The Research On Preparation Of MCM-41Modified By Pseudo Boehmite And Synthesis Of Bisphenol F Catalyzed By Modified MCM-41

Bisphenol F, one of the most important chemical intermediates, is condensed byphenol and formaldehyde. Bisphenol F is usually composed of three isomers, namely4,4’–diphenylhydantoin,2,4’–diphenylhydantoin, and2,2’–diphenylhydantoin[CH2(C-6H4OH)2]. The best performance is4,4’–diphenylhydantoin. Because of its chemicalstructure characteristics in the synthesis of epoxy resin, polyester resin, polycarbonateresin and phenolic resin as modifier and flame retardant, the products’ heat resistance,moisture resistance, insulation, processing and injection molding casting propertiesare far superior to the products by bisphenol A as raw materials.The choice of the catalyst is an important process for synthesis of bisphenol F. Inthis paper, using different modifiers and modified methods to synthesize Al-MCM-41mesoporous molecular sieve, and the Al-MCM-41mesoporous molecular sieve is usedas catalyst for synthesis of bisphenol F. The main content includes:1. Using pseudo boehmite as aluminum source, Al-MCM-41is synthesized bygrafting, sol-gel, template cation exchange and hydrothermal. The structure ofAl-MCM-41is characterized by XRD ray diffraction. The results show that theAl-MCM-41synthesized by grafting, template cation exchange and hydrothermalhave the typical structure of mesoporous molecular sieves. The regularity and orderdegree of Al-MCM-41with hydrothermal is relatively the best. On the contrary, theregularity and order degree of Al-MCM-41with sol-gel is relatively the worst.Bisphenol F is synthesized by4kinds of modified MCM-41. The order of catalyticeffect is: hydrothermal> template cation exchange> grafting> sol-gel.2. Al-MCM-41mesoporous molecular sieve is synthetized by hydrothermalmethod and1,3,5-three methyl benzene reaming as expanding agent to expand theAl-MCM-41’s aperture. The synthesized molecular sieve is characterized by XRD raydiffraction, N2adsorption desorption and NH3-TPD. The results show that thesynthesized molecular sieve are typical structure of mesoporous molecular sieves.When TMB/CTAB is increased from0to6mol/mol, Al-MCM-41’s (Si/Al=75mol/mol)aperture is increased from3.38nm to10.54nm. Bisphenol F is synthetized byAl-MCM-41(TMB/CTAB=0mol/mol) with different Si/Al mol/mol. The Al-MCM-41(Si/Al=100mol/mol) exhibited the best catalytic activity, and the product yield is62%. Bisphenol F is synthetized by Al-MCM-41(Si/Al=75mol/mol) with differentTMB/CTAB mol/mol. The product yield is increased with the increase of TMB/CTAB.When TMB/CTAB is6mol/mol, the prosuct yield is76.4%.3. The yield and selectivity of bisphenol F is efected by n (phenol)/n(formaldehyde), m (Al-MCM-41)/m (formaldehyde), reaction temperature andreaction time. The factors are discussed by modified molecular sieve as catalyst. Thebest technological conditions of the synthesis of bisphenol F are as follows:phenol/formaldehyde ratios=30mol/mol; Al-MCM-41/formaldehyde=25wt.%;reaction time=6h; reaction temperature=130°C.