Synthesis of Weil-Defined Dendrimer-like Branched Polymers and Block Copolymer by the Iterative Approach Involving Coupling Reaction of Living Anionic Polymer and Furictionalization

摘要

The first-,second-,and third-generation dendrimer-like branched poly(methyl methacrylate)s (PMMA)s were synthesized by an iterative divergent approach which involves a coupling reaction of alpha-functionalized living anionic PMMA with chain-end-functionalized PMMA with benzyl bromide moieties and a transformation reaction of the tert-butyldimethylsilyloxymethylpheny groups into benzyl bromide functionalities.The iterative reaction sequence could be repeated three times without problem to afford a series of three generations dendrimer-like branched PMMAs with well-defined architectures and precisely controlled chain lengths.Moreover,an amphiphilic dendrimer-like branched block copolymer was synthesized successfully in a similar manner by using the living anionic polymer of the protected 2-hydroxyethyl methacrylate (HEMA) instead of living anionic PMMA at the final reaction stage.The resulting polymer was made of the inner 1,4,and 8 PMMA segments and the outer 16 poly(HEMA) segments.The solution behaviors were followed by ~1H NMR spectra.The formation of micelles was strongly indicated in both CDCl_3/CD_3OD (98/2,v/v) and CDCl_2/CD_3OD (5/95,v/v) mixtures.