New polyurethanes with specific dielectric behavior through included of 1,3,4-thiadiazole derivative in their structure
| Autor: | Stefan Oprea, Veronica Oprea, Violeta Otilia Potolinca |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Organic Chemistry Relaxation (NMR) General Physics and Astronomy 02 engineering and technology Polymer Dielectric 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Chemical engineering Castor oil Materials Chemistry medicine Dielectric loss Fourier transform infrared spectroscopy 0210 nano-technology Derivative (chemistry) medicine.drug Polyurethane |
| Zdroj: | European Polymer Journal. 143:110177 |
| ISSN: | 0014-3057 |
| DOI: | 10.1016/j.eurpolymj.2020.110177 |
| Popis: | New polyurethanes, derived from heteroaromatic compound (5-amino-1,3,4-thiadiazole-2-thiol) and conventional urethane prepolymers with the same soft segment amount, were synthesized. A range of crosslinkers with flexible or rigid structures (bis(3-aminopropyl)amine, glycerin, castor oil and, 2,4,6, triaminopyrimidine) were used in order to obtain chemically crosslinked structures. The inclusion of the 5-amino-1,3,4-thiadiazole-2-thiol on the main polyurethane chain were studied by Fourier transform infrared spectroscopy. The synthesized polyurethanes were investigated of the thermal, mechanical and dielectric properties and we found that the heteroaromatic compound gives these polyurethanes improved properties, compared to conventional polyurethanes, such as thermal resistance up to 285 °C, high degree of elastic elongations, good mechanical strength and high modulus values. The relaxation behavior of polyurethanes based on 5-amino-1,3,4-thiadiazole-2-thiol is studied by broadband dielectric spectroscopy in the frequency 1 - 106 Hz and temperature ranges 120 °C to + 100 °C. In the studied temperature field the dielectric loss in the frequency domain exhibits α absorption, followed in increasing order of frequencies by two secondary absorptions β and γ. Heteroaromatic structure exerts constraints on the local movements (relaxation processes) within the resulting polymer matrices. These properties and possible antibacterial activity brought by 5-amino-1,3,4-thiadiazole-2-thiol make these polyurethane materials suitable for biomedical applications and beyond. |
| Databáze: | OpenAIRE |
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