基于纳米氢氧化镁稳定的Pickering乳液悬浮聚合制备盔甲结构聚苯乙烯@氢氧化镁复合微球

Preparation of Armor Structure Polystyrene@Magnesium Hydroxide Composite Microspheres by Pickering Suspension Polymerization with Nano-magnesium Hydroxide as Pickering Stabilizer

以苯乙烯为单体、偶氮二异丁腈(AIBN)为引发剂、片状纳米氢氧化镁(MH)为Pickering稳定剂,采用悬浮聚合法制备盔甲结构的聚苯烯@氢氧化镁(PS@MH)复合微球.采用扫描电子显微镜(SEM)、能谱分析(EDS)、傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、热失重分析(TGA)和微型燃烧量热分析(MCC)等对PS@MH复合微球进行表征,确认了其形貌和结构:纳米氢氧化镁紧密包覆在聚苯乙烯微球表面,形成了以纳米氢氧化镁为外层、聚苯乙烯为内球的盔甲结构复合微球;同时证明了具有盔甲结构的PS@MH复合微球能降低热释放速率,抑制聚合物的降解.该方法操作简单,成本低廉,制得的盔甲结构PS@MH复合微球粒径尺寸小、分布窄,球形度较高.

The unique properties of organic-inorganic composite microspheres with armor structure have aroused great interest.Armor structure organic-inorganic composite microspheres were prepared by Pickering suspension polymerization using styrene as monomer,azobisisobutyronitrile(AIBN)as initiator,magnesium hydroxide nanosheets as Pickering stabilizer.The composite microspheres were characterized by scanning election microscopy(SEM),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermal gravimetric analysis(TGA)and micro-scale combustion calorimetry(MCC).The morphology and structure of the composite microspheres were confirmed.Magnesium hydroxide was tightly coated on the surface of the polystyrene microspheres to form the armor structure composite microspheres with magnesium hydroxide as the outer layer and polystyrene as the inner sphere.When magnesium hydroxide content was 2%,the average particle size of the microspheres was 25μm,much lower than that of pure PS microspheres,760μm.It was also proved that the composite microspheres with armor structure could reduce the heat release rate and inhibit the cracking of polymers.And the acid etching of microspheres could remove completely the outer layer of magnesium hydroxide.This Pickering suspension polymerization is simple to operate,low cost,and the prepared armor composite microspheres have small particle size,narrow distribution and high sphericity.Moreover,the armor structure endows the material with a certain degree of flame retardant performance.