Thermochemical Approaches for the Characterization of Materials › archive › nasa › casi.ntrs.nasa.gov › 201400005… · Thermochemical Approaches for the Characterization

Thermochemical Approaches for the Characterization of Materials

Rodrigo Devivar, Ph.D.Jacobs Technology / NASA-Johnson Space Center

ES4 Materials Analysis LaboratoryHouston, Texas

November, 2013

https://ntrs.nasa.gov/search.jsp?R=20140000530 2020-07-17T05:32:42+00:00Z

NASA

Johnson Space Center (JSC) 9 Other NASA Centers

Engineering Directorate (EA) 8 Other Directorates

Structural EngineeringDivision (ES)

Materials and ProcessesBranch (ES 4)

ES 4 Materials Analysis Laboratory

5 Other Branches

5 Other Divisions

4 Other Laboratories

National Aeronautics and Space Administration

Analytical Chemistry Laboratory Equipment

Key Laboratory Equipment

– Optical Instrumentation• UV-Vis, Fluorimeter, Solar Reflectance,

Infrared Emittance, Raman– Thermal Analysis Instrumentation

• DSC, DMA, TGA, TMA, LFA, Rheometer– Chemical Analysis Instrumentation

• FT-IR, Ion trap GC-MS, Py-GC-MS, TGA-MS, TGA-IR

The Analytical Chemistry Cycle

Sample Measurement

Data Analysis

SamplePreparation

SampleCollection

InformationTo Customer

What Testis Needed?

Are the Results Valid?

Can the Sample

Be Destroyed?

How Much Sample is Available?

Is it Urgent?

Destructive Vs.

Non-DestructiveAnalysis

Optical Vs. Thermal Techniques

Material CuringThermal Transition-TgMelting Point/ Boiling PointResidual SolventIdentification of additivesMaterial DecompositionElimination of labile functional groupsIdentification of Material ComponentsIdentification of Inorganic Components

LightReflectance EmittanceAbsorbance/TransmissionFluorescenceUV-Vis AbsorbanceFT-IR AnalysisRaman Analysis

Heat

Thermogravimetric Analysis (TGA)

• A TGA instrument consists of an analytical balance and a furnace.• A small sample of material is heated and its change in mass is

measured as a function of temperature.• Experiments can be conducted under inert or oxidizing atmospheres.• Information gained from TGA includes:

– Thermal stability for conducting additional thermal analysis– Identification of the number of components in the sample if the

decomposition temperatures are different– Residual mass for assessing the extent of inorganic additives

18.05%

28.04%

40

60

80

100

120

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C) Universal V4.7A TA Instruments

Thermal Analysis of Composite

Traditional thermal analysis of materials is performed by DSC (Differential Scanning Calorimetry) and by TGA (Thermogravimetric Analysis) instrumentation. Most Thermal Analysis is performed at temperatures below the onset of decomposition. Thermochemical Techniques for Material Characterization will utilize elevated temperatures until the material is fully degradated.

Spectral Analysis of HDPE and LDPE

Many industrial laboratories have only one technique available for characterization of the manufactured product. In many situations, one type of analytical technique is not adequate for assessing the product.

Pyrolysis for GC-MS of Solids

• Sample size is relatively small:

50 to 200 g is sufficient for solids50 to 200 nL is sufficient for liquids

• Sample preparation is easy: Place sample inside 1.5 inch quartz tube containing filler tube and plug with glass wool.

• Samples can be solids, gels, viscous liquids, greases, crystalline, emulsions, foams, fabrics

• Pyrolysis temperatures are almost instantaneous

• Sample components can be quantified with the use of software

Pyrolysis is the thermal degradation of any substance through the fast application of heat.

