Study On The Effect Of Acidity And Basicity Of Catalyst On The Catalytic Synthesis Of Bisphenol F

As an important chemical material in the chemical industry,bisphenol F(a mixture of 4,4’-2,4’-,and 2,2’-isomers)can be synthesized by hydroxyalkylation of phenol with formaldehyde in the presence of active catalyst.It is synthesized by the reaction and is mainly used in the synthesis of materials such as low viscosity epoxy resin,special polyester resin raw material and information recording paper additive.However,in the process of industrially using liquid acid catalyzed synthesis of bisphenol F,there are the following problems:serious corrosion of equipment,high phenolic ratio of reaction,difficult separation between reaction products,and recycling of catalysts.In view of these disadvantages in the synthesis of bisphenol F,two solid-type catalysts,ie,the solid acid catalyst Sn-MCM-41 and the solid alkali catalyst calcium silicate,have been designed for the synthesis of bisphenol F.The specific research content and conclusions are as follows:(1)Sn-MCM-41 molecular sieves were successfully prepared by traditional hydrothermal synthesis method using CTAB as template,SnC12· 2H20 as tin source and TEOS as silicon source under different solvent systems.The structure of the catalyst was characterized by small angle XRD,low temperature N2 adsorption-desorption,FT-IR,and TEM.The characterization results showed that the Sn species was successfully introduced into the framework of the molecular sieve and the molecular sieve retained the original pure silica molecular sieve.In addition,using NH3-TPD to characterize the acid properties of the catalyst,the results show that the activity of-the catalyst has a great relationship with the amount of acid amount,which further shows that the introduction of Sn species significantly changes the activity of molecular sieve.The Sn-MCM-41 molecular sieve with a Si/Sn ratio of 10 prepared with ethanol as solvent has the best catalytic activity.(2)we use calcium carbonate and silica as raw materials to prepare a series of calcium silicate catalysts by calcining and hydrothermal method,and the structures of the catalysts were characterized by wide-angle XRD,BET,FT-IR,and CO2-TPD.For the first time,the use of solid bases as catalysts in the synthesis of bisphenol F has been reported.According to the analysis of experimental results,it can be seen that calcium silicate has good catalytic activity in the synthesis of bisphenol F and has specific selectivity for the 2,2’-isomer.This specific selectivity is mainly related to the nature of the catalyst.Furthermore,this catalyst has a low synthesis cost and is easy to operate,and can be applied to industrial applications.