The formation of unwanted polymer in the vapour phase during the distillation of unsaturated acid is inhibited by adding to the distillation unit, during the distillation, 0.001 to 0.1 weight percent, based on the weight of the acid, of non-metallic nitrite salt or nitrite ester.
在蒸馏不饱和酸时,向蒸馏装置中添加非
金属
亚硝酸盐或
亚硝酸酯,以防止在蒸汽相中形成不需要的聚合物。添加量为按酸重量计的0.001至0.1重量百分比。