MiniLab测定高聚物熔体流变曲线准确性的探讨

The Accuracy of the Polymer Melt Rheologicai Curves Measured by MiniLab Micro Compounder and Rheometer

MiniLab微型混合流变仪可直接测定样品熔融共混后熔体流变曲线,但因缺乏可靠的体积流量与螺杆转速的相关系数,其所得到的流变参数只是相对测量值。通过准确测定高聚物熔体在狭缝流道中的体积流量,校正了体积流量系数,使该仪器的流变参数测量由相对变为绝对,螺杆同向和反向旋转所测得的样品流变曲线经校正后完全重合,与经Bagley校正后的高压毛细管的流变曲线也有很好的重合性。因此,该仪器可用来准确测量高聚物熔体的流变曲线。

The polymer rheological curves in molten state could be directly measured by MiniLab Micro Compounder and Rheometer. Somehow,the obtained rheological data was relative value due to the absence of reliable correlation factor between volume flow and screw speed in the rheometer. The correlation factor had been corrected via the precise determination of polymer melt volume flow through the slit capillary,which resulted in the absolute measure of rheological data. After correction, the flow curves measured by co- or counter rotating screws were completely overlaid each other. They all followed the same rheological line with that determined by the high pressure capillary rheometer after Bagley correction. Thus, MiniLab could be then used as a reliable tool to accurately determine the polymer melt rheological curves.