SiO_2/聚丙烯酸酯复合乳液的制备和表征

Preparation and Characterization of SiO_2/polyacrylate Hybrid Emulsion

通过半连续种子乳液聚合法,在SiO2溶胶存在情况下,利用有机硅单体乙烯基三乙氧基硅烷(A-151)的桥接作用,制备得到SiO2/丙烯酸酯共聚物杂化乳液。对有机硅单体和二氧化硅用量对复合乳液稳定性能的影响进行了研究,采用投射电镜(TEM)和热重分析(TGA)对制备得到的复合乳液的形貌和耐热性进行测试表征。结果表明:在有机硅单体乙烯基三乙氧基硅烷用量为总单体4.0 wt%,SiO2溶胶用量为单体15 wt%以内,可制备出稳定的SiO2/丙烯酸酯共聚物杂化乳液。由于有机硅单体的桥接作用,部分SiO2粒子形成与乳胶粒上,形成草莓状的复合结构,且复合乳液具有较高的耐热性。

SiO2/polyacrylate hybrid emulsion was prepared by seedcd semi-continues emulsion polymerization in the presence of nano-SiO2 sol and siloxane coupling agent Vinyltriacetoxysilane （A-151 ）. Effects of nano-SiO2 sol and A-151 content to the stability and properties of the prepared hybrid emulsion were studied. The Micro-morphology and Thermal stability of the prepared SiO2/polyacrylate hybrid emulsion were characterized by TEM and TGA, respectively. The results showed that stable hybrid emulsion can be obtained when the A-151 content is 4 % and SiO2 sol content is under 15 %. Parts of the SiO2 particles are on the surface of the polyacrylate latex particles and therefore formed a raspberry-like structure due to the ＂bridge effect＂ of A-151. The thermal stability of the hybrid emulsion is better that the polyacrylate emulsion.