Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Summary Aluminum alkoxides carrying functional alkoxy groups are effective initiators for theɛ-caprolactone polymerization in toluene and tetrahydrofuran. The coordination-insertion type of polymerization is living and yields exclusively linear polyesters of a predictable molecular weight with a narrow molecular weight distribution within the period of time required for the total monomer conversion. The functional group associated to the active alkoxy group of the initiator is selectively attached to one chain-end, and the second end-group is systematically a hydroxyl function resulting from the hydrolysis of the living growing site. Asymmetric telechelic polyesters are thus obtained in a perfectly controlled way, including macromonomers. Beside (meth)acrylic double bond, the functional end-group derived from the initiator can be, for instance, an unsaturation, a halogen and a tert-amine. Coupling the asymmetric telechelic polymer via the OH end-group (or the precursor Al alkoxide end-group) is a direct way to the related symmetric telechelic of a twofold increased molecular weight.
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