Pickering乳液聚合制备聚苯乙烯/纳米SiO2复合微球与其性质

以两亲性纳米SiO2为稳定剂构筑Pickering乳液,分别采用偶氮二异丁腈(AIBN)及过硫酸铵(APS)作为引发剂引发苯乙烯单体聚合,制得了不同尺寸及形貌的聚苯乙烯/纳米SiO2(PS/SiO2)复合微球,并分析了Pickering乳液聚合的机理。通过傅里叶变换红外光谱仪(FT-IR)、凝胶渗透色谱-多角度激光光散射联用仪(GPC-MALLS)、热失重分析(TGA)及差示扫描量热仪(DSC)对产物进行了表征,结果表明,AIBN引发所得复合微球为微米级(0.5μm~2.0μm),而APS引发产物为亚微米级(0.1μm~0.5μm),两者引发所得聚合物重均分子量(-Mw)分别为4.780×104g/mol及3.411×105g/mol;复合微球的热性能因纳米SiO2的存在而得到增强。

Properties of Polystyrene/Nano-SiO2 Composite Microspheres Prepared by Pickering Emulsion Polymerization

Stable Pickering emulsion was fabricated using amphiphilic nano-SiO2 particles as stabilizer.Then,two kinds of polystyrene/nano-SiO2(PS/SiO2) composite microspheres,which had different size and different morphology,were synthesized with oil-soluble azobisisobutyronitrile(AIBN) and water-soluble ammonium persulfate(APS) as initiator respectively.The possible mechanisms of Pickering emulsion polymerization initiated by different initiator were discussed.The product was characterized by means of FT-IR,multi angle laser light scattering photometer(GPC-MALLS),TGA and DSC.When AIBN was used as the initiator,the diameters of the microspheres were micron-sized(0.5 μm~2.0 μm).While the sub-micron-sized(0.1 μm~0.5 μm) microspheres were obtained by using APS as the initiator.And the weight-average molecular weight(w) of two kinds of polymer is 4.780×104 g/mol and 3.411×105 g/mol,respectively.The results of TGA and DSC indicated that the thermal properties of composite were elevated duo to the existence of nano-SiO2.