title: Effect of fiber treatments on tensile and thermal properties of starch/ethylene vinyl alcohol copolymers/coir biocomposites.
abstract: Coir fibers received three treatments, namely washing with water, alkali treatment (mercerization) and bleaching. Treated fibers were incorporated in starch/ethylene vinyl alcohol copolymers (EVOH) blends. Mechanical and thermal properties of starch/EVOH/coir biocomposites were evaluated. Fiber morphology and the fiber/matrix interface were further characterized by scanning electron microscopy (SEM). All treatments produced surface modifications and improved the thermal stability of the fibers and consequently of the composites. The best results were obtained for mercerized fibers where the tensile strength was increased by about 53% as compared to the composites with untreated fibers, and about 33.3% as compared to the composites without fibers. The mercerization improved fiber-matrix adhesion, allowing an efficient stress transfer from the matrix to the fibers. The increased adhesion between fiber and matrix was also observed by SEM. Treatment with water also improved values of Young's modulus which were increased by about 75% as compared to the blends without the fibers. Thus, starch/EVOH blends reinforced with the treated fibers exhibited superior properties than neat starch/EVOH.
authors: Embrapa Agroindústria Tropical, Rua Dra Sara Mesquita, 2270, 60511-110, Fortaleza, CE, Brazil.
authors: Morsyleide F
authors: MF
authors: Rosa
authors: Bor-sen
authors: BS
authors: Chiou
authors: Eliton S
authors: ES
authors: Medeiros
authors: Delilah F
authors: DF
authors: Wood
authors: Tina G
authors: TG
authors: Williams
authors: Luiz H C
authors: LH
authors: Mattoso
authors: William J
authors: WJ
authors: Orts
authors: Syed H
authors: SH
authors: Imam
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D004055:Differential Thermal Analysis; D008031:Lignin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000648:ultrastructure; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011145:Polyvinyls / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013718:Tensile Strength; D013818:Thermogravimetry
chemical_list: D001672:Biocompatible Materials; D011145:Polyvinyls; C507903:coir; C020320:ethylene-vinyl alcohol copolymer; D013213:Starch; D008031:Lignin