SEC-NMR coupling

Polymers with well-defined chemical structures are a prerequisite for direct determinations of molecular weight distributions (MWDs) [1-3]. Ute and coworkers [6] have used on-line SEC-NMR coupling to determine the molecular weight distribution in isotactic poly(methyl methacrylate) (PMMA) samples. [Pg.305]

Keywords Crystallization analysis fractionation Field Flow Fractionation High performance liquid chromatography Hyphenated techniques Liquid chromatography Polyolefin analysis SEC-NMR coupling Size exclusion chromatography Temperature rising elution fractionation Two-dimensional liquid chromatography... [Pg.78]

Nuclear magnetic resonance (NMR) (see Chapter 10) Although stopped flow and online results have been published, SEC-NMR coupling is still not a standard technique [2]. The use of deuterated solvents or the need to suppress the intense solvent signals by special NMR pulse sequences has limited the applicability. An additional problem is the low sensitivity of NMR in combination with the low concentrations used in SEC. [Pg.184]