THE STRUCTURE OF A MPEG-b-PLA DIBLOCK COPOLYMERIN ITS SOLID PHASE STUDIED BY SOLID STATE NMR

Abstract

Abstract:

In this work, the structure of a poly(ethylene glycol) methyl ether-b- poly(L-alanine) copolymer (MPEG-b-PLA) in its solid- state was studied by ¹³C CP/MAS, DP/MAS and spin lattice relaxation time T₁ NMR experiments. The results revealed that the PEG blocks are crystallizable in the solid state of the diblock polymer, but the degree of crystallinity is considerably lower in the diblock polymer state than that in pure PEG. It was found that the PLA blocks is rigid not only because of the formation of a large number of α-helices and a small number of β-sheets as secondary structures, but also owing to PLA crystallinity in the solid state. The results also implied that Cβ is more mobile than Cα at room temperature, and the β-methyl group rotates freely around its axis.

Key words: NMR, solid-state NMR, MPEG-b-PLA, block copolymer

CLC Number:

O482.53

WU Guo-lin, SUN Ping-chuan, ZHANG Guo-lin, MA Jian-biao*. THE STRUCTURE OF A MPEG-b-PLA DIBLOCK COPOLYMERIN ITS SOLID PHASE STUDIED BY SOLID STATE NMR[J]. Chinese Journal of Magnetic Resonance.

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