Relationship of fracture behavior and morphology in polyolefin blends

• Published in: Polymer engineering and science Vol. 39; no. 6; pp. 1109 - 1118
• Main Authors: Niebergall, U., Bohse, J., Schürmann, B. L., Seidler, S., Grellmann, W.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.06.1999; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Exact sciences and technology; Mechanical properties; Morphology; Organic polymers; Physicochemistry of polymers; Polyethylene; Polymers; Polyolefins; Polypropylene; Properties and characterization; Strengthening; Polymer blends; Propylene polymer; High density ethylene polymer; Mechanical properties; Composition effect; Tensile property; Experimental study; Compatibilizer; Mechanism; Heterogeneous mixture; Impact strength; Morphology; Olefin polymer; Compatibility
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.11498

High‐density polyethylene (HDPE) and isotactic polypropylene (PP) were mixed either with a stabilizer or with a stabilizer and a compatibilizer in different mixing ratios. The structure and properties of these blends were analyzed by methods such as torsion pendulum measurements, mechanical short time experiments, electron microscopy, and fracture mechanical toughness tests. The results display a strongly increased impact strength in the HDPE/PP blend with compatibilizer within a specific mixing region. The deformation behavior and the mechanism leading to the increased impact strength of the blends were investigated in tensile tests by acoustic emission analysis and scanning electron microscopy: Increased fibrilation and strong strain was registered in the blend with compatibilizer. The impact strength was modeled, using experimentally measured properties such as energy release rate, matrix and inclusion volumes, the impact strength of each component. The inclusion volume that causes plastic deformation was chosen as an additional parameter. The calculated results are in good agreement with the experimental ones.