Eva Dipl Ing Votavova

Reactive polymers : XXXI. Thermally treated polymeric sorbents based on glycidylmethacrylate copolymers

Abstract Heating of polymeric sorbents based on glycidylmethacrylate-ethylenedimethacrylate copolymers to 250–280 °C for short periods in an inert nitrogen atmosphere leads to pronounced morphological changes. The chromatographic properties of sorbents thus treated are mainly characterized by a considerable shortening of the retention times of sorbates. This makes possible rapid chromatographic analyses of mixtures at low working temperatures (as much as 60 °C lower than with Porapak T), which is advantageous for the separation of thermally less stable compounds. The selectivity of separation of polar compounds is also higher for thermally treated copolymers.

Rearrangement of the porous structure of macroporous copolymers

Abstract Changes in the porous structure of the strongly crosslinked macroporous copolymers glycidyl methacrylate-ethylene dimethacrylate and styrene-divinylbenzene were studied. Via interaction with organic solvents (dioxane, methanol) changes are brought about in the specific surface areas and pore volumes, which are interpreted in terms of changes in the microporous and macroporous domains of the porous structure of the polymers. According to mercury porosimetry, there are also changes in pore distribution. The phenomenon has also been observed in microphotographs of polymer sections obtained by electron microscopy and in the sorption of solutes.

Reactive polymers: XL. Study of the internal structure of thermally treated polymeric sorbents based on glycidyl methacrylate copolymers

Abstract A decrease in the specific pore volume and specific surface area and an overall narrowing of the pore distribution are the main changes in the internal structure of thermally treated copolymers based on glycidyl methacrylate-ethylene dimethacrylate. They are also colsely connected with changes in the chromatographic properties of polymeric sorbents thus treated. The decrease in the pore volume may be directly correlated with the decrease in the retention volumes.