Preparation and Porosity Characterization of Highly Cross-Linked Polymer Resins Derived from Multifunctional (Meth)acrylate Monomers

Abstract

Permanently porous polymer resins derived from multifunctional (meth)acrylate monomers have been prepared by suspension polymerization. The dry state porosity characteristics have been evaluated using N2 sorption and Hg intrusion porosimetry, and the results correlated in terms of the three-dimensional cohesion parameter, δ t , of the polymers and porogens. The pore size distributions of almost all resins cover a broad range from micro- through meso- to macropores. The porosity data had to be computed from the adsorption branches of the N2 sorption isotherms, since an artifact arises in the pore size distributions if derived from the corresponding desorption data. The artifact is attributed to a percolation process in the desorption mechanism. The correlation of porosity data (e.g., the Brunauer, Emmett, and Teller (BET) surface area and the Barret, Joyner, and Halenda (BJH) average pore radius) with the nature of the porogen was found to be very limited if the one-dimensional Hildebrand solubility parameter, δ, only is used. However, by application of a group contribution method due to Hoftyzer−Van Krevelen and Hoy, three-dimensional cohesion parameters, δ t , and the porogen−polymer affinity parameters, d 0, could be calculated. Using the latter as the basis for a new correlation the N2 sorption BET computed surface areas of resins show an inverse proportional relationship with d 0, while BJH average pore radii show a proportional relationship.

The release of ibuprofen sodium salt from permanently porous poly(hydroxyethyl methacrylate-co-trimethylolpropane trimethacrylate) resins

“…Similar findings were presented before for permanently porous polymer resins derived from multifunctional (meth)acrylate monomers [2,14]. Flodin and co-workers have noted that the size of smaller pores of diameter about 4 nm (determined from N 2 sorption data) is independent both of TRIM and initiator concentrations, while the size of large pores (probed via Hg intrusion) is clearly dependent on monomer concentration.…”

“…In conclusion, they stated that the type of the used solvent as well as the monomer to the solvent ratio are the most important factors, since they affect the pore structure [14]. On the other hand, according Sherrington et al the pore size distributions of almost all TRIM-based resins cover a broad range from micro-through meso-to macropores [2]. Notwithstanding, the BJH pore size distributions calculated from the desorption branch of the isotherm always exhibit a sharp, often large maximum in the PSD curve.…”

Thiol-ene and thiol-yne chemistry in microfluidics: a straightforward method towards macroporous and nonporous functional polymer beads

“…The effect of porogen on the morphology of beads has been well studied in the literature for free radical copolymerization of vinyl monomers. 33,56,57 In the former section, it has already been shown that the nature of the porogen is also important for beads derived from thiol-ene formulations ( Figure 4). The output is of interest where xylene is used as the sole porogen or mixed with nbutyl acetate ( Figure 7) instead of using pure n-butyl acetate for the thiol-yne formulations given in Figure 5.…”

Batch and column separation characteristics of copper-imprinted porous polymer micro-beads synthesized by a direct imprinting method

“…The Cu(II)-containing polymer beads were collected after washing in an acetone:water (1:1) solution four times and dried in vacuo for 1 day. The Cu(II)-imprinted polymer beads were obtained after removal of the copper ions in solution using aqueous 1.0 M HNO 3 with vigorous agitation [22]. The non-imprinted polymer was also prepared for comparison in chemical structure, except without use of the Cu 2+ solution.…”