Submitted to: Polymer Preprints
Publication Type: Proceedings
Publication Acceptance Date: 7/15/2011
Publication Date: 8/26/2011
Citation: Sutivisedsak, N., Biswas, A., Finkenstadt, V.L., Cheng, H.N. 2011. Evaluation of composite films containing poly(vinly alcohol) and edible bean. Polymer Preprints. 52(2):256-257.
Interpretive Summary: Poly(vinyl alcohol) (PVA) is a major industrial polymer with good physical properties, water solubility, chemical resistance, biodegradability and biocompatibility, but it tends to be relatively expensive. One possibility is to produce blends and composites of PVA, preferably with cheaper and biodegradable fillers. A potentially promising filler is the edible bean (Phaseolus vulgaris L.) with a price of about 20 cents per pound. In this work we made blends and composites of PVA with pinto bean and its high starch fraction as low-cost fillers. Currently PVA-starch composites are being considered for use in agriculture for transportation of plants, as film to cover the surface of cultivated fields, as fertilizer encapsulant, and as water-soluble packaging material. PVA/edible bean composites may also have potential for these same applications in the future. This work is of primary benefit to bean growers.
Technical Abstract: The purpose of this work is to explore the possibility of using edible bean as a cheap and biodegradable filler for poly(vinyl alcohol)(PVA). Pinto bean was chosen as a representative bean material. It was milled and screened to give pinto bean flour (PBF); a further process produced a pinto bean high starch fraction (PBHSF). Both PBF and PBHSF were subjected to thermal and cold gelatinization processes, but the latter process produced easier and stronger composite films with PVA. As it turned out, PVA/PBHSF composite gave inferior mechanical properties. The films made from PVA/PBF composites gave reduced tensile strength and Young’s modulus, but enhanced elongation up to 40% PBF level. Currently there is a fair amount of research activity involving PVA-starch and PVA-protein composites, and even some potential commercial interest. Perhaps the PVA/edible bean composites can also be considered for these same applications in the future.