高含量玻璃纤维增强尼龙复合材料的制备与性能

Preparation and Properties of High Content Glass Fiber Reinforced PA Composites

采用双螺杆挤出机分别制备了质量分数60%玻璃纤维增强尼龙(PA)6(PA6+60%GF)和质量分数50%玻璃纤维增强PA66(PA66+50%GF)两种高含量玻璃纤维增强PA复合材料,研究了螺杆组合、尼龙树脂以及助剂对材料力学性能、注塑制品外观、长期耐热氧老化性能和耐乙二醇性能的影响。结果表明,采用厚、薄啮合块及齿形螺纹混合元件的螺杆组合以及减少玻璃纤维停留时间可制得力学性能优异的复合材料。通过金相显微镜观察材料粒子烧蚀后的玻璃纤维形态,发现力学性能优异的材料中玻璃纤维的长度较长(0.3~0.5 mm)且分布较均匀。PA树脂的黏度与种类对材料注塑制品的外观影响十分明显,采用流动性好的树脂材料尤其是具有星型结构的PA6树脂可获得更好的制品外观。除此之外,芳香胺类抗氧剂能显著提升PA6+60%GF的长期耐热氧老化性能,复配耐水解剂(含铜盐与有机胺)与芳香胺类抗氧剂并用能显著提升PA66+50%GF的长期耐热氧老化性能和对乙二醇的抵抗能力。

Two high content glass fiber reinforced nylon(PA)composites including 60%(mass fraction)glass fiber reinforced PA6(PA6+60%GF)and 50%(mass fraction)glass fiber reinforced PA66(PA66+50%GF)were prepared by twin-screw extruder.The effects of screw combination,PA resin and additives on mechanical properties,appearance of injection molded parts,long-term thermal oxidative aging and glycol resistance of the composites were studied.The results show that the composites with excellent mechanical properties can be made by using the screw combination of thick meshing block,toothed screw mixing element and thin meshing block and reducing the residence time of glass fiber.The morphology of the ablated glass fiber was observed by metallographic microscope.It is found that the length of the glass fiber is longer(0.3-0.5 mm)and the distribution is more uniform in the composites with excellent mechanical properties.The viscosity and type of PA resin have obvious influences on the appearance of injection molded parts,the resin with good fluidity,especially PA6 resin with star structure,has better appearance.Aromatic amine antioxidants can significantly improve the long-term thermal oxidative aging resistance of PA6+60%GF.The combination of complex hydrolytic agents(containing copper salt and organic amine)and aromatic amine antioxidants can significantly improve the resistance to long-term thermal oxidative aging and ethylene glycol of PA66+50%GF.