Deformation Behavior of Polymer Membrane used for Water Purification

Abstract

This study investigated the tensile deformation behavior of porous polymer membranes (polytetrafluoroethylene; PTFE and Polyvinylidene difluoride; PVDF), which are used for water purification. The membranes have micron and sub-micron pores with open-cell structure. The surface and cross section of the membranes was observed by FESEM to carefully investigate the microstructure (cellular structure). Uni-axial tensile tests were carried out, and it is found that the membranes underwent elastic deformation and plastic deformation. To investigate microscopic deformation behavior, in-situ observation during tensile deformation was conducted using SEM. Based on this observation, we discussed the mechanism of elasto-plastic deformation behavior of polymer membrane. In order to establish a mechanical model for such a deformation behavior, finite element method (FEM) was employed. In this FEM model, random pore structure was created to mimic open-cell structure of the present membrane, and we discuss the deformation behavior of membrane.