The practical applications of waterborne epoxy coatings are limited due to their poor barrier properties caused by the formation of numerous micropores and defects during the curing process. Herein, cellulose nanocrystals (CNCs)-reinforced waterborne epoxy coatings were fabricated by the direct addition of 0.2-1.0 wt% CNCs to waterborne epoxy emulsion followed by amine curing agent addition and spray coating. The incorporation of 0.2-0.5 wt% CNCs had no discernible impact on the stability of the waterborne epoxy emulsion. This led to the uniform dispersion of CNCs in the cured coating matrix, as evidenced by differential scanning calorimetry analysis. Because of the good compatibility, 0.2-0.5 wt% CNCs-reinforced epoxy coatings exhibited superior corrosion protection performance for steels. The impedance modulus of these coatings remained at 10 Ω cm after being immersed in a 3.5 wt% NaCl solution for 21 d. The hydroxyl groups present on the CNC surface undergo a reaction with the epoxy group, enhancing intermolecular interaction and leading to the formation of a defect-free dense structure that improves coating barrier properties. However, the incorporation of an excessive amount of CNCs (i.e., 0.8 and 1.0 wt%) significantly compromised the corrosion resistance of epoxy coatings due to aggregation-induced coating defects. Overall, this study provides a facile and green strategy for corrosion resistance improvement of waterborne epoxy coatings.
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http://dx.doi.org/10.1016/j.ijbiomac.2023.128755 | DOI Listing |
RSC Adv
December 2024
Inner Mongolia Key Laboratory of New Materials and Surface Engineering, School of Materials Science and Engineering, Inner Mongolia University of Technology Hohhot 010051 China
J Colloid Interface Sci
March 2025
Jilin Provincial Laboratory of Carbon Fiber and Composites, Jilin Province Key Laboratory of Carbon Fiber Development and Application, College of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, China. Electronic address:
The preparation of environmentally friendly and efficient waterborne polyurethane sizing agents for carbon fiber (CF) is difficult, especially to avoid the use of isocyanates. Herein, ellagic acid and CO were used to prepare a five-membered cyclic carbonate compound (EARBO). The polymerization between EARBO and diamines enabled the preparation of highly efficient and green aqueous non-isocyanate polyurethane (WNIPU) sizing agents.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China.
In research aimed at improving the brittleness of WER (waterborne epoxy)-modified emulsified asphalt, commonly encountered issues are that the low-temperature performance of this type of asphalt becomes insufficient and the long curing time leads to low early strength. Matrix-emulsified asphalt was modified with WPU (waterborne polyurethane), WER, and DMP-30 (accelerator). Firstly, the performance changes of modified emulsified asphalt at different single-factor dosages were explored through conventional performance tests and assessments of its adhesion, tensile properties, and curing time.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Payathai, Bangkok, 10400, Thailand.
Water-based coating has gained much attention globally due to environmental issues. This work aims to develop a waterborne epoxy coating incorporated with modified natural rubber (NR) latex for improved performance. For this purpose, the NR latex was modified into three types of low molecular weight epoxidized natural rubber (LENR) latex.
View Article and Find Full Text PDFChemSusChem
October 2024
Centre for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Albert Einstein 48, 01510, Vitoria-Gasteiz, Spain.
This work studies the use of epoxy and polyurethane formulations as binders for the aqueous processing of activated carbon (AC) electrodes used as positive and negative electrodes in Electrochemical Double Layer Capacitors (EDLCs). The use of amine and carbodiimide as crosslinkers is also evaluated. The mechanical properties of those different binders have been investigated, looking towards aqueous processable and flexible electrodes.
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