Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes

doi:10.1021/jacs.7b03967

CORC > 北京大学 > 化学与分子工程学院

	Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes
	Liu, Wen-Xing ; Zhang, Chi ; Zhang, Huan ; Zhao, Ning ; Yu, Zhi-Xiang ; Xu, Jian
刊名	JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
	2017
关键词	CROSS-LINKED POLYMERS BLOCKED ISOCYANATES PHENYL ISOCYANATE CLICK CHEMISTRY NETWORKS BONDS TEMPERATURE MECHANISM SYSTEMS PERFORMANCE
DOI	10.1021/jacs.7b03967
英文摘要	Polyurethanes (PUs) have many applications resulting from their preeminent properties, but being commonly used toxic catalysts, and the lack of processability for PU thermosets cause limitations. Herein, we report a new class of the PU-like dynamic covalent polymers, poly(oxime-urethanes) (POUs), which are prepared from the uncatalyzed polyaddition of multifunctional mimes and hexamethylene dlisocyanate (HDI) at ambient temperature. Kinetics studies reveal that almost complete polymerization (similar to 99% conversion) can be achieved in 3 h at 30 degrees C in dichloromethane (DCM), the most effective among the solvents evaluated, producing linear POUs with comparable molecular weights to, the catalyzed PUs. We find that the oxime-carbamate structures are reversible at about 100 degrees C through oxime-enabled transcarbathoylation via a thermally-dissociative Mechanism. The cross-linked POUs based on oxime carbamate bonds show efficient catalyst-free healable/recyclable properties. Density functional theory (DFT) calculations suggest that the fast oxime-urethanation and the mild thermoreversible nature are mediated by the characteristic nitrone tautomer of the oxime. Given widespread urethane-containing materials, POUs are of promising potential in applications-because of the excellent mechanical performances, facile preparation, and dynamic property without using catalysts.; NSFC [51522308, 201421061, 21232001]; MOST [2017YFB0703300]; SCI(E); ARTICLE; 25; 8678-8684; 139
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/472617]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Liu, Wen-Xing,Zhang, Chi,Zhang, Huan,et al. Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2017.
APA	Liu, Wen-Xing,Zhang, Chi,Zhang, Huan,Zhao, Ning,Yu, Zhi-Xiang,&Xu, Jian.(2017).Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY.
MLA	Liu, Wen-Xing,et al."Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2017).