不同密度的尼龙12/钨屏蔽复合材料的流变及使用性能

摘要

Through changing content of tungsten (W),Nylon(PA) 12 / W shielding composites with different density were prepared by means of melt blending and injection molding.The rheological,impact and shielding properties of the composites were characterized with melt flow indexer,impact testing machine and computed tomographic scanner.The results show that when the density is below 11.0 g / cm3,the flow behaviors of the composites accord with pseudoplastie flow behavior,and the shear rate has minimum effect on the melt viscosity of the composite with the density being 11.0 g/cm3 and it is most suitable for injection molding.With the density increasing,impact strength of the composites decreases,CT value and attenuation rate to X-ray increase.When the density is 11.0 g/cm3,the impact strength of the composite is 24 kJ/m2,the CT value reaches about 17 500 and is close to the value of plumbum,the attenuation rate to X-ray is 97％.According to the comprehensive properties,the composite with the density being 11.0 g / cm3 can be used for producing X-ray shielding parts.%通过改变钨(W)的含量,采用熔融共混、注射成型的方法制备了不同密度的尼龙(PA) 12/W屏蔽复合材料,利用熔体流动速率仪、冲击试验机、计算机断层扫描仪研究了PAl2/W屏蔽复合材料的流变、冲击及屏蔽性能.结果表明,密度低于11.0 g/cm3时,复合材料熔体为假塑性流体,其中密度为11.0 g/cm3的复合材料的剪切速率对其熔体黏度的影响最小,因而最适于注射成型；随密度的增加,复合材料冲击强度逐渐降低,CT值和对X射线的衰减率逐渐升高,当密度为11.0 g/cm3时,复合材料的冲击强度为24 kJ/m2,CT值达到17 500左右,已接近铅的CT值,对X射线的衰减率为97％.综合流变、冲击及屏蔽性能,优选密度为11.0 g/cm3的PA12/W屏蔽复合材料应用于X射线屏蔽制品的生产.