# A View on the Synthesis and Characterization of Porous Microspheres Containing Pyrrolidone Units
###### Abstract  
Porous materials are used in many important applications, such as separation technologies, catalysis, and chromatography. They may be obtained from various monomers via diverse polymerization techniques and a wide range of synthesis parameters. The study is devoted to the synthesis and characterization of crosslinked porous polymeric spheres containing pyrrolidone subunits. To achieve this goal, two methods were applied: direct synthesis from \(N\)-vinyl-2-pyrrolidone (NVP) with ethylene glycol dimethacrylate (EGDMA) and via a modification reaction of porous poly(glycidyl methacrylate-\(co\)-ethylene glycol dimethacrylate) with pyrrolidone (P). The polymerization was carried out with the use of different molar ratios of the monomers. In order to obtain highly porous materials, pore-forming diluents (toluene, dodecane, and dodecan-1-ol) were used. The synthesized copolymers were characterized using size distribution analysis, ATR-FTIR spectroscopy, scanning electron microscopy, thermogravimetry, and inverse gas chromatography. Determined by the nitrogen adsorption/desorption method, the specific surface area was in the range of 55-468 m\({}^{2}\)/g. The good thermal properties of the poly(VP-\(co\)-EGDMA) copolymers allowed them to be applied as the stationary phase in gas chromatography. polymeric microspheres; porous structure; thermal behavior +
Footnote †: journal: materials  
0000-0002-4000-0000-0000-0000-0000-00000-00000-0000-00000-  
evident, particularly in biotechnological applications where interaction with the aqueous environment is essential. To enhance the effectiveness of porous microspheres, the incorporation of **functional monomers** that can introduce polarity and chemical reactivity into the polymer matrix has become an important approach. One such monomer is **N-vinyl-2-pyrrolidone (NVP)**. It offers both a hydrophilic character and biocompatibility. Its incorporation imparts **pyrrolidone groups** into the resulting copolymer network, which can improve specific interactions with polar molecules. This phenomenon noticeably increases their selectivity and affinity in applications like chromatography, specific sorption, and controlled release [29; 30; 31; 32; 33]. However, the synthesis of porous copolymers containing a high amount of NVP can be a challenge, particularly related to achieving a balance between **monomer incorporation and porous structure development. ** Additionally, its hydrophilic character thereby constrains NVP use in aquatic environments. To overcome this problem, post-polymerization modification can be successfully applied. It offers an alternative and often more precise strategy to tailor the functionality of porous polymers. For instance, glycidyl methacrylate (GMA) is a reactive monomer whose epoxy groups can be chemically transformed post-polymerization [34; 35; 36]. By modifying GMA-based copolymers with pyrrolidone, it is possible to introduce pyrrolidone functionalities on the surface of the copolymer and maintain control over the porous structure [37; 38]. This dual approach--direct copolymerization and chemical modification--enables a comparative assessment of material properties and the optimization of synthesis routes for targeted performance. In this research, we present the synthesis, characterization, and thermal evaluation of novel porous materials bearing pyrrolidone units. Two complementary strategies were employed:  
1. Direct suspension copolymerization of NVP with ethylene glycol dimethacrylate (EGDMA) under varying monomer ratios and diluent systems to explore the influence on morphology, porosity, and thermal stability. 2. Post-polymerization modification of poly(GMA-co-EGDMA) copolymers via reaction with pyrrolidone to evaluate the functionalization efficiency and preservation of the porous architecture.