填充HDPE复合材料基体结晶形态的控制因素

本文以HDPE/玻璃微珠和HDPE/CaCO₃体系为研究模型,通过扫描电镜、红外光谱、偏光显微、小角激光散射和材料力学性能实验等方法考察了这两种体系的界面粘结性、填料含量、粒径及试样成型冷却速率等与其材料性能及基体结晶形态变化间的关系。实验结果表明;在复合材料试样成型过程中,因基体树脂冷却收缩而产生的界面应力可干扰基体中球晶的生长环境,应变诱导填料颗粒周围基体树脂的结晶,促使其表面伸展链晶体结构的形成,并由此而明显改变了复合材料的耐热性;复合材料的界面粘结性是产生这种应变诱导作用,并控制异相结晶的关键。

STUDIES ON THE INFLUENCE OF THE INTERFACIAL ADHESION ON THE PROPERTIES AND THE MATRIX CRYSTALLINE MORPHOLOGY OF THE FILLED HDPE COMPOSITES

The HDPE/glass spheres and the HDPE/CaCO 3 filled systems were taken as the investigated models, and the influence of the interfacial adhesion, the filler content and its particle size on the properties of filled HDPE composites and the crystalline morphology of their matrices was investigated by using scanning electron microscopy, infrared spectra meter, polarizing microscope, small angle light scattering, material universal testing machine, etc. The results show that in the higher interfacial bonding strength condition, the produced interfacial stress from the contraction of matrix in the composite injection molding can disturb the spherulites growing surroundings in the matrix, strain induces the crystallization of matrix in the area surrounding the filler, and leads to forming the extended chain crystal structure. Meanwhile, it was found that the properties of filled HDPE composites were also obviously changed, and that the interfacial bonding strength was an important factor in producing the strain induced crystallization, controlling the multiphase crystallization and modifying the properties of the filled composites.