Reactive Trapping of 3,3'-Dichlorobenzidine Decomposition Products in Polyethylene-Based Diarylide Pigment Concentrates

摘要

Concerns over the thermal decomposition products of diarylide pigments in polyethylene matrices have severely limited the use this versatile and cost-effective pigment family in many colorant applications. A strategy for the reactive trapping of 3,3'-Dichlorobenzidine, a potential human carcinogen formed during the high temperature processing of polyethylene concentrates, is discussed. Chemical trapping tests made using maleic anhydride modified polymer additives showed favorable reactivity towards 3,3'-DCB in model systems. The results of laboratory screening trials with Pigment Yellow 13 and Pigment Yellow 83 are also reported. The apparent complexity of the diarylide pigment decomposition reaction in LLDPE at typical processing temperatures (>200°C) made isolation, analysis and quantification of residual 3,3'-DCB levels extremely difficult.