MECHANICAL PROPERTIES AND CHARACTERIZATION STUDIES IN NATURAL FIBER/ LIGNITE FLY ASH REINFORCED HYBRID COMPOSITES

Abstract

In this project the variation of mechanical properties in lignite fly ash filled fiber reinforced composite with water absorption is studied. Hybrid composites are recent trends advancement of composite materials that consist of two reinforcement phase fiber-fiber, particle-particle & particle fiber. Hybrid composites will have the properties of both the reinforcement phases which improve the properties of material. In this project particle-fiber hybrid composite is considered for study of mechanical properties. The particle used is Lignite Fly Ash (LFA) and fiber used is Palmyra and the matrix phase is unsaturated polyester resin. The composites are fabricated in the combination of Palmyra/Fly ash.  The composite is fabricated using Compression molding process at 90:8:2 weight mixing ratios of raw materials. The fiber is extracted using water retting process; the extracted fiber chopped into 2 mm short length fiber and refined it by treating it with NaOH and CH3COOH. The refined fiber is spread over the die of dimension 300 x 125 x 3 mm, then mixture of unsaturated polyester resin, LFA, catalyst and accelerator is poured over the fiber. The die is closed and placed in compression molding machine under a compressive load of 5 to 10 tones and cured for 2 – 3 hours. The fabricated composites are cut as per ASTM standards for tensile, compressive, flexural and hardness test. One set of specimen is immersed in water for 24 hours for water absorption and tested. The other set is tested without water absorption and the variation in mechanical properties is studied. From the results obtained it is found the tensile, compressive & flexural properties increases with increase water absorption for Palmyra/Fly ash composite. The sample characterization was by X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) to probe the microstructure and geopolymerization reactions.