Stabilization of high nitrile polymers. I. Effect of dienophilic compounds

The effect of certain stabilizers on the discoloration of high nitrile polymers is discussed in terms of an in situ Diels-Alder reaction. Dienophiles react with cis azadienes formed during thermal degradation of the nitrile polymer to interrupt conjugated sequences prior to oxidative chromophore formation. Several nondienophilic additives decompose upon heating to release a strong dienophile that stabilizes the polymer.