【摘要】 由三聚氰胺与甲醛经羟甲基化反应再缩聚制得的密胺树脂,是一种用途很广的热固性树脂。本文研究了不同反应条件对上述反应和产物性质的影响。结果表明:随着甲醛用量的增加,甲醛结合量也增加,反应很容易进行;改变甲醛用量,可以制得由不同羟甲基三聚氰胺得到的密胺树脂;反应体系的pH=8.5时,副反应较少,反应容易控制;温度高,反应速度快,在54～80℃范围内对甲醛结合量影响不大。更多还原

【Abstract】 The melamine resin, which is prepared by hydroxymethylating reaction and condensation by methylol formaldehyde, is a widely used thermoset resin. The effects of different reaction condition on the reaction and properties of the product were studied. It was shown by the results that as the amount of formaldehyde increases, the reaction took place easily; varying the amount of used formaldehyde, the melamine resin, which was prepared by different methylol melamine, could be obtained. While the pH value of reaction system was 8.5, side reaction was less, and the reaction was controlled easily. When the temperature was high, the velocity was faster. The effect on the amount of combined formaldehyde was not obvious at 54～80℃.更多还原