Evidences of phase separation in moisture‐cured poly(urethane urea)s by means of temperature modulated differential scanning calorimetry |
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| Authors: | Ana Luísa Daniel‐da‐Silva João Carlos Moura Bordado José Miguel Martín‐Martínez |
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| Institution: | 1. Adhesion and Adhesives Laboratory, University of Alicante, 03080 Alicante, SpainAdhesion and Adhesives Laboratory, University of Alicante, 03080 Alicante, Spain;2. Chemical Engineering Department, Instituto Superior Técnico, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal;3. Adhesion and Adhesives Laboratory, University of Alicante, 03080 Alicante, Spain |
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| Abstract: | The degree of phase separation in several moisture‐cured poly(urethane urea)s (PUUs) was studied by FTIR spectroscopy, wide angle X‐ray diffraction (WAXD), and temperature‐modulated differential scanning calorimetry (TMDSC). This latter technique was shown to be particularly useful in analysing the degree of phase separation in PUU polymers. Both phase mixing and phase segregation coexisted in the PUUs and the degree of phase separation increased as the urea hard segment (HS) content in the PUU increased. The maximum solubility of urea HSs into the polyol soft segments (SSs) was achieved for 50 wt % urea HS content in diol‐based PUUs, whereas for triol‐based PUUs the highest solubility between HS and SS was reached for lower urea HS amount. Finally, the higher the urea HS content the higher the extent of phase separation in the PUU. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3034–3045, 2007 |
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| Keywords: | isocyanate ended prepolymer phase separation poly(urethane urea) temperature modulated DSC |
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