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Coordination‐insertion copolymerization of norbornene (N) and p‐substituted styrene (XS) (X = MeO, Me F, Cl, and Br) is carried out using anilinonaphthoquinone‐ligated nickel complexes [Ni(C10H5O2NAr)(Ph)(PPh3): 1a, Ar = C6H3‐2,6‐iPr; 1b, Ar = C6H2‐2,4,6‐Me; 1c, Ar = C6H5] with modified methylaluminoxane (MMAO) as a cocatalyst. The ligand of the nickel complex affects the catalytic activity. The effect of the p‐substituent on the activity is remarkable and the activity decreases in the following order, Br > Cl > F > Me > MeO. The molecular weight of the produced polymer also decreases with the same order. The activity increases with raising the temperature from 0 to 70 °C accompanied by the decrease in the molecular weight of the produced polymers. The incorporation of XS determined by 1H and 13C NMR decreases in the following order, MeO ≥ Me > F > Cl > Br. The glass transition temperatures of the N/XS copolymers determined by differential scanning calorimetry show a broad range from 120 to 365 °C according to the XS content. [ABSTRACT FROM AUTHOR]

ABSTRACT Terpolymerization of norbornene (NB), isoprene (IP), and 1-octene was achieved by using fluorenylamido-ligated titanium catalyst, which showed very high activity for the copolymerization of NB and various α-olefins. The content of IP in the terpolymer was controlled by the feed ratio and reaction temperature up to 7 mol %. The incorporated IP was mainly inserted in 1,4-addition. The polymer was dissolved into common solvents such as toluene and chloroform, which enabled the preparation of a transparent film by solution casting process. The degradation temperature of the terpolymer was comparable with other cyclic olefin copolymers and the glass transition temperature ( Tg) was higher than that of NB-1-octene copolymer with almost the same NB content. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2136-2140 [ABSTRACT FROM AUTHOR]

ABSTRACT A-B-A block copolymers which consist of poly(norbornene- co-1-octene) and atactic polypropylene (PP) segments were synthesized by using ansa-fluorenylamidotitanium complex as a catalyst varying the ratio of norbornene, 1-octene, and propylene. The copolymer was obtained quantitatively with high molecular weight (>100,000) and narrow molecular weight distribution (polydispersity index, <1.5). A-B block copolymers of poly(norbornene- co-1-octene) and poly(methyl methacrylate) (PMMA) was also obtained by the same procedure. Mechanical and optical properties of these copolymer films, which were obtained by solution casting process, were also investigated. Introduction of PP soft segment greatly improved mechanical properties, keeping their high transparency. Introduction of PMMA block also increased the tensile strength. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 267-271 [ABSTRACT FROM AUTHOR]

A series of cobalt(II) complexes having terpyridine derivatives such as 2,2′:6′,2″-terpyridine (1), 4,4′,4″-tBu3-2,2′:6′,2″-terpyridine (2), 5,5″-Me2-2,2′:6′,2″-terpyridine (3), 6,6″-Me2-2,2′:6′,2″-terpyridine (4) and 6,6″-(3,5-Me2C6H3)2-2,2′:6′,2″-terpyridine (5) was synthesized. The structures of 1, 3, and 4 were confirmed by X-ray crystallography. The coordination sphere around the cobalt center in 1 can be described as pseudo square pyramidal. On the other hand, complex 4 has pseudo trigonal bipyramidal structure. Upon activation with d-MAO (dried-methylaluminoxane), these complexes showed high activities for the polymerization of norbornene (NBE). In particular, polymerization of NBE with 4/d-MAO system at room temperature resulted in quantitative yield within several hours to give the polymers with relatively narrow molecular weight distributions and controlled molecular weight. The polymerizations of NBE with these cobalt catalyst systems proceeded in vinyl addition polymerization, which was confirmed by 1H NMR spectra of the resulting polymers. [Copyright &y& Elsevier]

