聚有机硅氧烷/蒙脱土纳米复合乳液的制备及稳定性研究

Preparation of Polydimethylsiloxane/Organophilic Montmorillonite Nanocomposite Emulsions and Its Stability

以十二烷基苯磺酸(DBSA)为插层剂改性蒙脱土(MMT),制得了有机蒙脱土(OMMT),采用原位插层聚合法,以八甲基环四硅氧烷(D_4)、乙烯基三甲氧基硅烷(A-171)和OMMT为原料制备了聚有机硅氧烷/蒙脱土(PDMS/OMMT)纳米复合乳液,研究了DBSA添加工艺、OMMT用量、反应温度、A-171及乳化剂用量等对D_4转化率和乳液稳定性的影响,并采用XRD、FT-IR等手段对OMMT及PDMS/OMMT低聚体的结构进行了表征。结果表明:在反应初始阶段通过外加DBSA,可使D_4在OMMT层间开环聚合,形成剥离结构;当m(OMMT):m(D_4)为20,反应温度为80℃、m(A-171):m(D_4)和m(乳化剂):m(D_4)分别为2.0和3.0时,D_4转化率达到71.3%,PDMS/OMMT乳液的稳定性最好。

Polydimethylsiloxane/organophilic montmorillonite （PDMS/OMMT） nanocomposite emulsions were prepared with octamethyl cyclotetrasiloxane （ D4 ）, vinyltrimethoxysilane （ A - 171 ） and OMMT which was prepared by modification of montmorillonite （MMT）with dodecylbenzene sulfonate acid（DBSA） as intercalating agent. The effect of charging technology of DBSA, amount of OMMT, reaction temperature and amount of A - 171 and emulsifier on conversion rate of D4 and the stability of emulsions were discussed. The structure of OMMT and PDMS/OMMT oligomers were characterized by XRD and FT - IR. The results showed that adding of DBSA at early stage of reaction was beneficial for the ring - opening of D4 within the OMMT layers, forming peeled structure. When m（OMMT）：m（D4） ratio was 20, reaction temperature was 80℃, m （A - 171 ） ： rn （ D4 ） and m （emulsifier） ： m （ D4 ） were 2. 0 and 3.0, respectively, the conversion rate of 1）4 was 71.3% and the stability of PDMS/OMMT was the best.