Albrecht Paul, Altepeter Matthias, Brüning Florian
Kunststofftechnik Paderborn, Paderborn University, 33098 Paderborn, Germany.
Polymers (Basel). 2025 May 28;17(11):1509. doi: 10.3390/polym17111509.
The degradation of polypropylene (PP) through thermal and mechanical stress, as well as the influence of oxygen, are unavoidable when processing on a co-rotating twin-screw extruder. In previous studies, a mathematical model was developed to predict the degradation while compounding on different twin-screw extruder sizes. Additionally, the examination of filled PPs was conducted. To this end, a range of operating parameters and extruder sizes were used to process PP, and the molar mass was then determined by melt flow rate (MFR) and gel permeation chromatography (GPC) measurements to derive the degree of degradation. The model was then modified by adjusting the sensitivity parameters to allow the degradation behavior of the PPs to be described independently of extruder size. Consistent with prior research, comprehensive measurements of a PP/titanium dioxide (TiO) compound revealed that, with a few exceptions, increasing temperatures and screw speeds and decreasing throughputs generally resulted in higher degradation. However, the application of the model to the compounds did not achieve good agreement with the measured degradation, indicating different degradation conditions due to the different thermodynamic and rheological properties of the compounds.
在同向旋转双螺杆挤出机上进行加工时，聚丙烯（PP）因热应力和机械应力而发生降解以及受氧气的影响是不可避免的。在先前的研究中，开发了一个数学模型来预测在不同双螺杆挤出机尺寸下进行配混时的降解情况。此外，还对填充PP进行了研究。为此，使用一系列操作参数和挤出机尺寸来加工PP，然后通过熔体流动速率（MFR）和凝胶渗透色谱（GPC）测量来确定摩尔质量，以得出降解程度。然后通过调整灵敏度参数对模型进行修改，以使PP的降解行为能够独立于挤出机尺寸进行描述。与先前的研究一致，对PP/二氧化钛（TiO）复合材料的全面测量表明，除了少数例外情况，温度升高、螺杆转速增加和产量降低通常会导致更高程度的降解。然而，将该模型应用于这些复合材料时，与测得的降解情况并未达成良好的一致性，这表明由于复合材料不同的热力学和流变学性质，存在不同的降解条件。
