Silacyclobutane-Based Diblock Copolymers with Vinylferrocene, Ferrocenylmethyl Methacrylate, and Dimethylsilaferrocenophane
ABSTRACT Well-defined diblock copolymers have been prepared in which three different ferrocene-based monomers are combined with 1,1-dimethylsilacyclobutane (DMSB) and 1-methylsilacyclobutane, respectively, as their carbosilane counterparts. Optimized procedures are reported for the living anionic chain growth following sequential monomer addition protocols, ensuring narrow polydispersities and high blocking efficiencies. The DMSB-containing copolymers show phase segregation in the bulk state, leading to micromorphologies composed of crystalline DMSB phases and amorphous polymetallocene phases.
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ABSTRACT: Statistical copolymers of methyl methacrylate (MMA) with 2-methacryloyloxyethyl ferrocenecarboxylate (MAEFC) were prepared by free radical polymerization. The reactivity ratios were estimated using the Fineman-Ross, inverted Fineman-Ross, Kelen-Tüdos, and extended Kelen-Tüdos graphical methods. Structural parameters of the copolymers were obtained by calculating the dyad monomer sequence fractions and the mean sequence length. The glass-transition temperature (Tg) values of the copolymers were measured and examined by means of several theoretical equations, allowing the prediction of these Tg values. The thermal degradation behavior of the copolymers was also studied and compared with the respective homopolymers. Cyclic voltammetry was employed to study the electrochemical properties of the copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011Journal of Polymer Science Part A Polymer Chemistry 07/2011; 49(14). DOI:10.1002/pola.24745 · 3.11 Impact Factor
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ABSTRACT: Boratabenzene-derived metallocene analogues are introduced as versatile new building blocks for metallopolymers. Bis(borinato)iron(II) complexes of the type Fe(C(5)H(5)B-R)(2) (R: C≡CH, C≡CSiMe(3), 4-(1-benzyl-1,2,3-triazolyl) were synthesized and spectroscopically, structurally, and electrochemically characterized. Polymerization via Sonogashira-Hagihara coupling of the alkynyl-substituted derivative Fe(C(5)H(5)B-C≡CH)(2) with 2,5-bis(dodecyloxy)-1,4-diiodobenzene yields a film-forming polymer in 50-69% yield. Polymer batches were obtained with number-average molecular weights (M(n)) of 11.7 and 20.5 kDa and polydispersity indices (PDI) of 1.55 and 2.65, respectively, as determined by gel permeation chromatography relative to polystyrene standards. Click-type polymerization of Fe(C(5)H(5)B-C≡CH)(2) through azide-alkyne cycloaddition with 1,4-bis(4-azidobutoxy)benzene gives the corresponding metallopolymer with an M(n) of 5.7 kDa and a PDI of 2.29 in 87% yield.Chemistry - A European Journal 09/2011; 17(40):11280-9. DOI:10.1002/chem.201101109 · 5.73 Impact Factor
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ABSTRACT: We report on the controlled free radical homopolymerization of 1-ferrocenylethyl acrylate as well as of three new ferrocene bearing monomers, namely 4-ferrocenylbutyl acrylate, 2-ferrocenylamido-2-methylpropyl acrylate, and 4-ferrocenylbutyl methacrylate, by the RAFT technique. For comparison, the latter monomer was polymerized using ATRP, too. The ferrocene containing monomers were found to be less reactive than their analogues free of ferrocene. The reasons for the low polymerizability are not entirely clear. As the addition of free ferrocene to the reaction mixture did not notably affect the polymerizations, sterical hindrance by the bulky ferrocene moiety fixed on the monomers seems to be the most probable explanation. Molar masses found for 1-ferrocenylethyl acrylate did not exceed 10,000 g mol−1, while for 4-ferrocenylbutyl (meth)acrylate molar masses of 15,000 g mol−1 could be obtained. With PDIs as low as 1.3 in RAFT polymerization of the monomers, good control over the polymerization was achieved. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012Journal of Polymer Science Part A Polymer Chemistry 01/2012; 50(1-1):108-118. DOI:10.1002/pola.24994 · 3.11 Impact Factor