Synthesis and branching structure detection of long-subchain hyperbranched polymers via pyrene-labelled methodology. (1st February 2022)

• Record Type: Journal Article
• Authors: Li, Chao; Han, Li; Bai, Hongyuan; Zhang, Songbo; Wang, Xuefei; Li, Yang; Ma, Hongwei
• Is Part Of: Polymer. Volume 240(2022)
• Publication Date: 2022-02-01
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2021.124479
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Long-subchain hyperbranched polymers (LHPs) are macromolecules with complex topological structures that have been extensively studied by researchers. However, the interior branching structure characterization of LHPs remains a challenging topic. In this contribution, LHPs were fabricated through stepwise growth of anionic polymerized AB2 polystyrene macromonomers bearing one Si–H group and two alkyne groups using a hydrosilylation coupling reaction. By varying the reaction solution concentration, LHPs with diverse weight-average degree of polymerization (Dpw) and branching factors ( g' ) were obtained. Pyrene moieties were efficiently attached to the obtained LHPs by thiol-yne click reaction, and the fluorescence manners of the pyrene chromophores on the LHPs were investigated. The fraction of residual double alkyne (DA) to total alkynes- f DA was proposed as a new parameter to describe the branching structure perfectness of LHPs. IE /IM to f DA calibration curves were built. f DA can be easily determined by IE /IM obtained from fluorescence tests. This study will offer a feasible method to character branching structure perfectness of complex topological polymers. Graphical abstract: Image 1 Highlights: Well-defined AB2 macromonomer bearing one Si–H and two alkynes was obtained via living anionic polymerization. LHPs with different branching structure were constructed using stepwise hydrosilylation of macromonomer. Branching structure perfectness of LHPs was evaluated based on pyrene-labelled methodology.