Crystalline phase transformation of polytetrafluoroethylene in a fatigue test
Article first published online: 7 JUL 2014
Copyright © 2014 Wiley Periodicals, Inc.
Journal of Applied Polymer Science
Volume 131, Issue 22, November 15, 2014
How to Cite
2014), Crystalline phase transformation of polytetrafluoroethylene in a fatigue test. J. Appl. Polym. Sci., 131, 41113, doi: 10.1002/app.41113, , and (
- Issue published online: 18 AUG 2014
- Article first published online: 7 JUL 2014
- Manuscript Accepted: 3 JUN 2014
- Manuscript Received: 21 APR 2014
- SSRF . Grant Number: BL15U1
- Chinese National Science Foundation . Grant Numbers: 11327801 , 11172188
- phase behavior;
- properties and characterization;
In this study, we aimed to characterize the mechanical response of polytetrafluoroethylene (PTFE) laminates under a tension–tension load-control fatigue test (frequency = 5 Hz, load ratio = 0) and provided an analysis of the failure patterns of the PTFE material with consideration of crystalline phase transformation. In the final results, the evolution of the cyclic creep strain and stress–number of cycles to failure (S–N) curves presented duplex properties accompanying the fatigue life increasing to high cycles (cycle fatigue > 105). A simple phenomenological damage index was defined in this study to describe the cyclic creep process. Additionally, the scanning electronic machine investigation suggested that local fibrosis caused by crystalline phase transformation to phase I led to the initiation of fatigue crack, and the fiber formation and orientation was found to be beneficial to a higher tensile strength and better resistance to crack propagation. The aspect of cyclic-load-induced crystallization was observed by the microfocus hard X-ray diffraction beamline from a new insight. The crystalline phase transformation led to a gradient distribution of crystallinity and lateral crystallite size along the crack propagation direction. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41113.