Abstract
Porous rods of poly(tetrafluoroethylene) (PTFE) were fabricated by molding PTFE powder and fumaric acid (FA) at room temperature and sintering at 400 °C. The microstructures of the molding mixtures were observed with a scanning electron microscope (SEM). Although rectangular crystals of FA immersed in the fibrous structure of PTFE were observed in the extrudates of PTFE before sintering, open holes were created by the sublimation of FA dispersed in PTFE after heating the extrudates at 310 °C; the open holes remained even after sintering at 400 °C. High-resolution images from SEM revealed that the fibrous structure heated at 310 °C was composed of small particles of PTFE connected with fibrils, and these particles were sintered into grains after heating at 400 °C. Pore size could be controlled by changing the volume fraction of FA. The dimensions of extrudates were measured to determine porosity and volume shrinkage. The mechanism for the formation of the porous structure is discussed on the basis of SEM images, porosity and volume shrinkage.
Similar content being viewed by others
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
References
Clark, E. S. The molecular conformations of polytetrafluoroethylene: forms II and IV. Polymer 40, 4659–4665 (1999).
Brown, E. N. & Dattelbaum, D. M. The role of crystalline phase on fracture and microstructure evolution of polytetrafluoroethylene (PTFE). Polymer 46, 3056–3068 (2005).
Brown, E. N., Dattelbaum, D. M., Brown, D. W., Rae, P. J. & Clausen, B. A new strain path to inducing phase transitions in semi-crystalline polymers. Polymer 48, 2531–2536 (2007).
Haneda, T., Takahashi, J., Nomura, H. & Kurokawa, M. The effect of rolling on the melting behavior of poly(tetrafluoroethylene). Kobunshi Ronbunshu 41, 397–405 (1984).
Yamaguchi, S. Studies on morphology of poly(tetrafluoroethylene) fine powder. III. Morphological change on annealing of drawn unsintered poly(tetrafluoroethylene) tape. Kobunshi Ronbunshu 41, 407–411 (1984).
Starkweather Jr, H. W. The effect of heating rate on the melting of poly(tetrafluoroethylene). J. Polym. Sci. Polym. Phys. Ed. 23, 1177–1185 (1985).
Khanna, Y. P. The melting temperature of polytetrafluoroethylene. J. Mater. Sci. Lett. 7, 817–818 (1988).
Grebowicz, J., Pan, R. & Wunderlich, B. Thermal properties of drawn polytetrafluoroethylene. J. Appl. Polym. Sci. 38, 707–716 (1989).
Androsch, R., Wunderlich, B. & Radusch, H- J Analysisof reversible melting in polytetrafluoroethylene. J. Therm. Anal. Cal. 79, 615–622 (2005).
Kondo, S., Kanazawa, T., Matsuda, Y. & Tasaka, S. Thermal behavior of powder pressed films of poly(tetrafluoroethylene). Kobunshi Ronbunshu 66, 585–590 (2009).
Starkweather Jr, H. W., Zoller, P., Jones, G. A. & Vega, A. J. The heat fusion of poly(tetrafluoroethylene). J. Polym. Sci. Polym. Phys. Ed. 20, 751–761 (1982).
Chanzy, H. D., Revol, S. P. & Francois, J. High-resolution electron microscopy of virgin poly(tetrafluoroethylene). J. Polym. Sci. Part C Polym. Lett. 24, 557–563 (1986).
Ariawan, A. B., Ebnesajjad, S. & Hatzikiriakos, S. G. Properties of polytetrafluoroethylene (PTFE) paste extrudates. Polym. Eng. Sci. 42, 1247–1259 (2002).
Ariawan, A. B., Ebnesajjad, S. & Hatzikiriakos, S. G. Paste extrusion of polytetrafluoroethylene (PTFE) fine powder resins. Can. J. Chem. Eng. 80, 1153–1165 (2002).
Kitamura, T., Kurumada, K., Tanigaki, M., Ohshima, M. & Kanazawa, S. Formation mechanism of porous structure in polytetrafluoroethylene (PTFE) porous membrane through mechanical operations. Polym. Eng. Sci. 39, 2256–2263 (1999).
Yamanoue, T., Sawai, D., Nakamura, K., Morooka, N. & Kanamoto, T. Solid-state extrusion of poly(tetrafluoroethylene) nascent powder. Nihon Reoroji Gakkaishi 30, 295–301 (2002).
Haneda, T., Kiyose, A., Takahashi, J., Nomura, H. & Kurokawa, M. Melting and recrystallization behavior of poly(tetrafluoroethylene). Kobunshi Ronbunshu 40, 383–391 (1983).
Haneda, T., Kiyose, A., Takahashi, J., Nomura, H. & Kurokawa, M. The effect of rolling on the melting behavior of poly(tetrafluoroethylene). Kobunshi Ronbunshu 41, 367–405 (1984).
Takeuchi, Y. & Mayama, M. Porous Materials: Characterization, Production and Application (Fuji Techno System, Yokohama, 1999).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kanazawa, T., Matsuda, Y. & Tasaka, S. Fabrication of a porous structure of poly(tetrafluoroethylene) from a mixture with fumaric acid. Polym J 42, 509–513 (2010). https://doi.org/10.1038/pj.2010.23
Received:
Revised:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/pj.2010.23
Keywords
This article is cited by
-
Performance properties and applications of polytetrafluoroethylene (PTFE)—a review
Advanced Composites and Hybrid Materials (2018)
