The account formula of the real con tent of free NCO was given, in the end, it discussed the effects of side reactions on the properties of the product and reaction time.

• 重点探讨了扩链过程中对于游离NCO基含量测定中存在的副反应，并给出实际NCO基含量的计算公式最后讨论了测量副反应对反应时间及其最终产品性能的影响。