. ,. . . I ,

2

ALTERNATIVE CLEANERS TECHNOLOGY DATA EXCHANGE

NASA OPERATIONAL ENVIR0"T TEAM MARSHALL SPACE FLIGHT CENTER (MSFC)

10&11 AUGUST 1993

._ - -. . . .. . . . .

EVALUATION OF AQUEOUS CLEANING AGENTS AS ALTERNATIVE TO

CHLORINATED SOLVENT DEGREASING

ALANR. BROWN MATERIALS ENGINEERING & TECHNOLOGY

CANOGA PARK. CALIFORNIA

ALTERNATIV

OBJECTIVES

0 ELIMINATE USE OF 1 ,I ,I ' TRICHLOROETHANE (TCA) AND CFC-113

0 REPLACE SOLVENT DEGREASING WITH AQUEOUS CLEANING

0 IDENTIFY MOST EFFECTIVE ALL-PURPOSE AQUEOUS CLEANER

AO120.1

0 IDENTIFY, TEST AND EVALUATE CLEANERS FOR BASIC REQUIREMENTS

MUST MEET ENVIRONMENTAL, HEALTH & SAFETY REGULATIONS

LOW FOAMING, STABLE, AND EASY TO MAINTAIN

COMPATIBLE WITH BASE MATERIALS

GOOD SOLUTION AND DRIED PRECIPITATE RlNSABlLlTY

GOOD CLEANING EFFECTIVENESS

A0120.2

I PRELIMINARY REVIEW OF MSDS I AN6~T.E.cHNicA~L~LiT~ERATuRE B v

I NICKEL SULFUR EMBRITTLEMENT TEST I

I TITANIUM

COMPATIBILITY

I I

RlNSABlLlTY TEST

I

RlNSABlLlTY TEST SOLUTION REMOVAL DRIED PRECIPITATE REMOVAL

CLEANING EFFECTIVENESS TEST

GENERAL ,

AND PHYSICAL PROPERTIES

1

I .I . STRESS CORROSION CRACKING TEST

I I I

ACCEPTABLE CLEANER FOR I PILOT PLANT EVALUATION A01203

ENVIRONMENTAL REGULATIONS ON VOC LIMITS

ENVIRONMENTAL REGULATION PROP. 65

ENVIRONMENTAL REGULATION LA COUNTY REG.

