Abstract: New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: ##STR1## 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; ##STR2## 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.

Abstract: Organo-lithium compounds of the formula: ##STR1## wherein R is an alkyl group of up to 5 carbon atoms, R' is either hydrogen or an alkyl group of up to 5 carbon atoms and n is an integer from 2 to 10. These bifunctional organo-lithium compounds are prepared without the use of any polar or complexing agent and are useful as polymerization initiators for the production of block copolymers.

Abstract: New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: ##STR1## 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 =0; and R is an alkyl radical of 1 to 4 carbon atoms.The initiators are prepared by reacting compounds of the formula: ##STR2## 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.

Abstract: Organo-lithium compounds of the formula: ##STR1## wherein R is an alkyl group of up to 5 carbon atoms, R' is either hydrogen or an alkyl group of up to 5 carbon atoms and n is an integer from 2 to 10. These bifunctional organo-lithium compounds are prepared without the use of any polar or complexing agent and are useful as polymerization initiators for the production of block copolymers.

Abstract: New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: ##STR1## IN WHICH R" is either a hydrogen atom or a methyl radial; 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 = 0; and R is an alkyl radical of 1 to 4 carbon atoms.The initiators are prepared by reacting compounds of the formula: ##STR2## 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.

Abstract: Elastomers with thermoplastic properties consist of polymers grafted on an elastomeric chain which includes double bonds and active sites. The latter are more particularly halogen atoms, especially chlorine, and the grafted polymer is a polyindene or a copolymer of indene with styrene derivatives, such as .alpha.-methylstyrene or para-alkyl-styrene. In the process for preparing these thermoplastic elastomers the choice of constituent proportions, catalyst and solvent is important. Elastomers possessing at 80.degree. C. a breaking strength of at least 60 kg/cm.sup.2 can be obtained.

Abstract: This invention relates to copolymers of a macromolecular compound having a non-halogenated and double-bonded chain and of a vinylaromatic monomer and the process for obtaining same. The reaction between the macromolecular compound and the vinylaromatic monomer takes place at a temperature of between -80.degree. C and +40.degree. C in the presence of 5.10.sup.-4 to 5.10.sup.-2 mol/l of a Lewis acid initiator and possibly in the presence of a co-initiator. These copolymers obtained by cationic grafting are thermoplastics elastomers.

Abstract: Organo-lithium compounds of the formula: ##STR1## wherein R is an alkyl group of up to 5 carbon atoms, R' is either hydrogen or an alkyl group of up to 5 carbon atoms and n is an integer from 2 to 10. These bifunctional organo-lithium compounds are prepared without the use of any polar or complexing agent and are useful as polymerization initiators for the production of block copolymers.