Molecular structure, thermal analysis and electrical properties of cyanoethyl and carbamoyl ethyl bagasse raw materials

Infrared absorption spectra, thermal analysis as well as dielectric properties of cyano and carbamoyl ethylated bagasse raw materials and their hydrolysis with NaOH were studied. A new band appeared in the infrared spectra at 2252 cm(-1), characteristic to cyano group and a new shoulder appeared at 3150 cm(-1), characteristic to NH2 of amide group for cyanoethyl and carbamoyl ethyl raw material, respectively. Also the band intensity at 1636 cm(-1) characteristic of the amide group in the carbamoyl ethyl bagasse was found to be higher than that in case of bagasse raw material. A new band was seen at 1736 cm(-1), characteristic to C=O of carboxyl group which formed due to hydrolysis of cyano or carbamoyl groups. The crystallinity indices of the produced bagasse derivative were calculated and the increase is attributed to cyano, carbamoyl and hydrolysis process. Incorporation of cyano group into bagasse increases its resistance against thermal degradation. So, loss in weight from TG curves under major decomposition temperature (350 degrees C) was about 59% for cyanoethyl bagasse raw material while it was about 69% at 350 degrees C for bagasse raw material and 60% for carbamoyl ethyl bagasse. A kinetic study of the thermal degradation process revealed that, bagasse and its derivatives followed a first order reaction and the degradation of derivatives was more complex. The dielectric constant (epsilon') and AC electrical conductivity were studied with frequencies over the range (50-2000 Hz) for cyanoethylated, hydrolyzed cyanoethylated and carbamoyl ethylated bagasse raw material at two fixed temperatures (30 and 100 degrees C). Generally, the dielectric constant decreased and the conductivity increased with increasing frequencies. The increase in the nitrogen content in bagasse raw material due to cyanoethylation, carbamoyl ethylation and their hydrolysis cyanoethylated resulted in an increase in the dielectric constant. (c) 2006 Elsevier B.V. All rights reserved.