LOW voc

NO CHROME

NO SULFIDES

INITIAL RESULTS OF LONG TERM TOXICITY STUDY INDICATE THAT D-LIMONENE MAY BE A I CARCINOGEN

NO TERPENES CONTAINING D-LIMONENE I 1 LOW TOXICITY 1 GENERAL HEALTH & SAFETY CONCERN

HIGH FLASH POINT I POTENTIAL EXPLOSION HAZARD IF CLEANER IS NOT COMPLETELY RINSED FROM INTERNAL CAVITIES I

I 1 GENERAL SHOP FIRE HAZARD

STRONG ODORS RESULT IN A I "PERCEIVED HEALTH HAZARD NO TERPENES OR OTHER CLEANERS I WITH STRONG ODORS

A0120.4

AQUEOUS CLEANER REQUIREMENTS

ME&T REQUIREMENTS

COMPATIBLE WITH BASE MATERIAL

LOW SULFUR CONTENT I LOW CHLORIDE CONTENT

GOOD SOLUTION AND DRIED PRECIPITATE RlNSABlLlTY

NO SlLlCATED CLEANERS THAT LEAVE A RESIDUE I GOOD CLEANING EFFECTIVENESS I

I LOW FOAMING

->

STABLE SOLUTION

GOOD SOLUTION MAINTENANCE I

REASON FOR REQUIREMENT

CLEANER MUST NOT HAVE DETRIMENTAL EFFECTS ON HARDWARE

NICKEL COMPATIBILITY

TITANIUM COMPATIBILITY GENERAL METALLIC CORROSION

CLEANER RESIDUE INTERFERES WITH DYE PENETRANT INSPECTION

REDUCES PROCESSING TIME

REDUCES REJECTION RATE

IMPROVES PROCESSING CONDITIONS

PREVENTS SOLUTION MAINTENANCE PROBLEMS

PROVIDES CONSISTENT CLEANING EFFECTIVENESS RESULTS

A0120.5

t

EVALUATION OF AQUEOUS CLEANING AGENTS AS ALTERNATIVE TO CHLORINATED SOLVENT DEGREASING

0 TEST METHOD FOR SULFUR EMBRITTLEMENT OF NICKEL

CLEANING SOLUTION IS ENCAPSULATED IN A Ni 200 TUBE

FULL CIRCLE CROSS SECTION IS EXAMINED AT 1OOX

Ni TUBE IS HEATED IN AIR FURNACE FOR 10 min. AT 130OOF

NO IGA DEPTH > 0.003”

A0120.6

EVALUATION OF AQUEOUS CLEANING AGENTS AS ALTERNATIVE TO CHLORINATED SOLVENT DEGREASING

0 TEST METHOD FOR TITANIUM SCC COMPATIBILITY

CLEANING SOLUTION IS APPLIED TO BENT BEAM Ti TEST PANELS

ONE PANEL, FLUID IS TESTED AFTER AIR DRY

ONE PANEL, FLUID IS TESTED WET

PANELS ARE HEATED IN AIR FURNACE FOR 4 hr. AT 1000" F

0 PANELS ARE BWT AROUND 10T DIA.

EXAMINED FOR CRACKS AT 30X AND 200X

NO EVIDENCE OF CRACKS

A0120.7

I

EVALUATION OF AQUEOUS CLEANING AGENTS AS ALTERNATIVE TO CHLORINATED SOLVENT DEGREASING

/

0 TEST METHOD FOR SOLUTION RlNSABlLlTY

Ni BASE ALLOY TEST PANELS ARE CLEANED, DRIED, & WEIGHED

CLEAN TEST PANELS ARE IMMERSED IN CLEANING SOLUTION 3 min.

PANELS ARE RINSED IN D.I. WATER & AIR DRIED

PANELS ARE REWEIGHED & INSPECTED FOR RESIDUES '%

WEIGHT CHANGE IS RECORDED NO VISUAL RESIDUE AFTER AIR DRY

NO WHITE RESIDUE AFTER APPLIED DROP OF IPA

A0120.8

0 TEST METHOD FOR DRIED PRECIPITATE RlNSABlLlTY

0 Ni BASE ALLOY TEST PANELS ARE CLEANED, DRIED, & WEIGHED

CLEAN TEST PANELS ARE IMMERSED IN CLEANING SOLUTION 3 min.

PANELS ARE DRIED AT 49ANGLE WITHOUT RINSING OFF CLEANING SOLUTION

PANELS ARE WEIGHED & AMOUNT OF RESIDUE RECORDED . PANELS ARE RINSED IN COLD AND/OR HOT D.I. WATER

9 PANELS ARE DRIED, REWEIGHED, & INSPECTED FOR RESIDUES

. LOOK FOR WATER BREAK FREE SURFACE

WEIGHT CHANGE IS RECORDED . NO VISUAL RESIDUE AFTER AIR DRY . NO WHITE RESIDUE AFTER APPLIED DROP OF IPA

A0120.9

0 TEST METHODS FOR CLEANING EFFECTIVENESS

TEST PANEL IS CLEANED, DRIED, & WEIGHED

TYPICAL SHOP SOIL IS APPLIED TO PANEL & BAKED lhr. AT 200'F

0 PANEL IS IMMERSED FOR 40 min., MAX. CLEANER SOLUTION AT RECOMMENDED OPERATING TEMPERATURE

PANEL IS REMOVED PERIODICALLY, RINSED & EXAMINED

LOOK FOB WATER BREAK FREE SURFACE

RECORD TIME IN CLEANER SOLUTION

WEIGH TO CALCULATE RESIDUE

AO120.10

I

0 CORROSION TESTS PERFORMED

0 GENERAL CORROSION

0 STRESS CORROSION CRACKING

0 METAL ALLOYS EVALUATED

CO ALLOY HAYNES 188 CU ALLOY NARLOY-Z

NI ALLOY 718 TI ALLOY 5 AL-2.5 SN

21-26-9 PH STEEL ALALLOY 2024

440C STEEL 4130 STEEL

A0 1 20.1 1 A

z 0 z 0 U U 0 0 -I <

CT w

z w

c3 U 0

LL

n 0 I

I- w

2

+ v)

