Development of Azeotropic Blends to Replace TCE and nPB in Vapor Degreasing Operations Darren L. Williams, Ph.D. Chemistry Department, Sam Houston State University, Huntsville, TX 77341 [email protected] (936)294-1529 December 21, 2016 Final Report Strategic Environmental Research and Development Program Weapons Systems and Platforms (WP-2522) US Army Corps of Engineers, Contract W912HG-14-C-0062 Dr. Robin Nissan, WP Program Manager [email protected] (571)372-6399 Table of Contents Table of Contents ............................................................................................................................ ii List of Tables ................................................................................................................................. iii List of Figures ................................................................................................................................ iv List of Acronyms ........................................................................................................................... vi Keywords ..................................................................................................................................... viii Acknowledgments.......................................................................................................................... ix Abstract ........................................................................................................................................... 1 Objectives ....................................................................................................................................... 3 Background ..................................................................................................................................... 4 Materials and Methods .................................................................................................................... 6 Results and Discussion ................................................................................................................. 20 Conclusions and Implications for Future Research ...................................................................... 39 Literature Cited ............................................................................................................................. 42 Appendix A – List of Contacts ......................................................................................................47 Appendix B – Standard Operating Procedures ..............................................................................50 Appendix C – SDS for all Solvents .............................................................................................119 ii List of Tables Table 1: The solvents that were explored as blend components. Listed are the Hansen solubility parameters (D, P, H in MPa1/2), flammability, global warming potential, and the Hansen distance (Ra in MPa1/2) from the average position of nPB and TCE in Hansen space. Sources for the GWP100 values are given. .......................................................................................................... 7 Table 2: Compositions (% v/v), boiling points, and flash point behavior of the azeotropes discovered by this project ............................................................................................................. 25 Table 3: The Hansen solubility parameters (D, P, and H), densities (ρ), volumetric expansion coefficients (β), viscosities (η), surface tension (γ), and wetting index (W) values for the azeotropic blends 6 and 7 along with their blend components ..................................................... 37 Table 4: Evaluation of the likelihood of the new azeotropes 6 and 7 to clean other soils ............ 38 iii List of Figures Figure 1: Initial solvent down-selection scheme ............................................................................ 6 Figure 2: Solvents plotted in spherical Hansen space (2D, P, and H in MPa1/2). Each data point is a blend of the colors of the HSP axes. The abbreviations are explained in the List of Acronyms. 9 Figure 3: The flash point of p-chlorobenzotrifluoride (CBTF) confirmed using a Tag closed cup flash point tester and ASTM-D56 ................................................................................................. 11 Figure 4: The 7.6-L (2-gallon) capacity Branson 125 vapor degreaser retrofitted with a sliding lid and sub-zero coils ......................................................................................................................... 12 Figure 5: The inside of the Branson 125 vapor degreaser showing the temperature zones (thermal image), the vapor zone, and the copper sub-zero coils ................................................................. 13 Figure 6: Cylindrical research vapor degreaser consisting of a silicone heater, magnetic stirrer, part basket, dual sub-zero cooling coils, thermocouple temperature monitor .............................. 14 Figure 7: The degreasing study coupons (brass, Al-7075, and SS-316) showing a typical load of ≅ 0.1 g of marine grade grease ..................................................................................................... 15 Figure 8: The HP 5890 GC oven that served as a temperature-programmable reflow oven for the vial-based defluxing tests .............................................................................................................. 17 Figure 9: Video-based falling ball viscometry apparatus ............................................................. 18 Figure 10: The Raman chemometric analysis of azeotrope number 1 of AE-3000 and methanol 21 Figure 11: The Raman chemometric analysis of azeotrope number 2 of HFE-7100 and methanol ....................................................................................................................................................... 21 Figure 12: The Raman chemometric analysis of azeotrope number 3 of HFE-7300 and tert- butylacetate ................................................................................................................................... 22 Figure 13: The Raman chemometric analysis of azeotrope number 4 of AE-3000 and Solkane 365................................................................................................................................................. 22 Figure 14: The Raman chemometric analysis of the light fraction (top layer) of the two-phase azeotrope number 5 of HFE-7500 and ethyl lactate ..................................................................... 23 Figure 15: The Raman chemometric analysis of the heavy fraction (bottom layer) of the two- phase azeotrope number 5 of HFE-7500 and ethyl lactate ........................................................... 23 Figure 16: The Raman chemometric analysis of azeotrope number 6 of Suprion and p- chlorobenzotrifluoride ................................................................................................................... 24 Figure 17: The Raman chemometric analysis of azeotrope number 7 of HFE-7500 and p- chlorobenzotrifluoride ................................................................................................................... 24 Figure 18: Photo of CBTF participating in burning below its flash point .................................... 26 Figure 19: Photo of HFE-7100 participating in burning up to its boiling point ........................... 27 iv Figure 20: Photo of azeotrope 6 (20% CBTF and 80% Sup) participating in burning at its boiling point .............................................................................................................................................. 27 Figure 21: Photo of azeotrope 7 (35% CBTF and 65% HFE5) participating in burning at its boiling point .................................................................................................................................. 28 Figure 22: The results of the vial-based solvent screening test .................................................... 29 Figure 23: The visual performance of nPB in the Branson 125 against marine grade grease on brass fitting #47 shows that the degreasing protocol works well. The visual performance of TCE was identical.................................................................................................................................. 30 Figure 24: The gravimetric performance of nPB in the Branson 125 against marine grade grease ....................................................................................................................................................... 31 Figure 25: The gravimetric performance of TCE in the Branson 125 against marine grade grease ....................................................................................................................................................... 31 Figure 26: The visual performance of azeotrope number 6 (AZ6) in the Branson 125 against marine grade grease ...................................................................................................................... 32 Figure 27: The gravimetric performance of azeotrope number 6 (AZ6) in the Branson 125 against marine grade grease .......................................................................................................... 33 Figure 28: The visual performance of azeotrope 7 (AZ7) in the Branson 125 against marine grade grease .................................................................................................................................