Study On Synthesis Technology Of Novel Long-Chain Alkyl Silane Coupling Agent

Silane coupling agents that have a wide applications, as well as silicone rubbers,silicone resins and silicone oils, constitute four categories of organic silicon products.Due to the hydrophobic and flexible long-chain, long-chain silane coupling agentshave unique advantage in improving the wettability of organic for filler, which is oneof a development directions for silane coupling agents.These products mainly rely onimport in China, that improves the production cost and damages the development ofrelated industries. Through researching and developing projects of long-chain silanecoupling agents, that can mak up the domestic shortage, break the foreign monopolyand also promote the healthy development of related industries.It is a common method that platinum catalyst catalyzed hydrosilylation reactionto synthesize long-chain alkyl silane coupling agent, while the activity and selectivityof platinum catalyst has great influence on the reaction, so suitable catalyst selected isthe key to hydrosilylation reaction. Alcoholysis reaction is a common method forpreparing alkylalkoxylsilane. If the by-product HCl can not be removed from thealcoholysis process timely, it would easily lead to a series of side reactions, thus theproduct yield would be reduced greatly. In response to these problems,methyldichlorosilane,1-dodecene and methanol as materials to synthesize novellong-chain silane coupling agents, including dodecylmethyldichlorosilane anddodecylmethyldimethoxysilane, then selecting suitable catalyst, developing newtechnologies and other basic research for providing basic data for further research andindustrial about two products.Then studying and verifying the GC external standard method for quantitativeanalyze the products, found that the GC external standard method has advantage onaccuracy and repeatability. The method can be used to analyze each componentcontent in the system and determine the optimum operating GC conditions forproviding effective support for the follow-up study. After comparing homogeneous platinum catalyst, supported platinum catalystwith supported cooperation platinum catalyst, find that the homogeneous platinumcatalyst has high catalytic activity in hydrosilylation reaction. Using homogeneousplatinum catalyst, the hydrosilylation reaction conditions have been optimizedthrough single factor experiment, under the optimized conditions, the product yieldcould reach92.5%, higher than the literature values(82%), then the structure ofproduct was characterized by means of FT-IR and1HNMR spectrum.Using dodecylmethyldimethoxysilane and methanol as material to synthesizedodecylmethyldimethoxysilane through gas-liquid alcoholysis reaction in tubularreactor. By examining the impact of different fillers to the reaction, found that theglass wire spring has good mass transfer. The alcoholysis reaction conditions havebeen optimized through single factor experiment, under the optimized conditions, theproduct yield could reach69.3%. The way that adding methanol several times caneffectively reduce the occurrence of side reactions, when adding methanol twice, theproduct yield could reach77.5%. By repeating alcoholysis experiment showed thatraw materials conversion and product yield can be improved by alcoholysis multiple,the product yield could reach90%or more after alcoholysis reaction three times.To achieve the continuous operation of industrial production and remove HCltimely, the alcoholysis reaction device was improved with continuous synthesisprocess and micro vacuum, it has some advantage, such as operating simply, highyield and continuous production, the yield of dodecylmethyldimethoxysilanecoupling agent could reach90.5%, higher than the literature values(76%), then thestructure of target compound was characterized by means of FT-IR,1HNMR and13CNMR spectrum.