固相拉伸作用对聚丙烯片材聚集态结构与力学性能和热性能的影响

Effect of Solid Phase Stretching on Aggregation Structure, Mechanical Performance and Thermal Properties of Polypropylene Sheet

针对固相拉伸作用对添加β成核剂等规聚丙烯(iPP)片材微观形貌、宏观物理性能的影响展开了研究。利用X射线衍射仪对片状iPP固相拉伸后的结晶行为进行了研究;利用扫描电子显微镜、偏光显微镜对其微观形貌进行了研究;利用万能拉伸试验机、摆锤式冲击试验机、软化点测试仪对其物理性能进行了研究。结果表明,在一定温度下,对片状iPP施加适当的拉伸作用,将改善其聚集态结构,提高力学性能;在130℃下拉伸时,片状iPP取向最优,片状iPP冲击强度接近于未拉伸的2倍,拉伸强度没有明显下降。

The effect of solid phase stretching on the microscopic crystalline structure and macroscopic physical properties of iPP sheet containing β-nucleating agent was investigated. The crystallization behavior of iPP sheet after solid phase stretching was studied by X-ray powder diffraction. The microstructure of iPP sheet was studied by scanning electron microscopy and polarized light microscopy. The physical properties of iPP sheet were evaluated by means of universal tensile testing machine, pendulum impact tester and softening point tester. The results indicated that the iPP sheet achieved the optimum mechanical properties at 130 ℃. The impact strength of iPP sheet was almost double of the value for the unstretched iPP one but its tensile strength showed an unchanged value.