Cyclic polymers via a solid-supported ruthenium-based metathesis catalyst system
A ruthenium-based solid-supported metathesis catalyst system was investigated for its propensity to form cyclic poly(alkenamer)s over linear poly(alkenamer)s. This system was used in the ROMP of a variety of cycloalkene monomers and produced the resulting poly(alkenamer)s in good yield; addnl., linear polymers of these cycloalkenes were synthesized via ROMP using traditional Grubbs-type metathesis catalysts. The presumed cyclo poly(alkenamer)s and linear poly(alkenamer)s were envisioned to possess sufficiently disparate phys. properties to discriminate them from one another. This hypothesis was tested using both melt- and soln.- state samples of cyclic and linear poly(alkenamer)s in conjunction with phys. blends thereof; this general process was predicted to provide a means to quantitate the cyclic: linear poly(alkenamer) ratio and thus provide the information necessary to optimize the cyclo polymns. to maximize this ratio. Addnl., novel ionophore-functionalized cyclooctene derivs. were synthesized to enhance the soly. properties of the resulting polymers in polar media and thus enable methods of anal. which are incompatible with traditional poly(alkenamer)s.
© 2015 American Chemical Society.