Polarity parameters and dynamic mechanical behaviour of chemically modified banana fiber reinforced polyester composites

Natural fibers are replacing synthetic fibers as reinforcement in various matrices. The composites so prepared can effectively be used as a substitute for wood and also in various other technical fields like automobile parts. However, to improve the adhesion between the fiber and matrix, chemical modification is suggested. The effect of chemical modification on the dynamic mechanical properties of banana fiber reinforced polyester composites has been analyzed to investigate the interfacial properties. The interfacial phenomenon in turn was found to be related to the acid base interactions involved, which occur due to the specific interactions between less reactive functional groups of each partner at the interface. The acid base interactions were investigated, by solvatochromy and the zeta potential measurements. Solvatochromy revealed that the overall polarity parameter was highest for the silane A151 (vinyl tri ethoxy silane) treated fiber, compared to other treatments. zeta-Potential measurements of the untreated and variously treated fibers also showed that the chemical modification alters the polarity of the already acidic cellulose fibers. The observations of the solvatochromic measurements and zeta-potential measurements are consistent. The results of the polarity parameters were correlated with the results of dynamic mechanical analysis. The storage modulus value was found to be the highest for the silane A151 treated fiber composite. (C) 2003 Published by Elsevier Science Ltd.