Study On Anionic Copolymerization Of VFc-Bd-St And Cyclization Of SSBR

Solution-polymerized styrene butadiene rubber (SSBR) is a kind of general synthetic rubber. The research of functional modification has significant appliance in industry. In this paper, two modification methods, functionalized monomer copolymerization and cyclization reaction are presented to investigate the properties of the modified polymers. The main research contents and conclusions are outlined as follows:Vinyl ferrocene (VFc), a new kind of metal-containing monomer which has attracted great interest was used to synthesize block copolymers containing metal elements. In the first part, we investigated the block copolymerization and atactic copolymerization reactions between vinyl ferrocene (VFc) and butadiene (Bd)/Styrene (St) in different solvents.1H-NMR results indicated that the sequence of the copolymerization activity was Bd>St>VFc. With the addition of cyclohexane, the polarity of the mixed solvent was decreased, and the ability of copolymerization of butadiene and VFc was enhanced. When the cyclohexane was used as the reaction solvent, the Bd-St-VFc copolymerization activity decreases, and the Bd-St-VFc block polymer with ten percent of VFc was finally obtained.The catalytic reaction of styrene butadiene rubber (SBR) with three fluorine methyl sulfonic acid system was studied in this paper. The influences of the microstructure, the cyclic time, the amount of catalyst, and the concentration of the catalyst on the cyclization rate of the reaction were investigated. GPC and 1H-NMR results found that the cyclization rate can be up to 100% after a 5 minutes cyclization if the concentration of the original copolymer is less than lg/lOml. DSC results indicated that the glass transition temperature (Tg) of the cyclized products increased significantly, up to 200?, but decreased gradually with the increased content of styrene in the original copolymers.The influence of the microstructure of the cyclic styrene butadiene rubber (CSBR) on its thermodynamic properties was also investigated. The influence of the three different structure on Tg was in the oder as:the conformation of butadiene with styrene>1,4-conformation with styrene>1,2-conformation with styrene.Manual drawing spinning was performed to obtain the CSBR fiber, results showed that the fibers had a diameter around 80?m and a smooth surface as well as no obvious defects in the cross-section.