A Novel PolyHIPE-like Catalyst for Esterification Reactions: on the Synthesis of Sulfonated Poly(styrene-co-n-acylglycerol) and its Use for Efficient Conversion of Oleic Acid to Methyl Oleate

The current work describes the synthesis of a new polyHIPE-like sulfonated poly(styrene-co-n-acylglycerol) and its use as an efficient heterogeneous catalyst to convert oleic acid into methyl oleate in esterification reactions. This new environmentally friendly polymer incorporates n-acylglycerol macromonomer as a versatile strategy for glycerol valorization. Macroporous micrometric polymer particles are synthesized through suspension polymerization process without using porogenic agents. polyHIPE-like copolymers formed with different feed compositions of styrene and n-acylglycerol are chemically modified via sulfonation reactions to form a highly efficient catalyst for esterification of oleic acid to methyl oleate, exhibiting conversions lying in the interval from 52% to 96%, depending mainly on the amount of n-acylglycerol macromonomer into the copolymer chains. The experimental results indicate the great potential of this new heterogeneous catalyst based on modified poly(styrene-co-n-acylglycerol) to be successfully employed in esterification reactions of vegetable oils intended for the production of long chain alkyl esters of carboxylic acids, widely used as biofuels.