THERMALLY REVERSIBLE POLYMERIC SORBENTS FOR ACID GASES .4. AFFINITY TUNING FOR THE SELECTIVE DRY SORPTION OF NOX

We have found that amino-functional polymers absorb and readily bind n itrogen oxides (NOx) namely NO2 and NO. Our previous results showed th at the reaction of NOx with polymer-grafted primary and secondary amin es yielded stable products, subsequently identified as nitrite and nit rosamine derivatives, which cannot be thermally degraded to regenerate the original amino-polymer and thereby release the absorbed NOx. Cons equently, we have prepared and evaluated polymers carrying pendant ste rically hindered tertiary amines with the proper electron donor-accept or properties to bind specifically NOx. The results of thermogravimetr ic analysis experiments showed that dipropylamine-functional polymers absorb and bind NO2 effectively and reversibly while they remain almos t/ completely inert when exposed to relatively weaker acid gases such as SO2 or CO2.