w

I-

o

n

W I

s n

a d

n

n-

a

z

W

LT -

W

z

W

6 a

cn -1

W

z a

3 L 0

n

W I

ki! W

rf

z

n

a

n-

n

n-

W

LT - W

cn z

LT

W

-

n-

2 6 W

LT

Y a

W

z a

0

0 TEST METHOD FOR STRESS CORROSION CRACKING

C-RINGS PER ASTM G38

STRESSED @ 75% YIELD STRENGTH DETERMINED BY STRAIN GAGE

EXPOSED TO CLEANER BY METHOD SlMllAR TO ASTMG44

0 ALTERNATE IMMERSION

10 MIN. IN SOLUTION 50MIN. OUT SOLUTION

SPECIMENS EXAMINED 2X PER DAY

0 CONTINUED UNTIL CRACKING OBSERVED

OR

FOR MAX. 30 DAYS

A0120.11C

0 QUALITATIVE ANALYSIS OF CHEMICAL & PHYSICAL PROPERTIES

FTlR FINGERPRINT OF ORGANIC CONSTITUENTS

EDXRF FOR PRESENCE OF ELEMENTS HIGHER THAN Na

ION CHROMATOGRAPHY

DETERMINE % NVR

FLASHPOINT'TEST PER ASTM D92 TEST

CLEVELAND OPEN CUP METHOD

A0120.11D

0 STATUS:

CONTACTED 95 SUPPLIERS TO REVIEW 200 CLEANERS

63 ELIMINATED THRU ME&T AND ENVIRONMENTAL REVIEW (v

L L,zA( $i?

INITIATED TESTING FOR 78 POTENTIAL CANDIDATES

78 TESTED FOR Ni COMPATIBILITY

39 TESTED FOR Ti COMPATIBILITY \ J ' \\b J $5

44 TESTED FOR RlNSABlLlTY t v \ A p +

12 TESTED FOR CLEANING EFFECTIVENESS

8 TESTED FOR CORROSIVE EFFECTS

A0 1 20.1 2

RESULTS:

