ao9b01234_si_001.pdf (1.01 MB)
Effect of the Ratio of Acetylacetate Groups on the Properties of a Novel Plant-Based Dual-Cure Coating System
journal contribution
posted on 2019-06-26, 18:35 authored by Dongdong Xu, Zhiyuan Cao, Tong Wang, Jinze Zhao, Jiang Zhong, Peng Xiong, Jiahui Wang, Fei Gao, Liang ShenA novel plant-based
dual-cure coating system based on a Michael
addition reaction between bismaleimide (BDM) and modified acetoacetylated
castor oil was developed. The BDM has a high reactivity toward acetylacetate
groups, and the catalyst 1,4-diazabicyclo[2.2.2]octane (TEDA) was optimized by the rheological
viscosity. The gel was characterized by Fourier transform infrared
(FTIR) spectroscopy. Then, three films were prepared with the TEDA
catalyst and analyzed with solid-state 13C NMR and FTIR
spectroscopy. The thermal and mechanical properties of the three films
were characterized by differential mechanical analysis, thermogravimetric
analysis, and differential scanning calorimetry. We found that the
cross-linking density, glass transition temperature (Tg), and Young’s modulus of the
coating films increased with an increase in the ratio of acetylacetate
groups from the modified acetoacetylated castor oil. This is the first
study of the reaction of BDM with plant-based acetylacetate groups.
Importantly, a quantitative ratio of acetylacetate groups can be obtained
by a thiol–ene coupling reaction and a transesterification
reaction, resulting in the formation of films having excellent performance.