Dimerization of methyl oleate using Thai clays as catalyst

Abstract

Three types of Thai clays, namely talcum, china and ball clay were used as catalyst for the dimerization of methyl oleate. The efficiencies of acid activated clays for dimer formation were investigated. The suitable condition for dimerization of methyl oleate was obtained at 250℃, 4 hours and 25 %wt clay. Talcum showed higher carbon-carbon linked dimer formation (17.20%) than did other clays. The synthesized dimers were identified by spectroscopic techniques, such as infrared spectroscopy, nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption ionization mass spectrometry. However, its dimerization capacity was not good. Therefore, dimerization of methyl oleate using cobalt naphthenate and tert¬butylhydroperoxide as cocatalyst was studied. The suitable condition for dimerization of methyl oleate was observed at 60 ℃, 24 hours, 15%wt clay, 1.5%wt tert-butylhydroperoxide and 0.05%wt cobalt naphthenate. It was found that carbon-carbon linked dimer formation (35.28%) was better than those using clay alone (17.20%).