On-line monitoring of reaction temperatures during anionic polymerization of poly(styrene-b-methyl methacrylate) and poly(styrene-b-2-vinyl pyridine) with a 1,1-diphenylhexyl lithium initiator in THF

Poly(styrene-b-methyl methacrylate) and poly(styrene-b-2-vinyl pyridine) block copolymers with narrow molecular weight distributions (1.05≤MWD≤1.17) were achieved via a pre-cooled monomer addition method using a diphenyl hexyl lithium initiator in tetrahydrofuran under sequential isothermal conditions. The styrene block was polymerized at −25 and −15 °C, and the second block copolymerization of PS-b-PMMA and PS-b-P2VP was carried out at −78 °C. A module-type reactor system was constructed under an inert atmosphere, which could monitor the temperature and torque during polymerization. Monomers for the second block were cooled and maintained at approximately −30 °C to control the exothermic reaction temperatures while being added to the reactor. The exothermic reaction temperature could be minimized (ΔTRMAX ≤+11 °C) by the addition of the pre-cooled monomer.