Premium
Chemical heterogeneity analysis of high‐conversion poly[styrene‐ co ‐(ethyl acrylate)]s by NMR and on‐line coupled SEC‐NMR
Author(s) -
Krämer Inge,
Pasch Harald,
Händel Heidrun,
Albert Klaus
Publication year - 1999
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19990701)200:7<1734::aid-macp1734>3.0.co;2-l
Subject(s) - ethyl acrylate , copolymer , styrene , molar mass , polymer chemistry , acrylate , proton nmr , chemistry , butyl acrylate , materials science , carbon 13 nmr , organic chemistry , polymer
Copolymers of styrene and ethyl acrylate are prepared by radical polymerization and analysed with respect to microstructure by means of nuclear magnetic resonance. Using 13 C NMR, the compositional styrene‐ and ethyl acrylate‐centered triads can be determined and compared to theoretical values. Good agreement between experimental and calculated triad concentrations are obtained for styrene‐rich copolymers. Ethyl acrylate‐rich copolymers exhibit significant deviations from the calculated values in particular for the ethyl acrylate homotriads. Using on‐line coupled SEC‐ 1 H NMR, the chemical composition across the molar mass axis can be monitored. It is found that ethyl acrylate‐rich copolymers exhibit a broader molar mass and chemical composition distribution than styrene‐rich copolymers. The results indicate that the block character of the copolymers with respect to ethyl acrylate units increases with increasing molar mass.