title: Efficient polymerization of azide and active internal alkynes.
abstract: The 1,3-dipolar cycloaddition of azides and active internal alkynes has been well studied, but is rarely utilized as a tool for polymer preparation. In this work, an efficient polymerization route is developed. Polycycloaddition of diazide (4) and bis(benzoylethynyl)-benzenes and -butane (3) at elevated temperature has produced the first examples of soluble 1,4,5-trisubstituted polytriazoles PI with satisfactory molecular weights (M(w)  up to 16 400) in excellent yields (up to 98.6%). All the obtained polymers are thermally stable, losing merely 5% of their weights at temperatures higher than 367 °C. They exhibit higher refractive indices than some commercial plastics and can be crosslinked upon UV irradiation to generate a 3D photopattern with high resolution. The metal-free feature of such a methodology offers a facile tool to prepare functional materials free from the contamination of metal species.
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China. qinaj@zju.edu.cn
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.forename: Haiqin
authors.initials: H
authors.lastname: Deng
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Cai
authors.forename: Jacky W Y
authors.initials: JW
authors.lastname: Lam
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Sun
authors.forename: Meng
authors.initials: M
authors.lastname: Gao
authors.forename: Anjun
authors.initials: A
authors.lastname: Qin
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D015394:Molecular Structure; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000480:Alkynes; D001386:Azides; D011108:Polymers