Synthesis and simple method of estimating macroporosity of methyl methacrylate–divinylbenzene copolymer beads

Abstract

Macroporous methyl methacrylate-divinylbenzene copolymer beads having diameter $ 300 lm were synthesized by free radical suspension copolymerization. The macroporosity was generated by diluting the monomers with inert organic liquid diluents. The macroporosity was varied in the range of $ 0.1 to $ 1.0 mL/g by varying a number of porosity controlling factors, such as the diluents, solvent to nonsolvent mixing ratios when employing a mixture of the two diluents, degree of dilution, and crosslinkage. Increase in pore volume from 0.1 to 0.45 mL/g resulted in a sharp increase in mesopores having diameters in the range of 3-20 nm whereas the macropores remained negligible when compared with mesopores. Increase in pore volume from 0.45 to 1 mL/g resulted in a sharp increase in macropores, whereas mesopores having diameters in the range of 3-20 nm remained almost constant. The mesopores having diameters in the range of 20-50 nm showed an increase with the increase in pore volume throughout the whole range of pore volume studied. Macroporosity characteristics, i.e., pore volume (V m ), surface area (SA), and pore size distributions were evaluated by mercury penetration method. Statistical analysis of the data obtained in the present study shows that the macroporosity characteristics can be estimated with a reasonable accuracy from the pore volumes, which in turn are determined from the densities of the copolymers. These results are explained on the basis of pore formation mechanism.

Study on the synthesis of a macroporous ethylacrylate‐divinylbenzene copolymer, its conversion into a bi‐functional cation exchange resin and applications for extraction of toxic heavy metals from wastewater

“…PV density distributions, which are defined as the linear derivatives of the cumulative PV curves with respect to their pore diameters, show that the pores of all sizes increase with an increase in PV in going from Experiment 2–6 with the exception of Experiment 4. Earlier studies on related porous copolymers conclude that pores of all sizes increase with an increase in PV when crosslinkage is >15% 15, 18. The exception to this general trend in this study, i.e., the copolymer from Experiment 4, had lower crosslinkage (10%) and it shows a significantly lower contribution from pores having diameters <0.03 μm toward the overall porosity.…”

“…Procedures for the synthesis of the copolymer, conversion of the copolymer to ion‐exchange resins, and characterization of the copolymers and the resins were same as reported earlier for similar copolymers 8, 9, 15…”

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

“…To our viewpoint, N 2 sorption analysis stands as the most straightforward method since it gives quite reliable data for surface area, total pore volume and pore size distribution unless the pores are extremely large. We also would like to note that there are reports with equations to calculate several aspects of porosity by using density measurements as the only variable [286][287].…”

Correlations for prediction of specific surface area and bulk and apparent densities of porous styrene‐divinylbenzene copolymers

“…Malik et al proposed correlations for prediction of the pore volume18 and specific surface area19 of the S‐DVB copolymers based on bulk density of the dry copolymer beads. Similar methods were also used for prediction of the pore volume and specific surface area in methylmethacrylate‐ethyleneglycol dimethacrylate,20 methylmethacrylate‐DVB,21 and 4‐vinylpyridine‐DVB22 copolymers. Because the bulk density in these correlations is itself a polymer property, which is a function of reaction conditions, an additional correlation is required for its prediction.…”