Development of a Sustainable Perchlorate-Free ... - ACS Publications

Subscriber access provided by United Arab Emirates University | Libraries Deanship

Article

Development of a Sustainable PerchlorateFree Yellow Pyrotechnic Signal Flare Eric J. Miklaszewski, Jonathan M. Dilger, and Christina M. Yamamoto ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.6b02261 • Publication Date (Web): 31 Oct 2016 Downloaded from http://pubs.acs.org on November 3, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Sustainable Chemistry & Engineering is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Sustainable Chemistry & Engineering

Development of a Sustainable Perchlorate-Free Yellow Pyrotechnic Signal Flare Eric J. Miklaszewski*, Jonathan M. Dilger, Christina M. Yamamoto

Spectrum Warfare Systems Department, Naval Surface Warfare Center Crane Division, 300 Highway 361, Crane, IN 47522-5001, USA

KEYWORDS: Pyrotechnic, Environmentally-sustainable, Perchlorate-free, Mk 144, Flare ABSTRACT

Novel yellow-light emitting pyrotechnic compositions absent perchlorate oxidizers were investigated for use in the Mk 144 marine smoke and illumination signal. In laboratory scale testing, three candidate formulations met or surpassed performance metrics of luminous intensity, dominant wavelength, color purity, and burn time when compared to a mock Mk 144 formulation which currently utilizes the environmentally-hazardous potassium perchlorate. Also, one identified formulation does not utilize any barium compounds which may be the focus of future regulations. Furthermore, these candidate systems exhibited similar insensitivity to electrostatic, friction, and impact ignition stimuli in comparison to the mock Mk 144 formulation.

Therefore, replacement formulations for the Mk 144 marine smoke and

illumination signal have been identified with increased performance, environmental sustainability, and acceptable safety characteristics.

Corresponding Author

*E-mail: [email protected]

ACS Paragon Plus Environment

1


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 23

INTRODUCTION Perchlorate oxidizers have been widely used in military and civilian pyrotechnics due to their high reactivity, low cost, and high stability. However, the Environmental Protection Agency (EPA) has advised that concentrations as low as parts per billion can pose serious health risks through inhibition of iodine uptake by the thyroid gland.1 In response to these health concerns, the EPA has advised the permissible perchlorate levels under the Safe Drinking Water Act of 1974. These advisories have motivated costly remediation efforts on perchlorate-contaminated Department of Defense (DoD) ordnance testing sites. For example, all live fire training at Camp Edwards was suspended in 1997 due to perchlorate groundwater contamination concerns.2 Since training and testing operations are imperative to maintain military readiness, it is vital to remove perchlorate oxidizers from commonly used pyrotechnic devices to avoid further contamination and potential closures at DoD training sites. Since 2002, various efforts throughout the DoD have targeted a wide variety of commonlyused KClO4-containing pyrotechnic items including perchlorate-free smoke generating formulations3-6, time-delay compositions7-10 and incendiary compositions11.

However, most

perchlorate reformulation efforts have been focused on red- and green-light emitting signal flares such as hand-held signals (e.g., M126A1, Mk124, M195), pen flares (e.g., Mk80 and A/P25) and marine smoke and illumination signals (e.g., Mk140 and Mk141).12-19 To achieve this goal, the formulator must consider the interdependence of key performance metrics (e.g. luminous intensity, burn time, and color purity) as well as the regulatory status, commercial availability, and safety of appropriate ingredients.


2

Page 3 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The objective of this work was to develop a perchlorate-free yellow flare composition for use in the Mk 144 marine smoke and illumination signal. New formulations were evaluated against a mock Mk 144 flare formulation via laboratory-scale experiments to characterize luminous intensity, burn time, dominant wavelength, color purity, and ignition sensitivity. EXPERIMENTAL SECTION Reactive Pyrotechnic Compositions.

