Biolubricants may be obtained from vegetable oils using appropriate chemical modifications, to improve their physicochemical properties for lubrication applications. In this study, the esterification of a free fatty acid (FFA) with long chain alcohols was performed using sulfonated mesoporous silica as catalyst. Fresh and functionalized MCM-41 samples were prepared to evaluate the effect of the sulfonic surface group on the esterification reaction. MCM-41 was functionalized via post-synthesis modification using 3-mercaptopropyltrimethoxysilane (MPTS) as silylating agent. The synthesized catalysts were characterized using several techniques. After the functionalization, a decrease in the apparent surface area and pore diameter were observed. The MCM-41/SO₃H sample was applied in the esterification reaction of oleic acid (as a FFA model) using two different long-chain alcohols (octanol and 2-ethylhexanol). The catalytic results reveal that sulfonated catalyst showed excellent conversions (~ 100% mol when using octanol and > 93% mol using 2-ethylhexanol) and selectivities to esters (ca. 90%).

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