A streocomplex membrane of isotactic and syndiotactic PMMA was prepared by mixing isotactic and syndiotactic resins synthesized separately at different conditions.
The isotactic PMMA was polymerized anionically with Grignard reagent at -30℃ and the syndiotactic PMMA was polymerized radically in bulk by thermal and photochemical initiation at -50,0,25,80℃.
The tacticity was measured by 60MHz NMR and the molecular weight was measured by viscometry in chloroform solution at 25℃.
Dope solution was formed by dissolving two tactic PMMAs in DMSO, which showed the thermoreversible sol-gel phase transition phenomenon.
The gel melting behavior was observed by DSC to see the effects of the tacticity, polymer concentration in the dope the tactic polymer ratio (isotactic/syndiotactic), and the molecular weight.
The time and temperature dependence of the gelation process was also observed and the gelation kinetic equation was obtained in Avrami form.
The effects of the same process parameters on the membranological properties were also observed from the dialysis and ultrafiltration test.
The water permeabilitydecreased as the degree of stereocomplex was increased but the solute permeability did not show any dependence on the streocomplex formation.
Therefore, PMMA membranes which had the same solute permeabilities could be made to have different permeabilities.
The PMMA membranes showed higher water permeabilities than the cellulose membranes because of its hydrophobicity although both membranes showed similar urea permeabilities.
They showed higher solute permeabilities of the middle molecular weight substances, which is a good advantage in the biomedical application.