Table 1 summarizes the vendor information and

nominal particle sizing for the commercially-available powders used within the experimental compositions. Table 1. Vendor information of reactants. Powder

Vendor

Nominal Particle Size

Asphaltum

Hummel Croton, Inc.

--

Al

Hummel Croton, Inc.

Gr C, Class 4, Type II

Ba(NO3)2

Barium & Chemicals, Inc.

MIL-B-162, Gr B, Class 1

KClO4


MIL-P-217A, 100 micron

KNO3

Hummel Croton, Inc.

--

Mg

Hart Metals, Inc.

MIL-DTL-382D, Type III

Mg0.5Al0.5 Alloy

READE Advanced Materials

-200 mesh

Na2C2O4

GFS Chemicals, Inc.

MIL-S-210A

NaNO3

Hummel Croton, Inc.

MIL-S-322C, Gr B

Polyvinyl Chloride


MIL-P-20307

Sr(NO3)2


MIL-S-20322B

All pyrotechnic compositions were hand-mixed with a metal spatula within a grounded metal beaker in relatively small quantities of 50 g or less. First, the fuel and binder were mixed until homogeneous.

All other ingredients (primarily constituting oxidizers) were premixed in a


3


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 23

separate container and added into the fuel/binder pre-mixture. The composition was again mixed until homogeneous while maintaining proper grounding of the mixing vessel. The binder used was a two-part thermoset-epoxy consisting of 70 wt. % Epon 813 and 30 wt. % Versamid 140. Combustion Experiments. The final composition was partially cured for 30 - 60 minutes prior to pressing into experimental pellets. Figure 1 shows a typical experimental pellet and a schematic of how samples are mounted and inhibited with Miller-Stephenson's Epoxy 90720 to facilitate linear burning. Experimental pellets of 0.75 inch diameter were pressed utilizing a 12ton Carver press at a load of 1500 lbs. for 10 seconds. Each pellet was comprised of a nominal mass of 15 grams of composition with 1 gram of a thermite-based igniter. After mounting, samples cured in an oven at 60 °C for 24 hours. A 15 gram form factor was utilized for these combustion experiments due to the increased safety concerns associated with the Mk 144 form factor utilizing more than 130 grams of pyrotechnic composition. Three to six pellets were prepared for each composition to provide statistical validity on the measurements. Pellets were ignited remotely by an electric match. Luminous intensity measurements were performed using SED 033 silicon detector photodiode fitted with a photopic response filter (Y-filter).

The average luminous intensity (ALI) is

determined by averaging the steady-state intensity and therefore does not account for ignition and extinction transients. The luminous efficiency (LE) is calculated by integrating the temporal luminous intensity profile and dividing by the mass of the reacting pellet (~15 grams). The burn time (BT) is the time difference at 5% of the maximum luminous intensity over the duration of the burn of the experimental pellet. Color purity and dominant wavelength were measured using an Optroniks FMS 10 tristimulus colorimeter which referenced the standard I. C. I. Chromaticity


4

Page 5 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Diagram and illuminant C as the white point.21

A StellarNet BLUE-Wave miniature

spectrometer was used to evaluate qualitative differences in the spectral emissions.

Figure 1. Image of 15 gram pyrotechnic pellet (left) and schematic of mounted and inhibited pellet (right). Sensitivity Analysis. Sensitivity testing on selected formulations was performed according to NAVSEA Instruction 8020.5C and MIL-STD-1751A.22-23 Electrostatic discharge, friction, and impact sensitivities were determined in accordance with MIL-STD-1751A method 1031, method 1023, and method 1013, respectively.23 Thermochemical Predictions. Thermochemical predictions were made using the NASA CEA combustion module (hp) at a constant pressure of 1 atm.24 In these calculations, the heat of formation for polyvinyl chloride (PVC) (C2H3Cl) and Epon/Versamid (H98C83O14N4) were 22495 and -876278 cal∙mol-1, respectively.18 RESULTS AND DISCUSSION Overview of the Pyrotechnic Generation of Yellow Light. The generic chemical equation for the in-service Mk 144 yellow-light emitting flare composition is Mg + Ba(NO3)2 + Na2C2O4 + KClO4 + Hydrocarbon binders  MgO(s) + Na(g) + BaCl(g) + BaOH(g) + C(s) + others, (Eq. 1)


