Investigation On Anionic Polymerization Of Primary Amine Substituted 1,1-diphenylethylene Derivatives

The studies on the synthesis of functionalized polymers have been carried out for many years,and the obtained structures were more precise and greater diversity.At present,the preliminary structures of functionalized polymers,like molecular weight,composition and topological structure,have been controlled,while the synthesis of the polymers with controlled sequence structures and complex topological structures have gradually become the focus of researches.The synthesis of sequence-controlled polymers was even known as one of the "holy grail" in the field of polymer synthesis.Many advanced polymerization methods have been developed to precisely regulate the sequence structure of polymers.Among them,living anionic polymerization(LAP)was the first reported living controllable polymerization.LAP could precisely regulate the molecular weight,molecular weight distribution and microstructure of diene.Meanwhile,the sequence distribution of 1,1-diphenylene(DPE)derivatives could be controlled in LAP,and the category,number and location of functionalized groups could be determined.However,due to the harsh polymerization condition,the types of functionalized groups introduced by copolymerization are limited.Hence,the functionalized groups can be greatly enriched by post-functional modification of polymers with efficient coupling reactions.Meanwhile,the flunctionalized groups can provide branching points for graft reactions.The topology-controlled polymers provide a broad platform for further studies on the influences of sequence structures and topological structures on the properties of polymers.Based on the above discussion and design concept,this article used 1-[4-[N,N-bis(trimethylsilyl)amino]phenyl]-1-phenylethylene(DPE-N(SiMe3)2)as functionalized monomer and used in situ 1H NMR to study the method of determining sequence distribution and regulating it.The click reaction and multicomponent reaction were used to post-modify the polymers to study the influence of sequence distribution on the properties of polymers.The"topological isomer" was synthesized to study the influence of sequence distribution and topological structure on the properties of polymers.The SBC was synthesized by the copolymerization of DPE derivatives,St and Bd to study the influence of composition distribution on the properties of polymers.The main results were as follows:(1)DPE-N(SiMe3)2 was synthesized and copolymerized with St in LAP to precisely prepare in-chain amine functionalized polymer.Via in situ 1H NMR,the sequences of the polymers were determined as average tetra-St-interval sequence in condition of 4/1 feed ratio and gradient deca-St-interval in condition of 10/1 feed ratio.Polymerization kinetics was studied and rst was determined as 1.04.Meanwhile,tri-copolymerizations of DPE-N(SiMe3)2/DPE-SiH|OMe/St were studied to synthesize diblock terpolymer via two-step feeding and one-pot terpolymer via one-step feeding.The sequence pattern of one-pot terpolymer was determined to be approximate alternant sequence,and the component ratio of DPE-SiH|OMe/DPE-N(SiMe3)2 was 6/4.Polymerization kinetics was studied and r'st was determined as 0.79.(2)The Ugi-4CR and epoxy-amine reaction were used to carry out efficient post-modification of in-chain amine functionalized polymer to synthesize in-chain multifunctionalized polystyrene and sequence-controlled fluoropolymers.After characterization and calculation,the structures of post-functionalized polymers were clear.The efficiencies of Ugi-4CR could reach 99%after modification,and the efficiencies of epoxy-amine reaction were over 95%.Based on the sequence-controlled fluoropolymers,the influence of sequence distribution on the properties of polymers was studied.The long perfluoroalkyl chain led to low surface tension and slight surface reconstruction,meanwhile sequence distribution effected the sensitivity of structural changes and surface reconstruction.The enrichment of fluorine in ideal chain of fluoropolymer was simulated by computer.Four models for film surface were proposed:long-compact,long-loose,short-compact and short-loose.(3)The "topological isomer" was proposed,which has similar molecular weight and different controlled topological structure,and the synthesis method was determined by combining Ugi-4CR and thiol-yne click reaction.The topological isomers were named as mono-brush,double-brush,mono-comb and double-comb polymer.Ugi-4CR efficiencies were above 91%,and the thiol-yne click reaction efficiencies were above 97%.The structure-performance relationship was also studied,and it was found that the four topological isomers had different molecular shapes,molecular sizes and flexibility of segment,which indicated that topological isomers could effectively reveal the influence of polymer structures on the properties.The mono-brush polymer was spherical conformation.The mean square radii of gyration were effected by branched degree.The hydrodynamic radii were effected by chain length.The double-tail polymer and compact sequence distribution improved the rigidity of the polymer backbone.(4)The amine functionalized SBC was synthesized by copolymerization of DPE-N(SiMe3)2/St/Bd.The molecular weight,molecular weight distribution and microstructure were all controlled.The composition distribution was studied via the method of sequence distribution research.The random SBC,block SBC and block gradient distribution SBC were synthesized,and the relative composition distribution tendencies were drawn.The thermal property,mechanical property and optical property were studied to reveal the structure-property relationship.The Tg of SBC was effected by 1,2-structure,composition distribution and the contents of DPE derivatives.The mechanical behavior of SBC could be varied from brittle resin,toughening resin to thermoplastic elastomer.The optical property of SBC was effected by the size of Bd phase,refractive index and transition section length.