Super-vibration damping thermoplastic elastomer blends and lower specific gravity articles made therewith

A low specific gravity polymeric article for mitigation of impact forces, comprising:

• (1) from about 90 to about 97 weight percent of a thermoplastic elastomer compound comprising:
• (a) hydrogenated styrenic block copolymer having a polyisoprene soft block;
• (b) styrene-isobutylene-styrene block copolymer;
• (c) tackifier having a softening point of at least about 80° C. according to ASTM 6493;
• and
• (d) optionally, one or more additional thermoplastic elastomers selected from the group consisting of thermoplastic polyurethanes, copolyesters, copolyamides, thermoplastic olefins, thermoplastic vulcanizates, olefinic block copolymers, and combinations thereof;
• wherein the compound has a Compound Tan Delta Peak Temperature of at least 10° C.;
• and
• wherein the compound has a Compound Tan Delta Peak Height of (i) at least 0.85, provided that no additional thermoplastic elastomer is present, and (ii) at least 0.60, provided that additional thermoplastic elastomer is present and comprises thermoplastic polyurethane;
• and
• (2) from about 3 to about 10 weight percent of a functional additive to impart lower specific gravity selected from the group consisting of foaming agents which yield closed cell polymer compound structures and blowing agents which yield open cell polymer compound structures.