| Abstract
| - Polycyclopentene with controllable molecular weight and polydispersity below 1.1 wasobtained by ring-opening metathesis polymerization (ROMP) of cyclopentene at room temperature usinga commercial Mo-based ROMP initiator in the presence of trimethylphosphine. Polydispersities werekept low by limiting the degree of cyclopentene conversion. These narrow-distribution polycyclopenteneswere catalytically hydrogenated to narrow-distribution linear polyethylenes, providing a facile route tomodel polyethylenes free from both short- and long-chain branching. The “living” nature of ROMP alsopermits the synthesis of well-defined diblock copolymers containing polycyclopentene, including poly(ethylidenenorbornene)−polycyclopentene diblocks. The hydrogenated derivatives of these diblocksrepresent a new type of crystalline−amorphous diblock, possessing much higher levels of crystallinitythan when block copolymers containing anionically polymerized high-1,4-polybutadiene are hydrogenated.
|
