Effect of fiber content on thermal and mechanical properties of euphorbia coagulum modified polyester and bamboo fiber composite

In the present experimental investigation, the utilization of euphorbia coagulum as a binder to fabricate euphorbia coagulum modified polyester bamboo fiber composite using a compression molding technique was studied. Composites were fabricated by varying the concentration of pristine bamboo fiber (BF) as well as alkali-treated bamboo fiber from 25% to 50% and also fabricated by the modification of polyester resin (PR) with euphorbia coagulum (EC). Structural and morphological changes of the fiber before and after alkali treatment were analyzed by XRD, SEM, FTIR, and the fabricated composites were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and mechanical properties by universal testing machine (UTM). Alkali treatment removed most of the hemicellulose and lignin content of the fiber which increases the surface roughness of the fiber and the nature of the fiber has been changed from hydrophilic to hydrophobic. It leads to facilitate the interlocking between fiber and matrix resulting in the improvement in mechanical properties of the composites. The maximum improvement in mechanical and thermal properties of composites were observed in case of 40% addition of both the pristine and alkali treated bamboo fiber in the polyester resin matrix. Moreover, it has been observed that with the addition of 30% euphorbia coagulum in the polyester resin further enhanced the mechanical and thermal properties of the composite and decreases the water absorption. The composites developed were found to be eco-friendly and cost effective, can be considered for the multipurpose panel, beam, pedestrian bridge.