5


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 23

where Magnesium (Mg) is the fuel and barium nitrate (Ba(NO3)2), sodium oxalate (Na2C2O4), and potassium perchlorate (KClO4) are the oxidizers. Besides being a strong oxidizer, KClO4 also donates chlorine to produce several desired light-emitting chlorinated species upon combustion.

The hydrocarbon binders include a two-part thermoset binder (Laminac

4116/Lupersol) as well as a dry binder, asphaltum. A pyrotechnic reaction will produce a variety of combustion species that emit photons over a range of spectral wavelengths. Table 2 lists the relevant light-emitting combustion products for the yellow-light emitting pyrotechnic formulations considered here. These products include the condensed-phase products of magnesium oxide (MgO) and carbon (C) as well as gas-phase products of sodium (Na), barium chloride (BaCl), barium hydroxide (BaOH), and barium oxide (BaO). The gaseous combustion products emit photons at specific wavelengths in the green, yellow, orange, and red portions of the visible spectrum.

Thus, the pyrotechnic reaction

described within Equation 1 achieves its yellow color via a color-mixing strategy.

The

condensed phase species (e.g., Cs and MgOs) produced by the reaction also emit blackbody radiation that generally increases the luminous intensity of the flare while degrading the color purity of the flame.25 The average photopic emissions give rise to a specific color and purity as defined by the I. C. I. Chromaticity Diagram.21 Table 2. Common emission bands of yellow-light producing flares. Species

Emission Wavelengths (nm) 25-27

Visible Color

BaClg

513.9, 524.1, 532.1

Green

BaOg

549.3, 564.4, 586.5, 604.0, 649.4

Green, Yellow, Red

BaOHg

487.0, 512.0

Green

Cs

blackbody

*


6

Page 7 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


MgOs

498.6, 499.7, 500.7, blackbody

Green, *

Nag

589

Yellow-Orange

*The blackbody emission profiles depend on the flame temperature Evaluation of Yellow-Light Emitting Pyrotechnic Formulations from Literature. The initial strategy to reformulate the Mk144 was to leverage existing yellow-emitting compositions that do not contain perchlorate for their viability as replacements for the current in-service composition (Table 3). 25 Sodium oxalate and nitrates of potassium and sodium were utilized as the key oxidizers in these three systems. These systems were further modified with the two-part Epon 813/Versamid 140 binder so as to mitigate other environmental safety concerns associated with other common pyrotechnic binders. Table 3. Modified yellow-light emitting, perchlorate-free formulations from literature. Ingredient (wt. %)

Mk 144 1 25

2 25

3

Mg (Gr 17)

*

16.15

29.38

22

NaNO3

--

53.20

--

58

Na2C2O4

*

--

29.38

--

Ba(NO3)2

*

--

--

--

KClO4

*

--

--

--

PVC

--

25.65

--

--

KNO3

--

--

36.24

15

Asphaltum

*

Epoxy

*

5

5

5

*The exact amount of each ingredient for the current Mk 144 formulation is not approved for public release. Table 4 lists the combustion performance metrics for laboratory-scale samples of the mock Mk 144 and the identified perchlorate-free formulations. Each of the perchlorate-free formulations is


7


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 23

predicted to have moderate adiabatic combustion temperatures. As compared to the performance of the Mk 144, formulation 1 is shown to burn significantly slower with an extraordinarily lower ALI and LE. Similarly, Formulation 2 displays a significantly lower (though less extreme) ALI and LE than the Mk 144. Formulation 3 was designed to have a predicted adiabatic combustion temperature similar to 2 while utilizing NaNO3 instead of Na2C2O4. The resulting burn time, luminous intensity, and luminous efficiency of formulation 3 was encouragingly similar or greater than that of Mk 144. However, the 77% color purity of 3 was significantly lower than the 89.0% color purity of the Mk 144 formulation (see Supplemental Table S1). Table 4. Performance characteristics of modified perchlorate-free formulations from literature. LE (cd s g-1)

