|Corradini, Elisangela - UFSCAR, SP, BRAZIL|
|Agnelli, Jose - UFSCAR, SP, BRAZIL|
|Mattoso, Luiz - EMBRAPA, BRAZIL|
Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 20, 2008
Publication Date: February 20, 2008
Citation: Corradini, E., Imam, S.H., Orts, W.J., Agnelli, J.A., Mattoso, L.H. 2008. Effect of coconut, sisal and jute fibers on the properties of starch/gluten/glycerol matrix. Journal of Applied Polymer Science. 17(1):1-9. Interpretive Summary: The coconut, sisal and jute fibers were used as reinforcement for a biodegradable matrix of starch/gluten/glycerol. The effect of fiber content on water absortion, mechanical, thermal and dynamical mechanical properties and morphology of the composites produced was studied. Compared to inorganic fillers, vegetable fiber offer several advantages such as: renewable nature, low cost, low density, high specific strenght and modulus, and comparatively easy processability due to their nonabrasive nature. Starch and gluten are also interesting natural polymers to be used as matrix in biocomposite due to their low cost, biodegradability and availability. They can be processed in the presence of plasticizers, similarly to some conventional synthetic thermoplastic polymers. The use of renewable resources such as natural polymers and vegetable fibers in the production of biodegradable materials contribute positively towards sustainability and environmental conservation. Furthermore, the use of surplus plant fibers in non-non-food application will help American farmers.
Technical Abstract: In this study, coconut, sisal and jute fibers were used as reinforcement for a biodegradable polymer matrix of gluten/starch/glycerol. The content of fibers used in the composites varied from 5% to 30% by weight of total of polymers (starch and gluten). The matrix and composites were processed in a Haake torque rheometer at 120¢XC, at 50 rpm for 6 min. The mixtures obtained were molded by hot compression and then characterized by water absorption experiments, thermogravimetric, tensile tests, dynamic mechanical properties and scanning electron microscopy (SEM). The addition of lignocelullosic fibers to the matrix decreased the water absorption at equilibrium. The diffusion coefficient decreased sharply upon of 5% of fiber and further fiber additions provoked only small variations. The TG tests showed that the thermal stability of matrix is improved upon addition of lignocelullosic fibers. The Young¡¦s modulus and ultimate tensile strength increased with fiber content. The storage modulus increased with increasing fiber content whereas tan ƒÔ curves decreased, confirming the reinforcing effect of the fibers. The morphology of composites analysed by SEM showed good interfacial adhesion between starch/gluten/glycerol matrix and the fibers.