SEC Method Development
Polymer samples must be dissolved in the solvent used as the mobile phase. In non-aqueous SEC, solvents that can be used as the mobile phase are limited to those compatible with the stationary phase as well as those that are solvents for the polymer samples. However in special cases, samples can be dissolved in a different solvent from the mobile phase. For example, urea-formaldehyde resin dissolves in both N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO), but DMSO is a much better solvent for the resin than DMF. Therefore, the resin is dissolved in DMSO and the solution injected into a system of polystyrene (PS) gel-stationary phase/DMF mobile phase. The other example is the SEC of isotactic polypropylene (iPP) with cyclohexane as the mobile phase at 70 °C. The sample iPP is insoluble in cyclohexane and is therefore dissolved in decalin at 140 °C and then diluted with hot cyclohexane and kept at about 70 °C prior to injection into the SEC system.
KeywordsIntrinsic Viscosity Solubility Parameter Exclusion Limit Retention Volume Kind Permission
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- 4.DIN 55672–1 Gelpermeationschromatographie (GPC) Teil 1: Tetrahydrofuran (THF) as Elutionsmittel (1995–02)Google Scholar