New Hydrosilylation Catalyst For The Synthesis And Application Of Research

Organosilicon is one of the most versatile groups of chemicals on the world,they can share some common features that give them special advantages over other materials.Organosilicon can make existing materials work better,longer,and more reliably.They fuel our imaginations and make new products possible.Recently,benefiting of the development of Materials Science,organosilicon material become the important branch of chemicals industry and held a very important status in our country's economy.It is widely used in aerospace,electrical and electronic,textile,light industry, building,machinery,medical,food,transportation and other industrial sectors.Hydrosilylation is a common method to prepare the carbon-silicon silicones.Although factory uses platinum catalysts in the hydrosilylation of olefins predominantly at present,the deficiencies are obvious.Firstly,the platinum-containing catalysts are very expensive.The recovery of catalysts is not easy.Secondly,in the case of olefins with electron-drawing substituents,conventional platinum catalysts are not effective.In this paper,a new kind of karstedt catalysts(Pt-1,3,5,7-Tetravinyl-1,3,5,7-Tetramethyl-cyclotetrasiloxane) used for hydrosilylation were prepared and the performance of the catalysts was evaluated by synthesis of several important silanes.This catalyst has high catalytic activity, selectivity,and low catalyst usage characteristics.The results are as follows:1.A new kind of Karstedt catalysts were Synthesized at different conditions using chloroplatinic acid,1,3,5,7-Tetravinyl-1,3,5,7-Tetramethylcyclotetrasiloxane(V4),ethanol, sodium bicarbonate as reactants.The effects of the amount of sodium bicarbonate and V4 on the conversion of Pt and catalytic activity were discussed.The catalysts were characterized by synthesizeγ-chloropropyltrichlorosilane by trichlorosilane and 3-chloropropene(AC).The reaction conditions,such as reaction time and the amount of catalyst were discussed.2.γ-chloropropyltrimethoxysilane was synthesized by hydrosilylation using 3-chloropropene(AC) and trimethoxysilane(TMS).The reaction conditions,such as temperature, reaction time,the kind of catalyst and aid catalyst,the sequence of adding reactants,were discussed.The product was characterized by GC-MS.The optimum experimental condition was got as follows:reaction temperature 80℃,the n(TMS):n(AC)=1.4,use RuCl₃ as catalyst,acetophenone as aid catalyst,the highest yield got to 96%.3.γ-chloropropylmethyldimethoxysilane was synthesized by two step using 3-chloropropene(AC),methanol and methyldichlorosilane.Pt-1,3,5,7-Tetravinyl-1,3,5,7-Tetramethyl- cyclotetrasiloxane was prepared and used as catalyst that has strengthened the catalytic and greatly improved the yield of the hydrosilylation of methyldichlorosilane with 3-chloropropene(AC).The optimum technologic condition was selected and the highest yield got to 85%.The alcoholysis reaction of synthesizingγ-chloropropylmethyldimethoxysilane was investigated.The highest yield got to 95%by continuous alcoholysis reaction.During the reaction no solvent was needed to add to alcoholysis reaction,which made the separation and purification easier.The method can save the cost a lot and reduce consumption of energy.4.γ-epoxy propoxy propylmethyldimethoxysilane was synthesized by two step using methanol,methyldichlorosilane and 1-Allyloxy-2,3-epoxy propane(AGE).In the alcoholysis reaction of synthesizingγ-chloropropylmethyldimethoxysilane,The reaction conditions,such as temperature,reaction time,the kind of solvent were investigated.In the second step of synthesizingγ-chloropropylmethyldimethoxysilane,Pt-1,3,5,7-Tetravinyl -1,3,5,7-Tetramethyl-cyclotetrasiloxane was used as catalyst that has strengthened the catalytic and greatly improved the yield of the hydrosilylation.The product was characterized by GC-MS.The optimum experimental condition was got as follows:reaction temperature 55～75℃,n(AGE):n(Me(OEt)₂SiH) =1.05:1,use Pt-C₁₂H₂₄Si₄O₄ as catalyst,the highest yield got to 84.8%.