51 MET ROCKETDYNE Ni COMPATIBILITY REQUIREMENTS

36 MET ROCKETDYNE Ti COMPATIBILITY REQUIREMENTS

15 MET ROCKETDYNE RlNSABlLlTY REQUIREMENTS

MOST CLEANERS CONTAINING SILICATES FAILED RlNSABlLlTY

SILICATE RESIDUE CAN INTERFERE WITH PENETRANT INSPECTION -

CLEANING EFFECTIVENESS AND CORROSIVE PROPERTIES ,

SOIL AND/OR SUBSTRATE SPECIFIC . CANNOT READILY SUMMARIZE RESULTS

A0120.13

0 CONCLUSIONS AND RECOMMENDATIONS:

AQUEOUS CLEANING CAN REPLACE TCA & CFC-113 CLEANING

0 OTHER REPLACEMENT CLEANERS PRESENT PROBLEMS

INCOMPATIBLE WITH OXYGEN-RICH ENGINE SYSTEMS

POSE H&S OR ENVIRONMENTAL CONCERNS

0 AQUEOUS CLEANER SELECTION REQUIRES EVALUATION & TEST

NO SINGLE AQUEOUS CLEANER CAN CLEAN ALL SOILS ENCOUNTERED

SOME SHOP SOILS ARE IMPERVIOUS TO AQUEOUS CLEANING

CLEANING AGENT SELECTION SPECIFIC TO SOILS & SUBSTRATES

~

MUST ESTABLISH YOUR SPECIFIC REQUIREMENTS

MUST TEST TO DETERMINE WHAT IS EFFECTIVE IN YOUR SHOP

A0120.14

0 SUMMARY

0 200 CLEANERS HAVE BEEN REVIEWED

DATA COMPILED IN TABULAR FORM

0 DATA INCLUDES CLEANERS MEETING ROCKETDYNE REQUIREMENTS FOR:

Ni COMPATJBILITY . Ti COMPATIBILITY RlNSABlLlTY . CLEANING EFFECTIVENESS vs. ROCKETDYNE SOILS

A0120.15

a AQUEOUS CLEANER SELECTION IS SUBSTRATE & SOIL SPECIFIC

REQUIREMENTS BASED ON ROCKETDYNE HARDWARE AND PROCESSES

MANY GOOD AQUEOUS CLEANERS AVAILABLE

0 WHAT WORKS WELL AT ONE COMPANY MAY NOT AT ANOTHER

a REJECTION OF A CLEANER IS NOT A REFLECTION OF ITS QUALITY

MANY GOOD CLEANERS REJECTED DUE TO UNIQUE REQUIREMENTS

I

A01 20.16

.\ I

I

I I I I I

I 100, 000 CLASS C LEANROO M I I Ye

b9 I I GENERAL SHOP AREA I

I I

I

I

I I

CFC 113

VERIFY

VAPOR DEG R EASE

CLEAN 1,1,1 - tric., VERIFY

EMULSION D EG R EASE

I

I I

I

I

I I I I I I I I I I - - _ _ - _ _ _ _ - _ - _ - _ _ _ _ _ - - - _

I I

I

I I CLEAN I

I - - - - - - - - - _ - - - - _ _ - - _

A01 28.17

I

M I CLEANROO ’ 100,000 c LASS I I I

I I

I I I I I I

I I I I I I

I I I I I I I I I VISUALLY I

’ CLEAN I

i GENERAL SHOP AREA I I

I 1 I I I

I I I I I

. . . . . . . . . . . . . . . . . . . . . . . .

ROUGH CLEAN I I

PROCESS

CLEAN 44 I I ,

3% I I 5

U I I

I I I

I

A0128.18

DEVELOPED AN AQUEOUS FINE CLEAN PROCESS

/ I CL 0 BASED ON ULTRASONIC CLEANING TECHNIQUES ?,?

USING IN-HOUSE AQUEOUS CLEANERS

FACILITY IS CURRENTLY IN BIDDING PROCESS

0 SCHEDULED FOR COMPLETION IN MARCH '94 -.\

A01 20.1 9

I AQUEOUS CLEANING FACILITY

CANOGA - FINE CLEAN -

r

ULTRASONIC CLEANING LINE BY NAPCO

.20

SPRAY ULTRASONIC RINSE

I

I SPRAY RINSE EVALUATE

FOR WATER BREAK FREE

SURFACE

- I CLEAN IN T:U.RC.02?4215,3 I ADDITIVE

1 I c

SPRAY RINSE

EVALUATE

500 ml SOLVENT FLUSH

PARTICLE COUNT \ & NVR \ AO120.22

.21

GROUNC LRlEl /

L I D

HIGH LIOUID LEVEL

EXHAUST HEADER

SPACE ALLOWED FOR TRANSDUCERS

1 ' MECHANICAL

ROOM -

ROOM ALLOWED FOR

(TYP) STEAM HEATING COILS

ELEVATION DRAWING -

AQUEOUS FINE CLEAN TANKS

AQUEOUS FINE

0 FACILITY IS DESIGNED TO

CLEAN BY 25-40 KHZ ULTRASONIC AGITATION 3 TANKS 4 ’X4 ’X4 :

3 TANKS 5 ’ X 5 ’ X 5 ’

, ,$AN/ RINSE BY HIGH PRESSURE, HIGH VOLUME D.I. WATER SPRAY 7-A +A.

