Abstract
The linseed oil glyceride (LOG) was synthesized by using a transesterification process with a glycerol/linseed oil molar ratio of 1.0. The waterborne urethane oil (WUO) wood coating was prepared by acetone process. First, dimethylolpropionic acid was reacted with hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI), followed by adding LOG at various NCO/OH molars of 0.7, 0.8, and 0.9, respectively, and the COOH-containing prepolymer was obtained. Then, the ionomer which was prepared by neutralizing prepolymer with trimethylamine, was dispersed by adding deionized water, and the water–acetone dispersion was obtained. Finally, the acetone was removed by vacuum distillation. In the whole synthesized process, the LOG and COOH-containing prepolymer could be steadily synthesized by FTIR analysis, and the weight-average molecular weight and polydispersity of COOH-containing prepolymer increased with an increase of NCO/OH molar ratios. During the water dispersion process of the ionomer acetone solution, the point of phase inversion was prolonged, meaning the solid content decreased with an increase of NCO/OH molar ratios. After acetone was removed, the color of WUO was milky-white, and it was weakly alkaline and possessed a pseudoplastic fluid behavior. The particle size of WUO increased with increasing of NCO/OH molar ratios, however, the storage stability was extended for HDI and shortened for IPDI synthesized with increasing of NCO/OH molar ratios.
Highlights
The application of coatings to wood surfaces protects the wood from damage, prolongs the lifecycle and carbon fixation duration of wood products, enables wood utilization to conform with principles of regeneration and sustainability, and enhances the value of the wood products by improving their surface quality and functionality
The mainProperties fatty acid component of linseed oil (LO) is linolenic acid (53.2%), followed by oleic
The main fatty acid component of linseed oil (LO) is linolenic acid (53.2%), followed by oleic
Summary
The application of coatings to wood surfaces protects the wood from damage, prolongs the lifecycle and carbon fixation duration of wood products, enables wood utilization to conform with principles of regeneration and sustainability, and enhances the value of the wood products by improving their surface quality and functionality. With an increase in the number of wood buildings, wood-based recreational facilities, and high-quality wood furniture in Taiwan, penetrating oil for wood finishing has received increasing attention. Such wood coatings are formulated using unsaturated triglycerides, such as linseed oil, with the addition of metal dryers, solvents, and other additives. Coatings with oxidative polymerization drying characteristics and urethane bonds are obtained, which can improve the physical properties of films and reduce the curing time of coating [1,2]. When solvent-borne UO coatings are used, the volatile organic compounds (VOCs) present in the solvents result in environmental and ecological damage. The development of Polymers 2018, 10, 1235; doi:10.3390/polym10111235 www.mdpi.com/journal/polymers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
