The intricate structure of polymeric foams may be examined using 3D imaging techniques such as MRI or X-ray tomography followed by image processing. Using a new 3D image processing technique, six images of polyurethane foams were analyzed to create computerized 3D models of the samples. Measurements on these models yielded distributions of many microstructural features, including strut length and window and cell shape distributions. Nearly 8000 struts, 4000 windows, and 376 cells were detected and measured in six polyurethane foam samples. When compared against previous theories and studies, these measurements showed that the structure of real polymeric foams differs significantly from both equilibrium models and aqueous foams. For example, previous studies of aqueous foams showed that about 70% of foam windows were pentagons. In the polymeric sample studied here, only 55% of windows were pentagonal.
Bibliographical noteFunding Information:
The authors thank Dr. Mark Listemann, Air Products and Chemicals, and Dr. Xiao Dong Zhang, Dow Chemical, for providing foam samples and input for this paper. We thank Andy Kraynik for his very helpful comments. This paper is based upon work supported by a National Science Foundation Graduate Research Fellowship. This work was also supported in part by grants from the National Science Foundation, the Air Force Office of Research, the Army Research Office, and MURI grant.
Copyright 2012 Elsevier B.V., All rights reserved.
- 3D image processing
- Minimal surface