聚烷基三烷氧基硅氧烷乳液的合成及性能表征

Synthesis and Performance Characterization of Poly(alkyltrialkoxysiloxane) Emulsion

采用复合乳化体系,以甲基三乙氧基硅烷与丙基三甲氧基硅烷为单体,通过乳液共聚反应合成了不同硅含量的水性聚烷基三烷氧基硅氧烷乳液。用傅立叶红外光谱仪(FT-IR)、透射电子显微镜(TEM)及粒径分布测定仪(PCS)分别对乳液聚合物的化学结构、乳胶粒大小及形貌进行了表征。讨论了亲水亲油平衡(HLB)值、反应温度及时间等因素对乳液粒子大小、形态及乳液稳定性的影响。测定了乳液的稀释、离心、耐电解质、耐高温及冻融稳定性。结果表明,随着HLB值的增加,乳胶粒的尺寸变小,离心稳定性增强;随着温度的升高,乳胶粒尺寸变大,离心稳定性降低;随着时间的延长,乳胶粒尺寸变化不大;乳胶粒形态为球形。乳液的贮存稳定性、稀释、离心、耐电解质、耐高温及冻融稳定性良好。在HLB值为12.06,反应温度为35℃条件下反应135 min合成的乳液乳胶粒形态为球形,具有良好的稀释、贮存、离心、耐电解质、耐高温及冻融稳定性。

Stable poly （alkyhrialkoxysiloxane） aquous emulsions with different polymer contents were prepared by copolymerization of methyl triethoxysiloxane and n-propyl trimethoxysilane. The structure of the copolymer and the morphology of emulsion particle were characterized by Fourier transform infrared spectroscopy （FT-IR）, transmission electron microscopy （TEM）, respectively. The particle size and particle size polydispersity index （PDI） were analyzed by photo correlation spectroscopy （PCS） technology. The effect of hydrophilic-lipophilic balance （HLB） value, reaction temperature and time on the particle sizes was investigated. The stability of dilution and centrifugal, electrolyte resistance, high temperature resistance and freeze- thaw stability of emulsion was also characterized. Results show that with the increase of HLB value, the latex particle size decreases, but the centrifugal stability enhances. On the other hand, with the increase of the temperature, its particle size increases, but the centrifugal stability weakens. With the reaction time extends, it slightly increases. The morphology of particles is spherical under the conditions of HLB value of 12. 06 at 35 ℃. The emulsion is excellent in the stability of dilution, storage, centrifugal stability, and electrolyte resistance, high temperature resistance and freeze-thaw stability.