Model for the fracture energy of glassy polymer-polymer interfaces

• Published in: Journal of polymer science. Part B, Polymer physics Polymer physics, 2002-10, Vol.40 (20), p.2377-2386
• Main Authors: Benkoski, J. J., Fredrickson, G. H., Kramer, E. J.
• Format: Article
• Language: English
• Subjects: adhesion; amorphous; Applied sciences; crazing; Exact sciences and technology; molecular reinforcement; Organic polymers; Physicochemistry of polymers; Properties and characterization; Surface properties
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.10288

The increase in the interfacial fracture energy (Gc) with increasing interfacial width (ai) goes through a transition at a critical value of ai that is unique to each polymer–polymer system. This transition point does not scale with the bulk entanglement spacing (dt) for different systems, implying that the role of chain friction in reinforcing these interfaces is more important than previously thought. A theoretical model has been developed to calculate Gc as a function of the interfacial stress transfer due to individual polymer chains. When including the effects of chain friction only, the model reproduces the nonuniversal behavior of Gc with respect to ai/dt but yields poor fits for ai/dt > 1. The effects of entanglements are then added by calculating the fraction of entangled chains as a function of ai/dt. This contribution, although not material specific, matches the qualitative behavior of Gc for large values of ai/dt. When both contributions are included in the model, excellent fits are obtained for all data sets. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2377–2386, 2002