螺杆挤出式毛细管测量聚合物熔体剪切粘度谱

Measurement for shear viscosity spectrum of polymer melts by using screw extruder capillary

为了准确表征聚合物熔体在挤出加工中,受到螺杆强剪切作用时的流变行为。依据流变学理论,研究了利用螺杆挤出式毛细管测量聚合物熔体剪切粘度的装置和数据处理方法。测试装置由单螺杆干挤出机和可更换模芯的毛细管模具构成。在数据处理中,利用不同长径比的毛细管模芯测得的原始数据,结合三次样条函数方法,完成了Bagley和Rabinowitsch校正计算。实验结果表明:利用该方法可以在近似实际加工的条件下,快速获得表征聚合物熔体流变行为的真实剪切粘度谱;对低密度聚乙烯的测试结果与Hakke流变仪在同样条件下所得结果相同,这一方法可以代替价格昂贵的流变仪,对热塑性聚合物材料共混改性进行评价,适合于工业应用。

In order to the rheological behavior of polymer melt is accurately characterized in extrusion processing by the screw strong shear action.A set-up and data processing method,which is used for measuring shear viscosity of polymer melts by using screw extruder capillary,is studied in this paper.According to principles of rheology and methods of cubic spline,Bagley and Rabinowitsch corrections are accomplished.Experimental results show that a true shear viscosity spectrum for characterizing rheo-property of polymer melts could be measured rapidly in an approximately actual processing condition by utilized the approach.Under the same conditions,the same test results were given by Hakke rheometer and this set-up for low-density polyethylene samples.The method,which can be replaced the expensive rheometer in industry,is especially suitable for the assessment of the modified properties of thermoplastic polymer blends.