聚醚改性硅油表面性质的研究

Study on Surface Characters of Methylsioxane-oxyalkylene Copolymers

对实验室自制聚醚改性硅油（以下简称硅醚）的表面张力及浊点进行测定,并对其表面性质的特征及趋势进行了研究。结果表明,随硅醚质量浓度的增加,硅醚水溶液的表面张力值下降,硅醚质量浓度增至约0.01 g/L后,表面张力值降幅渐缓,其表面张力最低值为29-42 mN/m;随着硅醚侧链聚醚中环氧丙烷链段所占比例增加,其水溶液的浊点略有下降,质量浓度约为0.1 g/L的硅醚以侧链聚醚结构n（EO）∶n（PO）=1∶4的硅醚的浊点最小,为9.5℃;随体系温度上升,质量浓度约为0.01 g/L的硅醚水溶液的表面张力降幅小于同样质量浓度的甲基硅油加乳化剂A25（硬脂醇/脂肪醇醚-25）的水溶液,并求得质量浓度约为0.01 g/L不同环氧乙烷与环氧丙烷摩尔比的硅醚的表面张力随体系温度下降的系数及方程,根据实验建立的方程所得的某温度下表面张力的计算值与实测值之间的平均相对偏差为7%。

A series of methylsioxane-oxyalkylene copolymers were prepared.Surface tension and cloud point of these siloxane surfactants were known through the testing experiments,and surface characters and trends were investigated.The results showed that the surface tension of the water solution of these siloxane surfactants decreased,when the concentration of the water solution increases.At the concentration of 0.01 g/L,the rate of decreasing of surface tension slowed down.The minimum surface tension was 29～42 mN/m.The cloud point of the water solution of these siloxane surfactants dropped,when the composition of polypropylene oxide increased,and the cloud point of the water solution of siloxane surfactants of n（EO）∶n（PO）=1∶4 was the minimum,whose cloud point was 9.5 ℃.The decreasing rate of surface tension of siloxane surfactants solution along with temperature was less than the rate of the surface tension of methyl silicone oil solution with A25（CETEARETH-25）.The equations of surface tension vs.temperature of siloxane surfactants solution were obtained and the average error between the calculated value and the measured value was 7%.