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  • cationic polymerization  (12)
  • polycondensation  (4)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Journal of inorganic and organometallic polymers and materials 10 (2000), S. 221-230 
    ISSN: 1572-8870
    Schlagwort(e): poly(arylene)s ; polycondensation ; organocobalt polymer ; liquid crystal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Novel organometallic poly(arylene)s containing 1,3-type (cyclobutadiene)cobalt moieties in the main chain were prepared by the Ni(0)-mediated dehalogenative polycondensation of monomers having (cyclobutadiene)cobalt moieties. The resulting poly(arylene)s were partly soluble in organic solvents and the number-average molecular weights (M n) of soluble fractions were estimated to be 16,700–22,000 by GPC. The polymers showed the formation of a π-conjugated structure, good solubility in common organic solvents, and thermotropic liquid crystallinity.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 1819-1822 
    ISSN: 0887-624X
    Schlagwort(e): cyclic carbonate ; L-phenylalanine ; ο-hydroxy carboxylic acid ; polycondensation ; DCC ; DMAP ; poly(ester-urethane) ; 1-methyl-2-fluoropyridinium salt ; trypsin ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 933-936 
    ISSN: 0887-624X
    Schlagwort(e): photocrosslinking ; vinylether ; sulfonium salt ; cationic polymerization ; swelling ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1845-1851 
    ISSN: 0887-624X
    Schlagwort(e): sulfonium salt ; cationic initiator ; effect of substituent ; cationic polymerization ; glycidyl phenyl ether ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Benzyl o-, m-, and p-substituted phenyl methyl sulfonium salts (2b-2g) were synthesized and their activities as cationic initiators were evaluated in the bulk polymerization of phenyl glycidyl ether (PGE). Especially, their activities were estimated with respect to the effect of substituents on the aryl groups. In the polymerizations of PGE with a series of benzyl p-substituted phenyl methyl sulfonium salts, the order of their activities was found to be 2c (CH3OCOO) 〉 2b (CH3COO) 〉 2d (CH3O) ∼ 2a (HO). In particular, 2c was the most active initiator of all, capable of initiating the polymerization of PGE even at room temperature. In the polymerizations with 2a, 2e (m-Cl), 2f (o-CH3), and 2g (m-CH3), the activity of 2e was the highest of all while those of 2a, 2f, and 2g were almost the same. These results strongly suggested that the electron-withdrawing group placed on the aryl group undoubtedly enhanced the activity of the sulfonium salts as the cationic initiators.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 2569-2576 
    ISSN: 0887-624X
    Schlagwort(e): photocrosslinking ; vinylether ; sulfonium salt ; cationic polymerization ; swelling ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Vinylether was used as a cationically polymerizable moiety and incorporated into sidechain of polymers as copolymers of vinyloxyethyl methacrylate (VEM) and styrene (St). Photoirradiation of the copolymers containing a small amount of benzyl(4-hydroxyphenyl) methylsulfonium salt (BSS) resulted in a high crosslinking density as evidenced by a low degree of swelling, which is ascribed to the high reactivity of the vinyloxy moieties. The sensitivity of this photoreaction is significantly high because of a large kinetic chain length of the cationic polymerization of vinylethers, while copolymers of glycidyl methacrylate and St showed crosslinking to much less extent when irradiated under the same condition. The ability of other sulfonium salts, (4-hydroxyphenyl) methyl(4-nitrobenzyl) sulfonium salt and (4-hydroxyphenyl) methyl(1-naphthylmethyl)sulfonium salt, to induce photocrosslinking was also examined. © 1992 John Wiley & Sons, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 581-584 
    ISSN: 0887-624X
    Schlagwort(e): cyclic carbonate ; polycarbonate ; cationic polymerization ; ring-opening polymerization ; alkyl halide ; decarboxylation ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 3193-3198 
    ISSN: 0887-624X
