wizyta

od 2020-09-20

Title: Nuclear magnetic resonance studies of molecular dynamics of beta-propiolactone homopolymer and its block copolymer with beta-butyrolactone

Source: Polymer

Year : 1989

Abstract:

Broad-line and pulse nuclear magnetic resonance (n.m.r.) investigations of β-propiolactone homopolymer and its block copolymer with β-butyrolactone are reported. Proton n.m.r. spectra and T1 and T1ϱ relaxation times studied in the temperature range from 113 K to the melting points are interpreted in terms of molecular motions and phase structure of the polymers investigated. Two regions with different mobilities in the amorphous phase of the block polymer have been found. The observed decrease of the second moment as well as the T1 and T1ϱ minima indicate the existence of molecular motions in the amorphous phase of both polymers far below their melting points. Rotation of methyl groups in the block polymer has been established.

DOI: 10.1016/0032-3861(89)90024-4   (Pobrane:  aktualizowanie)