A bridge-like polymer synthesized by tandem metathesis cyclopolymerization and acyclic diene metathesis polymerization

A facile synthesis of a novel bridge-like polymer was accomplished by the combined procedures of metathesis cyclopolymerization (MCP) and acyclic diene metathesis (ADMET) polymerization. A telechelic double-stranded polyacetylene (PA) with two terminal alkenyl groups was firstly prepared through the third generation Grubbs' catalyst-mediated chain terminating MCP of bis(1,6-heptadiyne), containing a perylene bisimide (PBI) segment, in the presence of 1,4-bis(10-undecenyloxy)-cis-2-butene. A symmetrical triolefinic ether acted as the functional terminating agent, and was then utilized as the macromonomer in subsequent ADMET polymerization to yield the resultant bridge-like polymer, consisting of the nonconjugated polyolefin backbone and the separated pier-like double-stranded PA. The molecular weight of the product increased (25.2-122.4 kDa) as the reaction time was prolonged, and there was a relatively broad polydispersity index (PDI = 1.41-1.75). The bridge-like polymer can assemble into an ordered ladder-like architecture and a fence-like ribbon morphology, and displays excellent thermal stability, with a T_d of above 300 °C and a high T_g between 175 and 189 °C, which is important for applications in devices.