W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1999 Additives for Increased Atomic Oxygen Resistance in Cyanate Ester Resins Sandeep Amar Saggar College of William & Mary - Arts & Sciences Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Polymer Chemistry Commons Recommended Citation Saggar, Sandeep Amar, "Additives for Increased Atomic Oxygen Resistance in Cyanate Ester Resins" (1999). Dissertations, Theses, and Masters Projects. Paper 1539626216. https://dx.doi.org/doi:10.21220/s2-nett-nt17 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Additives for Increased Atomic Oxygen Resistance in Cyanate Ester Resins A Thesis Presented to The Faculty of the Department of Chemistry The College of William and Mary In Partial Fulfillment of the Requirements for the Degree of Master of Arts by Sandeep Amar Saggar December 1999 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts ande Approved, December 1999 obert A. OrWoll, Ph. D. Richard L. Kieier, Ph. D Christopher J. Abek/Ph. D. Table of Contents Section Page Acknowledgments ...............................................................................................................................vi List of Tables ....................................................................................................................................... vii List of Figures ....................................................................................................................................viii Abstract............................................................................................................................................... xiii I Background ..............................................................................................................................2 1.1. Purpose .........................................................................................................................2 1.2. Spacecraft in Low Earth Orbit Environment .......................................................2 1.3. Polymeric Materials/Composites in Spacecraft Design ...................................6 1.4. Atomic Oxygen Interactions with Polymeric Spacecraft Materials .............. 8 1.5. M aterials.....................................................................................................................11 1.5.1. Motivation for Use of Additives ........................................................... 11 1.5.11. Boron .............................................................................................................12 1.5.111. Boron Carbide and Whisker Technology ........................................... 12 I.5.iv. Organoclays ............................................................................................... 13 I.5.v. Cyanate Resin............................................................................................15 1.6. Experim ental M ethods ........................................................................................... 20 1.6 .1. Scanning Electron Microscopy ............................................................. 20 1.6 .11. Thermogravimetric Analysis ................................................................ 22 1.6 .111. X-ray Photoelectron Spectroscopy ......................................................24 References............................................................................................................................. 27 II. Experimental ...........................................................................................................................29 II. 1. Materials......................................................................................... 29 II. 1 .i. Bisphenol A-based Cyanate Ester Resin ................................................ 29 Il.l.ii. Hexcel 954-3 Cyanate Ester Resin ..........................................................32 11.2. Ground-based Atomic Oxygen Plasma Generator ........................................34 11.3. Atomic Oxygen Exposures and Mass Loss Determinations ...................... 37 11.4. X-ray Photoelectron Spectroscopy ................................................................... 38 11.5. Scanning Electron Microscopy ..........................................................................38 11.6 . Thermogravimetric Analysis ..............................................................................39 11.7. Summary of Studies ............................................................................................. 40 R eferences..............................................................................................................................40 III. Results...................................................................................................................................... 41 III. 1. Atomic Oxygen Exposures and Mass Losses .....................................41 111.2. TGA Analysis........................................................................................................ 46 111.3. SEM A nalysis.................................. ...................................................................... 47 111.4. XPS Analysis......................................................................................................... 47 IV. Discussion ................................................................................................................................ 51 IV. 1. Polymer + Additive Preparation Success ........................................................51 IV.2. Analysis of BPA-based CE + Boron Samples ............................................... 51 IV.2.i. Mass Loss .................................................................................................. 51 IV.3. Analysis of BPA-based CE + B 4C Sam ples ...................................................52 IV .3.i. Mass L oss .................................................................................................. 52 IV.3.ii. SEM Analysis........................................................................................... 52 IV.3.iii.XPS Analysis............................................................................................54 iv IV.4. Deviations in Flux on Sample Holder ................................................................ 56 IV.4.i. First Method of Correction .....................................................................57 IV.4.ii. Second Method of Correction ................................................................ 58 IV.5. Analysis of the Third and Fifth Sets of AO Exposures .................................. 58 IV.5.i. Mass Loss ................................................................................................... 58 IV .6 . Analysis of the Sixth Set of AO Exposures .......................................................64 IV.6 .i. Mass L oss ................................................................................................... 64 IV.6 .ii.XPS Analysis............................................................................................ 65 IV .7. TGA A nalysis...........................................................................................................6 8 References..............................................................................................................................69 V. Conclusion .......................................................................................................................70 A ppendix .......................................................................................................................... 72 V ita...................................................................................................................................155 v Acknowledgements The research performed in this study was made possible by a NASA cooperative agreement, NCC-1-327. I would like to heartily thank Dr. Orwoll for his guidance and assistance in the undertaking of this project, as well as for advising me through my undergraduate and graduate career at The College of William and Mary. I would also like to thank Dr. Kiefer and Dr. Sheila Thibeault at NASA for getting me oriented with the Langley Research Center. Thanks to Dr. Abelt for his advice regarding graduate studies and to Dr. Cromer for his XPS analysis. In addition, I would like to thank William Gray at NASA LaRC for conducting the atomic oxygen exposures and teaching me about the atomic oxygen plasma generator. Finally, I would like to thank my family and close friends for their support. vi List of Tables Table 1: Fluences experienced at different surface orientations 6 Table 2: Bisphenol A-based Cyanate Ester Samples 31 Table 3: Hexcel 954-3 Cyanate Ester Samples 33 Table 4: Samples for XPS Analysis 38 Table 5: Summary of Studies 40 Table 6 : Abbreviations for sample locations on sample holder 41 Table 7: Mass Losses for BPA-based CE {first set of AO exposures} 41 Table 8 : Mass Losses for BPA-based CE {second set of AO exposures} 42 Table 9: Mass Losses for Hexcel 954-3 CE {third set of AO exposures} 43 Table 10: Mass Losses for Hexcel 954-3 {fourth set