采用分散聚合法制备了标称粒径为3 μm的单分散交联型聚苯乙烯(PS)微球。相对于线型μm级聚苯乙烯而言, 交联型μm级聚苯乙烯的耐热性和耐溶剂性明显提高, 其玻璃化温度提高了28.6 ℃, 在常用溶剂中保持不溶解状态。采用扫描电子显微镜(SEM)绝对测量法对交联型μm级聚苯乙烯粒度标准物质进行定值, 用美国国家标准技术研究院(NIST)的粒度标准物质校正其放大倍数。定值结果为2.84 μm, 扩展不确定度为0.08 μm。采用F检验法和t检验法检验了样品的均匀性和稳定性。定值过程和均匀性、稳定性都符合国家二级粒度标准物质的要求。μm级交联型聚苯乙烯微球粒度标准物质, 可用于高温和腐蚀等极端环境下的粒度分析。

The size reference material is used to test and calibrate apparatus, evaluate measure method, and ensure sample values. It is important in industry measurement, controling of products quality and science studying. In the present paper, crosslinked polystyrene microspheres with an average size of about 3.0 μm were prepared by dispersion polymerization. Compared with the micro PS particle prepared from linear PS, the PS micro particle prepared from cross-linked PS shows superior resistance to solvent and heat, with the glass transition temperature increasement of 28.6 ℃ and remains insoluble in normal solvents. F-test and t-test were used to test the uniformity and stability of the sample. The quantification was carried out by independent measurement techniques named scanning electron microscope (SEM), which was calibrated with NIST Standard Reference Material (SRM2800). It is shown that the sizes of these PS spheres samples are 2.84 μm and the expanded uncertainty is 0.08 μm. The quantification process, the uniformity and the stability of these samples meet the demands of secondary standard reference materials of China.