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Anion Polymerization

The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform

Anthony Ledwith – 1st expert on this subject based on the ideXlab platform

  • Photoinitiated cationic Polymerization of epoxide and vinyl monomers by p-trimethoxytrityl salts
    Journal of Polymer Research, 2007
    Co-Authors: Ideisan I. Abu-abdoun, Anthony Ledwith

    Abstract:

    Photoinitiated cationic Polymerizations of cyclohexene oxide, tetrahydrofuran and N -vinylcarbazole were investigated in dichloromethane at 25°C, using stable, soluble and nonhygroscopic p -trimethoxytrityl salts having nonnucleophilic Anions such as SbF_6 ^−, AsF_6 ^−, PF_6 ^−, BF_4 ^−, and SbCl_6 ^−. The effects of Anion, Polymerization time, concentration of the salt and the intensity of light on the Polymerization reaction are presented.

Jesús Sanz – 2nd expert on this subject based on the ideXlab platform

  • Effect of the SiO2/Na2O ratio on the alkali activation of fly ash. Part II: 29Si MAS-NMR Survey
    Microporous and Mesoporous Materials, 2020
    Co-Authors: Maria Criado, Ana Fernández-jiménez, Ángel Palomo, Isabel Sobrados, Jesús Sanz

    Abstract:

    Si MAS-NMR spectroscopy was used to characterize the reaction products resulting from the alkali activation of a type F fly ash. Specifically, analyses focused on the degree of Polymerization of the activating solution (SiO2/Na2O ratio = 0.0, 0.19, 0.69 and 1.17) and thermal curing time (from 8 h to 180 days at 85 °C). The results obtained showed that the degree of Polymerization of the predominant silica species in the activation solutions plays an important role in the kinetics, structure and composition of the gel initially formed. The alkaline aluminosilicate gel formed exhibits short-range order, with the silicon appearing in a wide variety of Q4(nAl) (n = 0, 1, 2, 3 and 4) environments. In the absence of soluble silica (SiO2/Na2O ratio = 0.0, 0.19), the Al-rich gels initially generated evolved rapidly into zeolites. At higher levels of Anion Polymerization (SiO2/Na2O ratio 0.5), zeolite crystallization was retarded.Funding for this research was provided by the Directorate General of Scientific Research under project BIA2004-04835; a post-doctoral contract associated with the study was awarded by the CSIC and co-financed by the European social fund (REF. I3P-PC2004L).Peer reviewe

  • Effect of the SiO2/Na2O ratio on the alkali activation of fly ash. Part II: 29Si MAS-NMR Survey
    Microporous and Mesoporous Materials, 2008
    Co-Authors: Maria Criado, Ana Fernández-jiménez, Ángel Palomo, Isabel Sobrados, Jesús Sanz

    Abstract:

    Abstract 29 Si MAS-NMR spectroscopy was used to characterize the reaction products resulting from the alkali activation of a type F fly ash. Specifically, analyses focused on the degree of Polymerization of the activating solution (SiO 2 /Na 2 O ratio = 0.0, 0.19, 0.69 and 1.17) and thermal curing time (from 8 h to 180 days at 85 °C). The results obtained showed that the degree of Polymerization of the predominant silica species in the activation solutions plays an important role in the kinetics, structure and composition of the gel initially formed. The alkaline aluminosilicate gel formed exhibits short-range order, with the silicon appearing in a wide variety of Q 4 ( n Al) ( n  = 0, 1, 2, 3 and 4) environments. In the absence of soluble silica (SiO 2 /Na 2 O ratio = 0.0, 0.19), the Al-rich gels initially generated evolved rapidly into zeolites. At higher levels of Anion Polymerization (SiO 2 /Na 2 O ratio ⩾0.5), zeolite crystallization was retarded.

Jianwen Yang – 3rd expert on this subject based on the ideXlab platform

  • Benzoylformamides as versatile photocaged bases for redox free radical photoPolymerization
    Photochemical and Photobiological Sciences, 2016
    Co-Authors: Ruixin Xu, Minghui He, Jianwen Yang

    Abstract:

    Benzoylformamides (BFAs) are proposed as photocaged bases for redox free radical photoPolymerization (FRP). Initially the dissolving capacity of BFAs was evaluated. Besides our previously reported photo-latent Anion Polymerization, BFAs, as versatile photocaged bases, can not only initiate the FRP of acrylates unassisted, but also perform redox FRP in combination with a benzoyl peroxide initiator. We detail a model photoPolymerization in the presence of BFA-dBA (N,N-dibenzyl-2-oxo-2-phenylacetamide) as the photocaged base. In combination with a benzoyl peroxide initiator, BFAs are able to initiate the amine-mediated redox photoPolymerization of acrylates, and enhance the photoPolymerization rate. Finally, we investigated the mechanism of the radical formation to initiate the redox FRP, as exemplified by BFA-dBA.

  • benzoylformamides as new photocaged bases for photo latent Anion Polymerization
    Chinese Chemical Letters, 2015
    Co-Authors: Minghui He, Meilin Su, Zhaohui Yu, Guangxue Chen, Zhaohua Zeng, Jianwen Yang

    Abstract:

    Abstract Benzoylformamide (BFA) derivatives are proposed as new photocaged bases with good solubility in epoxy resin. Initially their structures were confirmed by 1 H NMR, 13 C NMR, and elemental analysis. Next, we detail their thermal stability, solubility behavior, and photolysis products. Furthermore, the model photo-latent Anion Polymerization (AP) of epoxide system in the presence of BFA-dBA ( N , N -dibenzyl-2-oxo-2-phenylacetamide) as a photocaged base has been investigated, and excellent photoPolymerization profile is obtained.