Study On Coupling Reaction Of Epoxides For Preparation Of Butadiene And Styrene Nanometer Materials

The epoxide compound is an important kind of coupling agents for preparation of butadiene and styrene nanometer materials by anionic polymerization. In this thesis a new kind of epoxide compound used as coupling agents, epoxidized liquid polybutadiene, is prepared. The methods to measure epoxy value of epoxidized liquid polybutadiene, epoxidized soybean oil A, epoxidized soybean oil B, epoxidized castor oil and epoxidized cottonseed oil have been investigated. It is most important that study on the rules of the coupling reactions of epoxidized liquid polybutadiene and epoxidized soybean oil B.In this thesis the rules of the coupling reactions of butadiene homopolymerization, styrene homopolymerization and styrene homopolymerization capped with butadiene in the presence of THF, cyclohexane as solvent, n-BuLi as initiator are discussed. The results show that the coupling efficiency reaches the maximum when the mole ratio of epoxy group/n-BuLi is 1.0 in butadiene homopolymerization. With the increase of the amount of coupling agents, the relative number of arms decreases, the average number of arms passes through the maximum, and the molecular weight distribution becomes broader at the beginning and then turns to be narrower. The coupling efficiency passes through the maximum at the mole ratio of THF/h-BuLi is 1. The number of arms and the molecular weight distribution does not change much at different amount of THF. The higher the temperature of coupling reaction, the higher the coupling efficiency, and the temperature of coupling reaction does not affect much on the number of arms and the molecular weight distribution. With the increase of the time of coupling reaction, the coupling efficiency enhances, but it increases slowly after thirty minutes. The coupling reactions are considered to be completed approximately within thirty mintues. The time of coupling reaction does not have much effect on the number of arms and the molecular weight distribution. The rules of the coupling reactions of styrene homopolymerization and styrene homopolymerization capped with butadiene are similar to those of butadiene homopolymerization, and at same condition the number of arms and the molecular weight distribution do not have much difference. The coupling efficiency of butadiene homopolymerization is higher than that of styrene homopolymerization capped with butadiene, and the coupling efficiency of styrene homopolymerization capped with butadiene is higher than that of styrene homopolymerization. The coupling efficiency of polybutadiene with thirty thousand designed molecular weight is higher than that ofpolybutadiene with one hundred thousand designed molecular weight. At one hundred thousand designed molecular weight the relative number of arms is bigger, the average number of arms is smaller, and the molecular weight distribution is broader. The rules of the coupling reactions of butadiene homopolymerization of epoxidized liquid polybutadiene and epoxidized soybean oil B are similar to those of tetrachlorosilane.Butadiene and styrene nanometer materials are prepared with the application of the obtained rules of the coupling reactions of epoxidized liquid polybutadiene and epoxidized soybean oil B, and the impact resistant properties have been improved to a certain extent.