Applied Catalysis A: General, Vol.548, 83-88, 2017
Catalytic transesterification using a silica hybrid containing encapsulated polyacrylates
The CTA-MCM-41 silica hybrid contains basic sites due to the presence of siloxy anions (equivalent to SiO-) associated with CTA cations. A problem is that this material progressively loses its catalytic activity during successive reuse in transesterification reactions. The challenge of the present work was therefore to stabilize the catalytic activity of this silica hybrid by means of the encapsulation of polymers, using an initial emulsification step in the synthesis. Samples of monomers and polymers emulsified in colloidal solution were characterized using small angle X-ray scattering (SAXS), which confirmed their presence in the interior of the micelles. The solids were analyzed by X-ray diffraction, elemental analysis (CHN), infrared absorption spectroscopy, and thermogravimetry. The findings confirmed the presence of monomers and polymers in the channels of the CTA-MCM-41, and the polymers acted to increase the stability of these new materials during catalytic transesterification.