i ’

PARTS PROCESSED THRU 3 CLEANING AGENTS, EACH FOLLOWED P

Lf BY SPRAY RINSE

EMULSION DEGREASER: TURCO 3878,‘ 20% / VOL. MILD ALKALINE CLEANER: TURCO 4215 NC-LT, 3-3.5%/WT. DILUTE SURFACTANT: TURCO 421 5 ADDITIVE, 0.04% / VOL. CLEANING SOLUTIONS PREPARED USING D.I. WATER

0 EMULSION DEGREASER & MILD ALKALINE CLEANER ARE FILTERED TO 10 MICRONS .-

j.

0 SURFACTANT & ALL D.I. WATER ARE FILTERED TO 3 MICRONS

0 AFTER COMPLETING CLEANING CYCLES, PARTS ARE VERIFIED FOR CLEANLINESS . WATER FLUSH TO MEET PARTICLE REQUIREMENTS, ONLY

SOLVENT FLUSH FOR NONVOLATILE RESIDUE REQUIREMENTS

A0120.24

. .

0 AQUEOUS CLEANING CAN REPLACE TCA & CFC-113 CLEANING

0 OTHER REPLACEMENT CLEANERS PRESENT PROBLEMS

0 INCOMPATIBLE WITH OXYGEN-RICH ENGINE SYSTEMS

POSE H&S OR ENVIRONMENTAL CONCERNS

0 AQUEOUS CLEANER SELECTION REQUIRES EVALUATION & TEST

NO SINGLE AQUEOUS CLEANER CAN CLEAN ALL SOILS ENCOUNTERED

SOME SHOP SOILS ARE IMPERVIOUS TO AQUEOUS CLEANING

CLEANING AGENT SELECTION SPECIFIC TO SOILS & SUBSTRATES MUST ESTABLISH YOUR SPECIFIC REQUIREMENTS MUST TEST TO DETERMINE WHAT IS EFFECTIVE INYOUR SHOP

0 ROCKETDYNE COMMITTED TO ALL-AQUEOUS CLEANING

AQUEOUS FINE CLEAN FACILITY DEVELOPED

CONSTRUCTION COMPLETION SCHEDULED IN APRIL '94

A0120.23

s

To: J.A. Purvis

From: &%. Moan ~.zoH- Science & Technology

Subject Solvent Solubility Parameters And Their Application

Interoffice Memo

Bacchus Works Magna, Utah

December 18, 1992

,I. Backaround

Many commonly used solvents at Hercules and throughout the aerospace industry will be phased off of the produclion flcor due to their being classtied as Ozone Depletlng Substances (ODs) or due to other safety concerns. We have skuations where we need to olean 8 wide variety of contaminants from paints and b- staged polymers to dusting and general cleanlng. Solvent substitution has especially been troublesome for such versatile cleaners a8 1 ,I ,I Trichloroethane (TCA) for whioh no drop4 replaoement has been found,

. exoept for perhaps some of the other chlorinated solvents Which have been classtied as oarcinogefiic, . - . teratogenio, or having some other chronic efiects.

it appears from review of many solvent substitution studies throughout the industry that a trlal-and-error approach is being employed with large numbers of candidates from just a few ohemicai families and most being totally ignored. A more systematlo aRpmach must be used when attacking a large variety of contamlnants, substrates, and processing environments. The adage of like-dissolves~like is coned in philosophy, but can be a mideadlng guide, especially wlh the popular misconception that thls is refening only to polarity. A measurement system is needed that is well documented and acoepted thmughout the industry and that can be applied in an additive manner to estlmate the effect Of solvent blending to optimize propertles.

J~-K'

The solubility parameter system has pmven to be the most practical, quantkative guide for selecting solvent candidates for testing. If we have characterized the solute, we have a good starting point for determining the likely solvents and a guide to optimizing by blending. SP takes the Ilke-dlssolves-like logic backfo baslo themodynamlcs In evaluating the mixing compatbility of mategals by describing and quantifying the forces holding materials together or cohesive enem. The density of cohesive energy Is most useful for predicting the solubility and swelling pswer of sets of materials In conjunction with matching other ptCpertle$ mentioned later.

