Synthesis of High Molecular Weight Cyclic Poly(ε-caprolactone)s of Variable Ring Size Based on a Light-Induced Ring-Closure Approach
writer：Haodi Wang1, Li Zhang1, Binyuan Liu*, Bing Han, Zhongyu Duan, Cuiyun Qi, Dae-Won Park, IL Kim*
keywords：cyclic polymer
source：期刊
specific source：Macromol Rapid Commun, 2015, DOI: 10.1002/marc.201500171
Issue time：2015年
High molecular weight cyclic poly(ε-caprolactone)s (cPCLs) with variable ring size are synthesized via light-induced ring closure of α,ω-anthracene-terminated PCL (An-PCL-An). The ring size of cPCL is tunable simply by adjusting the polymer concentration from 10 to 100 mg mL?1 in THF. The cycloaddition via the bimolecular cyclization of An-PC-An is well characterized by a variety of analyses such as 1H NMR and UV–vis spectroscopies, gel-permeation chromatography, and differential scanning calorimetry. The reversible dimerization of An induced by heating enables the cyclic PCL to have a switchable “on–off” capability. This novel light-induced ring-closure technique can be one of the most powerful candidates for producing various well-defined cyclic polymers in highly concentrated polymer solution.