Cationic Host-Guest Polymerization of N-Vinylcarbazole and Vinyl Ethers in MCM-41, MCM-48, and Nanoporous Glasses
The synthesis of poly(vinyl ether)s or polyvinylcarbazole under the conditions of constricted geometry can be achieved by means of cationic host–guest polymerisation of the corresponding monomers in the pores of MCM‐41 (pore diameter 3.6 nm), MCM‐48 (pore diameter 2.4 nm) and in nanoporous glasses (...
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Veröffentlicht in: | Chemistry : a European journal 2001-09, Vol.7 (17), p.3722-3728 |
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Sprache: | eng |
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Zusammenfassung: | The synthesis of poly(vinyl ether)s or polyvinylcarbazole under the conditions of constricted geometry can be achieved by means of cationic host–guest polymerisation of the corresponding monomers in the pores of MCM‐41 (pore diameter 3.6 nm), MCM‐48 (pore diameter 2.4 nm) and in nanoporous glasses (Gelsil® with a pore diameter of 5 nm) with bis(4‐methoxyphenyl)methyl chloride (BMCC) or triphenylmethyl chloride as the internal surface initiator. The reaction products are new polymer/MCM‐41, polymer/MCM‐48 etc., host–guest hybrid materials. The molecular mass of the enclosed polymer and the degree of loading of the host compounds can be adjusted within certain limits. The molecular dynamics were investigated by using broad‐band dielectric spectroscopy. Under the conditions of constricted geometry, molecular fluctuation is observed as well as a secondary β‐relaxation, which is hardly affected (in comparison with the free melt) and which corresponds to the relaxation between structural substates (dynamic glass transition). This process is several orders of magnitude faster in its relaxation rate than in the free melt and thus follows a confinement effect. This is already well known in lower molecular weight systems with constricted geometry.
The synthesis of host–guest hybrid materials of polymers (poly(vinyl ether)s or polyvinylcarbazole) in mesoporous organic hosts can be achieved under the conditions of constricted geometry by means of cationic host–guest polymerization of the corresponding monomers in MCM‐41, MCM‐48, and in nanoporous glasses with bis(4‐methoxyphenyl)methyl chloride or triphenylmethyl chloride as the internal surface initiator (see scheme). |
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ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/1521-3765(20010903)7:17<3722::AID-CHEM3722>3.0.CO;2-J |