THIOLACTONE AND THIOL-ENE ONE-POT POLYMER GRAFTING REACTION ONTO SILICA FOR TUNABLE TEMPERATURE RESPONSIVE CHROMATOGRAPHY

STEVEN MARTENS; FREDERIC LYNEN; ANGEL J. SATTI; TIM VAN HOEYLANDT; PIETER ESPEEL; FILIP E. DU PREZ

Los Cocos

Simposio; XII Simposio Argentino de Polímeros; 2017

Laboratorio de Materiales Poliméricos (LaMaP) del Instituto de Investigación y Desarrollo en Ingeniería y Procesos y Química Aplicada (IPQA), dependiente de la Universidad Nacional de Córdoba (UNC) y del CONICET

Thermoresponsive polymers can be used as stationary phase in liquid chromatography. Thus, the polarity of the stationary phase can be varied by temperature changes, altering the power of separation without changing the column or solvent composition. The separation can also be controlled by the addition of functionalized moieties that enhance hydrophobic interaction, e.g., by reducing the lower critical solution temperature in the system. Therefore, this temperature responsive liquid chromatography (TRLC) has the potential to offer the same generic applicability as in reversed phase LC while avoiding the need of organic solvents providing the solutes are soluble in water. On the other hand, the potential of ?click? chemistry has enjoyed increasing appreciation in terms of reactivity, speed and versatility, when targeting stationary phase modifications for chromatographic purposes via the immobilization of specific macromolecules. Accordingly, this work is focused on a straightforward and efficient functionalization of aminopropylsilica with polymeric structures for the development of temperature responsive stationary phases applicable in purely aqueous liquid chromatography. The immobilization of the thermoresponsive polymers involves a thiolactone-based ring opening using the primary amines in aminopropylsilica, with a simultaneous one-pot, thiol-ene functionalization with an acrylate of choice. By variation of the acrylate for the thiol-ene reaction, different stationary phases can be obtained. Two stationary phases as a result of the modular modification of aminopropylsilica were evaluated with mixtures of hydrophobic analytes, like parabens, steroids and peptides. Analyses using the 5 µm material packed in columns revealed high hydrophobic retention, which proved adaptable as a function of the temperature in aqueous mobile phases. Moreover, the columns depict potential for diastereoisomeric peptide separation. Finally, the lower retention, observed when using PEGylated silica, illustrates the potential of the approach for modular stationary phase tuning [1]