Book excerpt: This unique multidisciplinary 8-volume set focuses on the emerging issues concerning synthesis, characterization, design, manufacturing and various other aspects of composite materials from renewable materials and provides a shared platform for both researcher and industry. The Handbook of Composites from Renewable Materials comprises a set of 8 individual volumes that brings an interdisciplinary perspective to accomplish a more detailed understanding of the interplay between the synthesis, structure, characterization, processing, applications and performance of these advanced materials. The Handbook comprises 169 chapters from world renowned experts covering a multitude of natural polymers/ reinforcement/ fillers and biodegradable materials. Volume 4 is solely focused on the Functionalization of renewable materials. Some of the important topics include but not limited to: Chitosan-based bio sorbents; oil spill clean-up by textiles; pyridine and bipyridine end-functionalized polylactide; functional separation membranes from chitin and chitosan derivatives; acrylated epoxidized flaxseed oil bio-resin and its biocomposites; encapsulation of inorganic renewable nanofiller; chitosan coating on textile fibers for functional properties; surface functionalization of cellulose whiskers for nonpolar composites; impact of chemical treatment and the manufacturing process on mechanical, thermal and rheological properties of natural fibers based composites; bio-polymers modification; review on fibers from natural resources; strategies to improve the functionality of starch based films; the effect of gamma-radiation on biodegradability of natural fibers; surface functionalization through vapor-phase assisted surface polymerization (VASP) on natural materials from agricultural by-products; okra bast fiber as potential reinforcement element of biocomposites; silane coupling agent used in natural fiber/plastic composites; composites of olefin polymer /natural fibers: the surface modifications on natural fibers; surface functionalization of biomaterials; thermal and mechanical behaviors of bio-renewable fibres based polymer composites; natural and artificial diversification of starch; role of radiation and surface modification on bio-fiber for reinforced polymer composites.