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Journal of Analytical & Bioanalytical Techniques | ISSN: 2155-9872 | Volume 9
World HPLC, Separation Techniques & Pharmacovigilance
World Analytical Chemistry & Mass Spectrometry
18th International Conference on
August 29-30, 2018 | Toronto, Canada
&
Molecular characterization of synthetic polymers with help of liquid chromatography
The most important tool for molecular characterization of synthetic polymers is High-performance liquid chromatographic
(HPLC) methods. Mean molar mass (MM) and molar mass distribution (MMD) of linear and branched homopolymers
is easily determined by gel permeation (size exclusion) chromatography (GPC/SEC). GPC/SEC provides several other useful
data such as limiting viscosity numbers, constants of viscosity law, sizes of macromolecules in solution - and even extent of
preferential solvation of polymers in mixed solvents. Recent progress in GPC/SEC comprises improved instrumental hardware
and data processing procedures. High sample throughput of the ultra-fast GPC/SEC enables acceleration of analyses, which
is especially important in combinatorial material chemistry and in production control. Still, further improvements of the SEC
method are needed, which include its hardware, especially columns and detectors, standardization of sample preparation,
measurement and data processing. GPC/SEC exhibits excellent intra-laboratory repeatability, which evokes a notion of its
high reliability. Recent series of the round robin tests, however, revealed surprisingly poor inter-laboratory reproducibility
of results. Evidently, an accuracy of many GPC/SEC results may be rather limited. In most cases, GPC/SEC does not enable
precise molecular characterization of complex polymer systems, which possess more than one distribution in their molecular
characteristics. Typically, polymer mixtures, copolymers and functional polymers exhibit beside MMD also distribution in their
chemical structure. To assess the above distributions, new HPLC procedures are developed. These are based on the controlled
combinations of entropic (exclusion) and enthalpic (interaction) retention mechanisms within one column or in a series of
independent separation systems. These approaches are denoted “coupled polymer HPLC” and “two- or multi-dimensional
polymer HPLC”, respectively. Enthalpic retention mechanisms in HPLC of synthetic polymers include adsorption, partition,
phase separation. We shall review recent progress and problems in GPC/SEC, as well as in the couple and two-dimensional
polymer HPLC procedures and outline anticipated future development.
Biography
Dusan Berek is employed at Polymer Institute, Slovak Academy of Sciences in Bratislava. Served as elected member of the Presidium of the Slovak Academy
of Sciences, President of the Slovak Chemical Society, Chairman of the Czecho-Slovak and Slovak National Committee of Chemistry for IUPAC. Corresponding
member of the Central European Academy of Sciences and member of the Learned Society of the Slovak Academy of Sciences. Author or co-author of two
monographs and 300+ scientific papers in extenso published in refereed periodicals, proceedings and chapters of books, as well as 60+ patents (four of them were
licensed) - cited more than 3,000x. Presented over 130 invited plenary, key and main lectures, as well as over 900 regular lectures and poster contributions on
symposia and conferences, as well as during lecturing tours to over fourty countries. Elected "Slovak scientist of the year 1999" and "Slovak innovator of the year
2002".
Dusan Berek
Polymer Institute of the Slovak Academy of Science, Slovakia
Dusan Berek, J Anal Bioanal Tech 2018, Volume 9
DOI: 10.4172/2155-9872-C1-026