Poly(norbornene-co-styrene)s were synthesized by the use of anilinonaphthoquinone-ligated nickel complexes [Ni(C10H5O2NAr)(Ph)(PPh3): 1a, Ar = C6H3-2,6-iPr; 1b, Ar = C6H2-2,4,6-Me; 1c, Ar = C6H5] activated with modified methylaluminoxane (MMAO) or B(C6F5)3 in toluene. The effects of the cocatalysts were more significant than those of the nickel complexes, and MMAO gave higher activity than B(C6F5)3. The structural characterizations of the products indicated the formation of statistical norbornene copolymers. An increase of the styrene ratio in feed led to an increase in the incorporated styrene (S) content of the resulting copolymer. The molecular weight of the copolymer decreased with increasing the S ratio in feed at 70 °C. The copolymerization activity, using MMAO as a cocatalyst, decreased with lowering of the temperature from 70 to 0 °C, accompanied by an increase in the molecular weight of the copolymer. The S incorporation up to 59% with Mn of 78,000 was achieved by the 1b-B(C6F5)3 catalytic system. The glass transition temperatures of the norbornene (N)/S copolymers determined by differential scanning calorimetry, decreased from 329 to 128 °C according to the S content. [ABSTRACT FROM AUTHOR]

The synthesis of norbornene copolymer with hydroxy groups was performed by the copolymerization of norbornene (NB) with 9-(7-octenyl)-borabicyclo[3.3.1]nonane (OctBBN) using ansa -dimethylsilyl(fluorenyl)(amido)titanium catalyst ( 1 ) activated by Ph 3 CB(C 6 F 5 ) 4 and successive oxidation. The glass transition temperature ( T g ) of the copolymer was higher than the polymer with the same hydroxy group content synthesized by the copolymerization of NB and ω-alkenylaluminum. The 13 C NMR spectrum of the copolymer clearly showed that alkylborane moiety was converted quantitatively to hydroxy groups. Copolymerization of NB and OctBBN by the 1 -MMAO/BHT system proceeded in a pseudo-living manner without chain transfer reaction. [ABSTRACT FROM AUTHOR]

Cyclic olefin copolymers (COCs), among which ethylene (E)/norbornene (NB) copolymer have been commercialized, are novel optical plastics but their brittleness narrows their application fields. In this research, star polymers with NB/1-octene (O) gradient copolymer arms and cross-linked cores were synthesized by adding norbornadiene (NBD)/E or 1,11-dodecadiene (DOD) after NB/O copolymerization using a ( t BuNSiMe 2 Flu)TiMe 2 (I)-[Ph 3 C][B(C 6 F 5) 4 ] catalyst system with 2,6-di- tert -butyl-4-methylphenol-treated tri- n -octylaluminum (Oct 3 Al/BHT) as a scavenger. The obtained star polymers possessed the O-rich soft segments close to the core and the NB-rich hard segments in the outer layer. The DOD-cored star polymers had a larger number of arms (15) and a higher star polymer content (68 wt%) than the NBD/E-cored ones (6 and 58 wt%, respectively). The films of the mixtures of the star and the corresponding arm polymers were molded by a melt-pressing procedure. The tensile properties of the films of the DOD-cored star polymer mixtures were significantly improved compared to those of the arm polymers. The Young's modulus, yield stress, strength, and strain at break were controlled by the NB content, the arm length, and the gradient structure of the arms. These results clarified the novelty of the star-shaped NB/ α -olefin copolymers and would expand the application fields of COCs. [Display omitted] • Star-shaped polymers with norbornene/1-octene gradient copolymer arms were synthesized by an "arm-first" strategy. • The star-shaped polymers showed two T g values assignable to an octene-rich soft core and a norbornene-rich hard sphere. • Transparent films were obtained from the blend of the star and the arm polymers by melt processing. • The of mechanical properties of the blend films were improved compared with those of the arm polymer films. • The thermal and the star polymers were controlled by the arm length and the norbornene content. [ABSTRACT FROM AUTHOR]