Tad (K)

BT (s)

ALI (cd)

Mk 144

42.3±0.7

1949±101 2599±135

2056

1

61.5±0.8

415±24

553±32

2665

2

40.7±0.3

1623±43

2165±57

2471

3

41.9±0.2

3130±228 4173±304

2407

It is clear from the performance evaluation that newly developed formulations are required as a Mk 144 replacement formulation. However, the high color purity of formulation 1 (93.2%) suggests that a reaction that primarily generates Nag in the combustion plume can yield highpurity yellow-light in comparison.

Hereafter, two distinctly different yellow-light emitting

pyrotechnic formulation systems were evaluated: one utilizing a color-mixing strategy with the use of barium nitrate and a chlorine donor and another exploring only sodium nitrate and sodium oxalate as the oxidizers. Formulation Development: Color-mixing with Barium Nitrate and PVC.

Initial

development efforts focused on simply replacing the potassium perchlorate oxidizer with


8

Page 9 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


sodium/barium nitrates for their oxidative potential as well as PVC as a chlorine donor. The generic form of the proposed perchlorate-free yellow-light emitting formulation is Mg + Mg0.5Al0.5 + NaNO3 + Ba(NO3)2 + Na2C2O4 + PVC + Hydrocarbon binders  MgOs + Nag + BaClg + BaOHg + Cs + others, (Eq. 2) where new ingredients include the sodium nitrate (NaNO3) and magnalium (Mg0.5Al0.5), which is used as an energetic additive. Magnalium was utilized in some formulations since the nitrate salts have less oxidative potential than the previously used potassium perchlorate. By comparing Equations 1 and 2, it is shown that all of the emitting species shown in Table 2 can be produced without the use of perchlorate oxidizers. New formulations and their corresponding performance data are shown in Table 5 and Table 6, respectively.16,28 As expected, the predicted adiabatic combustion temperature scales proportionally with the ALI and LE. Of these formulations, 5A and 6A are most efficient with similar burn times and increased luminous intensity in comparison to the Mk 144 composition, making them suitable replacement formulations. Due to the excess ALI (650 cd) and LE (870 cd s g-1) of 6A over Mk 144, we were able to tune the burn time and intensity of formulation 6A by increasing the epoxy binder content to 7 wt.% (6B). The resulting formulation achieved a more balanced performance in respect to the burn time and intensity of Mk 144. Similarly increasing the binder of formulation 5 to 7 wt.% (5B) resulted in luminous intensity and efficiency below that of the Mk 144 composition. All of the colorimetric data for these formulations were similar to that of the Mk 144 composition (see Supplemental Table S2). Table 5. Experimental color-mixed perchlorate-free formulations by weight %. 4

5A

5B

6A

6B


9


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table 6.

Page 10 of 23

Mg (Gr 17)

28.10 23.00 22.50 20.10 19.67

Mg0.5Al0.5

--

NaNO3

20.00 27.40 26.81 37.00 36.20

Ba(NO3)2

34.10 29.00 28.38 27.05 26.47

PVC

8.90

8.10

7.93

10.90 10.66

Asphaltum

3.95

3.95

3.86

--

--

Epoxy

4.95

4.95

7.0

4.95

7.0

3.60

3.52

--

--

Performance characteristics of the experimental color-mixed perchlorate-free

formulations. BT (s)

ALI (cd)

LE (cd s g-1)

Tad (K)

