Sophia, HalidaRadiman, Cynthia L2014-05-212014-05-212014-05-21978-602-18936-0-9wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/6269Polysulfone is one of the polymers frequently used in membrane preparation. Plysulfone membranes prepared by phase method shows a low mechanical strength when used in high pressure or self-supporting membranes. In order to improve the mechanical strength of membranes, dioctyl phthalate (DOP) was used as plasticizer. In his research, the membrane composition used were 18 % polysulfone (PSf),64 % dimetylacetamide and varied concentration of polyethyleneglycol (PEG) and dioctyl phthalate. The characterization included mechanical properties, hidrofility and morphology membranes. The showed that the presence of DOP in the membrane affected the membrane mechanical properties ; the optimum strength was 6.16 GPa Hidrofility Polysulfone membranes decrease. The morphology analysis by Scanning Electron Microscopy (SEM) showed the typical asymmetric structure where membranes skins had tiny pores and macro void structure in sub layer membraneenmembranepolisulfoneplasticizerdioctyl phthalateUR-Proceedings