Cationic Polymerization of 2-Vinylthiophene by Chloroarylmethanes as Surface Initiators on Silica and Consecutive Hydride Abstraction by Acceptors
✍ Scribed by Susanne Höhne; Andreas Seifert; Manfred Friedrich; Rudolf Holze; Stefan Spange
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 230 KB
- Volume
- 205
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Summary: 2‐Vinylthiophene (2‐VT) has been cationically polymerized using chloroarylmethane derivatives as the surface polymerization initiator on silica. By applying this procedure a soluble fraction of poly(vinylthiophene) (PVT) and PVT/silica composites can be simultaneously synthesized. The mass balance of the products (soluble fraction and hybrid particle fraction) depends significantly on temperature and 2‐VT/silica ratio. The hydride abstraction reaction of PVT both in solution and immobilized on silica particle surface has been studied using 2,3‐dichloro‐5,6‐dicyano‐1,4‐quinone (DDQ), tetrachloro‐1,4‐quinone (chloranile = ClA) and triphenylmethylium as reagents. The transformation process of PVT towards conjugated polymers has been studied with UV‐vis spectroscopy and ESR spectroscopy. Cyclic voltammetry shows that chloranil is complexated with the formed polymer. Radical formation increases with increasing degree of conversion. The soluble fraction of the conjugated PVT sections formed is capable of reacting with each other as evidenced by GPC data. Structure of PVT/silica and resulting hybrid materials have been investigated by solid state ^13^C {^1^H} CP MAS NMR‐spectroscopy showing a reaction of methine and methylene hydrogen atoms after treatment with DDQ or chloranil as hydride acceptors. For all poly‐(2‐vinylthiophene)/hydride acceptor systems studied, chloranil has been found to be the best reagent for the transformation of PVT towards conjugated polymers.
Transformation of PVT in poly(2‐ethinylthiophene) (PET) and PVT‐PET copolymers.
magnified imageTransformation of PVT in poly(2‐ethinylthiophene) (PET) and PVT‐PET copolymers.