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Analytical techniques for polymers with complex architectures
Author(s) -
Pasch Harold
Publication year - 2002
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200202)178:1<25::aid-masy25>3.0.co;2-n
Subject(s) - molar mass , polymer , molar mass distribution , adsorption , copolymer , size exclusion chromatography , mass spectrometry , chemistry , chemical composition , characterization (materials science) , materials science , chemical structure , chromatography , nanotechnology , organic chemistry , enzyme
Complex polymers are distributed in more than one direction of molecular heterogeneity. In addition to the molar mass distribution, they are frequently distributed with respect to chemical composition, functionality, and molecular architecture. For the characterization of the different types of molecular heterogeneity it is necessary to use a wide range of analytical techniques. Preferably, these techniques should be selective towards a specific type of heterogeneity. The combination of two selective analytical techniques is assumed to yield a two‐dimensional information on the molecular heterogeneity. For the analysis of complex polymers different liquid chromatographic techniques have been developed, including size exclusion chromatography (SEC) separating with respect to hydrodynamic volume, and liquid adsorption chromatography (LAC) which is used to separate according to chemical composition. Liquid chromatography at the critical point of adsorption (LC‐CC) has been shown to be a versatile method for the determination of the functionality type distribution of macromonomers, the molecular architecture of homopolymers and the chemical heterogeneity of block and graft copolymers. The present paper presents the principle ideas of combining different analytical techniques in multidimensional analysis schemes for the analysis of polymers with complex architectures. Branched block and graft copolymers can efficiently be analyzed with respect to chemical composition and molar mass by LC‐CC and two‐dimensional chromatography. The chemical heterogeneity as a function of molar mass can be determined by combining interaction chromatography and FTIR spectroscopy. For the analysis of star‐like polymers LC‐CC is shown to be a powerful technique when the molar mass of different segments (blocks, grafts) must be determined.