Styrenic Block Copolymers and Methods of Preparation Thereof

A hydrogenated styrenic block copolymer comprising:

• at least one polymer block A, at least polymer block B, and at least one copolymer block C;
• wherein prior to hydrogenation,
• each polymer block A is derived from a vinyl aromatic monomer,
• each polymer block B is derived from a conjugated diene monomer selected from the group consisting of isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 3-butyl-1,3-octadiene, farnesene, myrcene, piperylene, cyclohexadiene, and mixtures thereof, and
• each copolymer block C is derived from at least one vinyl aromatic monomer and 1,3-butadiene monomer;
• wherein after hydrogenation, the hydrogenated styrenic block copolymer has:
• a hydrogenation level in the polymerized conjugated diene monomer in the polymer block B of greater than 90%;
• a hydrogenation level in the polymerized 1,3-butadiene monomer in the polymer block C of greater than 90%;
• a total vinyl aromatic content of 15 to 60 wt. %;
• an aromatic blockiness index (ABI) of 20 to 80%;
• and
• a rubbery aliphatic methyl index (RAMI) of 10 to 35;
• wherein the hydrogenated styrenic block copolymer is characterized as having:
• a tan δ peak height of 0.7 to 2;
• a tan δ peak temperature of −40 to 25° C.;
• a temperature width value (in ° C.) at half the tan δ peak height of 17 to 40;
• and
• a temperature difference value (in ° C.) between the tan δ peak temperature and a maximum loss modulus peak temperature of 14 to 21, all measurements by Dynamic Mechanical Analysis (DMA) (10 rad/sec.).