| 摘要 |
The polymerisation of vinyl-substituted nitrogen-containing heterocyclic compounds having the formulae <FORM:0883809/IV (b)/1> <FORM:0883809/IV (b)/2> <FORM:0883809/IV (b)/3> in which m is 1 or 2, and R is hydrogen or alkyl, particularly methyl or ethyl, is inhibited by adding to the compounds, particularly during their distillation and storage, a stabilising agent chosen from the sulphonephthaleins and having the formula <FORM:0883809/IV (b)/4> in which R is a nitro, halide, hydroxyl, amino, sulphonic or cyanide substituent and n is 0-4. The preferred sulphonephthalein is Phenol Red. Preferably the inhibitor is added in an amount of 0.001-5% by weight based on the amount of vinyl compound. |
