We have found that amino-functional polymers absorb and readily bind nitrogen oxides (NOx) namely NO2 and NO. Our previous results showed that the reaction of NOx with polymer-grafted primary and secondary amines yielded stable products, subsequently identified as nitrite and nitrosamine derivatives, which cannot be thermally degraded to regenerate the original amino-polymer and thereby release the absorbed NOx. Consequently, we have prepared and evaluated polymers carrying pendant sterically hindered tertiary amines with the proper electron donor-acceptor properties to bind specifically NOx. The results of thermogravimetric analysis experiments showed that dipropylamine-functional polymers absorb and bind NO2 effectively and reversibly while they remain almost/ completely inert when exposed to relatively weaker acid gases such as SO2 or CO2.