Synthesis of Hyperbranched Polymers by Anionic Self-Condensing Vinyl Polymerization

摘要: Anionic self-condensing vinyl polymerization is achieved from an in situ creation of a monomer bearing active anion by the reaction equimolar amount 1,3-diisopropenylbenzene (DIPB) and butyllithium THF at 30 °C. Onset intermolecular-equilibrium between isopropenyl groups (α-methylstyrene) isopropenyl-α-methylstyryllithium sites oligomer restricts growth hyperbranched poly-(DIPB) -40 °C, Addition small styrene interrupts this equilibrium. Conversion isopropenyl-a-methylstyryllithium into styryllithium quickly directs consumption concurrent intermolecular-condensation remaining a-methylstyrene oligomers. Thus, equilibrium reestablished it has been shifted to right one or more units that increase molecular weight living polymer. Repeated additions are attended impressive multiplications weights. Up seven generations polymers have synthesized as reported paper, exhibit high broad distributions (1.8 < M w /M n 4). The Mark-Houwink exponent, α, found be 0.38 indicating densely packed three-dimensional structure resulting topology.