封闭水性异氰酸酯中检测有效—NCO含量的改进方法

An improved method for testing effective —NCO content in enclosed waterborne isocyanate

建立了一种基于二正丁胺法检测封闭型水性异氰酸酯中有效—NCO含量的改进方法,考察了反应温度、时间和介质种类等因素对测定结果的影响。研究结果表明:以DMAc(二甲基乙酰胺)作为溶剂,将封闭型水性异氰酸酯与二正丁胺溶液在解封温度下热处理30 min,以严格等量的未经热处理的样品/二正丁胺溶液作为空白试样,并且热处理过程中增加冷凝回流装置,即可得到封闭型水性异氰酸酯中有效—NCO含量的检测结果;该法应用广泛,并且方法简便、准确度较高。

An improved method for testing effective —NCO content in enclosed waterborne isocyanate wasestablished base on dibutylamine method,the influences of some factors（such as reaction temperature,timeand medium types） on tested results were investigated.The research results showed that the tested result ofeffective —NCO content in enclosed waterborne isocyanate was obtained when the DMAc（dimethyl acetamide）wasused as solvent,the enclosed waterborne isocyanate/dibutylamine solution was treated by heating 30 min atdeblocking temperature,but the untreated enclosed waterborne isocyanate/dibutylamine solution with strictly sameamount was used as blank sample,and the condenser reflux device was added in the heat treatment process.Themethod could be widely used,and this method with higher accuracy was simple.