邻位大位阻取代基胺双酚钛(Ⅳ)配合物的合成、表征和催化乙烯(共)聚合研究  

o-Bulky Substituted Amine-bis(phenolate)Ti(Ⅳ)Complexes:Synthesis,Characterization,and Catalysis on Ethylene(Co)Polymerization

作　　者：李丰[1] 何江浩[1] 母瀛[1] LI Feng;HE Jiang-hao;MU Ying(The State Key Laboratory for Supramolecular Structure and Materials,School of Chemistry,Jilin University,Changchun 130012,China)

机构地区：[1]吉林大学,超分子结构与材料国家重点实验室,长春130012

出　　处：《高分子通报》2021年第6期94-103,共10页Polymer Bulletin

基　　金：国家自然科学基金项目(51673078)。

摘　　要：合成了一系列邻位大取代基四齿胺双酚配体钛配合物Me_(2)NCH_(2)CH_(2)N[CH_(2)-2-(3-R-5-tBuC_(6)H_(2))O]_(2)TiCl_(2)[2a,R=CPhMe_(2);3a,R=CMePH_(2);4a,R=CPh_(3)),对其结构进行了表征,研究了其催化乙烯均聚、乙烯/丙烯共聚及乙烯/1-己烯共聚性能,考察了配体结构及聚合反应条件对聚合行为的影响。与R=tBu的已知配合物1a相比,这些新配合物在催化乙烯均聚和共聚时表现出较高的催化活性和良好的稳定性。在MAO活化下,催化乙烯聚合活性最高达1170kg PE/(mol Ti·h);在AliBu_(3)/Ph_(3)CB(C_(6)F_(5))_(4)活化下,用配合物2a~4a得到的聚乙烯分子量最高可达113×10^(4)g/mol。在MAO活化下,1a~4a催化乙烯/丙烯共聚及乙烯/1-己烯共聚活性分别达到640kg polymer/(mol Ti·h)和1220kg polymer/(mol Ti·h);乙烯-丙烯共聚物分子量为3.1×10^(4)~17.4×10^(4)g/mol、乙烯-1-己烯共聚物分子量为4.9×10^(4)~15.5×10^(4)g/mol;所得乙烯-丙烯共聚物中丙烯单元含量最高可达36.9%(mol),乙烯-1-己烯共聚物中1-己烯单元含量最高为12.5%(mol)。催化剂配体空间位阻对共单体插入率有明显影响,随配体空间位阻增大,共单体插入率降低。A series of o-bulky substituted amine-bis(phenolate)tetradentate Ti(Ⅳ)Complexes:Me_(2)NCH_(2)CH_(2)N(CH_(2)-(2-OC6H_(2)-3-R-5-tBu)2TiCl_(2)(2 a,R=CPhMe_(2);3 a,R=CMePH_(2);4 a,R=CPh_(3)),were synthesized and characterized.The catalytic performance of these complexes for ethylene polymerization,ethylene/propylene copolymerization and ethylene/1-hexene was studied and the effects of ligand structure and polymerization conditions on polymerization behavior were investigated.Compared with 1 a(R=tBu),these synthesized catalysts showed high catalytic activity and excellent stability in ethylene(co)polymerization.In the presences of MAO,the highest activity of these catalysts toward ethylene polymerization was 1170 kg PE/(mol Ti·h).Moreover,the highest Mw of polyethylene obtained by 2 a~4 a/AliBu_(3)/Ph_(3)CB(C_(6)F_(5))_(4)was 113×10^(4)g/mol.When activated by MAO,the highest activities of 1 a~4 a toward ethylene/propylene copolymerization and ethylene/1-hexene copolymerization were 640 kg polymer/(mol Ti·h)and 1220 kg polymer/(mol Ti·h),respectively;the molecular weight of obtained ethylene-co-propylene and ethylene-co-1-hexene are 3.1×10^(4)~17.4×10^(4)and 4.9×10^(4)~15.5×10^(4)g/mol,respectively.The highest content of propylene unit in the ethylene-propylene copolymer was 36.9 mol%,and the highest content of 1-hexene unit in the ethylene-1-hexene copolymer was 12.5 mol%.The content of comonomer in copolymers was dependent on steric hindrance of catalyst ligands,and it was found that the insertion of comonomer decreased with the increase of steric hindrance of catalyst ligands.

关 键 词：聚烯烃 钛配合物 烯烃聚合 乙烯聚合 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业] TQ426[理学—物理化学] O641.4[理学—化学]