Effect of expandable graphite on flame retardation of bamboo fiber reinforced polypropylene composite

Abstract

In order to develop flame-retardant composite materials from biomass and commodity plastics, bamboo powder (BP) including micro fibers/ whiskers and polypropylene (PP) were blended with some kinds of flame-retardants: mixed metal hydroxides, aromatic phosphate, and expandable graphite (EG). As a result, in BP/PP/flame-retardant composites, EG effectively functioned as an excellent flame-retarding agent to achieve class V-03V-1 of the UL94 specification. Moreover, to improve mechanical properties of BP/PP/EG (40:40:20 wt/wt/wt) composite, maleic anhydride-modified polypropylene (MAPP) was added as a compatibilizer. Fabricated BP/PP/EG/MAPP composites showed higher values of tensile modulus, flexural strength, and flexural modulus by 209, 104, and 146%, respectively, than original PP when MAPP was added at 1wt% only. Therefore, the biomass/PP composites balanced the excellent flame-resistance and improved the mechanical properties were achieved.