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Reactivity ratios and sequence structures of the copolymers prepared using photo‐induced copolymerization of MMA with MTMP
Author(s) -
Liu Xiaoxuan,
Zhang Yongtao,
Cui Yanyan,
Dong Zhixian
Publication year - 2012
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.3811
Subject(s) - copolymer , monomer , reactivity (psychology) , polymer chemistry , chemistry , tacticity , methyl methacrylate , piperidine , sequence (biology) , methacrylate , polymerization , polymer , organic chemistry , medicine , biochemistry , alternative medicine , pathology
4‐Methacryloyl‐2,2,6,6‐tetramethyl‐piperidine (MTMP) was applied as reactive hindered amine piperidine. Photo‐induced copolymerization of methyl methacrylate (MMA, M 1 ) with MTMP ( M 2 ) was carried out in benzene solution at ambient temperature. The reactivity ratios for these monomers were measured by running a series of reactions at various feed ratios of initial monomers, and the monomer incorporation into copolymer was determined using 1 H NMR. Reactivity ratios of the MMA/MTMP system were measured to be r 1 = 0.37 and r 2 = 1.14 from extended Kelen‐Tüdos method. The results show that monomer MTMP prefers homopolymerization to copolymerization in the system, whereas monomer MMA prefers copolymerization to homopolymerization. Sequence structures of the MMA/MTMP copolymers were characterized using 1 H NMR. The results show that the sequence structure for the main chain of the MMA/MTMP copolymers is mainly composed of a syndiotactic configuration, only with a little heterotactic configuration. Three kinds of the sequences of rr , rr ′, and lr ′ in the syndiotactic configuration are found. The sequence‐length distribution in the MMA/MTMP copolymers is also obtained. For f 1 = 0.2, the monomer unit of MMA is mostly separated by MTMP units, and for f 1 = 0.6, the alternating tendency prevails and a large number of mono‐sequences are formed; further up to f 1 = 0.8, the monomer unit of MTMP with the sequence of one unit is interspersed among the chain of MMA. Copyright © 2012 John Wiley & Sons, Ltd.