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制备了硬脂酸钙包覆的纳米碳酸钙(CaSt-nano-CaCO3),并采用熔融共混的方法制备出iPP/CaSt-nano-CaCO3和iPP/nano-CaCO3复合材料.与纯iPP相比,复合材料的弯曲强度和弯曲模量随着CaCO3粒子含量的增加而提高,冲击性能也得到改善.相对于iPP/nano-CaCO3,iPP/CaSt-nano-CaCO3复合材料的冲击强度略有改善,而弯曲强度和弯曲模量明显提高.偏光显微镜和示差扫描量热研究表明,随着CaSt-nano-CaCO3含量增大,复合材料的结晶温度升高,成核性能增大,但其结晶温度低于同等粒子含量的iPP/nano-CaCO3复合材料,即CaSt-nano-CaCO3对iPP结晶的成核作用弱于nano-CaCO3,表明CaSt的引入降低了CaCO3的成核活性.广角X射线衍射试验研究表明引入改性与未改性纳米碳酸钙后复合材料均未出现β晶型.熔体流动速率测试表明,相比于iPP/nano-CaCO3,硬脂酸钙的存在改善了复合材料的加工流动性能.
CaSt-nano-CaCO3 coated with calcium stearate was prepared and iPP / CaSt-nano-CaCO3 and iPP / nano-CaCO3 composites were prepared by melt blending method.Compared with pure iPP , The flexural strength and flexural modulus of the composites increase with the increase of the content of CaCO3 particles and the impact properties are also improved.The impact strength of iPP / CaSt-nano-CaCO3 composite is slightly improved relative to iPP / nano-CaCO3, While flexural strength and flexural modulus were significantly increased.Phosphorescence microscopy and differential scanning calorimetry studies showed that with the increase of CaSt-nano-CaCO3 content, the crystallization temperature of the composites increases and the nucleation performance increases, but the crystallization temperature is low The nucleation of iPP crystal in iPP / nano-CaCO3 composites with equivalent particle content, ie, CaSt-nano-CaCO3, is weaker than that of nano-CaCO3, indicating that the CaSt introduction reduces the nucleation activity of CaCO3. The results show that the β crystal is not observed in the composites with and without modified calcium carbonate.The melt flow rate tests show that the presence of calcium stearate improves the processing flow of the composites compared to iPP / nano-CaCO3 performance.