ppp dsc 1 thermal analysis fundamentals of analysis
TRANSCRIPT
![Page 1: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/1.jpg)
Thermal Analysis of Polymers
Thermal Analysis of Polymers
By
Muhammad Zafar Iqbal
P.E. Physical Properties of Polymers
![Page 2: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/2.jpg)
AgendaAgenda
• Introduction to Butyl Rubbers• Introduction to some important physical and chemical
properties of butyl rubbers• Typical Applications based on the above properties• Introduction to Thermoplastic elastomers• Some important applications of TPEs
04/11/23 Polymer & Process Engineering 2
![Page 3: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/3.jpg)
Thermal AnalysisThermal AnalysisDefinitionThe term thermal analysis (TA) is frequently used to describe analytical
experimental techniques which investigate the behavior of a sample as a function of temperature.
This (TA) includes the following techniques:
1. Differential Scanning Calorimeter (DSC)
2. Differential Thermal Analyzer (DTA)
3. Thermo-gravimetric analyzer (TGA)
4. Thermo-mechanical analyzer (TMA)
5. Dynamic Mechanical Analyzer
The operational simplicity of TA instruments belies the subtlety of techniques which, if improperly practiced, can give rise to misleading or erroneous results.
04/11/23 Polymer & Process Engineering 3
![Page 4: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/4.jpg)
Characteristics of TA techniquesCharacteristics of TA techniquesThe advantages of TA instruments over other techniques include but
not limited to:
(I) The sample can be studied over a wide temperature range using various temperature programmes.
(II) Almost any physical form of sample (solid, liquid or gel) can be accommodated using a variety of sample vessels or attachments
(III) A small amount of sample (0.1 μg-10 mg) is required
(IV) The atmosphere in the vicinity of the sample can be standardized
(V) The time required to complete an experiment ranges from several minutes to several hours
(VI) TA instruments are reasonably priced.
In polymer science, preliminary investigation of the sample transition temperatures and decomposition characteristics is routinely performed using TA before spectroscopic analysis is begun.
04/11/23 Polymer & Process Engineering 4
![Page 5: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/5.jpg)
• The recorded data are influenced by experimental parameters such as the sample dimensions and mass, the heating/cooling rate, the nature and composition of the atmosphere in the region of the sample and the thermal and mechanical history of the sample.
• The sensitivity and precision of TA instruments to the physicochemical changes occurring in the sample are relatively low compared with spectroscopic techniques.
• TA is not a passive experimental method as the high-order structure of a sample (for example crystallinity, network formation, morphology) may change during the measurement.
04/11/23 Polymer & Process Engineering 5
![Page 6: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/6.jpg)
04/11/23 Polymer & Process Engineering 6
![Page 7: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/7.jpg)
Variants of DSCVariants of DSC• Heat flux
– 1955 Boersma– 1 large (30 – 100 g) furnace
• Power compensated– Separate small (1 g) microheaters for sample and
reference• Hyper DSC
– Very fast scan rates 500°C/min– Mimic processing conditions
• StepScan DSC– Short dynamic and isothermal scan steps– Separate reversible and irreversible effects
![Page 8: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/8.jpg)
DSCDSC
04/11/23 Polymer & Process Engineering 8
![Page 9: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/9.jpg)
Heat Flux DSCHeat Flux DSCSet-up is similar to DTA: analysis sample and reference sample.
Heat-Flow DSC: each sample is surrounded by an inner ring and an outer ring of thermocouples. The average temperature difference between the two measures the heat flow into or out of the sample.
Outer ring of 30 thermocouples
Inner ring of 30 thermocouples
Reference
Analysis
![Page 10: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/10.jpg)
Output of DSCOutput of DSC
Temperature, K
Thermogram
dH/d
t, m
J/s
Glass transition
crystallization
melting
exo
endo
![Page 11: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/11.jpg)
Glass TransitionGlass Transition
• Step in thermogram
• Transition from disordered solid to liquid
• Observed in glassy solids, e.g., polymers
• Tg, glass transition temperature
Temperature, K
Thermogram
dH/d
t, m
J/s
Glass transition
Tg
![Page 12: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/12.jpg)
CrystallizationCrystallization
• Sharp positive peak
• Disordered to ordered transition
• Material can crystallize!
• Observed in glassy solids, e.g., polymers
• Tc, crystallization temperature
Temperature, K
Thermogram
dH/d
t, m
J/s
Crystallization
Tc
![Page 13: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/13.jpg)
MeltingMelting
• Negative peak on thermogram
• Ordered to disordered transition
• Tm, melting temperature
• Melting happens to crystalline polymers; glassing happens to amorphous polymers
Temperature, K
Thermogram
dH/d
t, m
J/s Melting
Tm
![Page 14: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/14.jpg)
ConclusionConclusion
14
![Page 15: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/15.jpg)
SamplingSampling
• Pan– Al– Au– Glass capillary tubes
• Maximize contact between sample and pan– Thin films– Fine granules of uniform size
• Grind!
