熔融共混法尼龙66/CaCO_3复合材料性能研究

Study on properties of melt blended nylon 66/CaCO_3 composite

本文通过熔融共混法在双螺杆挤出机上制备了尼龙66/纳米CaCO_3复合材料,采用扫描电镜(SEM)、偏光显微镜(PLM)、热失重(TGA)和差示扫描量热(DSC)的表征方法研究了纳米碳酸钙对尼龙66/纳米CaCO_3复合材料的多晶行为和热性能的影响。结果表明:纳米碳酸钙粒子在尼龙66基体中分散不均,以团聚体的形式存在;纳米碳酸钙具有异相成核作用,能够使球晶的尺寸减小;尼龙66的分解温度为400℃,纳米CaCO_3的添加使分解温度降低。同时,DSC测试表明,材料中的β晶型使材料的熔融温度降低;添加在尼龙66基体中的纳米碳酸钙会导致结晶温度的降低和吸热峰半高宽的增加;冷却速率越大,结晶温度越低,结晶温度范围越宽。

In this paper, nylon 66/nano CaCO3 composites were prepared by melt blending on twin- screw extruder. The effects of nano CaCO3 on the polycrystalline behavior and thermal properties of nylon 66/nano-CaCO3 composites were investigated by means of scanning electron microscopy （SEM）, polarizing microscope （PLM）, thermogravimetry （TGA） and differential scanning calorimetry （DSC）. The results showed that the nano CaCO3 particles dispersed unevenly in nylon 66 matrix and existed as aggregates; the nano CaCO3 particles had heterogeneous nucleation, which could reduce the size of spherulites; the decomposition temperature of nylon 66 was 400℃ , and the addition of nano-CaCO3 reduced the decomposition temperature. At the same time, DSC test showed that the melting temperature of the material was decreased due to the 13 crystalline form, the crystallization temperature and the half width of the endothermic peak were increased due to the addition of nano-CaCO3 in nylon 66 matrix, and the crystallization temperature range was widened with the increase of cooling rate and crystallization temperature.