非醋酐法合成DPT与pH值的关系

Influence of pH on Yield of DPT Prepared Without Acetic Anhydride.

该文利用ｐＨＳ－２９型酸度计测定ＤＰＴ合成过程中ｐＨ值的变化，发现反应体系中ＨＡ的存在对缩合终点有极大的影响，并研究确定了合适的加氨速度（滴加氨水的时间为１２０ｍｉｎ），终点ｐＨ值以７．５～８．０为宜，以及甲醛与硝酰胺的最佳料比为６．０～３．３（摩尔比），可使ＤＰＴ得率提高至８０％。

The variation of pH in condensation of DPT was mea-sured by pH S-29 meter in this paper.It is found that the HA has a great effect on condensation end-poin. The suitable dropping time of ammonia water is about 120 min,And the pH at end-point is 7.5～8.0 and the optimum mole ratio of formaldehvde and nitramide is 6 .0～3.3.The stable vield of DPT can be over 80%in the reaction con-ditions.