Enhancement of Thermal Stability and Selectivity by Introducing Aminotriazine Comonomer to Poly(Octadecyl Acrylate)-Grafted Silica as Chromatography Matrix

Abstract

This paper introduces a poly(octadecyl acrylate) (pODA)-based organic phase on silica, which is assisted by 2-vinyl-4,6-diamino-1,3,5-triazine (AT), for a chromatography stationary phase. The ODA-AT copolymer grafting onto silica surface was characterized by elemental analysis, FT-IR spectroscopy, scanning electron microscopy, thermo gravimetric analysis and differential scanning calorimeter (DSC). An endothermic peak top of the copolymer-grafted silica was increased to 46 °C from 38 °C, which was a peak top of pODA homopolymer. For high performance liquid chromatography (HPLC) application, the molecular selectivity increased with an increase in the AT contents of the ODA-AT copolymer as organic phase. The co-existence of an aminotriazine moiety in the copolymer promoted side-chain ordering of the poly(octadecyl) moiety, thus enhancing molecular planarity selectivity for PAHs in reversed-phase liquid chromatography.

Keywords

• organic-inorganic hybrid
• molecular shape selectivity
• crystalline-to-isotropic phase transition
• HPLC