Lab 4. Diffusion and Osmosis in Selectively Permeable Membranes
Elastomeric Selectively Permeable Membranes For Chemical ...
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Elastomeric Selectively Permeable MembranesFor Chemical and Biological Protective Clothing
2002 CBC Research Conference Presentation Qtruong Nov 02 espm
Quoc TruongPhysical Scientist
OFFICE SYMBOL: AMSSB-RIP-C(N)COM: (508) 233-5484; DSN: 256-5484 FAX: (508) 233-4994 or 4331 EMAIL: [email protected]
U.S. Army Soldier, and Biological Chemical Command (SBCCOM)Soldier Systems Center (SSC)Natick, MA 01760-5019
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1. REPORT DATE 01 JUL 2003
2. REPORT TYPE N/A
3. DATES COVERED -
4. TITLE AND SUBTITLE Elastomeric Selectively Permeable MembranesFor Chemical andBiological Protective Clothing
5a. CONTRACT NUMBER
5b. GRANT NUMBER
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) 5d. PROJECT NUMBER
5e. TASK NUMBER
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Soldier, and Biological Chemical Command (SBCCOM)Soldier Systems Center (SSC) Natick, MA 01760-5019
8. PERFORMING ORGANIZATIONREPORT NUMBER
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)
11. SPONSOR/MONITOR’S REPORT NUMBER(S)
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14. ABSTRACT
15. SUBJECT TERMS
16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT
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Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18
•ADVANCED LIGHTWEIGHT CB PROTECTION PROGRAM (DTO CB-06a-12-D) WAS SUCCESSFULLY COMPLETED IN FY00, WHERE SPM UNIFORMS WERE PREFERRED OVER CURRENT CHEMICAL PROTECTIVE GARMENTS
Accomplishments:Developed and demonstrated SPM garments that are 50% lighter weight than any fielded garment with equivalent or better protection.
Integrated novel closure systems and demonstrated their effectiveness via MIST @ERDEC, @DPG
Conducted field-assessments for field durability and perception of comfort of prototype CB duty uniforms.
•Ft. Lewis, WA with the ManeuverSupport Battle Labs (MSBL)•Pohakuloa and Kaneohe Bases, Hawaiiwith the Marine Corps and Army MSBL
Transition to JPACE, JIG, SOF, and JCBE
Impacts:
Reduced thermal stressReduced logistics burdenIncreased CB agent protectionEliminated dependency on charcoal adsorbent
Chemical Agent Test Results (Cumulative Penetration)
SPM 1 SPM 2 AUIB Gore-Tex® Fabric(20 hrs) (20 hrs) (21 hrs) (4 hrs)
20
15
10
5
0
>40
0.6
3.5
HDTGD
SPM 1: Polyallylamine-Based SPM 2: Cellulose-BasedAUIB: Aircrew Uniform Integrated Battlefield (Carbon loaded foam + Gore-Tex fabric)
µg/cm2
TGD/VX Breakthrough
level
HD Break through
level
1.31.0 < 0.1<0.1
VX
<0.1
Nyl
on F
abri
c
Nor
mex
Pla
in F
abri
c
Bat
tle D
ress
Ove
rgar
men
t(B
DO
)
US
Mar
ine
Cor
ps S
arat
oga
Ove
rgar
men
t N
omex
Pla
in F
abri
c w
ithC
hem
ical
Pro
tect
ive
Und
erga
rmen
t (C
PU
)C
amou
flage
Pri
nted
Nom
exFa
bric
with
CPU
Flu
orop
olym
er-B
ased
Mem
bran
e/Fa
bric
Sys
tem
SP
M2
- C
ellu
lose
-Bas
edPo
lym
er M
embr
ane/
Fabr
icSy
stem
SPM
1 - P
olya
llyla
min
e-B
ased
Mem
bran
e/F
abri
cSy
stem
Shap
e M
emor
y P
olym
erM
embr
ane/
Fabr
ic S
yste
m
0 .0E+00
5.0E+05
1.0E+06
1.5E+06
2.0E+06
2.5E+06
3.0E+06
3.5E+06
Ave
rage
Par
ticle
Cou
n(M
ean
Siz
e: 3
.5 m
icr o
Aerosol Penetration Through Various Fabrics
AEROSOL PROTECTION
SPM 1 JSLIST+BDU
337
99
400
300
200
100
0
Ave
rage
Tot
a l P
rote
ctio
n Fa
ctor
@2h
rs, 1
00 m
g/m
3 M
eS C
halle
nge
JSLIST: Joint Service Lightweight Integrated Suit Technology
SPM 1: Polyallylamine-Based
BDU: Battle Dress Duty Uniform
DPG: Dugway Proving Ground, Utah
MIST: Man-In-Simulant System Vapor Test
DPG MIST Data
VAPOR PROTECTION
In trin s ic W aterV ap o r R es is tan ce
(m 2.P a /W att)
C hem P ak F ab ric II
In trin s ic Th e rm al R es is tan ce
(m 2.K /W att)
C hem pak F ab ric II
C hem ica l P ro tec tive F abric IC hem ica l P ro tec tive F abric IIC hem ica l P ro tec tive F abric III
C hem ica l P ro tec tive F abric IV
C hem pak F ab ric I
C hem P ak F ab ric I
0 .0270 .027
0.0340.063
0 .065
0 .075
7.077.15
9 .1810 .65
12 .5913 .83
E V A PO R A T IV E C O O L IN G PO T E N T IA L S o f S P M s v s. V A R IO U S C B F A B R IC S Y S T E M S
C hem ica l P ro tec tive F abric IC hem ica l P ro tec tive F abric IIC hem ica l P ro tec tive F abric III
C hem ica l P ro tec tive F abric IV
C h em ical Protective F ab rics I-IV : V arious C B Fabric Sy stem s
High Pressure Hydrostatic Resistance
300
275
250
225
200
175
150
125
100
75
50
25
0Hig
h Pr
essu
re H
ydro
stat
ic R
esis
tanc
e, lb
/in2
PerformanceGoal
Semi-permeableFabric(Gore-Tex®)
SPM 1 SPM 2 CarbonLoadedFoam/Fabric
> 35 (Goal*)
*Being Waterproof
LIQUID PROTECTIONREDUCED HEAT STRESS
•Many Tests and Evaluation have been conducted to evaluate SPM fabrics; however, NOISE AND SIZING REMAIN SIGNIFICANT BARRIERS TO OVERCOME.
