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Titolo:
CRITICAL INTERACTION STRENGTH FOR SURFACTANT-INDUCED MESOMORPHIC STRUCTURES IN POLYMER-SURFACTANT SYSTEMS
Autore:
RUOKOLAINEN J; TORKKELI M; SERIMAA R; VAHVASELKA S; SAARIAHO M; TENBRINKE G; IKKALA O;
Indirizzi:
HELSINKI UNIV TECHNOL,DEPT TECH PHYS FIN-02150 ESPOO FINLAND HELSINKI UNIV TECHNOL,DEPT TECH PHYS FIN-02150 ESPOO FINLAND UNIV HELSINKI,DEPT PHYS FIN-00014 HELSINKI FINLAND UNIV GRONINGEN,POLYMER CHEM LAB NL-9747 AG GRONINGEN NETHERLANDS UNIV GRONINGEN,CTR MAT SCI NL-9747 AG GRONINGEN NETHERLANDS
Titolo Testata:
Macromolecules
fascicolo: 20, volume: 29, anno: 1996,
pagine: 6621 - 6628
SICI:
0024-9297(1996)29:20<6621:CISFSM>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRICALLY CONDUCTING POLYANILINE; LIQUID-CRYSTALS; PHASE-BEHAVIOR; SIDE-CHAINS; ACID; COMPLEXES; BLENDS; STATE; SOLVENTS; ORDER;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
41
Recensione:
Indirizzi per estratti:
Citazione:
J. Ruokolainen et al., "CRITICAL INTERACTION STRENGTH FOR SURFACTANT-INDUCED MESOMORPHIC STRUCTURES IN POLYMER-SURFACTANT SYSTEMS", Macromolecules, 29(20), 1996, pp. 6621-6628

Abstract

The critical interaction strength to induce mesomorphic structures inflexible polymers by complexing with surfactants is determined by using surfactants with different hydrogen-bonding strengths;. Two essential requirements have to be satisfied: (i) the association has to be strong enough, otherwise the structure dissociates. (ii) The polar-nonpolar repulsion has to be sufficiently strong to induce microphase separation. If the latter requirement is not satisfied, but the associationis sufficiently strong, a characteristic comb polymer-like SAXS peak will still be present in the homogeneous melt state. To address these issues experimentally, poly(4-vinylpyridine) (P4VP) was combined with different classes of hydrogen-bonding surfactants: alkyl aromatic alcohols, alkyl carboxylic acids, alkyl aliphatic alcohols, and alkyl aliphatic amines. FTIR, SAXS, WAXS, and optical microscopy demonstrate that alkyl aromatic alcohols, such as 1-dodecyl 3,4,5-trihydroxybenzoate yield mesomorphic structures at not too high a temperature. Alkyl carboxylic acids are somewhat less effective. In the melt state, the SAXS data still show a peak, but because no birefringence could be found, the peak is attributed to block copolymer-like concentration fluctuations in an otherwise homogeneous state. Aliphatic alkyl alcohols yield still weaker hydrogen bonding. In the melt the short alkyl aliphatic alcohol surfactants form a homogeneous mixture with P4VP, but a SAXS peak is no longer observed. The longer ones macrophase separate. Both thealkyl carboxylic acids and the short alkyl aliphatic alcohols partly macrophase separate at lower temperatures due to crystallization.

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Documento generato il 24/11/20 alle ore 11:00:42