%0 Journal Article
%T Thermal and Photoresponsive Studies of Starch Modified with 2-(5-(4-Dimethylamino-benzylidine)-4-oxo-2-thioxo-thiazolidin-3-yl)acetic Acid
%A Ambily Chandran
%A Sunny Kuriakose
%A Tessymol Mathew
%J International Journal of Carbohydrate Chemistry
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/356563
%X The present study describes the synthesis of a chromophoric system 2-(5-(4-dimethylamino-benzylidin)-4-oxo-2-thioxo-thiazolidin-3-yl)acetic acid and its incorporation into starch through esterification of the hydroxyl group by the free carboxyl function of the chromophoric system by DCC coupling. The products were characterized by UV-visible, fluorescence, FT-IR, and NMR spectroscopic methods. The newly developed system was subjected to photoresponsive studies such as light absorption, light stabilization and fluorescence emission. The free chromophoric system and the coupled product were also subjected to thermal analysis. The results show that modification enhances the light absorption and light fastening properties of the chromophoric system. Thermal stability of the polymeric system greatly enhances on attaching the chromophoric system. In view of these results the newly developed system is proposed as a nature friendly, green, and photoactive product which could find application in dyes, inks, paints, and so forth. 1. Introduction Starch is an inexpensive commodity that has been used for food and many nonfood purposes for centuries. Starch, one of the main polysaccharides in the world, has been paid much attention because of its biodegradability and abundance as a renewable resource. It has been widely used as a raw material for biodegradable plastics. The chemical modification of starch is of interest because the modification would not change the fundamental skeleton of starch, would keep the original physicochemical and biochemical properties, and finally would bring new or improved properties. Chemically, starch is composed of two different molecules, amylose and amylopectin. In amylose, the glucose molecules are linked in a ¡°linear¡± fashion; however, the tetrahedral chemistry of carbon (and the bond angles that result from this chemistry) gives amylose an overall spiral shape. Amylopectin, on the other hand, has a linear arrangement of glucose molecules which includes, at regular intervals, a different kind of linkage between two adjacent glucoses. This different linkage results in the formation of a branched structure and an overall treelike shape for this molecule. Starch consists of amylose and amylopectin, which are polymers of glucose, linear and branched, respectively. Each glucose unit potentially has three reactive hydroxyl groups that are the basis of all derivatizations. Native starches in its derivative forms open a wide scope in pharmaceutical-, food-, and nonfood based industries. Starch modification is generally achieved through
%U http://www.hindawi.com/journals/ijcc/2012/356563/