| Azodicarbonamide (ADC blowing agent) is a kind of widely used organic foaming agent in rubber and plastic products. ADC blowing agent has lots of advantages with large gas production, non-toxic, non-polluting properties, and cheap price and so on. But its high decomposition temperature and decomposition rate can not meet processing needs for all of the foaming products. In order to make it more widely used in a variety of foaming products, one or several active agents are often added to modify its performances. In this paper, biurea was successfully synthesized using ketazine, urea and water by one-step process, and the synthesized biurea was oxidized by hydrogen peroxide to prepare azodicarbonamide. The reaction conditions of affecting quality of products were studied. The structure and physical properties were confirmed by IR, NMR and TG-DTA, DSC. And the ADC performances were studied when different amount and types of active agents were changed.The azodicarbonamide synthesized by the synthetic method achieved excellent quality of product as stated in HG/T 2097-2008. The decomposition temperature and gas evolution of ADC blowing agent were controled in some extent by changing activator amounts of zinc acetate, zinc oxide, zinc stearate, calcium stearate, stearic acid, urea, sodium bicarbonate, hexamethylenamine, citric acid, etc.In this paper, the synthesis improvement of azodicarbonamide is reviewed. And compared with the traditional process, this procedure is the most ideal one with shorter reaction process, lower energy consumption and less environmental pollution. The application of the modified ADC blowing agents was expanded in manufacturing field of foaming products.
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