Thermal analysis characterization of polymers and plastics acs webinar

© 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?