had a mark ed influence on the amount of esterified product and its degree of substitu tion. Using pure cellulose as well as cellulose-enriched agricultural resid ues, we have shown that the cellulose was totally recovered after this pret reatment and that partial hydrolysis of cellulose chains occurred during th e drying step, which probably improved the accessibility to chemical reagen ts. The possible role of sulfuric acid as catalyst for the esterification r eaction of the cellulose by lauroyl chloride was discussed. (C) 1999 John W iley & Sons, Inc.