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考察了酸性和不同表面活性剂存在条件下脲醛树脂微球的合成反应过程.中性Tween80和阳离子CTAB表面活性剂中生成的微球粒径分布窄,而阴离子表面活性剂中所得产物明显团聚,当预聚脲醛树脂粒子生成后加入中性和阳离子表面活性剂使产物微球的分散性和球形完整性明显改善.表面活性剂存在条件下产物的结晶性增强,初始反应的速率减慢,但中性和阳离子表面活性剂中初级粒子生成的诱导期延长、拉曼吸收增强、所得微球带正电荷;而阴离子条件下生成产物的相应特征正好相反.以上结果可以用表面活性剂的两亲性和电性对脲醛树脂微球的成核和生长过程的影响来解释.
The synthesis of urea-formaldehyde resin microspheres under acidic and different surfactants was investigated.The distribution of the microspheres in neutral Tween80 and cationic CTAB surfactants was narrow, while the products from anionic surfactants agglomerated obviously, When the prepolymerized UF resin particles are formed, neutral and cationic surfactants are added to improve the dispersibility and spherical integrity of the product microspheres. The crystallinity of the product is enhanced in the presence of surfactant and the initial reaction rate is slowed down. However, The induction period of primary particle formation in neutral and cationic surfactants is prolonged, the Raman absorption is enhanced, the resulting microspheres have a positive charge, while the corresponding characteristics of products generated under the anionic conditions are the opposite. The above results can be used with amphiphilic surfactants Sexual and electrical properties of urea-formaldehyde resin microspheres nucleation and growth process to explain.