ACYCLIC DIENE METATHESIS POLYMERIZATION OF TAILOR-MADE MONOMERS TOWARDS SEQUENCE-REGULATED VINYL COPOLYMERS  

作　　者：Zi-long Li Lei Li Fu-sheng Du 李子臣 

机构地区：[1]Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry & Physics of Ministry of Education, Department of Polymer Science & Engineering, College of Chemistry and Molecular Engineering,Peking University

出　　处：《Chinese Journal of Polymer Science》2013年第2期355-362,共8页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 21090351);National Basic Research Program of China (973 Program: No. 2011CB201402)

摘　　要：Acyclic diene metathesis polymerization （ADMET） enables convenient transfer of sequential information of the designed monomers to the corresponding sequence-regulated copolymers. In this study, two structurally symmetric monomers, M1 and M2, were synthesized via atom transfer radical addition （ATRA） of diethyl meso-2,5- dibromohexanedioate with 1,5-hexadiene and 1,7-octadiene, respectively. Thus, sequenced segment of VB-EA-EA-VB （VB and EA represent vinyl bromide and ethyl acrylate, respectively） was incorporated into the ADMET diene monomers. ADMET polymerization of these two monomers with Grubbs first generation catalyst （Grubbs-I） was performed in CH2C12 at 40℃ for 5 days under nitrogen purge. Effects of catalyst amount, monomer concentration and methanol precipitation on the Mp and PDI of polymers were investigated by GPC, and the structures of the formed polymers were characterized by NMR. Our results indicate that using 3.0 mol% of Grubbs-I to monomer can afford polymers with high Mp. Moreover, selective precipitation in methanol enables complete removal of low molecular weight components from the crude products. Meanwhile, M2 exhibits higher ADMET polymerization reactivity than M1 due to its capability of suppressing negative neighboring group effect.Acyclic diene metathesis polymerization （ADMET） enables convenient transfer of sequential information of the designed monomers to the corresponding sequence-regulated copolymers. In this study, two structurally symmetric monomers, M1 and M2, were synthesized via atom transfer radical addition （ATRA） of diethyl meso-2,5- dibromohexanedioate with 1,5-hexadiene and 1,7-octadiene, respectively. Thus, sequenced segment of VB-EA-EA-VB （VB and EA represent vinyl bromide and ethyl acrylate, respectively） was incorporated into the ADMET diene monomers. ADMET polymerization of these two monomers with Grubbs first generation catalyst （Grubbs-I） was performed in CH2C12 at 40℃ for 5 days under nitrogen purge. Effects of catalyst amount, monomer concentration and methanol precipitation on the Mp and PDI of polymers were investigated by GPC, and the structures of the formed polymers were characterized by NMR. Our results indicate that using 3.0 mol% of Grubbs-I to monomer can afford polymers with high Mp. Moreover, selective precipitation in methanol enables complete removal of low molecular weight components from the crude products. Meanwhile, M2 exhibits higher ADMET polymerization reactivity than M1 due to its capability of suppressing negative neighboring group effect.

关 键 词：ADMET ATRA Sequence-regulated copolymers. 

分 类 号：O631.3[理学—高分子化学]