Abstract:
A number of copolymers and subsequently anion-exchange resins were prepared by the reaction of 4 vinylpyridine (4 VP) and divinylbenzene (DVB) by using the technique of suspension polymerization. A mixture of cyclohexanone (CHN) and petroleum ether (Pet. Ether) of various composition was used as a diluent in the polymerization experiments. The resulting copolymers were thoroughly washed and sieved. The required fraction from 45 to 75 urn was saved for its further characterization such as bulk density, pore volume, pore size distribution, capacity and self diffusion coefficient by using ferric chloride complex. The copolymers were converted into anion-exchange resins by their treatment with hydrochloric acid solution to study their properties as resins. The pore volume of the copolymers increases from 0.007 to 2.647 ml/g, 0.130 to 2.599 ml/g and 0.234 to 1.188 ml/g with the increase in pet. ether or decrease in CHN ratio of organic phase with the increase in the amount of diluents as compared to monomers (Fs) and with the decrease in the cross-linking agent, DVB respectively, used in the respective polymerization experiments. The bulk density of the copolymers varies from 0.59 to 0.14 g/ml, 0.43 to 0.09 g/ml and 0.49 to 0.20 g/ml with the % increase in the ratio of pet. ether from zero to 100% as compared to CHN, with the increase in solvent fraction from 0.3 to 0.7 and with the decrease in DVB from 30 to 10% respectively. The relatively larger size pores were observed in the beads of copolymers formed with the increase in the pet. ether contents of the, diluent, increase in the amount of diluents as compared to monomers and also with the decrease in the cross-linking agent. The capacity of 4VP-DVB, anion-exchange resins decreases from 7.0 to 2.6 meq/g with the increase in the cross-linking agent from 10 to 30% whereas it does not change significantly with the change in the composition and the amount of diluent used in the polymerization experiments at a given 20% cross-linking agent. The diffusion coefficient, D determined for the two sets of resins using 59Fe isotope as a tracer. The values of D decreases from 6.65 x 10-7 to 2.17 x 10-7 cm2/sec with the increase in the "1/0 crosslinking agent from 10 to 30%.
Page(s):
41-49
DOI:
DOI not available
Published:
Journal: Proceedings of Pakistan Academy of Sciences, Volume: 32, Issue: 1--4, Year: 1995