Conversion of cotton byproducts to mixed cellulose esters

► Cotton byproducts, such as cotton burr and cottonseed hull, are cheap and easily available. ► These cellulosic byproducts were converted into mixed cellulose esters, e.g., cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB). ► An iodine-promoted process was used that required no chlorinated solvent in the reaction mixture. ► Product ester ratios and degrees of substitution were determined by 1H NMR spectroscopy. ► At the conditions studied, acetic anhydride was only slightly more reactive than propionic anhydride but noticeably more reactive than butyric anhydride in the formation of mixed cellulose esters.