Crosslinking reaction and properties of two‐component waterborne polyurethane from terpene‐maleic ester type epoxy resin |
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| Authors: | Guo‐min Wu Zhen‐wu Kong Cai‐feng Chen Jian Chen Shu‐ping Huo Jian‐chun Jiang |
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| Affiliation: | 1. Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing 210042, China;2. Key Laboratory of Biomass Energy and Material, Jiangsu Province, Nanjing 210042, China;3. National Engineering Laboratory for Biomass Chemical Utilization, Nanjing 210042, China;4. Key and Open Laboratory on Forest Chemical Engineering, State Forestry Administration, Nanjing 210042, China |
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| Abstract: | A two‐component waterborne polyurethane (2K‐WPU) is prepared with the terpene‐maleic ester type epoxy resin‐based polyol dispersion and a hydrophilically modified hexamethylene diisocyanate tripolymer. Laser particle size analyzer and transmission electron microscopy are used to characterize the particle size distribution and the micromorphology of the 2K‐WPU. Crosslinking reaction kinetics of the 2K‐WPU is examined by fourier transform infrared spectrometry (FTIR) spectra. In the preliminary stage of the crosslinking reaction, it shows a very good fit with a second order reaction kinetics, and the apparent activation energy is 94.61 kJ mol?1. It is also shown from the FTIR spectra that the complete crosslinking reaction of the 2K‐WPU needs 7 h at 70°C. The crosslinked products of the 2K‐WPU have good thermal resistant properties, with glass‐transition temperatures (Tg) in the range of 35–40°C and 10% weight loss temperatures (Td) in the range of 275–287°C. The films obtained from the crosslinked products have good water‐resistance, antifouling, blocking resistance properties and impact strength of >50 cm, flexibility of 0.5 mm, adhesion of 1 grade, pencil hardness of HB‐2H. The pencil hardness and thermal‐resistant properties of the crosslinked products increase with the molar ratio of isocyanate (? NCO) group to hydroxyl (? OH) group. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 |
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| Keywords: | polyurethanes resins water‐soluble polymers |
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