In order to improve fiber distribution and poor adhesion between fiber and rubber, the fiber was treated with a silane coupling agent. The silane coupling agent is capable of forming an oxane bond between the rubber matrix and cellulose fiber as shown in Figure 6. The amount of the coupling agent was 0.5%w/w as suggested by Derringer.(7) The treated fiber was then used in the rubber compound. The hardness, tensile strength, modulus, and abrasion resistance of the cured rubber reinforced
with treated fiber were shown in Figures 2-5, respectively.