4

39.9±2.0

1649±32

2198±42

2270

5A

42.6±0.3

1989±49

2652±65

2542

5B

45.6±0.4

1888±55

2518±74

2533

6A

43.5±0.1

2602±72

3469±96

2915

6B

49.5±0.5

2179±75

2905±100

2841

The burn time and intensity of formulation 5A and 6A can be further improved by changing the particle size of the magnesium fuel. Table 7 showcases this effect on performance with the use of granulation 18 and granulation 15/18 sized magnesium powders. For each formulation, particle size scaled proportionately with burn time and luminous efficiency and inversely with luminous intensity. A granulation 17 sized magnesium fuel was found to be the optimum particle size for formulations 5A and 6A to meet or surpass the burn time and luminous intensity of the mock Mk 144 formulation. Particle size was not observed to significantly affect the colorimetric output of these formulations as shown in Supplemental S3. Table 7. Effect of Mg particle size on performance of formulations 5A and 6A.


10

Page 11 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Mg. Granulation

BT (s)

ALI (cd)

LE (cd s g-1)

Formulation 5A Gr 15/18*

37.6±0.5 2308±100 3077±134

Gr 17

42.6±0.3 1989±49

2652±65

Formulation 6A Gr 15

29.7±0.1 3960±103 5279±137

Gr 15/18*

36.7±0.6 3034±6

4046±7

Gr 17

43.5±0.1 2602±72

3469±96

Gr 18

65.1±1.0 1705±18

2274±23

Development of Mg/NaNO3/Na2C2O4 Formulations.

In order to develop a simplistic

yellow-light producing formulation, the Mg/NaNO3 was also considered. As shown in Table 8, formulations 7 and 8A were designed so that their predicted adiabatic combustion temperatures are similar to those which previously yielded promising results (i.e., 2400 - 2900 K). As shown in, these formulations had superior luminous efficiency in comparison to the Mk 144 formulation. However, the luminous intensity profile (Figure 2) of 8A was excessively noisy due to the far off-stoichiometric conditions of these reactions (stoichiometry of ~ 0.4). Furthermore, the ~80% color purity of formulations 7 and 8A were lower than the 89% of the mock Mk 144 formulation (Supplemental Table S4). Therefore, formulation 9A was developed to incorporate Na2C2O4 to reduce the MgOs species29, thereby cooling the reaction temperature and still producing the key yellow-emitting gaseous sodium (Nag). Spectral intensity profiles of these formulations (Figure 3) show how the addition of Na2C2O4 increased the color purity of formulation 9B by minimizing the green MgOs emission described in Table 2. With the addition of Na2C2O4, formulation 9A produced a superior color purity of 90% while greatly surpassing the


11


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 23

luminous intensity and efficiency requirements but falling short of the burn time requirement. Due to the higher than required luminous intensity and efficiency of formulations 8A and 9A, the effect of increasing the binder content to 7 wt. % was again explored to balance the performance metrics.

While the color purity of formulation 8B was still lacking, formulation 9B was

identified as a replacement for Mk 144 due to a superior burn time, luminous intensity, luminous efficiency and color purity while having a similar dominant wavelength to that of the Mk 144 formulation. Table 8. Mg/NaNO3/NaC2O4 formulations by weight %. 7

8A

8B

9A

9B

Mg (Gr 17)

23

26

25.5

26

25.5

NaNO3

72

69

65.6

39

38.2

Na2C2O4

--

--

--

30

29.4

Epoxy

5

5

7

5

7


12

Page 13 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 9. Performance of Mg/NaNO3/NaC2O4 formulations. LE (cd s g-1)

Tad (K)

BT (s)

ALI (cd)

7

40.9±2.7

4106±164 5475±219

2418

8A

37.5±0.9

5050±318 6733±424

2720

8B

46.2±0.8

4275±80

5700±106

2830

9A

39.1±0.2

4936±159 6581±211

2310

9B

46.2±0.5

3101±122 4135±163

2099

Figure 2. Luminous intensity profiles of the Mk 144 (red) and 8A (black) formulations.

Figure 3.

