ABSTRACT

Nano boron oxide (B₂O₃) was firstly produced from granular B₂O₃ by ball milling under cryogenic conditions. Then, PMMA/B₂O₃ nanocomposites were synthesized by melting method and then characterized. Finally, the rheological properties of PMMA/B₂O₃ nanocomposite were investigated using a high pressure capillary rheometer. Brauner-Emmet-Teller (BET) surface area analysis showed that the surface area of B₂O₃ increased with cryogenic grinding. Transmission electron microscopy (TEM) images revealed that B₂O₃ particles were nano-sized. Scanning electron microscopy (SEM) images showed that the morphology changed with the increase of B₂O₃ amount. The thermal stability of nanocomposites was found to be better than PMMA. PMMA degraded in two steps, while nanocomposites degraded in one step. It was determined that the amount of residue increased with increasing amount of B₂O₃. Both PMMA and nanocomposites exhibited non-Newtonian shear thinning flow behavior. In addition, rheological data were found to be highly compatible with the Power Law model.

摘要

纳米氧化硼（B ₂ O ₃）首先是在低温条件下通过球磨从粒状B ₂ O _{3制备的。}然后，采用熔融法合成了PMMA/B ₂ O _{3纳米复合材料，并对其进行了表征。}最后，使用高压毛细管流变仪研究了PMMA/B ₂ O ₃纳米复合材料的流变性能。_{Brauner-Emmet-Teller (BET) 表面积分析表明，B 2} O ₃的表面积随着低温研磨而增加。透射电子显微镜 (TEM) 图像显示 B ₂ O ₃颗粒是纳米级的。_{扫描电子显微镜（SEM）图像显示，随着B 2} O ₃量的增加，形貌发生了变化。发现纳米复合材料的热稳定性优于 PMMA。PMMA 分两步降解，而纳米复合材料一步降解。确定残留量随着B ₂ O ₃量的增加而增加。PMMA 和纳米复合材料均表现出非牛顿剪切稀化流动行为。此外，流变数据被发现与幂律模型高度兼容。