Blocking and Deblocking of Diisocyanate to Synthesize Polyurethanes
| Autor: | Sellamuthu N. Jaisankar, Mir Muhammad Fahad, Sourita Jana, Hongdoo Kim, Debasis Samanta |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Thermogravimetric analysis
Materials science Polymers and Plastics Organic chemistry Infrared spectroscopy coatings deblocks Article Contact angle chemistry.chemical_compound QD241-441 Differential scanning calorimetry 3-(4-bromophenyl)-1H-pyrazole Fourier transform infrared spectroscopy Polyurethane blocking agent Toluene diisocyanate General Chemistry Nuclear magnetic resonance spectroscopy chemistry toluene diisocyanate polyurethane polyol blocked adduct Nuclear chemistry biomaterials |
| Zdroj: | Polymers Volume 13 Issue 17 Polymers, Vol 13, Iss 2875, p 2875 (2021) |
| Popis: | Diisocyanates, particularly toluene diisocyanate (TDI), are useful for the preparation of various polyurethanes with specific applications as leather-like materials, adhesives and insoles, etc. Blocking agents can be used for the operational simplicity and to reduce the hazards of TDI. In this paper, we reported the use of 3-(4-bromo-phenyl)-1H-pyrazole to block toluene diisocyanate (TDI). FTIR, NMR, thermogravimetric analysis, contact angle analysis and differential scanning calorimetry (DSC) were used for the characterization. The effectiveness of the blocking was confirmed by spectroscopic techniques. The DSC thermogram showed that blocked adducts deblock at 240 °C, causing the regeneration of TDI, and causing the diisocyanates to react with polyols of different molecular weights, forming polyurethanes. The characterization of the polyurethanes was performed by infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry and a contact angle study. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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