Biguanide-functionalized mesoporous SBA-15 silica as an efficient solid catalyst for interesterification of vegetable oils

• The catalyst was effective in the interesterification reaction of vegetable oils.
• The prepared catalyst was characterized by various techniques.
• The catalytic activity and stability of the catalyst were investigated.

The biguanide-functionalized SBA-15 materials were fabricated by grafting of organic biguanide onto the SBA-15 silica through covalent attachments, and then this organic–inorganic hybrid material was employed as solid catalysts for the interesterification of triacylglycerols for the modification of vegetable oils. The prepared catalyst was characterized by FTIR, XRD, SEM, TEM, nitrogen adsorption–desorption and elemental analysis. The biguanide base was successfully tethered onto the SBA-15 silica with no damage to the ordered mesoporous structure of the silica after the organo-functionalization. The solid catalyst had stronger base strength and could catalyze the interesterification of triacylglycerols. The fatty acid compositions and triacylglycerol profiles of the interesterified products were noticeably varied following the interesterification. The reaction parameters, namely substrate ratio, reaction temperature, catalyst loading and reaction time, were investigated for the interesterification of soybean oil with methyl decanoate. The catalyst could be reused for at least four cycles without significant loss of activity.