19-08-2014, 10:20 AM
Drying commonly describes the process of thermally removing volatile substance (Moisture) to yield a solid product. Drying is an important unit operation used in many industrial sectors including food, chemicals, plastic, fertilizers and minerals, among others. It is a major unit operation with high energy consumption. The present work is divided into three parts. In the first part, graft polymerization of starch was studied. The grafted polymer was then used as a binder to obtain the starch granules of suitable characteristics, which finds application as sizing agent in textile industries.
Drying commonly describes the process of thermally removing volatile substance (Moisture) to yield a solid product. Drying is an important unit operation used in many industrial sectors including food, chemicals, plastic, fertilizers and minerals, among others. It is a major unit operation with high energy consumption. The present work is divided into three parts. In the first part, graft polymerization of starch was studied. The grafted polymer was then used as a binder to obtain the starch granules of suitable characteristics, which finds application as sizing agent in textile industries. In the second part copolymerization of acrylic acid and butyl acrylate was studied. The product characteristics were analyzed in terms of re-dispersiblity, viscosity, wettability, dissolution rate. Further, the acrylic copolymer was sized on the cotton yarn to study its application in textile processing. In the third part starch gelatinization and drying was carried out using single screw extruder (SSE). The degree of gelatinization, structural properties of extrudate and performance of SSE were studied. The performance of SSE was compared with drum gelatinized powders in terms of product quality parameters.
Graft Copolymers of Starch and its Application in Textiles: Starch graft copolymers are becoming increasingly important because of there potential applications related to agriculture, industry, medical treatment. The graft copolymerization of Styrene (ST), Methylmethacrylate (MMA) / Butylacrylate (BA) onto starch was carried chemically using ferrous ion-peroxide redox system. The reaction product analyzed in term of percentage conversion, grafting efficiency, grafting percentage and graft yield. The grafting efficiency of the starch-g-polyST/polyMMA and Starch-g-polyST/polyBA of 80/20 ratio found to be higher as compared to other ratio systems. The optimum concentration of the hydrogen peroxide initiator was found to be 50mM. The maximum grafting efficiency was found in case of Starch-g-polyST/polyBA system. The grafting of starch was conformed by FTIR analysis. Spray Drying of Copolymer of Acrylic Acid (AA) and Butyl Acrylate (BA): The water borne polymers have substituted, almost entirely the traditional organic solvents based polymer in the field of textiles, adhesives and architectural coatings etc. The present study was carried out to synthesis and investigates the effect of process variables and anti caking agents on the spray drying of re-dispersible polymer dispersion of acrylic acid and butyl acrylate. The re-dispersibility of spray powder with neutralization base i.e. NaOH and Na2CO3 was higher as compared to other base components used and without using base. The wettability of polymer product was found to be less as compared to commercial sample, but the dissolution rate was found to be better as compared to commercial sample.
Starch Gelatinization and Drying Using Screw Extruder: The present work is to gelatinize starch under high shear and temperature environment in a single screw extruder which requires less floor area, it is easy to handle and high in productivity as against the drum dryer. The degree of gelatinization (DG), color analysis, swelling properties, solubility, apparent and true density, expansion ratio and the porosity of extruded maize starch were analyzed. The extrudate starch product shows more degree of gelatinization, higher expansion ratio and solubility index as compared to the drum gelatinized sample.