Layer Morphology of a Poly(ester imide) LCP in Different Solid States

Autor: Christoph Wutz, Norbert Stribeck
Rok vydání: 2002
Předmět:
Zdroj: Macromolecular Chemistry and Physics. 203:328-335
ISSN: 1521-3935
1022-1352
DOI: 10.1002/1521-3935(20020101)203:2<328::aid-macp328>3.0.co;2-7
Popis: Full Paper: A poly(ester imide) (PEI) in the smectic crystalline (SE) state exhibits both a medium-angle X-ray scattering (MAXS) peak and discrete small-angle X-ray scattering (SAXS). Based on quantitative analysis of absolute scattering data the observed SAXS is attributed to the formation of a sandwich structure in which a central, wellordered layer-shaped zone is enclosed in disordered buffer zones. Additionally the MAXS of material in the frozen liquid-crystalline SA and SB states is analysed. The results show that the SA state is characterised by long ranging correlation in the direction of the chain, whereas the lateral correlation range is short. Thus the smectic layer is considerably warped. The lateral range of order is wider in the SB state and approaches infinity in the SE state. This increase of lateral order and layer flatness goes along with considerable loss of longitudinal order. Nevertheless the range of longitudinal order remains high enough to assure correlation among the mesogens from the ordered zone with those from the disordered zones. Thus chain-folding cannot be the primary reason for the formation of ordered and disordered zones. Results indicate that asymmetry, orientation and internal twist of mesogenic groups in a liquid-crystalline main-chain polymer are important parameters controlling structure formation of the smectic morphology.
Databáze: OpenAIRE
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