US 10,889,676 B2
Method for synthesizing a thermoplastic elastomer comprising at least one poly(α-methylstyrene) block
Rachid Matmour, Clermont-Ferrand (FR); and Robert Ngo, Clermont-Ferrand (FR)
Assigned to COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
Appl. No. 16/63,988
Filed by COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
PCT Filed Dec. 8, 2016, PCT No. PCT/FR2016/053275
§ 371(c)(1), (2) Date Jun. 19, 2018,
PCT Pub. No. WO2017/109325, PCT Pub. Date Jun. 29, 2017.
Claims priority of application No. 15 62986 (FR), filed on Dec. 21, 2015.
Prior Publication US 2019/0077900 A1, Mar. 14, 2019
Int. Cl. C08F 297/04 (2006.01); B60C 1/00 (2006.01); C08F 236/10 (2006.01); C08F 236/06 (2006.01); C08F 136/06 (2006.01); C08K 5/56 (2006.01); C08L 9/06 (2006.01)
CPC C08F 297/04 (2013.01) [B60C 1/00 (2013.01); C08F 136/06 (2013.01); C08F 236/06 (2013.01); C08F 236/10 (2013.01); C08F 297/042 (2013.01); C08K 5/56 (2013.01); C08L 9/06 (2013.01)] 20 Claims
 
1. A method for synthesizing a thermoplastic elastomer comprising at least one polydiene block and at least one other poly(α-methylstyrene) block, wherein the method comprises the following steps:
1. polymerizing at least one diene monomer in a starting reaction medium comprising an anionic polymerization initiator and an aprotic non-polar solvent to obtain a living polydiene chain;
2. polymerizing α-methylstyrene to the living polydiene chain obtained in the preceding step comprising:
a. at the end of the polymerization of step 1., maintaining a reaction medium containing the living polydiene chain obtained previously and α-methylstyrene at a temperature above 20° C. and below the ceiling temperature for the polymerization of α-methylstyrene for at least one minute;
b. cooling the reaction medium obtained at the end of the preceding step a., to a temperature below 0° C.;
c. simultaneously, successively or prior to the cooling step, adding a purified aprotic polar solvent to the reaction medium with a volume ratio of the polar solvent to the non-polar solvent of less than 1; and
d. propagating the polymerization of α-methylstyrene to the living polydiene chain;
3. terminating the polymerization and recovering the thermoplastic polymer.