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).本研究开展了1,2-二苯基-1,3-丁二烯与1,1-二苯基-1,3-丁二烯的阴离子聚合反应，并通过前驱体的后续环化过程得到耐热烃类聚合物。聚合反应的可控性取决于溶剂种类与反应温度。当在环己烷（cyclohexane, CHX）/四氢呋喃（tetrahydrofuran, THF）混合溶剂中于室温下进行聚合时，1,2-二苯基-1,3-丁二烯可与正丁基锂（n-BuLi）发生阴离子聚合，定量得到分子量可控且分子量分布窄的聚合物。在室温下的四氢呋喃溶剂中，1,1-二苯基-1,3-丁二烯可进行阴离子聚合，单体转化率可达84 wt%。随后，将所得聚（二苯基丁二烯）前驱体置于三氟甲磺酸（trifluoromethanesulfonic acid, CF3SO3H）环境中进行环化反应。得到的环化产物具有较高的玻璃化转变温度（Tg，约170~233 ℃），与聚环己烷（polycyclohexane, Tg=231 ℃）等环烃类聚合物的玻璃化转变温度相近。