Preparation Of PAN-based Copolymer Microporous Membrane By Thermal Phase Separation And Its Properties

Polyacrylonitrile(PAN)membranes has attracted more and more attention due to its superior solvent resistance,chemical stability and biological affinity.It was used in various aspects,such as oil/water separation,heavy metal adsorption and dye removal.Most of PAN membranes are prepared by nonsolvent induced phase separation(NIPS)process due to its special structure.Large amounts of polar solvents are needed in the NIPS method,resulting in the waste of resources and environmental pollution.Compared with the NIPS process,the structures of membrane formed by thermally induced phase separation(TIPS)are easy to be adjusted and the mechanical properties were improved meanwhile.In this work,the melt processable poly(acrylonitrile-co-methyl acrylate)(P(AN-MA))was hydrolyzed firstly and then formed into microporous membrane via thermally induced phase separation.In order to optimize the hydrolysis conditions.A series of hydrolysis experiments were performed to indicate the effects of hydrolysis temperature,alkaline species and time on the structure and properties of the membrane.It was found that with the increase of hydrolysis temperature,pure water flux(PWF)increased firstly and then decreased.When the hydrolysis temperature was set as 30?,the PWF of the H-P(AN-MA)membrane was up to the maximum of 6712.7 L/m2h,the PWF of H-P(AN-MA)membrane was improved 24.7%.When 1 wt%sodium dodecyl sulfate(SDS)was incorporated into the diluents,the PWF increased dramatically,especially at high hydrolysis temperature.Besides,it also showed a better surface structure with good connectivity.When the hydrolysis temperature was up to 70?,the PWF of H-P(AN-MA)membranes containing 1 wt%SDS increased 2.3 times compared to the sample without SDS.When 2 wt%amino functionalized multi walled carbon nanotubes(MWCNTs-NH2)were employed as an additive,the tensile strength was up to 4.55 MPa.With the addition of 1 wt%SDS and 0.5 wt%MWCNTs-NH2,the bovine serum albumin(BSA)rejection increased from 31.2%to 40.9%and porosity came to 72.1%without much more loss in other properties.