ANALYSIS OF LOW-MOLECULAR-WEIGHT POLYMERS WITH GEL-PERMEATION CHROMATOGRAPHY

Intrinsic viscosities and gel permeation chromatography (GPC) elution times were determined in toluene on commercially available standards of polystyrene (PSTY) and polymethyl methacrylate (PMMA) having M(n) in the range of 10(3) to 10(5) and 10(4) to 10(6), respectively. In addition, elution times were determined on the discrete GPC peaks of dimer, trimer, tetramer, etc. as seen in lower molecular weight PSTY and PMMA. Intrinsic viscosities of oligomers were estimated by extrapolation of the Mark-Houwind-Sakurada equations determined from our data, and the results were used to establish a universal calibration curve over a wide range of molecular weights. A similar approach was taken by using literature data for the intrinsic viscosities of PSTY and PMMA in tetrahydrofuran. It was verified by proton NMR that the universal calibration curve so constructed is useful at M(n) values as low as 300. No correction was necessary for chain length dependence of the detector response.