【摘要】 用偏光显微镜和X射线衍射对气体辅助成型聚丙烯制件的结晶形态分布和β晶分布进行了分析研究,并与传统注射成型聚丙烯制件的结晶形态分布进行了对比。结果表明,气辅助成型制件在厚度上呈现取向层-过渡层-大球晶层非对称分布;取向层厚度与延气时间呈"V"字形关系,而随着延气时间的延长,过渡层变厚;过渡层的β晶含量比取向层和大球晶层要高。基于上述现象,提出高压气体延时充入引起二次剪切,并主要集中在过渡层,其次是取向层,气熔界面没有剪切发生,使得该处的晶体形态为大球晶。更多还原

【Abstract】 Crystalline morphology of gas assisted injection molded part for PP have been investigated using wide-X-ray diffraction and Polarized light microscopy.And the morphological of part of GAIM compared with that of CIM.The results show that microstructure contains orientation layer,transition layer and spherulite layer;the relationship between orientation layer thickness and gas delay time has a "V" shape profile caused by molecular relaxation time and second shear which induces by pressurized gas.The transition layer thickness increases with increasing gas delay time;the content of β-form crystal of orientation layer is higher than that of orientation and spherulite layers.In this work,therefore,we considered that the second shear stress was induced by pressurized gas focused on orientation layer and no shear stress appeared at interface between melt and gas.更多还原