Tandem metathesis depolymerization and cyclopolymerization toward flexible-rigid block copolymers with unique damping properties

作者：Zhang, Lingli; Quan, Ying; Wang, Hao; Han, Huijing; Liao, Xiaojuan; Sun, Ruyi^*; Xie, Meiran^*

来源：Polymer Chemistry, 2022, 13(24): 3670-3680.

DOI：10.1039/d2py00521b

• RUTHENIUM-BASED CATALYST
• 1,7-OCTADIYNE DERIVATIVES
• OLEFIN METATHESIS
• CROSS-METATHESIS
• DANGLING CHAINS
• NATURAL-RUBBER
• POLYMERIZATION
• PERFORMANCE
• POLYMERS
• POLYISOPRENE

Metathesis depolymerization (MDP) of natural rubber (NR) was readily conducted to afford depolymerized NR (dNR(x)) bearing a living chain end, which can initiate metathesis cyclopolymerization (MCP) of 1,6- heptadiyne monomers to yield conjugated polyacetylene (PA) derivatives, and thus block copolymers consisting of a rubbery dNR(x) segment and a plastic PA segment were achieved by this newly constructed tandem MDP-MCP strategy. Importantly, triblock copolymers containing a flexible dNR(x) segment and rigid ionic PA segment possessed good mechanical properties, and exhibited distinctive damping performance with a unique relaxation plateau covering a broad temperature range, which could be further enhanced by modifying triblock copolymers with bromo-functionalized triazolinedione derived from bio-based oleic acid. Therefore, the developed MDP-MCP method should become a feasible technique with expanded applications in the remodeling of unsaturated polymers for providing flexible-rigid functional block copolymers.