ThisisthefirstreportofgastransportpropertiesofpolymerElvaloy4170.Elvaloy4170isacommerciallyavailablepolymer,whichhasverylowpriceandgoodmechanicalproperties.Inthiswork,mixedmatrixmembranes(MMMs)werefabricatedbyembeddingthemulti-walledcarbonnanotubes(MWNTs)intoEl-valoy4170.Additionally,theeffectsoffunctionalizationofthenanotubeswithacidtreatmentandtheirloadingswereevaluatedonmorphologyandgaspermeationpropertiesofthemembranes.ThefabricatedmembraneswerecharacterizedbyRamanspectroscopy,fieldemissionscanningelectronmicroscopy(FESEM)anddifferentialscanningcalorimeter(DSC).Moreover,theeffectsoffillerloadingandfeedpressure(from2to6bar)onCO2/CH4transportpropertieswereconsideredinpuregasexperiment.ThegaspermeabilityresultsofElvaloy4170membranerevealedthatwithincreasingthepressurefrom2to6bar,CO2permeabilityandCO2/CH4selectivityincreased30%and14%,respectively.Furthermore,comparedtoneatmembrane,theMMMwith1wt.%off-MWNTsincreasedCO2andCH4permeabilitiesby30%and40%,respectively.Inaddi-tion,itwasfoundthattheCO2/CH4selectivityincreasedasthecontentoff-MWNTsincreasedfrom1wt.%to4wt.%inthepolymermatrix.Finally,thisstudyrevealsthatmembranesfabricatedfromcommercialpolymerElvaloy4170werepermeableandhavethegreatpotentialtobeappliedforothergasseparationmembraneapplications.Besides,duetotheconsiderablereactivityoftheepoxidegroupofElvaloy4170,ittendstotakepartinchemicalreactionsandformcovalentbondwithfunctionalizedgroupstoconstructmoreefficientMMMs.