改性纳米碳酸钙用于硅酮胶挤出性研究

采用碳化法合成纳米碳酸钙,在反应过程中,调整反应起始温度合成不同晶型大小的纳米碳酸钙。通过透射电镜（TEM）、激光粒度仪对碳酸钙的物相、形貌、粒度进行分析,将改性纳米碳酸钙应用于硅酮胶基料制备及挤出性研究,分析改性纳米碳酸钙的颗粒大小、分散性、流变性能及表面改性剂对挤出性的影响。结果表明：粒径介于50~90 nm,屈服值介于66.4~148.9 Pa,黏度介于0.5~0.75 mPa·s,硬脂酸钠与LH-2、LH-3两种包覆剂进行复配改性的纳米碳酸钙用于硅酮胶基料具有较好的挤出性能。

Study on extrudability of silicone sealant by using modified nano-sized calcium carbonate

Nano-sized calcium carbonate was prepared by carbonization method.In the process of reaction,the initial reaction temperature was adjusted to synthesize nano-sized calcium carbonate with different crystal sizes.The phase,morphology and particle size of calcium carbonate were analyzed by transmission electron microscope（TEM） and laser particle size analyzer.The modified nano-sized calcium carbonate was applied to the preparation and extrudability of silicone sealant base material. The effects of particle size,dispersibility,rheology and surface modifier on extrudability of modified nano-sized calcium car-bonate were analyzed.The results indicated that the particle size was in the range of 50~90 nm,the yield value was in the range of 66.4~148.9 Pa and the viscosity was in the range of 0.5~0.75 mPa·s,the nano-sized calcium carbonate compounded and modified by sodium stearate and two kinds of low molecular weight fatty acid coating agents（LH-2 and LH-3） showed good extrudability for silicone sealant base material.