Methacrylate‐based chromatographic media

Abstract

This review summarizes the preparation and application of chromatographic separation media based on methacrylate monomers with a major focus on highly crosslinked macroporous beads prepared from 2-hydroxyethyl methacrylate and glycidyl methacrylate, respectively. The effects of process variables such as composition of the polymerization mixture that includes monomers, porogenic solvents, and free radical initiator, suspension stabilizer, reaction temperature, and stirring are detailed for both classical and templated suspension polymerization. In addition, specific features of the preparation of monodisperse beads are also discussed. The performance of methacrylate-based separation media is demonstrated on numerous separations in a variety of chromatographic modes.

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…These nuclei agglomerate via inter-nuclei crosslinking and the final bead is formed. In contrast to the previous case, macropores are predominant, resulting in particles with a significantly lower surface area but larger pore volumes [2]. Moreover, suspension polymerization of monomers like vinyl chloride and acrylonitrile yields intrinsically macroporous particles without the addition of an external nonsolvent due to the fact that these monomers cannot dissolve/swell their corresponding polymers [7,14]; this could be referred to as the 'self-porogen' effect.…”

“…Toluene is a thermodynamically good solvent for the polymer, which means that it can readily swell the final crosslinked beads. A good solvent is characterized by a Hildebrand solubility parameter close to that of the polymer [2]. Inside every discrete phase monomer droplet, a continuous network grows by addition of monomer and after a certain time, the network becomes incapable of absorbing more toluene due to an increasing amount of crosslinking.…”

“…The amount of crosslinker is of great importance as it determines the time of precipitation and the extent of porosity. Micro-and mesopores are predominant, resulting in beads with high surface area values but low pore volumes [2]. This type of pore formation is called ν-induced syneresis [1].…”

“…It is important to note that Okubo et al [19][20] reported that the amount and the nature of polymeric porogen may either induce a porous or a nonporous hollow final structure. The pioneers of methacrylate based porous particles, Svec and Horák, reported the differences between the use of a good solvent (toluene), nonsolvent (dodecanol) and a polymeric porogen (polystyrene in toluene, 15%) for the synthesis of a copolymer of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) [2]. In the order of good solvent, nonsolvent and polymeric porogen, the specific surface area decreases below 1 m 2 /g whereas the size of microglobules and total pore volume increase (Fig.…”

“…The closest review on this topic by Okay in 2000 [1] deals more with particle characteristics, explains the methods of production and characterization briefly and lacks discussion about applications. Although in literature there are several reviews for polymer particles (not specifically porous), the older ones [1][2][3] merely cover the conventional methods (suspension, emulsion, dispersion, precipitation, seeded) while the new ones [4][5][6] only focus on the new methods (membrane/microchannel emulsification and microfluidics). To the best of our knowledge, we gathered in this review for the first time all the manufacture methods, including some less known methods.…”