Thermal Analysis of HDPE and LDPE

C h r o m a t o g r a m P l o t s

2 . 5 5 . 0 7 . 5 1 0 . 0 1 2 . 5 1 5 . 0m i n u t e s

1 0

2 0

3 0

4 0

5 0

M C o u n t s

1 0

2 0

3 0

4 0

5 0

M C o u n t s

R I C 1 M A R 1 4 6 1 2 l o t 2 . x m s 1 2 0 0 C E N T R O I D R A W ( + ) E I Q 1 M S 1 0 . 0 - 8 0 0 . 0 >

R I C 1 M A R 1 4 6 1 2 l o t 1 . x m s 1 2 0 0 C E N T R O I D R A W ( + ) E I Q 1 M S 1 0 . 0 - 8 0 0 . 0 >

5.7

79

min

6.6

55

min

7.4

57

min

8.8

93

min

9.5

46

min

1.8

76

min

2.2

86

min

2.8

74

min

3.7

72

min

4.7

89

min

5.7

64

min

6.6

41

min

6.6

94

min

7.4

41

min

7.4

91

min

8.1

84

min

8.2

26

min

8.8

79

mi

+ 8

.91

9 m

in

9.5

33

min

+ 9

.57

0 m

in

10

.15

3 m

in

DSC of HDPE vs LDPE

-4

-3

-2

-1

0

1

2

0 50 100 150 200 250 300

Temperature

Heat

Flo

w

-1

0

1

2

3

4

Der

iv. W

eigh

t (%

/°C

)

-50

0

50

100

150

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

LDPE––––––– HDPE– – – –

Universal V4.7A TA Instruments

TGA

Pyrolysis-GC-MS

Polyethylene: -CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-

C15C14C13C12C11C10

C9C8C7C6

FT-IR Analysis of Silicone Materials

FT-IR is a non-destructive technique that is very diagnostic. However, if infrared light cannot penetrate the sample, any signal obtained through reflectance is only valid for the external surface of a sample.

1. Silicone O-ring2. RTV 5603. Red, Tacky RTV4. PDMS

Thermal Analysis of Silicone Materials

350.65°C96.30%

0

20

40

60

80

100

Wei

ght (

%)

0 100 200 300 400 500 600 700 800 900

Temperature (°C)

RTV 560––––––– Silicone O-ring– – – – Tacky RTV––––– · PDMS––– – –

Universal V4.7A TA In

The Silicone samples that were nearly identical by FT-IR displayed very different properties by thermal analysis.

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

Hea

t Flo

w (W

/g)

-100 -80 -60 -40 -20 0 20 40

Temperature (°C)

PDMS––––––– Red Tacky RTV– – – – RTV 560––––– · Silicone O-ring––– – –

Exo Up Universal V4.3A TA Instrume

TGA Analysis of Fluorinated Materials

-20

0

20

40

60

80

100

120

Wei

ght (

%)

0 100 200 300 400 500 600

Temperature (°C)

––––––– Krytox 143AZ oil in N2 to 1000C.001– – – – Krytox 143AZ oil in air to 1000C.001


-20

0

20

40

60

80

100

120

Wei

ght (

%)

0 100 200 300 400 500 600 700

Temperature (°C)

––––––– Brayco 815Z oil in N2 to 1000C.001– – – – Brayco 815Z oil in air to 1000C.001


Brayco 815ZKrytox 143 AZ

0

20

40

60

80

100

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

––––––– Krytox 143AZ oil in N2 to 1000C.001– – – – Brayco 815Z oil in N2 to 1000C.001


Krytox 143 AZBrayco 815Z

-20

0

20

40

60

80

100

120

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

MAR 15411 PTFE––––––– MAR 15411 KelF opaque– – – – MAR 15411 Brayco 815Z––––– ·



5 1 0 1 5 2 0 2 5m i n u t e s

0

5

1 0

1 5

2 0

GCps

0

5

1 0

1 5

GCps

T I C ; F E P 3 m i n d l y 7 5 0 . x m s ; F i l t e r e d

T I C ; P T F E 3 m i n d l y 7 5 0 . x m s ; F i l t e r e d

FEP Vs. PTFE Teflon

497.48°C89.29%

562.04°C57.61%

521.69°C81.55%

995.85°C42.90%

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

200 400 600 800 1000

Temperature (°C) Universal V4.7A TA Instr

563.05°C46.16%

-0.5

0.0

0.5

1.0

1.5

2.0

Der

iv. W

eigh

t (%

/°C

)

