thermal analysis characterization of polymers and plastics acs webinar
TRANSCRIPT
© 2009 PerkinElmer© 2009 PerkinElmer© 2009 PerkinElmer© 2009 PerkinElmer
Presented By: Kevin P. MenardGlobal Manager – Thermal Analysis
Thermal Analysis: A Powerful Technique for
Characterization of Polymers and Plastics
Thermal Analysis
Thermal Analysis is a collection of techniques that looks at the change in polymer properties as a function of temperature.
Polymer Properties Amorphous Semi-crystalline Crystalline
Function of Temperature Tg Tg, Tm Tm
Thermal Techniques
DSC*/DTA TGA
Melting PointsTgHeat of FusionSpecific HeatRate of ReactionCure timesPurity
Weight Loss
% MoistureDecompositionOxidative Induction Time% Ash% Composition
Heat Flow (DSC)Delta T (DTA)
* includes DPA and HP accessories
STA
Weight Loss and Heat Flow
What TGA and DSC doesLess preciselyLess accuracy
Thermal Techniques
Modulus (E*, E’, E”)Viscositytan delta or damping Stress Strain StudiesTg and TransitionsCure times & kineticsCreep and RecoveryShrinkage & Shrinkage Forces
Phase lag & amplitude (DMA)
CTE Penetration FlexureSoftening Point Delamination temperature
DMATMA
Thermal Techniques
A range of products coupling a thermal analysis, normally TGA or STA to FTIR, MS, or GCMS
Hyphenation
Differential Scanning Calorimetry (DSC)
Most common thermal tool used for polymersAllows fast and accurate determination of glass transition, melting point, and other propertiesHeat Flux DSC and DTA use a single furnace and measure Delta THeat Flow DSC uses dual furnaces and measures heat flow
Shift in Cp
Exothermic
Endothermic
Endo
up
DSC Techniques
DSC Techniques: Conventional DSC (heat-cool-heat cycles) Recrystallization Studies (controlled cooling and cooling to an isotherm from the melt) Modulated Temperature Techniques (non-linear temperature ramps) Fast Scanning Techniques (in excess of 200°C/minute)
Other DSC Techniques we won’t discuss today: Oxidative Induction Times Isothermal Curing Sample Modification Techniques like UV DSC Spectral DSC techniques like DSC-Raman, DSC-XRD, and DSC-NIR
Why Thermal Analysis? Let’s look at a polymer recycling problem
The FTIR for PE
DSC for Polyethylene – grades 2, 4 and other
Importance of First versus Second Heat
Page 9
2 PET samples as received and second heat
Thermoplastics and Thermal History
Isothermal Recrystallization
Time (min)
Tem
pera
ture
C
Hea
t Flo
w
StepScan DSC
Step Scan DSC of Epoxy Resin
HyperDSC™ - Tg of an Epoxy Resin
Separation of Tg from Cure at 500°/min
TGA and/or STA
• Weight loss or gain as a function of temperature• STA also gives heat flow• Derivative curve allows one to see changes in rate of loss
TGA of coffee beans
TG-IR
TG-IR Data - Viton O-ring
GS Profile (Temperature based Extract of Viton oring 02.sWeight (Viton oring 02 .stad)
Name°C
Arb
30.41
Spectrum at 589.6 °C (Temperature based Extract of VitoCoadded Spectrum at 470.2 °C (Temperature based ExtraFlat Coadded Spectrum at 502.5 °C (Temperature based ECoadded Spectrum at 520.3 °C (Temperature based Extra
Name
4000 3500 3000 2500 2000 1500 1000 500404550556065707580859095
100
Wavenumber
%T
3000.98
Spectrum at 724.4 °C (Temperature based Extract of VitoCoadded Spectrum at 588.7 °C (Temperature based ExtraCoadded Spectrum at 797.7 °C (Temperature based Extra
Name
4000 3500 3000 2500 2000 1500 1000 500
55
60
65
70
75
80
85
90
95
100
Wavenumber
%T
1201.27
TG*-IR Data - Ethylene vinyl acetate (EVA)
GS Profile (Temperature based Extract of EVA 70 30 20CWeight (EVA 70 30 20Cmin 01 .stad)
Name
