Studies on the carboxymethylation and methylation of bisphenol A with dimethyl carbonate over TiO2/SBA-15

Carboxymethylated species were selectively synthesized from dimethyl carbonate (DMC) and bisphenol A (BPA) over TiO2/SBA-15. On the basis of catalyst characterization by means of XRD, FT-IR, HPLC and GC–MS, the relations between catalytic performance and catalyst properties were discussed. Si–O–Ti was active sites for reaction, and the interaction mode between Ti–O–Si and DMC was main factor to determine carboxymethylation and methylation. When DMC was attacked by Ti–O–Si on two oxygen atoms of CH3–O moiety, BPA attacked carbonyl carbon to form carboxymethylated products. If the interaction occurs through the oxygen of CO moiety, BPA attacked methyl carbon to form methylated products. Chemisorbed H2O over TiO2/SBA-15 made DMC to act as methylating agent. After chemisorbed H2O was removed, carboxymethylated species of two-methylcarbonate-ended-BPA (DmC(1)) and one-methylcarbonate-ended-BPA (MmC(1)) were selectively synthesized.

Carboxymethylated species were synthesized from dimethyl carbonate (DMC) and bisphenol A (BPA) over TiO2/SBA-15, and Si–O–Ti was active sites for reaction. When DMC was attacked by Ti–O–Si on CH3–O moiety, BPA attacked carbonyl carbon to form carboxymethylated products. Chemisorbed H2O over TiO2/SBA-15 made DMC to act as methylating agent. After chemisorbed H2O was removed, carboxymethylated species were selectively synthesized.Figure optionsDownload as PowerPoint slide