![Page 16: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/16.jpg)
CruciblesCrucibles
Choice of crucible is critical.
• Thermal properties of crucible.
• Reactive properties with samples.
• Catalytic behaviour with samples.
Aluminum: inexpensive, low temp
Copper: used as catalyst (testing polymers)
Gold: higher temp, expensive
Platinum: still higher temp, expensive.
Alumina (Al2O3): very high temp
Sapphire: crystalline alumina, more chemically resistant than amorphous Al2O3.
![Page 17: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/17.jpg)
CalibrationCalibration• Calibrants
– High purity– Metals
• In 156.4°C• Sn 231.9°C• Pb 327.4°C• Zn 419.5°C• Al 660.4°C
– Inorganics• KNO3 128.7°C• KClO4 299.4°C
– Organics• Triphenylmethane• Polystyrene 105°C• Higher thermal conductivity
than metals
– Accurately known enthalpies• EX: indium (5 – 10 mg) H(fusion) = 6.80 cal/g, mp
156.4°C– K * (Area/mass) =
H(fusion) = 6.80 cal/g
– Not hygroscopic– Not light sensitive– High thermal stability– Relatively unreactive
• Pan• Atmosphere
![Page 18: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/18.jpg)
What Can You Measure with DSC?What Can You Measure with DSC?
• Qualitative analysis– Fingerprinting of minerals, clays, polymers
• Sample purity– Melting points
• Heat capacity, cp
• Glass transition temperature, Tg
• Crystallization temperature, Tc
• Phase diagrams
![Page 19: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/19.jpg)
Most Important to RememberMost Important to Remember
04/11/23 Polymer & Process Engineering 19
![Page 20: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/20.jpg)
Where Used?Where Used?
• Pharmaceutical industry– Purity
• Food industry– Characterization of fats and oils
• Polymer industry– Synthetic blends
![Page 21: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/21.jpg)
Poly (Lactic Acid)Glass transition temperature, Tg.
30 40 50 60 70 80 90-800
-600
-400
-200 GlassTransition, T
g
DD
SC
, W
/min
DS
C,
W
Temperature, oC
-40
0
40
80
120
160
200
240
DSC
DDSC
![Page 22: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/22.jpg)
DSC traces for melting and crystallization
of a polymer sample.
![Page 23: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/23.jpg)
DSC traces of Low Crystallinity PLA treated in Water at 70C and 100C. The higher the crystallinity achieved
at 100 C, the higher and the less defined the Tg
0 50 100 150 200
-2000
0
2000
1hr@ 70oC
1hr@100oC
Weak Tg
Strong TgDS
C1
00
C W
Temperature, oC
-1000
0
1000
CrystallizationBefore Melting
Same MeltingPattern
Weak ColdCrystallization
Me
ltin
g
DS
C7
0C W
![Page 24: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/24.jpg)
Melting of two semicrystalline HDPE samples.
110 120 130 140 150-20.0k
-15.0k
-10.0k
-5.0k
0.0
EN
DO
H: 165 mj/mg
H: 132 mj/mg
134oC
132oC
DS
C, W
Temperature, oC
HDPE Detergent Bottles HDPE Milk Bottles
![Page 25: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/25.jpg)
Considering H = 200 mJ/mg as the enthalpic change for the melting of a 100% crystalline HDPE sample, from DSC data of these two recyclable HDPE it can be found that:
• the polymer derived from detergent bottles was (132/200)x100 = 66% crystalline
• the polymer used for milk bottles was (165/200)x100 = 82.5% crystalline.
![Page 26: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/26.jpg)
Sample PreparationSample Preparation
04/11/23 Polymer & Process Engineering 26
![Page 27: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/27.jpg)
04/11/23 Polymer & Process Engineering 27
![Page 28: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/28.jpg)
Temperature Gradient in SampleTemperature Gradient in Sample
04/11/23 Polymer & Process Engineering 28
![Page 29: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/29.jpg)
Mass of SampleMass of Sample
04/11/23 Polymer & Process Engineering 29
![Page 30: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/30.jpg)
Why should we work on micro level..?
Why should we work on micro level..?
04/11/23 Polymer & Process Engineering 30
![Page 31: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/31.jpg)
Sample PackingSample Packing
04/11/23 Polymer & Process Engineering 31
![Page 32: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/32.jpg)
04/11/23 Polymer & Process Engineering 32
![Page 33: Ppp Dsc 1 Thermal Analysis Fundamentals Of Analysis](https://reader037.vdocuments.site/reader037/viewer/2022102801/554b3dfeb4c905b5378b48ed/html5/thumbnails/33.jpg)
Scanning RateScanning Rate
04/11/23 Polymer & Process Engineering 33