Improvement of functional properties of jute-based composite by acrylonitrile pretreatment

Cyanoethylation of jute fiber in the form of nonwoven fabric was successful ly achieved using an acrylonitrile monomer which is said to react with the hydroxyl groups of fiber constituents. The degrees of cyanoethylation to di fferent extents were undertaken by varying the reaction time. An IR study s howed that extent of cyanoethylation increases with increase of the reactio n time. Cyanoethylated fibers thus obtained were further treated with unsat urated polyester resin to obtain modified fiber composites. These composite s have been found to be tolerant against cold and boiling water where water absorption and thickness swelling are much reduced compared to those of un modified fiber composite. It is also observed that the moisture content of the modified fiber composites is remarkably reduced. Cyclic tests reveal th at use of cyanoethylated fiber leads to improvement of the dimensional stab ility of the fiber composites. The mechanical properties of the modified fi ber composites improved remarkably due to better bonding at the fiber-matri x interface and this effect is more pronounced with a higher degree of cyan oethylation. A scanning electron micrograph of the fractured surfaces of cy anoethylated jute composite showed excellent retention of resin on broken f iber ends, whereas the unmodified composite showed uncoated fibers and hole s in the matrix. DSC data demonstrated that the moisture content of the com posites reduces with increase of the cyanoethylation. Both TG and DSC therm ograms showed an additional peak due to decomposition of cyanoethyl group w hich is shifted to a higher value with the extent of cyanoethylation. Howev er, the cellulose degradation temperature remained almost the same. (C) 200 0 John Wiley & Sons, Inc.