1,1-Diphenylethylenes (DPEs) copolymers, as thermoplastic resin alternatives to polystyrene (PS), were synthesized, characterized for their thermal, viscoelastic, and tensile properties, and upcycled using Brønsted-Lowry superacid. By the choice of the vinyl copolymer and selective hydrogenation, the glass transition temperature (Tg) of DPE copolymers varied from 100 to 194 °C, showing a remarkably tunable thermal properties for target applications, i.e., as an alternative to PS or high-temperature use. The Tg’s diene-DPE copolymers are 100 to 120 °C, close to the Tg of PS, and selectively and fully hydrogenated copolymers, poly(butane-alt-diphenylethylene) (Bt-DPE), poly(butane-alt-1,1-dicyclohexylethylene) (Bt-DCHE), displayed similar or better tensile properties to those of PS, respectively. The accelerated degradation of DPE copolymers using triflic acid was documented. The initial chain degradation rates of the DPE copolymers were approximately 10 to 100 times faster than the degradation rate of PS in low-temperature environments, 25 °C and 35 °C. The major products of the superacid-assisted upcycling are benzene, derivatives of benzene and indane, and polyaromatic hydrocarbons (PAHs). Those results demonstrate that DPE copolymers are excellent thermoplastic polymers with tunable physical properties and economically viable upcyclability.
