“GREEN” COMPOSITES USING MODIFIED SOYPROTEIN CONCENTRATE AND WOVEN FLAX FABRIC

摘要

“Green” composites made from environment-friendly, fully biodegradable resins and fibers offeran attractive alternative to the conventional composites made using petroleum-based or syntheticresins and fibers that do not degrade over many years. Woven fabric reinforced composite offerseveral advantages over unidirectional composites such as good stability in mutually orthogonalwarp and weft direction, more balance properties in the fabric plane and better impact resistance.This paper discusses two-dimensional ‘green’ composites prepared using glutaraldehydemodified soy protein concentrate (MSPC) and flax fabric. Soy protein concentrate (SPC)polymer has low tensile properties, poor moisture resistance and is brittle. SPC polymer with15% glycerin, as an external plasticizer, exhibited fracture stress and Young’s modulus of 17Mpa and 368 Mpa, respectively. In the present study, SPC was cross-linked with glutaraldehyde(GA) to increase its tensile properties and improve its processability as a resin to manufactureflax fabric reinforced composites.SPC forms a miscible blend with GA and reacts with free amine groups in the protein. MSPCshowed 35% increase in fracture stress and 55% increase in Young’s modulus as well asimproved moisture resistance compared to SPC. Besides mechanical properties, MSPC was alsocharacterized for its thermo-gravimetric and dynamic mechanical properties.Composite laminates, approximately 1 mm thick, were made using flax fabric and MSPCpolymer. Composite specimens were prepared with two different orientations, namely, 0° and90°. Composite specimens exhibited a fracture stress of 56 Mpa and 42 Mpa in the longitudinaland transverse directions, respectively. The laminates exhibited a Young’s modulus of 1.3 Gpaand 1.09 Gpa in the longitudinal and transverse directions, respectively.