Raw spectral intensity profiles of Mk 144 (red), 8A (black) and 9B (blue)

formulations.


13


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 23

Ignition Sensitivity Analysis. Sensitivity analysis of the most promising formulations is shown in Table 10. Here, the 50% fire energy is reported for impact sensitivity, the minimum fire energy is reported for friction sensitivity, and the maximum no-fire energy is reported for electrostatic sensitivity. All formulations tested were found to be insensitive to impact stimuli as they were not initiated at the maximum height according to MIL-STD-1751A method 1013.23 The electrostatic sensitivity of these formulations was relatively similar to that of the Mk 144 formulation except for 5A which is more sensitive to electrostatic stimuli due to its use of Mg0.5Al0.5. The data obtained from MIL-STD-1751A method 1013, rotary friction method, can only be interpreted that each formulation is moderately sensitive to friction stimuli. A relative comparison of the friction ignition energy thresholds is not valid for this method. In summary, all of the formulations have similar ignition sensitivity to that of the Mk 144 formulation and would likely be approved for use in military items. Table 10. Sensitivity data of yellow-light emitting flare compositions. Impact Sensitivity

Sensitivity Electrostatic Sensitivity

(Joules)

Friction (ft lbs)

RDX*

17.5

116.3

0.080

Mk 144

32.6

158.4

0.180

5A

35.0

271.6

0.080

6

35.0

183.6

0.125

8B

35.0

110.4

0.125

9A

35.0

211.4

0.125

9B

35.0

239.8

0.125

Formulation

(Joules)

*RDX Class 5 Type II


14

Page 15 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


CONCLUSIONS Several perchlorate-free yellow-light emitting pyrotechnic compositions were developed for use in the Mk 144 marine smoke and illumination signal.

In laboratory-scale testing,

formulations 5A, 6B and 9B met or surpassed the luminous intensity, dominant wavelength, color purity, and burn time of currently used Mk 144 formulation which utilizes the environmentally-hazardous potassium perchlorate. Formulation 9B does not utilize any barium salt oxidizers, which may be the focus of future regulations due to the known adverse health effects of some barium compounds.

Furthermore, these candidate systems exhibit similar

insensitivity to electrostatic, friction and impact ignition stimuli, making them safe for handling. In conclusion, multiple perchlorate-free formulations which utilize commercially available ingredients have been identified for the Mk 144 marine smoke and illumination signal with increased performance, environmental sustainability and acceptable safety characteristics. ASSOCIATED CONTENT Supporting Information. Colorimetric performance of modified perchlorate-free formulations from literature (Table S1); Colorimetric performance of perchlorate-free formulations 4 – 6B (Table S2); Effect of Mg particle size on colorimetric performance of formulations 5A and 6A (Table S3); Colorimetric performance of Mg/NaNO3/NaC2O4 formulations (Table S4). This material is available free of charge via the Internet at http://pubs.acs.org. AUTHOR INFORMATION Corresponding Author

*E-mail: [email protected]


