An analysis of the accuracy of determining molar-mass averages of polymers by GPC with an on-line light-scattering detector

✍ Scribed by Ondřej Procházka; Pavel Kratochvíl

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 544 KB
• Volume: 34
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1987.070340622

✦ Synopsis

The dect of ermra of concentration and-molar-mass detectora in GPC on the accuracy of determining molar-mass averages a,, and M , was analyzed. Model calculations show &at by means of GPC with an on-line low-angle 1 -light-scattering (LALLS) photometer only M , can be detennined with acceptable accuracy. M , --b e determined with acceptable accuracy only for poiymem that have very small polydispersities. M , can be determined with greater accuracy from data of a concentration detector and ematographic-column-calibration data. The most suitable procedure for the determination of M , seems to be a direct integration of the molar-mass detector output, even if the error due to neglecting the second virial coefficient term is sigdcant. Compared with the inaccuracy of detectors, axial dispersion appears not to be the main source of errom in GPC with an on-line molar-mase detector.