Effects of crosslinking agents and inert diluents on the characteristics of crosslinked polystyrene copolymers

Abstract

The suspension copolymerization of styrene with various vinyl crosslinking monomers, that is, dimethacrylates and divinylbenzene, was carried out with poly (vinyl alcohol) as the suspending agent. The effect of the crosslinking monomers on the characteristics of the styrene copolymers was also studied, and the styrene-divinylbenzene copolymers were found to be the most thermally stable. Inert diluents were added during styrene and divinylbenzene copolymerization to achieve porous, crosslinked polystyrene. Furthermore, the influence of the diluents on the formation of porous styrene-divinylbenzene copolymers was investigated by surface area, pore volume, pore diameter, apparent density, swelling percentage, and compressive strength measurements and the surface morphology. It was observed that among the inert diluents studied, cyclohexanol was the most effective diluent, leading to the styrene-divinylbenzene copolymer beads with maximum porosity. A surface morphology study of the polystyrene copolymer beads supported the porosity in these copolymers.

Heterogeneous Structures in the Synthesis of Hydrophobic Lauryl Acrylate-Styrene-Ethylene Glycol Dimethacrylate Copolymer Particles

“…Furthermore, more holes, voids, and microdefects were left with the increasing of 1-octanol. These results are in agreement with the reported literature [17,24].…”

“…Thus, copolymer particles with higher swelling capacity were obtained under high 1-octanol and low EGDMA content [24,37].…”

“…In order to exhibit swellabilities of the particles, swelling ratios of the particles were obtained as follows [24]: Swelling (%) in toluene was measured with a 5 g oven-dried sample in a stoppered test tube. The sample was soaked with 20 mL of toluene for 24 h at the ambient temperature.…”

“…As early as the end of the 1950s, Du s sek [6], Kunin [7,8], and Millar et al [9][10][11] had already discovered this polymerization technique. According to the present reports [12][13][14][15][16][17][18][19][20][21][22][23][24], it was concluded that porous matrices can be obtained by suspension copolymerization, using monovinylic monomers and crosslinking reagents in the presence of inert porogens. These porogens may be extracted after polymerization, leaving holes or pores in the copolymer structures.…”

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

“…In the preparation of the polymer beads, the dispersion of the organic phase in the continuous phase is the determining step in establishing the particle size distribution of the final polymer beads. This is influenced by the geometrical factors of the reactor, operating parameters and substance parameters (type and concentration of stabilizers, viscosities of continuous and dispersed phases, interfacial tension) [31,32]. …”