Blended graft copolymer of carboxymethyl cellulose and poly(vinyl alcohol) with banana fiber

Conducting hydrogel copolymer was prepared by graft copolymerization of carboxymethyl cellulose (CMC) and boric acid onto poly(vinyl alcohol) (PVA). The dielectric properties of CMC-g-PVA/prehydrolyzed banana blend have been investigated as a function of frequency, with special reference to pure prehydrolyzed banana. Also, the static bending for the blend was determined and no abrupt failure was observed. The dielectric properties measured were dielectric constant (epsilon'), dissipation factor (tan delta), and loss factor (epsilon). At high frequencies, a transition in the relaxation behavior was observed, whereby the dielectric constant, loss tangent, and loss factor decreased with frequency. Experimental epsilon' values of the blend are greater than those of prehydrolyzed banana. The dielectric behavior depends greatly on the nature of the present group, the crystallinity of the system, and the degree of hydrogen bonding between the different chains. The variation of the dielectric properties was correlated with blend morphology and also to the possibility for interfacial polarization that arises because of the differences in conductivities of the two phases. It was found from the infrared spectra that the incorporation of CMC-g-PVA copolymer decreases the crystallinity of the blend and also decreases the degree of hydrogen bonding, which results in a high dielectric constant. (c) 2006 Wiley Periodicals, Inc.