High-glass-transition-temperature hydrocarbon polymers produced through anionic polymerization of 1,2/1,1-diphenyl-1,3-butadiene and subsequent cyclization

The anionic polymerization of 1,2-diphenyl-1,3-butaidiene and 1,1-diphenyl-1,3-butaidiene is conducted and a heat-resistant hydrocarbon polymer is obtained through subsequent cyclization of precursors. The controllability of polymerization depends on the type of solvent and temperature. When polymerization is conducted in a cyclohexane (CHX)/tetrahydrofuran (THF) solvent at room temperature, 1,2-diphenyl-1,3-butaidiene undergoes anionic polymerization with n-BuLi to quantitatively afford polymers of well-controlled molecular weights and narrow molecular weight distributions. In THF at room temperature, 1,1-diphenyl-1,3-butaidiene undergoes anionic polymerization to high monomer conversion (84 wt %). These Poly(diphenyl-butadiene) precursors are then cyclized in the presence of trifluoromethanesulfonic acid (CF₃SO₃H). The resulting cyclized product reached a high Tg value (approximately 170–233 °C) similar to that of cyclic hydrocarbon polymers such as polycyclohexane (Tg = 231 °C).