| The synthesis of chain end functionalized polymers was effected using protected functional initiators. Living anionic polymerization was employed to generate polymers with controlled, well-defined structures, narrow molecular weight distributions and predictable molecular weights. Protected functional organolithium initiators also provided a unique opportunity to prepare functionalized telechelic and star-branched polymers.;Research has concentrated on the hydroxy-functional group which was protected by the tert-butyldimethylsiloxy, tert-butoxy, or tert-amyloxy group. The novel functionalized initiators, 3-(tert-butyldimethylsiloxy)-1-propyllithium (TBDMSPL), 3-(tert-butoxy)-1-propyllithium (TBPL) and the chain extended analog with 2 units of isoprene (TBPL-CE), and the chain extended analog of 3-(tert-amyloxy)-1-propyllithium (TAPL-CE) which contain these protecting groups exhibited efficient initiating ability for diene polymerization and easy deprotection using acidic reagents. Linear polybutadienes synthesized with protected functional initiators have narrow molecular weight distributions ;Also the thermal stabilities of polymeric living chain ends were studied at elevated temperature (i.e., at 100... |
