In　this　study,　Polyvinyl　alcohol　(PVA)　blended　with　Polyethylene　glycol　(PEG),　Monosodium　glutamate　(MSG)　and　Glutamic　acid　(GA)　was　cast　on　a　reverse　osmosis　membrane　to　form　a　composite　membrane.　It　is　expected　that　the　ether　group　can　increase　the　CO2　affinity　of　the　membrane.　Sodium　tetraborate　(Borax)　as　a　crosslinker　can　increase　membrane　basicity　and　glutamic　acid　(salt)　can　provide　an　enhanced　transport　mechanism,　thereby　improving　the　permeability　and　selectivity　of　carbon　dioxide.　FTIR　spectra　show　that　the　thickness　of　coating　is　sufficiently　low,　while　SEM　results　show　that　PVA-PEG　series　have　a　dense　surface,　and　particles　are　observed　on　the　surface　of　MSG/GA　series.　The　gas　permeance　and　separation　performance　of　the　composite　membrane　was　tested　using　a　single　gas.　Results　showed　that　CO2　had　higher　permeance　(GPU)　at　lower　pressure　differential.　PEG　with　an　ether　group　had　the　greatest　effect　on　improving　CO2　permeance　and　selectivity.　However,　MSG　and　GA　with　amine　groups　could　not　effectively　improve　CO2　selectivity　due　to　solubility.　The　best　coating　solution　was　provided　by　PVA-PEG-1.2.　The　CO2　selectivity　of　the　composite　membrane　was　10.05　with　a　pressure　differential　of　1.00　bar　in　a　humid　environment　and　no　obvious　deterioration　was　observed　over　a　10-day　period.　Borax　can　improve　selectivity,　water　absorption,　and　thermal　stability　while　avoiding　the　need　for　high　temperature　and　long　crosslinking　time　of　aldehydes,　which　makes　it　possible　to　be　used　in　a　PVA　carbon　dioxide　separation　membrane.