Polybutadienyllithium systems, with high 1,4-microstructure, low polydispersity and M ¯n in the range (2-10) × 103, have been produced in hydrocarbon solvents by using n-butyllithium or 3-dimethylamino-propyllithium as initiator. Termination of these 'living' polymers with chlorophosphine, ClPR2 (R = Ph, Et or Cy), occurs to give oxidatively unstable phosphine derivatives Y-(C4H6)n-PR2, in up to 93% efficiency. Oxidation products include the related phosphine oxides. Quaternization of the phosphinated polymers in situ with iodomethane gives a quantitative conversion into the cationomeric polymers Y'-(C4H6)n-PR2Me+I-, including the novel dicationic telechelic systems with Y' = I+NMe3(CH2)3, which show thermoplastic elastomeric properties. The products have been characterized by gel permeation chromatography, end-group analysis and 1H, 13C and 31P nuclear magnetic resonance spectroscopy. Model quaternary phosphonium derivatives, trans- and cis-t-BuCH2CHCHCH2PR2Me+I- and t-BuCH2CH(CHCH2)PR2Me+I-, are reported and help establish the terminal geometry of the quaternary phosphonium-capped polybutadienes: the addition of phosphorus to the terminal butadienyl follows the order cis-1,4>trans-1,4>1,2 with the amount of 1,2-termination being smallest when R is the bulky cyclohexyl group. © 1990.
|Number of pages||5|
|Publication status||Published - Jul 1990|
- anionic polymerization
- phosphonium group
- telechelic poly-1,3-butadiene