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Crosslinking reaction and properties of two‐component waterborne polyurethane from terpene‐maleic ester type epoxy resin
Author(s) -
Wu Guomin,
Kong Zhenwu,
Chen Caifeng,
Chen Jian,
Huo Shuping,
Jiang Jianchun
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.38130
Subject(s) - polyurethane , materials science , isocyanate , epoxy , polymer chemistry , fourier transform infrared spectroscopy , polyol , maleic anhydride , composite material , chemical engineering , polymer , copolymer , engineering
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 ( T g ) in the range of 35–40°C and 10% weight loss temperatures ( T d ) 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