During !he dssoluuon pmcess, the Intermolecular bonds of materials A and B are broken while new bonds between the difterent materials are formed, if these A-A, E-$, and A.8 bonds are similar, little energy will be needed to replace the broken A-A and 8.8 bonds with the newly formed A-B bonds. But if the A-A b n d IS much stronger than the A.8 and 6-9 bends, breaking the A-A bond will be thermodynamically unfavorable.'

i

. . . .I .. , .

!

. . . 8. ' Gardcn, J.L. "Cchssive Energy Density" Vol. 3

Solubility Parameters and Their Applicatlcn 18 December 1992

Comparisons of SP ala the mo$t important fador in determining the AH (heat of mixing) of two materials. This AH must be minimized to drive the process since AG-AH-TAS (Eq. 1) must be negative for the process to proceeda.

.

AQ = Excess Gbbs free energy

AS = Change in entropy T = Absolute temperature

AS Is Invariably positive in the solution process since it involves sepaation of molecules in a liquid or exxpandocln al degrees o! freedom in a gel. Therefore, at constant temperature, the sign of dG Is controlled by AH. The most u6eful treatment for determining AH is from Hildebranb

1 I

Ahn vfn

AE V $

I I

- Overall heat of mkirtg (ea0 - Total mixture volume (cm') - Energy of vaporkation (oal/mol) - Molar volume (cma/mco - Vclume fraction

Eq. 2

The factar ( A W ) Is the energy of vaporization per om3 for each oomponent, also known as the "cohesive energy density". This Is a measurement af the energy needed to totally separate (vapodze) the molecules of 1 c d of mafebal to Infinity by overcoming the intermolecular forces holding the material together.

The square root of the oohesive enefgy density is of primary 'mgortance In the heat of mixing term and Hildebrand defined it as the material's solubilitv Parameter CSl.

Eq. 3

The units are in (MefQyNol)" which converts to (caVcma)P*s = 2.05 MPa".

with the two moei common unks being

- ~ ~~

Hildebrmd, J. and Scott, R. "The Solubility of NOn.EImoW (1949)

lbld

2

' WG I.? '93 I @ : Z I G M THIGKGL RXrD _ I .

P. 5/9

Solubility Parameters and Their Appiication 18 December 1992

If no other detailed Information Is available, havlng the &and general H bonding class of a material Can give a suitable general solubility description of the material. A more recent overvlew of the data and testing techniques was used by Burrell' to classify the major chemlcal familles into three groups:

-

Strong I4 Bond - Alcohols, Amines, Amides, Aldehydes, Acids Mcderate H Bond - Esters, Ketones, Ethers, Glycol monoethers Poor H b n d - Aliphatios, .k"tic6, Chlorinated hydrocarbons, Nitrohydrocarbons

IV. Polar Sondlnu Effects

Polar effects arise from Induced polarby by atomic charge migration In non-polar materials (dispersion 01 London foross), orientation of 2 polar molecules (Uipole-dlpole or Keesom interacllon), or by dipole-induced dlpole effeots for a polar and ncn-polar molecule pa!! (Debye lnteraotlon).

There is some disagreement on the importance of dipolar bonding role In Intermolecular attraotlon by permanent or Induced dlpoles. Studies by Hildebrand and Small7 agree that the dipole interaction plays only a small roie in these forces. Small states tor acetone, one of the most polar llquids wfth a dipole moment of 2.9 Debye unffs, the dipole interadion only Oontrlbutes a small amount of the total cohesive energy density. Gardon asserts, though, that In the swelling of polymers, matchlng the fraclional polarlies (p) Is as important as having simiiar 8s. Fractional polarly being calculated from the material's polarizability and ionization potential. This measurement is dccumented for only a small number of solvents and fewer polymers.

