Physical, chemical and mechanical properties of pehuen cellulosic husk and its pehuen-starch based composites

Pehuen cellulosic husk was characterized and employed as reinforcement for composite materials. In this research, thermoplastic pehuen starch (TPS) and TPS/poly(lactic acid) (PLA)/polyvinyl alcohol (PVA) composites, reinforced with Sand 10% of pehuen husk, were prepared by melt-blending. Comparative samples of pehuen TPS and TPS/PLA/PVA blend were also studied. Physical, thermal, structural and mechanical properties of composites were evaluated. Pehuen husk mainly consists of cellulose (50 wt%), hemicellulose (30 wt%) and lignin (14 wt%). In respect to lipids, this husk has only a 0.6 wt%. Its surface is smooth and damage-free and it is decomposed above 325 degrees C. The incorporation of pehuen husk improved considerably the thermal stability and mechanical properties of the studied composites, mainly in TPS composites. Their thermal stability enhances since biofiber hinders the out-diffusion of volatile molecules from the polymer matrix, while mechanical properties could raise due to the natural affinity between husk and starch in the pehuen seed. (C) 2012 Elsevier Ltd. All rights reserved.