VOC-FREE COUPLING AGENTS FOR RUBBER COMPOSITIONS

A coupling agent, a rubber composition, and a shaped article formed from the rubber composition, such as a pneumatic tire, are described. The coupling agent is represented by Formula I, and is capable of linking a substrate, such as a mineral oxide, carbon black or brass, to an unsaturated elastomer: FG1_LG1_Sa_LG2_FG2 (Formula I)where FG1 and FG2 each represent a functionalized arylene group, which can be the same or different; LG1 and LG2 each represent a linking group, which can be the same or different; and Sa represents a sequence of two or more connected sulfur atoms, where a is a number which is at least 2.