    Schlagwort(e): γ-poly(glutamic acid) ; biosynthesized polymer ; cationic polymerization ; initiator ; N-vinylcarbazole ; N-vinyl-2-pyrrolidone ; carboxyl group ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The cationic polymerization of vinyl monomers initiated by biosynthesized γ-poly(glutamic acid) (γ-PGA) powder surface was carried out in a heterogeneous system. It was found that the polymerization of N-vinylcarbazole (NVC) and N-vinyl-2-pyrrolidone (NVPD) is initiated by γ-PGA powder. The grafting of polymers onto γ-PGA surface was scarcely observed. The apparent activation energy of the polymerization of NVC and NVPD was estimated to be 20.2 and 24.8 kJ/mol, respectively. The polymerization was totally inhibited by the addition of triethylamine and pyridine, but not hydroquinone. The polymerization rate in nitrobenzene was larger than that in toluene. These results indicated the cationic nature of the polymerization. γ-PGA treated with KOH did not show the initiating activity of the polymerization. Therefore, carboxyl groups on γ-PGA powder surface play an important role in the initiation of the polymerization. It may be suggested that the polymerization is initiated by proton addition to monomer from carboxyl groups on γ-PGA powder surface and the propagation proceeds with carboxylate anion on the surface as counter ion. © 1993 John Wiley & Sons, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 583-587 
    ISSN: 0887-624X
    Schlagwort(e): α-methylphenylallene ; γ-methylphenylallene ; cationic polymerization ; Lewis acid ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The cationic polymerizations of γ-methylphenylallene (1) and α-methylphenylallene (2) were carried out with some Lewis acids at 25 and 0°C in dichloromethane to obtain the corresponding polymers through allyl cations, respectively. Tin (IV) chloride was found to be an effective catalyst for the cationic polymerization of both allenes 1 and 2 compared with other Lewis acids. Thus, in the polymerization of 1, methanol-insoluble polymer was only obtained using Tin (IV) chloride, and M̄n of methanol-insoluble polymer obtained by Tin (IV) chloride was the highest in the polymerization of 2. From the analysis of 1H- and 13C-NMR spectra of the obtained polymers, the polymer from 1 consisted of two kinds of units polymerized by each double bonds of allene 1, whereas the polymer from 2 consisted of only one unit polymerized by terminal double bond of allene 2. Moreover, effect of solvent on the cationic polymerizations of 1 and 2 were discussed.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3673-3682 
    ISSN: 0887-624X
    Schlagwort(e): seven-membered cyclic sulfite ; cationic polymerization ; desulfoxylation ; volume expansion ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Cationic ring-opening polymerization behavior of a seven-membered cyclic sulfite (1) was examined. 1 was prepared by the reaction of 1,4-butanediol with SOCl2 in 58% yield. The cationic polymerization of 1 was carried out at 0, 25, 60, or 100°C with trifluoromethanesulfonic acid (TfOH), methyl trifluoromethanesulfonate (TfOMe), BF3 · OEt2, SnCl4, methyl p-toluenesulfonate (TsOMe), or MeI as an initiator in bulk under a nitrogen atmosphere to afford the polymer with M̄n 1000-10,400. The order of activities of the initiators for 1 was as follows, TfOH ≅ TfOMe 〉 SnCl4 〉 BF3 · OEt2 〉 TsOMe ≅ MeI. The polymerization of 1 with TfOMe afforded a poly(sulfite) below 25°C, but afforded a polymer containing an ether unit at 60°C, which was formed by a desulfoxylation. The higher the activity of the initiator was, the more easily the desulfoxylation occurred. We expected volume expansion on polymerization because cyclic sulfites have large dipole moment values, but it turned out that 1 showed 4.34% shrinkage on polymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3673-3682, 1997
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1957-1960 
    ISSN: 0887-624X
    Schlagwort(e): cationic polymerization ; thermally latent initiator ; fluorenyltriphenylphosphonium salt ; epoxide ; glycidyl phenyl ether ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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