烯丙基聚醚改性四硅氧烷表面活性剂的表面活性和润湿性能

Study of surface activity and wetting performance of allyl polyether modified tetrasiloxane surfactants

通过1,1,1,3,5,7,7,7-八甲基四硅氧烷与不同聚合度的烯丙基聚氧乙烯醚反应合成了系列烯丙基聚醚改性四硅氧烷表面活性剂(TESE),用1HNMR和29SiNMR对产物进行了表征。通过对表面张力和接触角的测定,研究了其水溶液的表面活性以及在PET(聚对苯二甲酸乙二醇酯)和PMMA(聚甲基丙烯酸甲酯)基板上的润湿性能,同时探究了其在水中的溶解性以及亲水基结构(聚醚EO链长)对其表面活性和润湿性能的影响。结果显示,这类表面活性剂具有优异的表面活性和良好的润湿性能。随着EO链长的增加,TESE的表面活性存在最佳EO链长(EO单元数为8)。其中,在较短EO链长的一定范围内,TESE水溶液的最低表面张力(γcmc)变化幅度均较小,而EO链长超出一定范围后,γcmc增大幅度较为显著;TESE的润湿性能,在EO单元数小于12时变化不大,当EO单元数超过12时明显减弱。

A series of allyl polyether modified tetrasiloxane surfactants （TESE） were synthesized by the reaction of allyl polyether with different degree of polymerization and 1,1,1,3,5,7,7,7 - octamethyltetrasiloxane. The TESE products were characterized by 1HNMR and 29 SiNMR. The surface activity and the wetting performance of aqueous solution of the TESE products on PET （ polyethylene glycol terephthalate） and PMMA （polymethyl methacrylate） substrate were investigated by surface tension and contact angle measurement. Solubility performance as well as effects of structure of hydrophilic group （ EO chain length of the allyl polyether） on surface activity and wetting performance of the TESE products were examined. Results showed that the TESE products exhibit excellent surface activity and good wetting performance. Surface activity of the TESE products exhibits an optimum value at a specific EO chain length （ EO unit number as 8 ）. Under a certain value of EO chain length, change of γcmc of aqueous solution of the TESE product vs. the EO chain length is rather small ; while as the EO chain length exceeds a certain value, amplitude of increase of the γcmc becomes significant. When the EO chain length is less than 12 EO, change of wetting performance of the TESE product vs. the EO chain length is not big;while as the EO chain length exceeds 12 EO, decline of the wetting performance becomes significant.