200 400 600 800 1000

Temperature (°C) Universal V4.7A TA Instruments

PTFEFEP Teflon

O ve r la id C h ro m a to g ra m P lo ts

4 .00 4 .2 5 4 .5 0 4 .75 5.0 0 5 .25m in u te s

0

5

1 0

1 5

2 0

GCps

T IC ; FE P 3m in d ly 75 0 .x m s ; F ilte re dT IC ; PT F E 3m in d ly 75 0 .x m s ; F ilte re d

FEP Teflon Heated at Different Rates


1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0m i n u t e s

0

5

1 0

1 5

2 0

GCps

0

1

2

3

4

5

6

7

8

GCps

0

1

2

3

4

5

6

7

GCps

T I C ; F E P 3 m i n d l y 7 5 0 . x m s ; F i l t e r e d

T I C ; F E P 2 C P M . x m s ; F i l t e r e d

T I C ; F E P 0 _ 2 C P M . x m s ; F i l t e r e d

Heating Rate: 12oC per minGC Method run time: 100 min



During pyrolysis, materials undergo thermal degradation via chemical pathways dictated by the thermal stability of the components. When pyrolysis is slowed to simulate TGA conditions, a thermal response pattern similar to what was observed with TGA first derivative plot.

497.48°C89.29%

562.04°C57.61%

521.69°C81.55%

995.85°C42.90%

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

200 400 600 800 1000

Temperature (°C) Universal V4.7A TA Instr

TGA

Cotton Vs. Silicone

-20

0

20

40

60

80

100

120

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

PDMS N2––––––– Cotton N2– – – –


110oC

The large difference in thermal stability between cotton and silicones can be used to easily characterize the silicone sample collected on a cotton swab.

The cotton may be completely decomposed by application of heat without adversely affecting the silicone.

TGA Comparison of Gaskets

-0.5

0.0

0.5

1.0

1.5

2.0

Der

iv. W

eigh

t (%

/°C

)

20

40

60

80

100

120

Wei

ght (

%)

0 200 400 600 800 1000

Temperature (°C)

16435 New.002––––––– 16435 old.002– – – –


Area of difference

Under conditions of increasing temperature, the only difference between the two VitonGaskets was found below 400oC, where the old sample lost a larger percentage of its mass compared to the new sample.

Thermal Extraction of SamplesChrom atogram P lots

2.5 5.0 7.5 10.0 12.5 15.0 m inutes

25

50

75

100

125MCounts

25

50

75

100

MCounts

16435 New 400C.xm s 10.0 :800.0>10.0 :800.0>

16435 Old 400C.xm s 10.0 :800.0>10.0 :800.0>

+ 1

.19

9 m

in1

.353

min

+ 1

.365

min

1.5

93

min

7.1

86

min 8.4

85

min

New

In Service Sample1,4-Dioxane

Carbon Dioxide

Carbon Dioxide

Glycerin

HOO

OHHO

OO

OOH

HOO

OOH

BHT

Thermal extraction of the two samples was performed to account for the difference observed in the TGA experiments at temperatures below 400oC. Such an experiment indicated the Old sample contained various fragments that are attributed to polyethylene oxide. Other substances found included Glycerin and Butylatedhydroxy toluene (BHT).

