The Investigation On The Synthesis Of Periodic Copolymers With The 1,1-Diphenylethylene (DPE) Derivatives

The application of polymer materials provides an important support for human development.Whether it is in the daily clothing,food,housing or front-end materials research,the polymer materials occupy an important position.The unique performance of polymer materials depends on the diversity of chemical structure,including different chemical compositions,structural units,sequence distributions,and molecular conformations.In terms of sequence,the monomer distribution on the polymer chain includes statistical structure,blocks and alternating periodic structures.The unique structure of the periodic copolymer greatly enriches the type and properties of the polymer material.How to realize the precise,convenient and controllable synthesis of the periodic copolymer and the"structural-effect"relationship between the structure and properties of the polymer have become the present attention in polymer field.In this project,1-(4-dimethylsilylphenyl)-1-phenylethene(DPE-SiH),1,1-diphenyl-ethylene(DPE)and 1-propyl-4-(1-phenylvinyl)benzene(DPE-propyl)have been designed for copolymerizing with styrene via the living anionic polymerization system,and various periodic structures with precise,controlled molecular weight and distribution were obtained.In this paper,the sequence structure in the polymer chain of obtained copolymer was analyzed precisely,and the kinetic mechanism of generation of periodic structure,by the copolymerization of DPE derivatives with styrene under living anionic copolymerization system,has been studied deeply.1.Three DPE derivatives are selected as comonomers,including1-(4-dimethylsilylphenyl)-1-phenylethylene(DPE-SiH),1,1-diphenyl-Ethylene(DPE)and1-propyl-4-(1-phenylvinyl)benzene(DPE-propyl),which were copolymerized with styrene,with various feed ratios were designed for each DPE derivative,under living anionic copolymerization system.In situ ~1H NMR monitoring was used to monitor the chain growth process of copolymerization in real time,and the copolymerization kinetic curves were obtained by scientific in-situ ~1H NMR calculation.The effect of reaction activity of DPE derivatives and monomer feed ratios on copolymerization kinetics and the copolymerization kinetics of the formation of periodic structures based on DPE derivatives in living anion systems were further studied.2.Based on the copolymerization kinetics research of DPEs with styrene,the sequence structure of copolymer were deduced by in situ ~1H NMR calculation,which indicates the successful synthesis of a variety of periodic copolymers containing different DPEs with precise and controllable structure.The DSC test of the obtained periodic copolymers is carried out to explore the structure-effect relationship of the sequence structure and the glass transition temperature-T_g.Preliminary results indicate that the glass transition temperature is affected to some extent by the polymer sequence structure.