High sulfur content copolymers were prepared via the inverse vulcanization of elemental sulfur with styrene. This reaction was carried out at a relatively low temperature and invokes a new chain transfer mechanism of abstraction of benzylic protons to form stable copolymers. The use of styrene as a comonomer for inverse vulcanization was attractive due to the low cost and wide spread industrial use of styrenics in free radical processes. The copolymers were used as the active cathode material in Li-S batteries that exhibited outstanding device performance, maintaining 489 mAh/g capacity after 1000 cycles. (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 107-116