Self-healing, recyclable, and removable UV-curable coatings derived from tung oil and malic acid. Issue 16 (24th July 2021)

• Record Type: Journal Article
• Authors: Zhang, Jinshuai; Huang, Jia; Zhu, Guoqiang; Yu, Xixi; Cheng, Jianwen; Liu, Zengshe; Hu, Yun; Shang, Qianqian; Liu, Chengguo; Hu, Lihong; Zhou, Yonghong
• Is Part Of: Green chemistry. Volume 23:Issue 16(2021)
• Page Start: 5875
• Page End: 5886
• Publication Date: 2021-07-24
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d1gc01726h
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Self-healing, recyclable, and removable UV-curable coatings were obtained by integrating renewable tung oil and malic acid resources, microwave synthesis, UV-curing, and dynamic covalent chemistry into coatings. Abstract : This study reports the development of super "green" smart coatings by integrating renewable resources, microwave-assisted synthesis, and dynamic covalent chemistry into UV-curable coatings. First, a novel UV-curable oligomer (TMG) was synthesized from renewable tung oil (TO) via microwave technology, and a biobased reactive diluent (MM) was derived from malic acid under ambient conditions. Afterward, a set of UV-curable coatings containing plentiful hydroxyl and ester groups were prepared by photo-polymerizing the TMG oligomer with the MM diluent. The resulting coatings demonstrated a high biobased content (49.2%–58.1%), good mechanical and thermal properties ( e.g. T g of 70.6–78.6 °C), and excellent coating adhesion and flexibility. Furthermore, by activating dynamic transesterification reactions at elevated temperatures with a zinc catalyst, the resulting UV-curable materials exhibited excellent repairability, removability, recyclability, malleability, and shape memory properties. For instance, the TMG material containing 10% of MM demonstrated a crack repair efficiency of 92.5%, a welding efficiency of tensile strength up to 171.8%, a recycling efficiency of tensile strength up to 404.3%, and a shape fixity ratio of 98.2%.