Peculiar effect of acylamino and cyan groups on thermal behavior of 2-(1-cyano-1-methylethyl)azocarboxamide

Abstract 2-(1-Cyano-1-methylethyl)azocarboxamide (CABN) is a representative of new-type azo initiator in the radical polymerization industry. The peculiar water and oil soluble characters make it a versatile rising star for the industry to initiate the polymerization of monomers in either polar or nonpolar solvents based continuous phases. This paper decodes the effect of acylamino and cyan groups on thermal stability and hazards of CABN via advanced thermokinetic analysis and numerical simulation. Initially, simultaneous thermogravimetric analyzer was employed to evaluate the thermal stability of CABN and its two structurally similar azo compounds (azos), azobisisobutyronitrile (AIBN) and azodicarbonamide (AC). Followed with calorimetric experiments by differential scanning calorimetry, the effect of two functional groups on thermal behavior parameters, such as decomposition temperature, melting point, and heat of decomposition was estimated. The results indicated that the acylamino group can improve the thermal stability of CABN but with bulkier heat release. Ultimately, through the medium of thermokinetic analysis, the thermal hazard of AIBN, CABN, and AC was simulated based on auto-ignition and thermal explosion theory. The research results would provide references for the synthesis of new-type azo initiators and process safety parameters to the polymerization industry.