Hao Pei, Siebers Charmayne, Ragaert Kim, Gilabert Francisco A
Department of Materials, Textiles and Chemical Engineering (MaTCh), Mechanics of Materials and Structures (MMS), Tech Lane Ghent Science Park-Campus A, Ghent University (UGent), Technologiepark-Zwijnaarde 46, 9052 Ghent, Belgium.
Circular Plastics, Department of Circular Chemical Engineering, Faculty of Science and Engineering, Maastricht University, Urmonderbaan 22, 6167 RD Geleen, The Netherlands.
Polymers (Basel). 2024 Apr 19;16(8):1153. doi: 10.3390/polym16081153.
The blending of polyolefins (POs), such as polyethylene (PE) and polypropylene (PP), is a growing area of research, particularly for recycling mixed polyolefin (MPO) waste through flotation sorting techniques. However, understanding the thermomechanical behavior of these recycled blends is challenging due to limitations in the existing characterization methods. This paper introduces a combined experimental and numerical method to accurately assess the complex mechanical behavior of high-density PE, PP, and their blends. We conducted detailed thermomechanical analyses using a high-speed stereo digital image correlation (DIC) system paired with an infrared camera to capture temperature variations alongside mechanical stress and strain. This approach allowed us to correct for distortions caused by necking and to derive accurate stress-strain relationships. We also applied a cutting-edge unified semi-crystalline polymer (USCP) model to simplify the analysis, focusing on the effects of strain rate and temperature, including self-heating and thermal softening phenomena. Our results, which closely match experimental observations of stress-strain behavior and temperature changes, offer new insights into the thermomechanical properties of PO blends, which are essential for advancing their practical applications in various fields.
聚烯烃（POs），如聚乙烯（PE）和聚丙烯（PP）的共混是一个不断发展的研究领域，特别是在通过浮选分选技术回收混合聚烯烃（MPO）废料方面。然而，由于现有表征方法的局限性，了解这些回收共混物的热机械行为具有挑战性。本文介绍了一种结合实验和数值的方法，以准确评估高密度PE、PP及其共混物的复杂力学行为。我们使用高速立体数字图像相关（DIC）系统与红外相机进行了详细的热机械分析，以捕捉温度变化以及机械应力和应变。这种方法使我们能够校正由颈缩引起的变形，并得出准确的应力-应变关系。我们还应用了前沿的统一半结晶聚合物（USCP）模型来简化分析，重点关注应变速率和温度的影响，包括自热和热软化现象。我们的结果与应力-应变行为和温度变化的实验观察结果密切匹配，为PO共混物的热机械性能提供了新的见解，这对于推动它们在各个领域的实际应用至关重要。