Many of the general screenings for solubiflties only depend on the soiubilfty parameter and the H bond class to classify the solvents. This method should work well In most cases. If polaraj data Is available, it car) be included to help further diiierentiate solvents.

j-lansen-Hildebra@d Sclubllitv Parameter

AS aforementioned, the Hlldebrand parameter assumes non-assodating molecules (1.e. no H bonding or polar coupling). The calculation of S from molecular studure can have large errors due to thls assumption (&e. aiwhols,ester$, ketones) and the overall 6 gives no idea how to balance the factors contributing to 6.

Hansen8 expanded an the Hildebrand parameter an4 included all of the major coheslve strength factors which include nan-dlspersive polarity (Q, hydrogen bonding Jh), and dlspershe forces (8,) and comblne to farm the total Solubility parameter (Q.

6,2 = 6,2+6,2CS,2 Eq. 5

' Small, PA., J. APDI. Chem, 3 (1853)

Hansen, C., J, Paint TechrIoloaL Feb. 1867

4

.,

. . Solubility Parameters and Their Appllcation - - 18 December 1992

3 There are a number of ways to graphically represent the important solubility parameters for a material. Various 2- and 3- dimensional graphs have Included 6, 4, ad, 5B, %, ye# p, and dipole moment (p), The format we find the mast useful is S, vs. S,, shoe they vary the most over the solvents of interest. The & of all of the solvents in our database only span 10.3 (Acetonarile) to 26.1 MPaO.’ (Propylene Carbonate). This is only a general deson’ption with the commdn representatlves in our database. The key ’alongside the charts gives the dlspersive parameter (&) in parentheses.

. .

I 1 1 1 1 5 10 I S 20 25

8,(MPa“)

Figure 1 - Solubility Charts For Various Solvents 2 Chemical Families

4j Yaiuena (16.4) 5) Xylene (e&) (16.7) 6) Dipentene (-Limonene) (16.3) 71 CVdoheXme (16.5)

(14.4 14) Pmpylene glycol methyl ether

ammm (PMA) (16.1) 16) Oihsxyl ertrer (15,l) 6) Methylene Chlaride (13.4) 17) Melhyl e!hyi ketone (MEK) (14.1) le) EWl batate (13.4) le) Butyl lacgte (EL) (15.8) 20) Dipropylsne glycol methyl ether

(DPM) (15.5) 21) Acatone (13.0) 22) AcatoniMle (10.8) 23) y Bulymlaomne (KO of GEL)

24) N-Medlyl Wrralidone (NMP)

25) Methyl lactate (MY (16.5) 26) l-Nonanol (15.3) 27) Propylene qlycol memyl ether

(PM) (15.6) 28) Isopropyl doohal (IPA) (15.8) ‘29) E U ” l (16.E) 30) Melhkanol (11.6)

(18.6)

(16.6)

6

. . . . . . . . .

,

Solubility Parameters and Their Application 18 December 1992 .

As part Of the ODs replacement Process Sewice project, we were asked to determine what solvenWcbaners would be best used to remove cured D5 propellant (vn-1). A simple solvent swell screening was done with a sample of available WAK-2 propellant (IC-08934) which Is almost ldentlcal to V N - ' I . The swelling of the propellant was determined by ohange In volume In WAK-I chips after 48 his. (weight gain had stopped), The conclusion drawn was that the optimum 8, was about 24.0 MPa"" which is between NMP and acetonitrile. This agrees pertectly wth the 5 given in the CRC reference'' for Poly(ethy1ene oxlde) which is the dominant ohemlcal strocture of the propellant polymer. The actual 0 swell pohts are estimated at DPM and ethanol since we have ne better resolution with the materials on hand. Several other solvents with 8, below DPM were also tried with no swelling. Note that the blend calculated in the preceding section (67/33 wt MeCVAcetonitriie) was also tested and fell well irl line with the estimated swelling.

I I

Banon, A.F.M., Ed., 'CRC Handbook of Polymer-Uquld intsractlon Panrmeters and Solublllty . , , 13