Dynamic fracture toughness of polypropylene reinforced with cellulose fiber

• Published in: Polymer engineering and science Vol. 37; no. 6; pp. 1012 - 1018
• Main Authors: Clemons, Craig M., Giacomin, A. Jeffrey, Koutsky, James A.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-06-1997; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Cellulose fibers; Exact sciences and technology; Fracture mechanics; Mechanical properties; Physical properties; Polymer industry, paints, wood; Polypropylene; Properties and testing; Technology of polymers; Stress analysis; Stress intensity factor; Fracture mechanics; Charpy impact test; Wood fiber; Propylene polymer; Fiber reinforced material; Fiber orientation; Fracture surface; Composite material; Atactic polymer; Fracture toughness
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.11746

To better understand mechanisms of fracture under impact loading in cellulose‐reinforced polypropylene, dynamic fracture analysis was performed based on linear elastic fracture mechanics. Dynamic critical energy release rates and dynamic critical stress intensity factors were deduced from instrumented Charpy impact test measurements. Dynamic fracture toughness increased with cellulose content. However, the assumption of linear elasticity began to break down for cellulose fiber contents exceeding 40% by weight. Scanning electron microscopy showed considerable fiber curl in the composites, especially at low fiber contents; at high fiber contents, composites developed a three‐layer structure.