Thermo-mechanical study of jute reinforced polyester composites

Jute is an important lignocellulosic fiber, relatively inexpensive and abundantly available. These fibers have excellent specific properties and have proved to be potential reinforcing filler in plastics. In order to improve the mechanical performance of composites, the fiber needs to be modified chemically. In the present work jute fabrics were modified chemically and jute-unsaturated polyester composite laminates were prepared from both modified (bleached, alkali treated and acetylated) and natural (unmodified) jute fabrics by hand lay-up technique. The effect of chemical modification and effect of fiber loading (number of stacks) on the mechanical, thermal and hygrothermal properties were studied. Optimum tensile and flexural properties are achieved by composites having two stacks of fabrics. Chemical surface treatments of fabrics decreased the tensile strength and modulus of fabrics. Tensile strength of natural jute composites was 47.7 MPa. Flexural strength and modulus of composites increased by surface treatment of fabrics except flexural strength of bleached jute composite which is decreased by 11.97%. Flexural modulus of bleached jute composite was highest among all i.e. 5.27GPa. Some improvement of impact properties due to surface treatment also noticed. Highest thermal stability achieved by alkali treated jute composites. Bleached jute composites were more resistant to water absorption and degradation through hot water immersion. The fractured surface morphologies of modified, natural and degraded jute composite specimens were studied through SEM.