Vegetable oil - based polymers and lignocellulosic derived composites

Abstract

The growing environmental concerns together with the reduction of petroleum resources have been a motor for revitalizing the interest in using raw materials from renewable resources. Among those, vegetable oils constitute a valuable renewable source. Their chemical modification is a promising alternative to substitute (at least partially) petrochemical materials used in polymer formulations. In this chapter, the focus will be on the use of castor and tung oils for synthesizing polyols for the polyurethane industry. The polymers derived from these polyalcohols present different properties depending on the vegetable sources, synthesis path for the polyol, additives, etc., and thus, polyurethanes can be produced to fit the requirements for different applications. The addition of lignocellulosic reinforcements like wood flour or plant fibers noticeably affect the properties of the polyurethanes due to the strong interaction that these fillers/reinforcements develop with the polar polyurethane matrix. The biocomposites prepared from the bio-based polymers and biofillers/biofibers can be a useful alternative to substitute synthetic composites (from solid composites to filled foams) reducing the environmental impact usually associated to traditional polymers. The physical, thermal and mechanical properties of the neat polyurethanes and derived composites are presented and analyzed in this chapter.