15


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 23

ACKNOWLEDGMENT This work was supported at NSWC Crane by the Naval Innovative Science and Engineering program as well as by the Strategic Environmental Research and Development Program under project WP-1280. The authors gratefully thank the sponsors of this work. REFERENCES 1. United States Environmental Protection Agency. Interim Health Advisory for Perchlorate, 2008. http://www.epa.gov/safewater/contaminants/unregulated/pdfs/healthadvisory perchlorate interim.pdf. 2. Government Accountability Office. GAO-10-769 Perchlorate occurence is widespread but at varying levels; federal agencies have taken some actions to respond to and lessen releases;, August 2010. 3. Shaw, A. P.; Poret, J. C.; Gilbert, R. A. J.; Domanico, J. A.; Black, E. L. Development and Performance of Boron Carbide-Based Smoke Compositions. Propellants Explos. Pyrotech. 2013, 38 (5), 622-628. 4. Chen, G.; Showalter, S.; Raibeck, G.; Wejsa, J. Environmentally Benign Battlefield Effects Black Smoke Simulator; Defense Technical Information Center, Accession Number : ADA481520, 2006. 5. Moretti, J. D.; Sabatini, J. J.; Shaw, A. P.; Gilbert, R. J. Promising Properties and System Demonstration of an Environmentally Benign Yellow Smoke Formulation for Hand-Held Signals. ACS Sustainable Chem. Eng., 2014, 2 (5), 1325-1330. 6. Moretti, J. D.; Sabatini, J. J.; Shaw, A. P.; Chen, G.; Gilbert, R. A.; Oyler, K. D. Prototype Scale Development of an Environmentally Benign Yellow Smoke Hand-Held Signal Formulation Based on Solvent Yellow 33. ACS Sustainable Chem. Eng. 2013, 1 (6), 673-678. 7. Miklaszewski, E. J.; Shaw, A. P.; Poret, J. C.; Son, S. F.; Groven, L. J. Performance and Aging of Mn/MnO2 as an Environmentally Friendly Energetic Time Delay Composition. ACS Sustainable Chem. Eng. 2014, 2 (5), 1312-1317. 8. Miklaszewski, E. J.; Poret, J. C.; Shaw, A. P.; Son, S. F.; Groven, L. J. Ti/C-3Ni/Al as a Replacement Time Delay Composition. Propellants, Explos., Pyrotech. 2013, 39 (1), 138-147. 9. Poret, J. C.; Shaw, A. P.; Csernica, C. M.; Oyler, K. D.; Estes, D. P. Development and Performance of the W/Sb2O3/KIO4/Lubricant Pyrotechnic Delay in the US Army Hand-Held Signal. Propellants, Explos., Pyrotech. 2012, 38 (1), 35-40. 10. Poret, J. C.; Shaw, A. P.; Csernica, C. M.; Oyler, K. D.; Vanatta, J. A.; Chen, G. Versatile Boron Carbide-Based Energetic Time Delay Compositions. ACS Sustainable Chem. Eng. 2013, 1 (10), 1333-1338.


16

Page 17 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


11. Moretti, J. D.; Sabatini, J. J.; Chen, G. Periodate Salts as Pyrotechnic Oxidizers: Development of Barium- and Perchlorate-Free Incendiary Formulations. Angew. Chem. Int. Ed. 2012, 51 (28), 6981-6983. 12. Sabatini, J. J.; Nagori, A. V.; Chen, G. C. P.; Damavarapu, R.; Klapötke, T. M. HighNitrogen-Based Pyrotechnics: Longer- and Brighter-Burning, Perchlorate-Free, Red-Light Illuminants for Military and Civilian Applications. Chem. Eur. J. 2012, 18 (2), 628-631. 13. Shaw, A. P.; Poret, J. C.; Grau, H. A. J.; Gilbert, R. A. J. Demonstration of the B4C/NaIO4/PTFE Delay in the U.S. Army Hand-Held Signal. ACS Sustainable Chem. Eng. 2015, 3 (7), 1558-1563. 14. Moretti, J. D.; Sabatini, J. J.; Poret, J. C. High-Performing Red-Light-Emitting Pyrotechnic Illuminants through the Use of Perchlorate-Free Materials. Chem. Eur. J. 2014, 20 (28), 8800-8804. 15. Dye, D. F.; Shortridge, R. G.; Yamamoto, C. Y.; Chen, G. Elimination of Perchlorate Oxidizers from Pyrotechnic Flare Compositions, ESTCP WP-200730 Final Report, 2015. 16. Shortridge, R. G.; Wilharm, C. K.; Yamamoto, C. Y. Elimination of Perchlorate Oxidizers from Pyrotechnic Flare Compositions, SERDP WP-1280 Final Report, 2007. 17. Shortridge, R. G.; Wilharm, C. K.; Yamamoto, C. M.; Dreizin, E. L. Development and Testing of Perchlorate-Free Red and Green Pyrotechnic Flare Compositions. 33rd International Pyrotechnic Seminar, Fort Collins, CO, 2006, 281-290. 18. Sabatini, J. J.; Freeman, C. T.; Poret, J. C.; Nagori, A. V.; Chen, G. An Examination of Binder Systems and Their Influences on Burn Rates of High-Nitrogen Containing Formulations. Propellants Explos. Pyrotech. 2011, 36 (2), 145-150. 19. Sabatini, J. J.; Raab, J. M.; Hann, R. K. J.; Damavarapu, R.; Klapotke, T. M. HighNitrogen-Based Pyrotechnics: Development of Perchlorate-Free Green-Light Illuminants for Military and Civilian Applications. Chem. Asian. J. 2012, 7 (7), 1657-1663. 20. "Two-Part Epoxy Adhesive Kit," Miller-Stephenson Chemical Company, Inc., 2015. [Online]. Available: http://www.miller-stephenson.com/products/detail.aspx?ItemId=60. 21. Judd, D. B. 1931 I. C. I. Standard Observer and Coordinate System for Colorimetry. J. Opt. Soc. Am. 1933, 23 (10), 359-374. 22. Peletski, C. NAVSEAINST 8020.5C: Qualification and Final (TYPE) Qualification Procedures for Navy Explosives; DTIC Accession Number: ADA509544; Technical Report for Naval Sea Systems Command: Arlington, VA, 2000. 23. Department of Defense Test Method Standard, Safety and Performance Tests for the Qualification of Explosives (High Exploxives, Propellants and Pyrotechnics); MIL-STD-1751A; Technical Report for Department of Defense: 2001.


