Multiblock copolymers of ethylene oxide, with four and five different blocks, were synthesized by the sequential anionic polymerization of styrene, isoprene, 2‐vinyl pyridine, t‐butyl methacrylate, and ethylene oxide with benzyl potassium as an initiator. The monomer sequence was based on the relative nucleophilicity of the active centers. Characterization of the multiblock copolymers by size exclusion chromatography (with refractive‐index and UV detectors), membrane osmometry, and NMR spectroscopy confirmed that benzyl potassium is an efficient initiator for the synthesis of well‐defined multiblock multicomponent copolymers of ethylene oxide. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2166–2170, 2002

This study shows that benzyl potassium is an efficient initiator for the polymerization of ethylenoxide. Well‐defined diblock copolymers and triblock terpolymer of ethylenoxide have been synthesized using this initiator.

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A series of ethylene-norbornene copolymers were synthesized using Me 2 Si(Me 4 Cp)(NtBu)TiCl 2 as the metallocene catalyst and methylaluminoxane (MAO) as the cocatalyst, with the same molecular characteristics except the molecular weight, to evaluate its influence on the determination of the glass transition temperature (T g ). The polymers were characterized using wide-angle X-ray scattering, differential scanning calorimetry, microhardness measurements, and dynamic mechanical thermal analysis. The value of the T g , for the same norbornene content and determined from the last three mentioned methods, increases significantly up to a limit of M n about 6 -10 ϫ 10 4 (g/mol). Above this value, T g remains practically constant.

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