Structural and electrical conductivity of CH:MC bio-poly-blend films: optimize the perfect composition of the blend system

[摘要] In this study, solid polymer blend films based on chitosan (CH) and methylcellulose (MC) were prepared in various compositions by the solution cast technique. The features of structure and complexation of the blend polymer filmswere studied using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The shift of FTIR peaks of the amino groups of CH and the hydroxyl groups of MC reveals the formation of interchain hydrogen-bonding between CH and MC chains in blend films. From the XRD pattern, the semi-crystalline structure of CH was depressed with the addition of MC and shows the CH:MC blend system with ratio 75:25 has the minimum degree of crystallinity. The highest room temperature conductivity was found to be $0.05\times 10^{−6}$ S cm$^{−1}$ for 75CH:25MC blend polymer composition. The dc conductivity exhibits Arrhenius-type behaviour with temperature. The drastic increase in conductivity up to $37.92 \times 10^{−6}$ S cm$^{−1}$ at 373 K, can be explained by free volume model. The highest value of electrical conductivity for all prepared samples was associated with the minimum value of activation energy.

[学科分类] 材料工程

[关键词] Polymer blend films;degree of crystallinity;electrical conductivity;activation energy.