Abstract: Health and sustainability are the major concerns that drive researchers to find novel materials to replace artificial hazardous materials. In this investigation, the mechanical properties of Cissus quadrangularis Stem Fiber (CQSF) reinforced with unsaturated polyester composite were optimized by varying the fiber length and content. To substantiate the findings, chemical property, thermal property, microstructure, and water absorption property were analyzed. Progressive enhancement of mechanical properties was observed with increasing the fiber content and fiber length up to 30 wt.% and 40 mm. However, beyond that limit, there was a decline in the strength due to improper bonding of fiber with matrix. Optimal values of mechanical property for CQSF composite were obtained at 30 wt.% fiber content and 40 mm fiber length, which are comparable with that of common artificial fiber-reinforced polymer composites.

Key words: CQSF, mechanical properties, thermogravimetric anlaysis, microstructure, water absorption