| Résumé : |
Two-pack (2K) waterborne polyurethanes are increasingly used in coatings technologies. Examples of such coatings can be encountered in many different fields including metal coatings (for railway carriage, car refinish ... ), wood coatings (e.g., parquet flooring, furniture) or soft-feel coatings for plastic in the automotive industry. The benefits brought by waterborne technology can explain this growth. It is fully compliant with the new volatile organic compounds (VOC) regulations and contributes to better health and safety conditions for both workers and end users. Of course, switching from solvent-based to waterborne technology implies technical challenges. Many improvements have been achieved during the past years to develop waterborne systems that can compete with solvent-based coatings. In the case of polyisocyanates, for instance, the ease of miwing in the formulation and the control of side reactions with water have been greatly improved by using hydrophilically modified polyisocyanates.
However, a deeper understanding of the film formation mechanisms and the impact of different key parameters is still essential in order to finetune the formulation and achieve optimal results. Many techniques have been used to investigate these aspects such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), or even mechanical measurements. Confocal Raman spectroscopy has also been widely used but only a few reports mention its use for the investigation of aqueous systems.
Here we present the use of Inverse Micro Raman spectroscopy (IMRS in order to investigate the drying behavior and fim composition of 2K waterborne polyurethanes. |
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Ajouter le résultat dans votre panier Affiner la rechercheFilm formation of 2K waterborne polyurethane systems / Philippe Olier in COATINGS TECH, Vol. 7, N° 7 (07/2010)
