writer：Shengli Chen, Fenfen Wang, Yongjin Peng, Tiehong Chen, Qiang Wu, Pingchuan Sun*
keywords：Diels-Alder, Recyclable, Cross-Linked Polymers
source：期刊
specific source：Macromolecular Rapid Communications, 2015, 36, 1687-1692.
Issue time：2015年

A triol-functional crosslinker combined the thermo-reversible properties of Diels-Alder (DA) adducts in one molecule is designed and synthesized, and has been used as an ideal substitute of the traditional crosslinker to prepare thermal recyclable cross-linked polyurethanes with excellent mechanical properties and recyclability in a very simple and efficient way. The recycle property of these materials is achieved by the DA/retro-DA reaction at suitable temperature, and has been verified by DSC and in-situ variable temperature solid-state NMR experiments during the cyclic heating and cooling processes. The thermal recyclability and re-mending ability of the bulk polyurethanes has been well demonstrated by three polymer processing methods, including the hot-press molding, injection molding and solution casting. It is notable that all the recycled cross-linked polymers display nearly invariable elongation/stress at break compared to the as synthesized sample. Further end-group functionalization of this single molecular DA crosslinker provides the potential in preparing a wide range of recyclable cross-linked polymers.