硫化促进剂DM工业合成机理探讨

Investigation of mechanism for industrial synthesis of DM vulcanization accelerator

硫化促进剂DM是一种应用广泛的橡胶硫化促进剂,工业化生产方法主要为亚硝酸钠法。目前行业普遍采用的化学反应方程式存化学计量比与实际不符、反应物的角色不明确及化学反应类型不明晰。提出两种最可能的多相催化氧化反应机理,即亚硝酸催化机理和二氧化氮(或一氧化氮)催化机理。工业生产中存在的催化效应衰减现象由氧化过程中排空造成的氮氧化合物大量损耗和发生较多的副反应引起。

DM is widely used as the rubber vulcanization accelerator, which is mostly produced by sodium nitrite method. There existed three unscientific points in widespread accepted reaction equation. Two het- erogeneous catalytic oxidation mechanisms which were most possible for the synthesis reaction, namely catalytic mechanism of nitrous acid and nitrogen dioxide （or nitric oxide） catalytic mechanism were put forward. The reason for and influence of the catalytic effect decreasing phenomenon were discussed, and it was concluded that the catalytic effect decreasing phenomenon of commercial production was caused by more side reaction and the loss of a large amount of nitrogen oxide due to emptying during oxidation process.