New composites based on starch/Ecoflex®/biomass wastes: Mechanical, thermal, morphological and antimicrobial properties.

Different biomass wastes were successfully blended with starch and Ecoflex® viz. poly(butylene adipate-co-terephthalate), without glycerol addition, to obtain biocomposite materials. The mechanical properties, as well as thermal and surface properties, of the developed composites were evaluated. It was found that the tensile strength and impact strength improved upon the addition of lignin, while the water uptake capacity decreased. The presence of 5% lignin determined an increase in tensile strength of 125.4% for materials comprising celery (CEL), 109.6% for materials comprising poplar seed hair fibers (PSH), 92.9% for materials comprising pomace (POM) and 127.7% for materials comprising Asclepias syriaca fibers (ASF), compared with a reference sample. The addition of lignin to all the formulations conferred good antimicrobial properties against different microorganisms, S. aureus and especially E. coli. The good mechanical properties, water resistance and antimicrobial activity against pathogens recommend these composites to be used in the manufacture of packaging materials.