100 200 300 400 500 600°C
-0.000.010.020.030.040.050.060.070.080.090.100.11
-02468
101214 Coadded Spectrum at 362.3 °C (Temperature based Extra
Coadded Spectrum at 445.4 °C (Temperature based ExtraCoadded Spectrum at 462.1 °C (Temperature based ExtraCoadded Spectrum at 479.2 °C (Temperature based Extra
Name
4000 3500 3000 2500 2000 1500 100020
30
40
50
60
70
80
90
100
Wavenumber%
T
* STA 6000 used as TGA
TG-MS
TG-MS Data
METHANOL 32
P 1 TGA – Turbomass 600 C MS Data - Rubber
MS data at 225 CTG Run on Data
Rubber continued
, 21-Oct-2008 + 11:47:34TGA-MS
13.02 14.02 15.02 16.02 17.02 18.02 19.02 20.02 21.02 22.02 23.02 24.02 25.02 26.02 27.02Time16
100
%
102108_04 Scan EI+ TIC
1.02e920.86
20.14
15.03
14.5714.20
15.5216.40
21.50
, 21-Oct-2008 + 11:47:34TGA-MS
13 63 113 163 213 263 313m/z0
100
%
102108_04 2108 (15.056) Scan EI+ 7.95e744
4328
184
55698397 111 135
166 207
, 21-Oct-2008 + 11:47:34TGA-MS
18 68 118 168 218 268 318m/z0
100
%
102108_04 2978 (20.858) Cm (2956:3008) Scan EI+ 1.21e843
29
27
18
14
44
58
73 87 111 135
TG-GCMS
TGA: Coffee Beans
TG-GCMS: Large Coffee Beans
The Details of the Peak A
(replib) Caffeine0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
0
50
100
27
42
55
6782
94
109
137 165
194
N
N
N
N
O
O
The Details of MS data for Peak B
(rep lib) Diethyl Phthalate0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
0
50
100
29
39 5065 76 93 105
121132
149
177
222
O
O
O
O
What do we gain?
Blend of Natural Rubber and SBR
TG GC-MSFrom 350°C TG GC-MS
from 450 C
TG MSClarus 500 MS
PerkinElmer Spectrum 100 TimeBase SW
Thermomechanical Analysis (TMA)
Mostly used to measure coefficient of thermal expansion (CTE)Glass transition appears as a change in CTEOther tests can also be preformed:
z
Y
X
Basics of TMA
Tg
FreeVolume
Occupied Volume
Temperature/K
Volu
me/
mm
3As the space betweenthe chains increases, the chains can move
CTE
Results of Tg and CTE measurement of a film
Tg = 304
Dynamic Mechanical Analysis (DMA)
Measures changes in stiffness and dampingReported as E’ and tan deltaCommonly used for weak glass transitions: 100x DSC in sensitivity
tan
Temperature
1.0
0.5
0.0
0 hours
1 hour
150 200175
Hea
t flo
w (m
W)
21.8
23.8
tan
Heat flow
2 - 8 hours
Idealized DMA ScanE
’/Pa
Temperature /K
Tm - melting (1)
Rubbery Plateau (2)
T or Tg
(6) local bend side gradual large chainmotions and groups main scale slippage
stretch chain chain
Rubbery plateau is related to Me between crosslinks or entanglements.
For thermosets,no Tm occurs.
Beta transitions are oftenrelated to the toughness.
Tg is related to Molecular massup to a limiting value.
For purely crystallinematerials, no Tg occurs.
In semicrystalline polymers,a crystal-crystal slip, T* occurs.
Tll in some amorphouspolymers
Beta Transition and Impact Strength
Epoxy : 2 heats
First heat
Second heat
Frequency Effects
Transitions shiftBehavior changes
0.0
0.5
1.0
50 75 100Temperature (C)
Tan
Del
ta
Tan Delta 0.1HzTan Delta 0.316 HzTan Delta 1.0 HzTan Delta 3.16 HzTan Delta 10.0 HzTan Delta 31.6 Hz
Frequency
E’
Morefluid
Moreelastic
From the Frequency Scans
Time Temperature SuperpositionPMMA
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
1.00E+08
1.00E+09
0.0001 0.001 0.01 0.1 1 10 100 1000 10000 100000Frequency (Hz)
Mod
ulus
0.1
1
10
Tan
delta
wicket p lo t
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
1.2000
1.000E+04 1.000E+05 1.000E+06 1.000E+07 1.000E+08 1.000E+09 1.000E+10 1.000E+11 1.000E+12
modul us, E '
Tan Delt a
We could also calculate theActivation Energy.
Tg shift
Thank you!
Questions?