COMPOSITIONS CONTAINING STYRENE-ISOBUTYLENE-STYRENE AND STYRENE-ETHYLENE/BUTYLENE-STYRENE BLOCK COPOLYMERS

摘要

The present invention provides for a composition that includes a hydrogenated styrenic block copolymer that has at least one block A and at least one block B, and about 10 to about 90 percent by weight of an styrene-isobutylene-styrene block copolymer. Each A is an monoalkenyl arene and each B block is a controlled distribution copolymer of at least one mono alkenyl arene and at least one conjugated diene, having the general formula A-EB/A-A and (A-EB/A)nX. Each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units. Oil-free compositions that result in the combination of low gaseous permeability, low thermal conductivity, strong vibration and sound attenuation, and optionally high levels of light transmission with relatively low haze values while maintaining melt flow rates suitable for easy processability are preferred.