EFFECT OF ADHESION ON THE EQUILIBRIUM SWELLING OF SHORT SISAL FIBER-REINFORCED NATURAL-RUBBER COMPOSITES

Solvent swelling of natural rubber composites, containing both untreated and acetylated short sisal fiber, has been investigated in a series of normal alkanes such as pentane, hexane, heptane and octane. The restriction on elastomer swelling exerted by sisal fiber as well as the anisotropy of swelling of the composite have been confirmed by this study. The results showed that increased fiber content and the addition of bonding agent reduced the swelling considerably. It has been demonstrated that with improved adhesion between short fiber and rubber, the factor, (V-I - V-F)/ V-I, decreases, where V-I and V-F, are the volume fraction of rubber in dry and swollen samples, respectively.