纳米碳酸钙二次粒径对有机硅密封胶力学性能的影响

采用X射线衍射仪、扫描电子显微镜、激光粒度分布仪分析了纳米活性碳酸钙的相组成及粒子结构、形貌、粒径分布;研究了几种一次粒径相近、不同二次粒径的纳米活性碳酸钙对脱酮肟型单组分室温硫化(RTV)有机硅密封胶力学性能的影响。结果表明,一次粒径小的碳酸钙,经表面处理后的二次粒径不一定小;二次粒径比一次粒径对RTV有机硅密封胶的力学性能影响更大:随着二次粒径的减小(而非一次粒径的减小),RTV有机硅密封胶的拉伸强度、断裂伸长率和硬度都呈增加趋势。

Effect of Secondary Particle Size of Nano Calcium Carbonate on the Mechanical Properties of Silicone Sealant

The phase composition and particle structure,morphology,particle size distribution of the active nano calcium carbonate were measured respectively by X-ray diffraction,scanning electron microscopy and laser particle size distribution instrument.The influence of the different secondary particle size of the active nano calcium carbonate which had similar primary particle size on the mechanical properties of the one-component deoxime room temperature vulcanized(RTV) silicone sealant was investigated.Results showed that the primary particle size of the sample was small,but the secondary particle size of the sample was not necessarily small after the surface treatment;the secondary particle size affected more significantly than the primary particle size on the mechanical properties of RTV silicone sealant.With the decrease of the secondary particle size of the active nano calcium carbonate,the tensile strength,the breaking elongation and the hardness of RTV silicone sealant were increased.