Loading...
Please wait, while we are loading the content...
Similar Documents
Zr-containing 4,4'-oda/pmda polyimide composites. parts 1 & 2
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | He, L. Chen, Y. Illingsworth, M. L. Betancourt, J. A. Rutledge, S. K. Terschak, J. A. Banks, B. A. Cales, M. |
| Copyright Year | 2001 |
| Description | The objective of this research is to improve the atomic oxygen resistance of Kapton(TM), a polyimide (PI) made from pyromellitic acid dianhydride (PMDA) and 4,4'-oxydianiline (ODA), while retaining or enhancing the desirable properties of the pure polymer. Toward this end, zirconium-containing complexes and polymers were used to make composites and blends. Tetra(acetylacetonato)zirconium(IV), Zr(acac)4, which is commercially available, was identified as the best zirconium-containing complex for enhancing the atomic oxygen resistance of polyimide composites of the 10 complexes screened. Films prepared from the commercially available polyamic acid (PAA) of PMDA-ODA (DuPont) have good uniformity, flexibility, and tensile strength. A 24-layer 10% (mol) Zr(acac)4/PI composite film showed significant improvement (ca. 20 fold) of atomic oxygen resistance over the pure polyimide. However, 10% (mol) Zr(acac)4 represents an upper concentration limit, above which films undergo cracking upon thermal imidization. In order to increase the Zr complex concentration in PMDA-ODA PI films, while retaining good film properties, [Zr(adsp)2-PMDA]n coordination polymer [bis(4-amino-N,N'-disalicylidene- 1,2-phenylenediamino)zirconium(IV)-pyromellitic dianhydride] and [Zr(adsp)2-PMDA-ODA-PMDA]n terpolymer were synthesized and blended with commercial PAA, respectively. Several techniques were used to characterize the films made from the polymer containing Zr(acac)4. Plasma studies of films having 2% (mol) incremental concentrations of Zr in the Kapton up to 10% (mol) show that the overall rate of erosion is reduced about 75 percent. |
| File Size | 5995503 |
| Page Count | 138 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20010092697 |
| Archival Resource Key | ark:/13960/t1zd2w00d |
| Language | English |
| Publisher Date | 2001-08-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Anhydrides Coordination Polymers Scanning Electron Microscopy Zirconium Oxygen Atoms Amines Plasmas Physics Polyimides Synthesis Chemistry Polymeric Films Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
