CHa) was used as a blowing agent for the production of polymer foams. Thiele and Heuser4 had previously prepared 2, 2'-azo-bis-isobutyronitrile as well as the tetramethyl succinonitrile, the latter by decomposition of the azo compound by heating a suspension of the solid in water or a solution of the azo compound in phenol or amyl alcohol. This product probably resulted from the coupling of the two tertiary radicals produced in the ...