Opportunities for hardwood hemicellulose in biodegradable polymer blends

Hardwoods indigenous to the northeastern U.S., including birch, beech, maple and short-rotation woody crops such as willow, are relatively rich in the hemicellulose xylan. In this study, a combined biodelignification and hot water extraction procedure was employed to isolate polymeric xylan in its native acetylated state. To enhance the mechanical properties of xylan as a biodegradable material, solutions of xylan were mixed with solutions of commercially available cellulose esters followed by casting into solid films. In this fashion, it was possible to prepare acetylated xylan / cellulose triacetate "blends" with mechanical properties comparable to the cellulose triacetate itself up to 25 wt% xylan. Plasticizers were effective in increasing the strain to break for these materials but lowered the modulus at 1% strain.