Phosphorylated cashew nut shell liquid prepolymer modified kaolin as a reinforcing filler for natural rubber

Abstract

At least a partial substitution of carbon black/precipitated silica being used in the rubber industry with low cost reinforcing fillers based on china clay (kaolin) — a non-replenishable natural resource could lead to technical and economic viability. Low cost industrial byproducts/renewable natural resources such as Cashew Nut Shell Liquid (CNSL) or Rubber Seed Oil (RSO) or their derivatives may be used as organo modifiers for kaolin to impart excellent compatibility with non-polar rubbers along with desired physico-mechanical properties for various applications. Results of the present study as obtained from XRD, TEM, SEM, TGA, CLD (chemical crosslink density) and tensile properties show that low dosages of kaolin modified with a solution of Phosphorylated Cashew Nut Shell Liquid prepolymer (PCNSL) in toluene could act as potential nano-reinforcing fillers for natural rubber (NR), as evidenced by improvements in filler dispersion, thermal stability and tensile properties of the vulcanizates.