Pyrolysis-GC-MS of Ultem 1000

5 6 7 8 9 1 0 1 1m inu te s

0

1 0 0

2 0 0

3 0 0

4 0 0

M C o u nt s

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

M C o u nt s

R IC M erg e d u lte m _ 2_ 7 5 0. xm s 1 2 0 0 C E N TR O ID R AW (+ ) EI Q 1 M S 1 0. 0 - 8 0 0 .0 >

R IC M erg e d u lte m _ 3_ 7 5 0. xm s 1 2 0 0 C E N TR O ID R AW (+ ) EI Q 1 M S 1 0. 0 - 8 0 0 .0 >

4.440

min

4.895

min

+ 5.16

3 min

+ 5.3

49 m

in

+ 5.6

79 m

in

5.904

min

6.338

min

6.811

min

7.074

min 7.4

25 m

in

7.549

min

+ 8.06

1 min

8.197

min

8.407

min

8.874

min

+ 9.13

4 min

9.516

min

+ 9.57

8 min

9.824

min

9.939

min

4.402

min

+ 4.7

60 m

5.118

min

5.307

min

6.293

min

6.773

min

7.431

min

+ 7.4

72 m

in

7.63

6 min

+ 8.0

27 m

in8.1

48 m

in

+ 8.36

3 min

8.82

9 min

+ 9.0

89 m

in

9.471

min

+ 9.52

9 min

9.777

min

9.890

min

Relay sensor boxes along the shuttle’s wing leading edge were composed of Ultem 1000.

One lot used to make these relay sensor boxes had failed

Various manufacture lots of sensor boxes were analyzed by Py-GC-MS and an extra peak was noted in one of those lots. The extra peak was due to dichlorobenzene, a solvent used during manufacture of Ultem1000.

Thermal Response of Travertine in Different Atmospheres

599.46°C97.25%

800.75°C55.58%

732.56°C65.50%

745.03°C66.43%

599.46°C97.97%

800.75°C56.79%

60

70

80

90

100

Wei

ght (

%)

0 200 400 600 800 1000 1200

Temperature (°C)

Travertine N2––––––– Travertine air– – – –


CaCO3 CaC2 or Calcium Bentonite

Travertine

Travertine TGA ashes (Helium or Nitrogen)

Travertine TGA ashes (Air)

599.46°C97.25%

800.75°C55.58%

732.56°C65.50%

745.03°C66.43%

599.46°C97.97%

800.75°C56.79%

60

70

80

90

100

Wei

ght (

%)

0 200 400 600 800 1000 1200

Temperature (°C)

Travertine N2––––––– Travertine air– – – –


Calcium Carbonate

Calcium Carbide

Calcium Bentonite

The Role of Gaseous AtmosphereDuring Thermal Decomposition of Travertine

TGA of Travertine inAir

TGA of Travertine in Nitrogen

TGA-MS Analysis of Travertine

Substances being measured during mass loss near 700oC include CO2, CO, and O.

TGA Analysis of Geothite in Helium

Detected Mass Losses of Goethite

At 120oC, Mass losses include: m/z 14 (CH2), 16 (O), 32 (O2)

At 308oC, Mass losses include: m/z 17 (OH), 18 (H2O), 32 (O2)

At 1290oC, Mass losses include: m/z 16 (O), 18 (H2O), 32 (O2)

Goethite-FeO(OH)

TGA Analysis of Kieserite

Detected Mass Losses of Kieserite

At 78oC, Mass losses include: m/z 17 (OH), 18 (H2O), 28 (CO)

At 382oC, Mass losses include: m/z 16 (O), 17 (OH), 18 (H2O), 28 (CO)

At 1136oC, Mass losses include: m/z 16 (O), 28 (CO), 32 (O2), 48 (SO), and 64 (SO2)

At 1315oC, Mass losses include: m/z 17 (OH), 48 (SO), and 64 (SO2)

KieseriteMgSO4·H2O

Applying Thermal Energy to Extract Chemical Information

Using Thermal Energy:

•How much Thermal Energy do weadd

•How fast do we add the ThermalEnergy

•What atmosphere do we use

•How much sample do we use

Chemical Information

•Trapped solvent

•Organic additives

•Labile Functional Groups

•Monomer identification

•Off-gassing information

•Inorganic additives

TGA Pyrolysis-GC-MS TGA-MS-IR

Documents

Thermochemical Approaches for the Characterization of Materials › archive › nasa › casi.ntrs.nasa.gov › 201400005… · Thermochemical Approaches for the Characterization