Polymerization Sc

Scheme 4.27 Multicomponent reactions using polymeric Sc(lll)-catalyst (42).

Nomura N, Taira A, Tomioka T, Okada M (2000) A catalytic approach for cationic living polymerization Sc(OTf)3-catalyzed ring-opening polymerization of lactones. Macromolecules 33 1497-1499... 

B snd multi-mode polymerization sc niques, (a) Single-mode polymeriza-Ih addition of monomers) ... 

Another interesting approach of polymeric Sc (III) catalyst is a use of nanos-tructured, polymer support. Nanostructured, polymer-supported Sc(III) catalyst... 

Mashima K, Nakayama Y and Nakamura A 1997 Recent trends in polymerization of a-olefins catalyzed by organometallic complexes of early transition metals Adv. Polym. Sc/. 133 1-54... 

Desai S D, Gordon R D, Gronda A M and Cussler E L 1996 Polymerized microemulsions Curr. Opin. Colloid Interface Sc/. 1 519-22... 

Barton J 1996 Free-radical polymerization in inverse microemulsions Prog. Polym. Sc/. 21 399-438... 

Tieke H, Lieser G and Wegner G 1979 Polymerization of diaoetylenes in multilayers J. Polymer Sc/. Polymer Chem. Edn. 17 1631-44... 

Dissolution of the oxide or hydroxide in the appropriate acid provides the most convenient method for producing the salts of the colourless, diamagnetic M ions, Such solutions, especially those of Sc , are significantly hydrolysed with the formation of polymeric hydroxy species. 

The quantum yield of polymerization is 6.72 and for photoinitiation < / = 2.85 x 10 . The polystyrene produced with this initiator shows photosensitivity when irradiated with UV light (A = 280 nm). This polymer, which carries two photosensitive end groups of - SC(S) N(CH3)2, behaves as a telechelic polymer and it is useful for production of ABA block copolymer. 

Yu. F.C.L., Periodic Operation of a Non-Isothermal Polymerization Reactor, M.Sc. Thesis, University of Massachusetts, 1969. 

Hiroshi Fukumura received his M.Sc and Ph.D. degrees from Tohoku University, Japan. He studied biocompatibility of polymers in the Government Industrial Research Institute of Osaka from 1983 to 1988. He became an assistant professor at Kyoto Institute of Technology in 1988, and then moved to the Department of Applied Physics, Osaka University in 1991, where he worked on the mechanism of laser ablation and laser molecular implantation. Since 1998, he is a professor in the Department of Chemistry at Tohoku University. He received the Award of the Japanese Photochemistry Association in 2000, and the Award for Creative Work from The Chemical Society Japan in 2005. His main research interest is the physical chemistry of organic molecules including polymeric materials studied with various kinds of time-resolved techniques and scanning probe microscopes. 

The side-by-side diffusion cell has also been calibrated for drug delivery mass transport studies using polymeric membranes [12], The mass transport coefficient, D/h, was evaluated with diffusion data for benzoic acid in aqueous solutions of polyethylene glycol 400 at 37°C. By varying the polyethylene glycol 400 content incrementally from 0 to 40%, the kinematic viscosity of the diffusion medium, saturation solubility for benzoic acid, and diffusivity of benzoic acid could be varied. The resulting mass transport coefficients, D/h, were correlated with the Sherwood number (Sh), Reynolds number (Re), and Schmidt number (Sc) according to the relationships... 

Low molecular weight poly(/3-peptide)s may be synthesized in an analogous manner via the ROP of /3-amino acid-N-carboxyanhydrides.9 Longer chain materials may be prepared by the ROP of /3-lactams (Scheme 28). This polymerization is initiated by a range of metal amides, of which Sc[N(TMS)2]3 offers particularly high levels of control.997... 

A scandium complex, Cp ScH, also polymerizes ethylene, but does not polymerize propylene and isobutene [125]. On the other hand, a linked amidocyclo-pentadienyl complex [ Me2Si( / 5-C5 Me4)( /1 -NCMe3) Sc(H)(PMe3)] 2 slowly polymerizes propylene, 1-butene, and 1-pentene to yield atactic polymers with low molecular weight (Mn = 3000-7000) [126, 115]. A chiral, C2-symmetric ansa-metallocene complex of yttrium, [rac-Me2Si(C5H2SiMe3-2-Buf-4)2YH]2, polymerizes propylene, 1-butene, 1-pentene, and 1-hexene slowly over a period of several days at 25°C to afford isotactic polymers with modest molecular weight [114]. 

Kumari A, Yadav SK, Yadav SC (2009) Biodegradable polymeric nanoparticles based drug delivery systems. Colloids Surf B 75 1-18... 

FC Chen, SC Chang, G He, S Pyo, Y Yang, M Kurotaki, and J Kido, Energy transfer and triplet exciton confinement in polymeric electrophosphorescence devices, J. Polym. Sci. B Polym. Phys., 41 2681-2690, 2003. 

Five-coordinate aluminum alkyls are useful as oxirane-polymerization catalysts. Controlled polymerization of lactones102 and lactides103 has been achieved with Schiff base aluminum alkyl complexes. Ketiminate-based five-coordinate aluminum alkyl (OCMeCHCMeNAr)AlEt2 were found to be active catalyst for the ring-opening polymerization of -caprolactone.88 Salen aluminum alkyls have also been found to be active catalysts for the preparation of ethylene carbonate from sc C02 and ethylene oxide.1 4 Their catalytic activity is markedly enhanced in the presence of a Lewis base or a quaternary salt. 

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