Study of jute fiber reinforced polyester composites by dynamic mechanical analysis

Cyanoethylation of jute fibers in the form of nonwoven fabric was studied, and these chemically modified fibers were used to wake jute-polyester compo sites. The dynamic mechanical thermal properties of unsaturated polyester r esin (cured) and composites of unmodified and chemically modified jute-poly ester were studied by using a dynamic mechanical analyzer over a wide tempe rature range. The data suggest that the storage modulus and thermal transit ion temperature of the composites increased enormously due to cyanoethylati on of fiber. An increase of the storage modulus of composites, prepared fro m chemically modified fiber, indicates its higher stiffness as compared to a composite prepared from unmodified fiber. It is also observed that incorp oration of jute fiber (both unmodified and modified) with the unsaturated r esin reduced the tan delta peak height remarkably. Composites prepared from cyanoethylated jute show better creep resistance at comparatively lower te mperatures. On the contrary, a reversed phenomenon is observed at higher te mperatures (120 degrees C and above). Scanning electron micrographs of tens ile fracture surfaces of unmodified and modified jute-polyester composites clearly demonstrate better fiber-matrix bonding in the case of the latter. (C) 1999 John Wiley & Sons, Inc.