17


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 23

24. McBride, B. J.; Gordon, S. Computer Program for Calculations of Complex Chemical Equilibrium Compositions and Applications, II. User Manual and Program Description; NASA Refernce Publication; National Aeronautics and Space Administration: Cleveland, 1996. 25. Conkling, J. A. Chemistry of Pyrotechnics: Basic Principles and Theory; CRC Press, 1985. 26. Pearse, R. W. B.; Gaydon, A. G. The identification of Molecular Spectra, Fourth Edition; Chapman and Hall, 1976. 27.

Gaydon, A. G. The Spectroscopy of Flames, Second Edition; Springer, 1974.

28. Yamamoto, C. M.; Shortridge, R. G. Perchlorate-free yellow signal flare composition. US8,568,542 B2, Oct. 29, 2013. 29. Kosanke, K. L.; Kosanke, B. J.; Pyrotechnic Chemistry – Ch 9. The Chemistry of Colored Flame; Journal of Pyrotechnics, Inc., 2004.


18

Page 19 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


For Table of Contents Use Only Development of a Sustainable Perchlorate-Free Yellow Pyrotechnic Signal Flare Eric J. Miklaszewski*, Jonathan M. Dilger, Christina M. Yamamoto Spectrum Warfare Systems Department, Naval Surface Warfare Center Crane Division, 300 Highway 361, Crane, IN 47522-5001, USA Novel yellow-light emitting pyrotechnic compositions absent the environmentally-hazardous potassium perchlorate were developed as a replacement formulation for the Mk 144 marine smoke and illumination signal.


19


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Page 20 of 23

0.75 inch

Ignition Increment

~0.1 inch Flare Pellet

~1.2-1.6 inch Epoxy Inhibitor Mounting Block


Page 21 of 23

12000 10000 Intensity (cp)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42


8A

8000 6000

Mk 144

4000 2000 0 0

5

10

15

20 25 Time (seconds)


30

35

40

45

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Spectral Intensity (a.u.)


Page 22 of 23

Legend BaCl MgO Na

400

450

500

550 Wavelength (nm)

600


650

700

Page ACS23Sustainable of 23 Chemistry & Engineering

1 2 3 4 5 6 7


Development of a Sustainable Perchlorate-Free ... - ACS Publications

Recommend Documents