Molecular mobility of liquid crystalline polyurethanes modified by polyhedral oligomeric silsesquioxanes
Authors:
- Artur Bukowczan,
- Konstantinos N. Raftopoulos,
- Jacek Nizioł,
- Krzysztof Pielichowski
Abstract
Molecular mobility and liquid crystalline order formation of liquid crystalline polyurethanes (LCPU) modified by trisilanolphenyl-POSS was investigated by using dielectric spectroscopy (DRS), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Hybrid materials with 2, 4 and 6 wt% of POSS load were studied. Small-angle X-ray scattering (SAXS) results suggested that the nanoscale morphology was not significantly altered by the introduction of POSS into the LCPU matrix. The presence of liquid crystal phase transitions was confirmed by both DRS and DSC measurements. Dielectric study showed changes in relaxation steps and conductivity in the LC transitions region due to a shift in phase order. Using partially cross-linked POSS particles, an enhancement of the material's rubber modulus was observed in the DMA measurement. Deterioration in charge transfer was observed for the composites, which was attributed to the crosslinking nature of the silsesquioxane used. Further, dynamic calorimetric studies in different cooling rates were performed for detailed study of liquid crystalline transitions. In summary, it was found that the addition of POSS causes a nucleation effect and does not impair LC phase formation.
- Record ID
- CUT79e6926b40a74176a35039cd6f5ce430
- Publication categories
- ;
- Author
- Journal series
- Polymer, ISSN 0032-3861, e-ISSN 1873-2291
- Issue year
- 2023
- Vol
- 277
- Pages
- [1-12]
- Article number
- 125981
- Other elements of collation
- tab.; wykr.; Bibliografia (na s.) - 10-12; Bibliografia (liczba pozycji) - 64; Oznaczenie streszczenia - Abstr.; Numeracja w czasopiśmie - Vol. 277
- Keywords in English
- liquid crystalline polyurethanes, POSS, molecular mobility, glass transition
- ASJC Classification
- ;
- DOI
- DOI:10.1016/j.polymer.2023.125981 Opening in a new tab
- URL
- https://www.sciencedirect.com/science/article/abs/pii/S0032386123003117 Opening in a new tab
- Language
- eng (en) English
- Score (nominal)
- 100
- Score source
- journalList
- Score
- Publication indicators
- Additional fields
- Indeksowana w: Scopus
- Uniform Resource Identifier
- https://cris.pk.edu.pl/info/article/CUT79e6926b40a74176a35039cd6f5ce430/
- URN
urn:pkr-prod:CUT79e6926b40a74176a35039cd6f5ce430
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