High styrene high vinyl styrene-butadiene rubber with narrow molecular weight distribution and methods for preparation thereof
AssigneeStyron Europe GmbH
InventorsEvemarie Hamann, Silvia Valenti, Gabriele Holtz
Life of this patent
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Abstract
A polymer having at least the following characteristics: (a) a block styrene content with more than 4 consecutive styrene units from about 40 to about 70 weight percent based on total styrene content in the polymer; (b) a vinyl content from about 25 to about 80 weight percent based on total amount of polymerized 1,3-diene; (c) a styrene content from about 20 to about 75 weight percent based on total weight of polymer; and (d) a molecular weight distribution (Mw/Mn) of 1.5 or less.
Claims13
A polymer having at least the following characteristics:
- (a) a block styrene content with more than 4 consecutive styrene units from about 40 to about 70 weight percent based on total styrene content in the polymer;
- (b) a vinyl content from about 25 to about 80 weight percent based on total amount of polymerized 1,3-diene;
- (c) a styrene content from about 20 to about 75 weight percent based on total weight of polymer;
- (d) a molecular weight distribution (Mw/Mn) of 1.5 or less;
- and
- (e) a weight-average molecular weight (Mw) of greater than or equal to 250,000 g/mol.
A process for polymerization of a polymer comprising monomeric units derived from a styrene monomer and a 1,3-diene monomer, the process comprising:
- polymerizing the monomers in the presence of n butyllithium, potassium-3,7-dimethyl-3-octylate, and a polar agent;
- wherein the polar agent comprises a structure I:
- wherein R1 and R2 are each independently an alkyl group;
- wherein R3, R4, R5, R6, R7 and R8 are each independently selected from the group consisting of an alkyl group and hydrogen.
Dependencies are inferred from the claim text.