Effects of collagen fiber addition on the combustion and thermal stability of natural rubber

Collagen fiber(CF) and silane coupling agent-modified collagen fiber(MCF) were used as flame retardant filler for natural rubber(NR) modification.The combustion phenomena and properties of composites blended with different dosages of CF or MCF were compared to elucidate the flame retardant mechanism of the composites.The flame retardancy of NR can be enhanced effectively by increasing nitrogen content(the nitrogen content of CF is about 18%),creating air pockets,and structuring the flame retardant network in the composites.MCF failed to structure a flame retardant network in the composite,indicating that its modification effects of MCF are weaker than those of CF.When CF dosage was 30 wt%,the composite can achieve the best flame retardancy,with limited oxygen index of 29.4% and without smoke and dripping during burning.This study demonstrated a new method for the flame retardant modification of NR.