Blends of polar thermoplastic polymers and modified block copolymers

A multiphase thermoplastic composition comprising:

• (a) one phase containing at least one polar thermoplastic polymer each containing at least one polar functional group;
• and
• (b) at least one other phase containing at least one functionalized, selectively hydrogenated block copolymer to which has been grafted on the average an effective amount of carboxyl functional groups for imparting improved tensile strength, high temperature mechanical properties and oil resistance to said multiphase thermoplastic composition, said functionalized block copolymer comprising
• (1) a base block copolymer which comprises
• (i) at least one polymer block A, said A block being predominantly a polymerized alkenyl arene block, and
• (ii) at least one selectively hydrogenated polymer block B, said B block prior to hydrogenation being predominantly a polymerized conjugated diene block,
• (2) wherein substantially all of said carboxyl functional groups are grafted to said base block copolymer on said A blocks,
• (c) said one phase (a) being present in a weight ratio of about 1:99 up to less than about 50:50 relative to said at least one other phase (b), and
• (d) said polar thermoplastic polymer excluding said functionalized block copolymer.