二甲胺聚醚改性有机硅表面活性剂的合成

Synthesis of polyether amino silicone modified surfactant for agrochemical additives

以不饱和的聚醚和环氧氯丙烷为原料,合成出环氧不饱和聚醚;再与低含氢硅油进行硅氢加成反应,合成出环氧聚醚改性聚甲基硅氧烷;接着用二甲胺对环氧基开环,得到二甲胺聚醚改性有机硅表面活性剂。研究了硅氢加成反应条件对含氢硅油转化率的影响、用IR谱图表征了关键中间体及产物的结构、测定了产物的表面特性。硅氢加成反应的最佳工艺为:反应温度75℃、反应时间5h、聚醚中的CC键与含氢硅油中的SiH基的量之比为1·1∶1·0;二甲胺聚醚改性有机硅表面活性剂的表面张力为21·4mN/m,在农药螟施净水溶液中的临界胶束质量分数为3%,在临界胶束浓度下螟施净水溶液的表面张力值为24·8mN/m,能大幅降低农药的表面张力(降幅达24%);从亲水亲油平衡(HLB)值看,二甲胺聚醚改性有机硅表面活性剂的亲油性稍强于亲水性,且HLB值在一定范围内随着pH值的降低而提高。

The unsaturated epoxy-containing polyether was synthesized by unsaturated polyether macromolecules and 1-chloro-2,3-epoxy propane. It was then reacted with low hydrogen containing silicone oil via hydrosilylation to produce epoxy-containing polyether silicone. In the end, dimethylamine was used to open the epoxy bond to get the final product. The effects on the condition of hydrosilylation and the conversion of hydrogen-containing silicone oil were studied. The key intermediate and the structure of the product was characterized by IR, and its surface activity was determined. The result showed that the best hydrosilylation conditions were that the reaction temperature 75 ℃, reaction time 5 h, the mass ratio between CC in polyether and Si H in hydrogen containing silicone oil was 1.1∶1.0. When the surface tension of polyether amino silicone was 21.4 mN/m, the mass fraction of critical micelle in pesticide MINGSHIJING was 3%. When the surface tension of polyether amino silicone was 24.8 mN/m, it could greatly depress the surface tension of pesticide as much as 24.2%. The lipophilicity of polyether amino silicone was better than its hydrophily. HLB was increased in some range as pH decreased.