An environment friendly hemp fiber modified with phytic acid for enhancing fire safety of automobile parts

Abstract

Abstract To overcome the pollution to the environment with the application of flame retardants in automobiles, complete environment-friendly flame retardants have aroused wide concern. Furthermore, natural fibers have replaced artificial fibers in various fields due to their excellent performance and environmentally friendly. Thus, in this work, modified hemp fiber (HF-P) via phytic acid was obtained and used as a green flame retardant for automobile parts containing unsaturated polyester resins (UPR). The flame retardance of UPR composites were tested by thermogravimetric analysis, limiting oxygen index (LOI), and cone calorimeter test. A total of 3 wt% HF-P imparted UPR matrix excellent flame retardancy. The LOI value of UPR/HF-P-3 composites was increased from 18.9% of pure UPR to 22.1%, and the values of AHRR and THR were reduced to 401.9 kW/m2 and 150.6 MJ/m2, respectively. TGA test shows that HF-P can effectively improve the carbon-forming ability of UPR composites, which provides a material basis for condensed phase flame retardancy. For mechanical properties, the incorporation of HP-F endows a better enhancement on flexural strength of UPR composite.