title: Comprehensive triblock copolymer analysis by coupled thermal field-flow fractionation-NMR.
abstract: Thermal field-flow fractionation (ThFFF) is used as a novel fractionation technique to investigate the molecular heterogeneity of PB-b-PVP-b-PtBMA triblock copolymers. Such copolymers cause major problems in liquid chromatography due to very strong polar interactions with the stationary phase. ThFFF separates the copolymers with regard to size and/or chemical composition based on the normal and thermal diffusion coefficients. The separation mechanism in ThFFF and the chemical composition of the separated species is elucidated by online (1) H NMR. Based on the compositional analysis and a calibration of the system with the respective homopolymers, the samples are quantified regarding their molar masses, chemical compositions, and microstructures providing comprehensive information on the complex structure of these block copolymers.
authors.affiliation: Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, 7602 Matieland, South Africa.
authors.forename: Werner
authors.initials: W
authors.lastname: van Aswegen
authors.forename: Wolf
authors.initials: W
authors.lastname: Hiller
authors.forename: Mathias
authors.initials: M
authors.lastname: Hehn
authors.forename: Harald
authors.initials: H
authors.lastname: Pasch
mesh_terms: D002070:Butadienes / Q000737:chemistry / Q000302:isolation & purification*; D005591:Chemical Fractionation / Q000379:methods*; D020724:Elastomers / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D011108:Polymers / Q000032:analysis*; D011109:Polymethacrylic Acids / Q000737:chemistry / Q000302:isolation & purification*; D011145:Polyvinyls / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002070:Butadienes; D020724:Elastomers; D011108:Polymers; D011109:Polymethacrylic Acids; D011145:Polyvinyls; C058671:poly(2-vinylpyridine); C028834:polybutadiene; C068872:polybutyl methacrylate
keywords: NMR; block copolymers; compositional analysis; thermal field-flow fractionation