Novel Solid Catalysts In Methylenation Reaction Of Phenol And Formaldehyde

The epoxy resin industry had experienced a vigorous development during the twelfth five-year period,China is becoming the world’s largest epoxy resin production and consumption country.But the varieties of the epoxy resin products in our country is single,mainly are basic production.The development of science and technology together with the improvement of national economy are both setting higher requirements on every technical performance index of epoxy resins.The supply of high performance and high value-added epoxy resins cannot meet the demand in our country,mainly rely on imports from abroad to solve the problem.The high quality epoxy resin market in China shows a huge potential,developing bisphenol-F type epoxy resin to replace traditional bisphenol-A type epoxy resin has a far-reaching social and economic benefits.Liquid protonic acid like sulfuric acid,phosphoric acid are widely used catalyst in chemical industry,but they also exposed several problems such as equipment corrosion,difficulties in separation,and increased by-products.As solid acid catalysts have the advantages like easily separation,excellent reusability,they are becoming the favor of researchers with the popularization of the theory of green catalysis development.As the most used catalyst in industrial production,solid catalyst can bring on huge environmental and economic benefit.Thus,it’s attracting people to innovate in solid catalyst and explore preparation of new solid catalyst.In this paper,a novel solid catalyst based on polyvinyl chloride(PVC)as carbon chain skeleton was prepared,which is cheap and easily got.Firstly take advantage of the activity of Cl atom,use organic amine to get crosslinking modified polyvinyl chloride(PVC-EDA),then successfully introduced acid center via the treatment of sulfuric acid and finally got the solid catalyst PVC-EDA-SO4H.This paper studied the effect of preparation condition on the catalysis activities and got the optimal preparation route of the catalyst.The characterization of FT-IR,TG-DTG,XRD,elemental analysis et al showed that the functional group had been successfully introduced into the carbon chain structure of PVC.The catalyst made under the optimal condition had an acid amount of 1.12mmol/g and a good heat stability.The catalyst was used in the synthesis of BPF and cyclohexanone ethylene ketal.The results showed that under the condition of n(Phenol):n(Formaldehyde)=20:1,reaction temperature=80 ℃,reaction time=30 min,catalyst amount =0.5%(wt),yield and selectivity of BPF are both over 95%.After 6 times repeated use,the catalyst remained almost the same.The catalysts also had excellent performance in ketalation reaction and esterification reaction.After 10 times repeated use,the catalysts remained quite stable.The product of bisphenol-F was refined in this study.Firstly,the catalyst was recycled from the reaction mixture via suction filtration.Then the reduced pressure distillation unit was used to remove phenol and water in the mixture were,after that,Toluene recrystallization was operated to get bisphenol-F with high content of 4,4’-bisphenol-F.The characterization of the product via FT-IR,HPLC and H-NMR showed a purity of 98.6%.This study also prepared a series of catalysts of the same type and explored the catalytic activity of the catalysts.The results showed that the catalysts had successfully introduced the acid site in spite of the different catalytic activity.The suty provided new ideas for the preparation of solid acid catalysts.