Synthesis And Characterization of Diaminomaleonitrile Functionalized Polystyrene Grafts and Heterocyclic Crosslinked Polymer Membrane of MicroporosityAuthor(s): H.H.Abdel-Razik
Polystyrene (PS) was grafted in water with diaminomaleonitrile (DAMN) using azobisisobutyronitrile (AIBN) as an initiator. Variations of percentage grafting with time, temperature, monomer, initiator concentration and type of solvent were studied. It was observed that the percentage of grafting and grafting efficiency increased as time and temperature rose up to a certain value, and then they leveled off. The percentage of grafting was found to rise with increasing monomer and initiator concentrations, and then decrease. Optimum conditions for grafting were found to be maleonitrile=0.5 M, [AIBN]=1.5×10-3 M, T = 80ºC and t=4h. The effect of the degree of grafting on the swelling of the PS graft membranes was also established. The structure properties of all membranes were investigated by contact angle measurements. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry (DSC) and thermal gravimetric analysis. Crosslinked PS graft membrane with degree of grafting up to 87% was found to be useful for pervaporation separation of phenol/water mixtures.