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Determination of molar mass distributions of poly(methacrylates) in the analytical ultracentrifuge with schlieren and UV optics
Author(s) -
Ortlepp Bernhard,
Panke Dietrich
Publication year - 1992
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19920610114
Subject(s) - molar mass , polymer , methacrylate , analytical chemistry (journal) , size exclusion chromatography , materials science , schlieren , light scattering , optics , chemistry , chromatography , scattering , composite material , physics , organic chemistry , copolymer , enzyme
The significance of the analytical ultracentrifuge (AUC) for industrial research has not decreased during the last decades and seems to be growing. The AUC is used for the development and for controlling the production of emulsion polymers (via measurement of particle size distributions) as well as for the determination of molar masses and molar mass distributions of polymers which cause difficulties with conventional methods like light scattering or size exclusion chromatography. In order to speed up the principally very time‐consuming AUC measurements, our machines were equipped with multiplexers for multiple place rotors and with video systems for digital recording and processing of the schlieren images. Furthermore for measurements with the UV scanner the optical system had to be considerably improved in order to assess wavelengths down to 210 nm because of the unfavourable UV absorption of the poly(methacrylates). The experimental methods and the data evaluation will be explained and discussed using a very high‐molecular‐weight poly(methylmethacrylate) and a cationic polyelectrolyte, viz. poly(trimethylammoniumethylmethacrylate hydrochloride), as examples.