CROSS-LINKING OF NATURAL RUBBER WITH PENTAERYTHRITOL TETRAKIS(3-MERCAPTOPROPIONATE) IN THE PRESENCE OF ANHYDROUS CERIUM CHLORIDE, IN THE SOLID-STATE, AT AMBIENT TEMPERATURE

ABSTRACT Natural rubber is cross-linked with a tetrafunctional thiol using anhydrous cerium chloride as catalyst, at ambient temperature. The cured rubber is characterized by infrared spectroscopy, cross-polarization magic angle spinning solid-state nuclear magnetic resonance spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The cross-linked rubber is observed to biodegrade in soil and partially breakdown when immersed in esterase buffer solution. This method involving thiol cross-linking of natural rubber could find application in developing coated rubber products using a variety of thiols, including natural thiols, from a solvent as well as in solid-state fabrication of molded rubber products.