| abstract |
New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: <IMAGE> +TR <IMAGE> in which R'' is either a hydrogen atom or a methyl radical; either n is 1, in which case R'=H and m and p are integers, the sum of which is between 0 and 10 inclusive, or n is 2, R' then being an alkyl radical of 2 to 8 carbon atoms and m=p=o; and R is an alkyl radical of 1 to 4 carbon atoms. The initiators are prepared by reacting compounds of the formula; <IMAGE> with an alkyl-lithium RLi in a non-polar solvent in the absence of any polar solvent or complexing agent. The initiators are used to prepare polydienes of high stereoregularity by reacting with a diene, and the polydiene is used to prepare a three-block or star copolymer by reacting with an anionically polymerizable monomer. |