•Problems: Noise and Sizing
•Capability/Enhancement:
•Reduce/Eliminate multiple size requirement•Conformable Clothing•Reduce logistic concerns, and improved operational readiness•Reduced Noise when “being quiet” is important
StretchablePerm-selectiveMembrane
•Material Concept:
-Multiple sizes
-Many concerns (Costs, Weight, Logistic, Comfort, Mobility, etc.)
-Many variations of chemical protective clothing
Technical Approach --- Prepare dendrimer containing membranes
Dendrimer Packing and Cross
Linking shows reactive binding
polymer molecules for further
filtration efficiency
Blocking efficiency for dendrimers as a function of the density of the peripheral groups.
Experimental Results: Dendrimer containing membranes
ElastomericTo be doneTo be done5. PU dispersions mixed with ICET proprietary polymer
Not elastomeric0WSPC: 0 after 3 hrs
3,000WSPC: 2,000-2,500
4. Self-assembled dendrimer
Elastomeric0WSPC: 0 after 3 hrs
3,000WSPC: 2,000-2,800
3. Incorporate dendrimers in ICET water based proprietary polymer
Elastomeric2,000 – 3,00019,0002. Estane Cross linked dendrimers
Elastomeric10,0002,0001. Estane Coated with dendrimer
Elastomeric10,000 to 20,0001,000 – 2,000Hytrel/Noveon Membrane (Control –2mil thick)
Special NotesTCE Permeation (E96-BW) (g/m2/day)
MVTR (E96-BW) (g/m2/day)
Methods
Natick’s Water/Simulant Permeation Cell (WSPC) Test Results
Method 3. Incorporate dendrimers in ICET water based proprietary polymer
Water/Simulant Permeation Cell (WSPC) Test Results
Method 4. Self-assembled dendrimer
Static Permeation Test Results
Static Moisture Vapor Permeation Data (E96-BW)
1000
2000
19000
3000 3000
19000
2000
0
5000
10000
15000
20000
Control M-1(Method 1) M-2(Method 2) M-3(Method 3) M-4(Method 4) M-5(Method 5)
Material
Flux(g
/m2/da
Static TCE Vapor Permeation Data (E96-BW)
10000 10000
2000
0 0
6000
20000
3000
0
5000
10000
15000
20000
25000
Control M-1(Method 1) M-2(Method 2) M-3(Method 3) M-4(Method 4) M-5(Method 5)
Material
Flux (g/m
2/da
Discussions:Dendrimers are highly hydrophilic and viscous materials. They are very expensive.
The direct coating on elastomers through anchoring by surface interactions
resulted in coatings that never cured.
Direct incorporation of dendrimers into polymeric dispersions results in
tough but flexible membranes.
Using optimal cross-linking of a thin coating appears to over come this
difficulty while dramatically improving the moisture vapor permeation and
dramatically reducing cost of the eventual commercial products.
This could be a preferred way for optimization for achieving better perm-selectivity.
Conclusions:•Extremely thin coating of cross-linked dendrimer were achieved on water vapor
Permeable polyurethane elastomers.
•Such coatings improve water vapor transport properties significantly while
maintaining resistance to organic vapors.
•Further optimization work are underway with ICET, Inc. to develop elastomeric
SPMs for resistance to both polar and non-polar molecules.
Recommendations:•Follow on work will be on developing dendritic polymers cross-linked coatings
where the cross linking agent is flexible PEO segments with reactive end groups
on water vapor permeable polymer materials such as TPU latexes modified
with ICET fillers and formulations
Acknowledgments:
Dr. Shantha Sarangapani, Innovative Chemical and Environmental
Technologies, Inc. (ICET), Norwood, MA for her dedication in working to
Support the US Army Natick Soldier Center’s needs to protect our soldiers in
Various R&D work since 1985.