Green Microcomposites from Renewable Resources: Effect of Seaweed (Undaria pinnatifida) as Filler on Corn Starch–Chitosan Film Properties

Abstract

Natural seaweed microparticles obtained from Undaria pinnatifida waste (A) were used as fillers in thermoplastic starch (TPS)–chitosan (CH) blend in order to obtain microcomposites films for application in sustainable agriculture. The adequate proportion of both polymers was optimized with regards their mechanical, barrier, water interaction and morphological properties. Then, the effect of different content of seaweed on microcomposites properties was investigated. The seaweed used showed good interaction with the TPS–CH matrix. Its addition produced an increase in the tensile strength and a slight increase in the elongation at break. Contents of 10% of A lead to a more heterogeneous structure with the formation of aggregates. Low contents of A reduced the mobility of the polymer chains resulting in a lower moisture content and higher Tg, although the WVP increased with the content of A. The improvements achieved with microcomposites were finally discussed under the light of new agricultural mulch films regulations.