Die Makromolekulare Chemie · 1986 · 124 citations · 9 references
Natural SciencesChemical EngineeringChemistryOrganic ChemistryPolymer ChemistryPolymer EngineeringPolymer CharacterizationPolymer SynthesisPolymerization ChemistryPolymerization KineticsPolymerization ProcessesRing-opening PolymerizationAnionic Ring-opening PolymerizationBimodal DistributionBimodal Molecular Weight DistributionsControlled Polymerization KineticsOptimum TemperatureRing-chain EquilibriumTemperature OptimumViscosity
Abstract The anionic ring‐opening polymerization of 2,2‐dimethyltrimethylene carbonate in solution with sec ‐butyllithium as initiator was found to result under suitable conditions in a bimodal molecular weight distribution, vic. cyclic oligomers and a high‐molecular‐weight polymer. The concentration of cyclic oligomers approaches that of a ring chain equilibrium. In the kinetically controlled regime high polymer yields were obtained. Optimum reaction conditions for a polymer yield of 85 – 95% are a temperature of −10°C, an initial monomer concentration of 10 weight‐% and toluene as solvent. In THF the ring chain equilibrium is achieved readily. The ceiling temperature was determined to be ≈ 30°C. The homopolymer was characterized by spectroscopic, thermoanalytical and viscosity measurements. A high degree of crystallinity was observed.
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