Biofillers from rice husk for polymer composites

The aim of RiceRes project is to upgrade the residues and wastes of the rice productive chain by transforming them into a portfolio of bio-products with different added value. In this work, the rice husk, an abundant and cheap cost agricultural residue, was used to prepare four different fillers: i) micronized rice husk powder obtained by ball-milling; ii) lignin isolated adopting acidolytic extraction procedure; iii) silica prepared by combustion at 800°C; iv) rice husk ash obtained by controlled pyrolysis process. Recently biofillers have been widely used as reinforcing fillers in thermoplastic polymer composite materials. In general, these biofillers promise some advantages compared to traditional ones, such as their low cost, renewability, biodegradability and absence of associated health hazards. The fillers obtained from rice husk were compounded with thermoplastic biopolymers (PLA and PHVHB) and polyolefins. Structural and physicochemical characterization were carried out on composites of different composition. Results obtained suggest useful interactions among selected fillers and polymer matrices in the composites. Main research efforts have been devoted to the understanding of the correlations among chemical, morphological and physical characteristics of the rice biofiller and the thermal, mechanical and structural properties of the composite.