Swelling of porous copolymers based on alkyl methacrylate esters in water

Abstract

Porous copolymers based on alkyl methacrylate esters (AMA) were prepared in the presence of toluene as the inert diluent, and their swelling properties in water were investigated by measuring the water uptake of the copolymers with or without being pretreated with methanol. With ethylene glycol dimethacrylate (EGDM) being used as the crosslinking agent, the obtained AMA/EGDM copolymers, regardless of their inherent hydrophobic nature, were found to be able to swell in water directly. The swelling was negligible in the lower degree of crosslinking region. However, once it increased to a value beyond a certain EGDM percentage, the swelling transition occurred, and the water uptake, which was measured by direct contact of the copolymers with water for all three kinds of AMA/EGDM copolymers based on methyl MA (MMA), ethyl MA (EMA), and butyl MA (BMA), reached very high values. The direct swelling of highly crosslinked AMA/EGDM copolymers in water was very fast at the beginning of the swelling with the swelling rate order of MMA/EGDM > EMA/EGDM > BMA/EGDM, but thereafter it progressed very slowly with most swelling being achieved. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 250–258, 2000

Water‐swellable hydrophobic porous copolymer resins based on divinylbenzene and acrylonitrile. II. Pore structure and adsorption behavior

“…Copolymer resins were prepared, as described in the previous paper,1 by using purified DVB (98.8%) or technical DVB (79.3%), through a usual suspension copolymerization method 8, 9. For all resin samples the contents of DVB and AN in the starting reaction mixture are expressed as a mole percentage of the total amount of monomers.…”

Water‐swellable hydrophobic porous copolymer resins based on divinylbenzene and acrylonitrile. I. Water‐swelling behavior

“…However, the result in Figure 1 or Table I is contrary to the predictions based on these factors. In a previous paper,1 on the basis of the facts observed by us,1, 4–6 and reported by other authors,18–20 the driving forces for the swelling of the MA/DVB resins in water were considered to originate from the inner stresses in the strained polymer network and the weak interaction between polymer and water, which were, respectively, related to the rigidity and the formation history of the polymer network and the polymer polarity of the resins. We think these discussions are applicable to the explanation of the water‐swelling behavior of the AN/DVB resins presented in Figure 1 and Table I.…”

“…Copolymer resins were prepared by using purified DVB (98.8%) or technical DVB (79.3%), through a usual suspension copolymerization method 4, 5. DCE and other pure or mixed solvents were used as porogen for the preparation.…”

Water‐swelling behavior of hydrophobic porous copolymer resins composed of two kinds of crosslinkers

“…The apparent density ( d a , g/mL) and true density ( d t , g/mL) of the resins were measured according to the methods previously described,6, 8 from which the pore volume V p (mL/g) was calculated using the following equation: The solvent (toluene or water) uptake (mL/g) was measured by a centrifuge method, with a relative error of 3% or less for samples where the value of solvent uptake was above 0.3 mL/g 6, 9. For the swelling experiments in water, all the values of water uptake V w were measured by direct contact of the resin sample with water (direct swelling).…”