Copolymerization Of Styrene Derivatives With Conjugated Dienes By Half-sandwich Scandium Complexes

The functional styrene thermoplastic elastomer maintains the excellent properties of the styrene elastomer material while improving the disadvantages of lacking functional groups,further improving the adhesion,surface properties and miscibility with other polymers,In particular,it imparts new functions such as photoelectric,medical,and ion exchange materials.Therefore,the synthesis of functional styrene thermoplastic elastomers has great application prospects.In this thesis,the copolymerization of styrene derivatives with conjugated olefins was studied.A series of catalysts with excellent catalytic properties in the copolymerization of styrene derivatives and conjugated olefins were developed,and a series of different sequence structures and stereoscopic selective functionalized styrenic thermoplastic elastomer were obtained.1.C₅Me₄SiMe₃-ligated scandium complex?C₅Me₄SiMe₃?Sc?CH₂C₆H₄NMe₂-o?₂?1?can achieve styrene derivatives with groups of NEt₂,NPh₂,Cl in para-position copolymerized with myrcene,the product is separated by n-hexane to remove a small amount of homo-polymyrcene,obtained block copolymer having a high melting point?T_m=210°C-321°C?and a low glass transition temperature?T_g=-40°C?.The polystyrene derivative segment is syndiotactic,and the polymyrcene is mainly composed of 3,4-structure.C₅H₅-ligated scandium complex?C₅H₅?Sc?CH₂C₆H₄NMe₂-o?₂?2?can effectively achieved copolymerization of styrene derivatives with NPh₂ group with myrcene,high activity to obtain a pure block copolymer,which the poly-NPh₂St segment in the copolymer is syndiotactic,polymyrcene segment cis-1,4-selection is as high as 96%.After achieved the polymerization of NPh₂St by using of scandium complexes 2,the mixture of NPh₂St and myrcene was added to continue the polymerization.The syndiotactic NPh₂St-cis-1,4-polymyrcene-syndiotactic-NPh₂St triblock with controlled composition and molecular weight was obtained.2.Copolymerization of several styrene derivatives?NEt₂St,NPh₂St,ClSt?with isoprene by using of 1 and 2 can highly activety to obtain a series of adjustable composition,molecular weight controllable polystyrene derivative-polyisoprene copolymer.The copolymerization of chlorostyrene?ClSt?with isoprene by using of 1 to obtain a gradient copolymer,while the poly?chlorostyrene?segment in the copolymer is syndiotactic,and the polyisoprene segment is mainly 3,4-structure.The copolymerization of N,N-diphenylaminostyrene?NPh₂St?with isoprene by using of 1 to obtain a multi-block copolymer,which poly NPh₂St is syndiotactic,and the polyisoprene 3,4-structure is as high as 75%.Copolymerization of N,N-diphenylaminostyrene?NPh₂St?with isoprene by using of 2 to obtain diblock copolymer,poly NPh2St segment in the copolymer is syndiotactic,the polyisoprene 1,4-structure is as high as 96%.After achieved the polymerization of NPh₂St by using of scandium complexes 2,the mixture of NPh₂St and isoprene was added to continue the polymerization.The syndiotactic NPh₂St-cis-1,4-polyisoprene-syndiotactic-NPh₂St triblock with controlled composition and molecular weight was obtained.