Synthesis of Ultrahigh Molecular Weight Polymers Containing Reactive Functionality with Low PDIs by Polymerizations of Long-Chain α-Olefins in the Presence of Their Nonconjugated Dienes by Cp*TiMe2(O-2,6-iPr2C6H3)-Borate Catalyst

Abstract

Copolymerizations of 1-decene (DC) with 1,9-decadiene (DCD), 1-dodecene (DD) with 1,11-dodecadiene (DDD), and 1-tetradecene (TD) with 1,13-tetradecadiene (TDD), using Cp*TiMe₂(O-2,6-ⁱPr₂C₆H₃) (1)-[Ph₃C][B(C₆F₅)₄] (borate) catalyst in the presence of AlⁱBu₃/Al(n-C₈H₁₇)₃ proceeded in a quasi-living manner in n-hexane at -30 to -50 °C, affording ultrahigh molecular weight (UHMW) copolymers containing terminal olefinic double bonds in the side chain with rather low PDI (M_w/M_n) values. In the DC/DCD copolymerization, the resultant copolymer prepared at -40 °C possessed UHMW (M_n = 1.40 × 10⁶ after 45 min) with low PDI (M_w/M_n = 1.39); both the activity and the PDI value decreased at low polymerization temperature (M_n = 5.38 × 10⁵, M_w/M_n = 1.18, after 120 min at -50 °C). UHMW poly(TD-co-TDD) was also obtained in the copolymerization at -30 °C (M_n = 9.12 × 10⁵, M_w/M_n = 1.51, after 120 min), using this catalyst.

Keywords: borate; bottlebrush polymer; catalyst; half-titanocene; nonconjugated diene; polymerization; titanium complex; α-olefin.