Synthesis and characterization of block copolymers of poly(ethylene oxide) and poly(methyl methacrylate)

Abstract

Anionic polymerization of methyl methacrylate (MMA) was initiated with the disodium salt of poly(ethylene oxide) (PEO) in tetrahydrofuran (THF) in both the presence and absence of a crown ether or cryptate. The resulting block copolymer of poly(methyl methacrylate) (PMMA) and PEO was characterized by 1H- and 13C-NMR spectroscopies, gel-permeation chromatography and solvent extractions. The transesterification reaction between PEO and methoxy group in MMA was accompanied by polymerization, resulting in a PEO grafted triblock copolymer. A benzylamino derivative of PEO (PEO舑N) was prepared as a new initiator system for the polymerization of MMA. The initiation with disodium or dilithium amide of PEO舑N resulted in a linear triblock copolymer of PMMA舑PEO舑PMMA having a unimodal and narrower molecular weight distribution. The stereosequence distributions of the PMMA part in the copolymers were essentially atactic and the addition of the crown ether or the cryptate increased the fraction of the rr triad. © 1980 The Society of Polymer Science, Japan.