Quasiliving Carbocationic Polymerization. XVII. Synthesis Of Poly (Styrene-β-Isobutylene-β-Styrene) |
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| Authors: | Zs Fodor J P Kennedy T Kelen F Tüds |
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| Institution: | 1. Central Research Institute for Chemistry Hungarian Academy of Sciences , H-1525, Budapest, Hungary;2. Institute of Polymer Science The University of Akron , Akron, Ohio, 44325;3. Central Research Institute for Chemistry Hungarian Academy of Sciences , H-1525, Budapest, Hungary;4. Institute of Applied Chemistry Kossuth Lajos University H-4010 , Debrecen, 10, Hungary;5. Department of Chemical , Technology E?tv?s Loránd University , H-1088, Budapest, Hungary |
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| Abstract: | Poly(styrene-b-isobutylene-b-styrene) has been synthesized by sequential carbocationic polymerization under quasiliving conditions at -90°C. The quasiliving synthesis was effected by first continuously and slowly condensing gaseous isobutylene (IB) to a bifunctional initiating system (p-dicumyl chloride/TiCl4) dissolved in a hexane-methylene chloride (60:40 v/v) mixture. After the quasiliving polyisobutylene (PIB) sequence had reached a desired molecular weight, styrene (St) was continuously and slowly added to produce the polystyrene (PSt) sequence. The products consisted of the target triblock. However, due to initiation by impurities and possibly to chain transfer to both IB and St, it also contained diblocks and small amounts of homopolymers. While the latter could be removed by selective fractionation, the triblocks and diblocks could not be separated. The mechanism of quasiliving polymerization leading to PIB/PSt blocks is discussed. |
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| Keywords: | gum arabic polyaniline graft copolymer conducting biomaterial redox behavior sensor |
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