Synthesis Of Multiarm And Miktoarm Star Isotactic Polypropylenes

The thesis is devoted to the synthesis of isotactic polypropylenes with multiarm and miktoarm star topological structure,exploring a new strategy for high performance and high functionalization of isotactic polypropylenes.We demonstrated the preparation of a new chain-end reactive isotactic polypropylene?iPP?via characteristic of the insertion reaction of functional styrene monomer during propylene polymerization.The chain-end reactive iPP is used as building block,combining sol-gel technology,to prepare iPP-based copolymers with star topology.Some main research content and the corresponding results are summarized herein.?1?The propylene polymerization catalyzed by the catalytic system of rac-Et?Ind?₂ZrCl₂/dMAO was studied in detail in this paper,and we contrast the effectiveness for the preparation of i PP macromonomer using?p-vinylphenyl?methyldichlorosilane?DCSSt?and?p-vinylphenyl?trichlorosilane?TCSSt?as the end-capping agent,respectively.The result shows that methoxysilane-capped iPP macromonomer with controllable molecular weight and capping rate can be successfully synthesized using either of the end-capping agent,and TCSSt has higher capping rate?up to 80%?.?2?We studied the synthetic method of multiarm star isotactic polypropylene by using the TCSSt-terminated iPP macromonomer.And the 3⁸ arm star isotactic polypropylene with controllable arm numbers were successfully synthesized by timing the sol-gel reaction under the application of the sol-gel technology to the iPP macromonomer for condensation reaction.?3?Methoxysilane-capped atactic polystyrene macromonomer prepared by RAFT reaction was used to the condensation reaction with isotactic polypropylene macromonomer above-mentioned.And isotactic polypropylene/atactic polystyrene miktoarm star polymer with controllable arm numbers between 3⁷ and controllable ratio of isotactic polypropylene and atactic polystyrene in the star polymer were synthesized via the sol-gel reaction.?4?This paper discussed the solution behaviors and coating properties of isotactic polypropylene/atactic polystyrene miktoarm star polymer.This miktoarm star polymer in DMF solution can self-assemble into stability micelles?particles between 400⁶00 nm?with isotactic polypropylene as nucleus and atactic polystyrene as shell.When using miktoarm star polymer as coating materials,controllable hydrophobicity properties between general hydrophobic?water contact angle is 108.5°?and super hydrophobic?water contact angle is153.0°?was realized by adjusting material composition.