Post-polymerization crosslinking of polystyrene solutions followed by sulfonation has been studied for the preparation and characterization of macronet crosslinked sulfonated polystyrene. A bifunctional benzene derivative (1,4-dichloromethyl-2,5-dimethyl benzene) was used as the crosslinking agent for the main crosslinking reaction. Extensive sulfone-type bridging was found to occur during sulfonation. In addition, the ion-exchange resins that were achieved by this process show increased network density at high sulfonating agent molar ratios. Determination of the porosity and the degree of swelling of the polymers in water was also performed in order to demonstrate the effects of the nominal sulfonating agent concentration on network properties.
Посилання на статтю:
Sulfone-type crosslinks in sulfonation of macronet polystyrene backbone / A. G. Theodoropoulos*, V. T. Tsakalos~ and G. N. Valkanas // Polymer. – 1993. – Vol 34. – P. 3905-3910.