Joon-Pyo JeunKorea Atomic Energy Research Institute

Phil-Hyun Kang*, Young-Chang Nho

Effect of EB Effect of EB Effect of EB Effect of EB iriririrradiation radiation radiation radiation on the physicochemical characteristics on the physicochemical characteristics on the physicochemical characteristics on the physicochemical characteristics of polyimide film for aerospace materialof polyimide film for aerospace materialof polyimide film for aerospace materialof polyimide film for aerospace material

ContentContentContentContent

• Historical background of Polyimide

• Radiation process (EB curing)

• Effect of EB radiation on Polyimide film

Map of PlasticsMap of PlasticsMap of PlasticsMap of Plastics

PI

PEEK

LCP

PPS

PAI

PEI PES

PSF

PA POM

PBT PETPC

m-PPO

PAR

PE PP ABS PS

PMMA

CrystallineCrystallineCrystallineCrystalline AmorphousAmorphousAmorphousAmorphousCommodity Plastics

Engineering Plastics

Super Engineering Plastics

Price

High High

Heat resistance

LowLow

Development of Development of Development of Development of PolyimidesPolyimidesPolyimidesPolyimides (PI)(PI)(PI)(PI)

DuPontDuPontDuPontDuPontKaptonVespelPyralin

NASANASANASANASA(PI3N)

DynamitDynamitDynamitDynamitNobelNobelNobelNobel(PEsI)

AmocoAmocoAmocoAmoco(PAI)

TRWTRWTRWTRW(PMR-15)

GEGEGEGE(PEI)

Injection moldable PI

UBEUBEUBEUBE(UpilexUpimol)

NissanNissanNissanNissanJSRJSRJSRJSR

HitachiHitachiHitachiHitachi(PI coatingsfor LCD and

semiconductor)

1962

1962

1970

1972

1982

1984

1990~Film,

Molding

Adhesives

Composites

Coatings

N N

O

O O

O

O

n

Characteristics of PICharacteristics of PICharacteristics of PICharacteristics of PI• Structure of typical polyimide: Kapton

• Advantages– Excellent high temperature mechanical performance– Very high tensile and compressive strength– Outstanding bearing and wear properties– Very high purity– Good chemical resistance

• Disadvantages– Difficult to fabricate and require venting of volatiles– Hydroscopic and subject to attacks by alkaline– Comparatively high cost

Typical ApplicationTypical ApplicationTypical ApplicationTypical Applicationssss of PI (1)of PI (1)of PI (1)of PI (1)

•Electric motor and generator insulation

•Flat cable and wire insulation•Magnet wire and capacitor insulation

•Magnetic and pressure sensitive tapes and tube

Electric

•Flexible printed circuit board (FPCB)•Tape automated bonding (TAB)•Bar code label•Spiral tubes•Masking tapes

ElectronicApplicationsFields

FPCBFPCBFPCBFPCB((((www.desow.com/Upfiles)

Magnetic Wire Magnetic Wire Magnetic Wire Magnetic Wire (www.madewww.madewww.madewww.made----inininin----china.comchina.comchina.comchina.com) Flexible flat cableFlexible flat cableFlexible flat cableFlexible flat cable(www.indiamart.com/chainelectronicswww.indiamart.com/chainelectronicswww.indiamart.com/chainelectronicswww.indiamart.com/chainelectronics)

Typical ApplicationTypical ApplicationTypical ApplicationTypical Applicationssss of PI (2)of PI (2)of PI (2)of PI (2)

•Vacuum bags in fabrication of advanced resin matrix composite

•Traction belts on computer printers

•Heating elements and insulator

Composite

•Diaphragms•Alternator heat insulator pads•Sensor and switches•Seals and gasket•Spark plug boot•Speaker part•Disposal pin carrier •3 Radiator plug

Automotive

SpeakerSpeakerSpeakerSpeaker((((www.autotoys.comwww.autotoys.comwww.autotoys.comwww.autotoys.com)Switching systemSwitching systemSwitching systemSwitching system((((www.solvayadvancedpolymers.comwww.solvayadvancedpolymers.comwww.solvayadvancedpolymers.comwww.solvayadvancedpolymers.com) Check ballCheck ballCheck ballCheck ball((((www.plalution.com/4.htmlwww.plalution.com/4.htmlwww.plalution.com/4.htmlwww.plalution.com/4.html)

Traction beltTraction beltTraction beltTraction belt((((www.serpent.comwww.serpent.comwww.serpent.comwww.serpent.com) Dielectric substrate Dielectric substrate Dielectric substrate Dielectric substrate ((((http://http://http://http://www.fraivillig.comwww.fraivillig.comwww.fraivillig.comwww.fraivillig.com)

Typical ApplicationTypical ApplicationTypical ApplicationTypical Applicationssss of PI (3)of PI (3)of PI (3)of PI (3)•Wire and cable insulation•Motors/alternators (insulation)•Smoke hoods•Composite bagging film•Cockpit sun shade•Multilayer thermal blankets (satellite)•Speakers (airports) and acoustic insulation•Antenna system (satellite)

Aerospace

www.algor.com/news_pub/cust_app/srs/srstech.aspwww.algor.com/news_pub/cust_app/srs/srstech.aspSatellite antenna systemSatellite antenna systemSatellite antenna systemSatellite antenna system

Cockpit sun shade Cockpit sun shade Cockpit sun shade Cockpit sun shade ((((www.bizbuzzmedia.comwww.bizbuzzmedia.comwww.bizbuzzmedia.comwww.bizbuzzmedia.com) Acoustic insulation Acoustic insulation Acoustic insulation Acoustic insulation ((((www.ferret.com.auwww.ferret.com.auwww.ferret.com.auwww.ferret.com.au)

Chemical structures Chemical structures Chemical structures Chemical structures (commercially(commercially(commercially(commercially available)available)available)available)• AURUM (MITSUI)

• ULTEM (GE)

• UPILEX-R (UBE)

• UPILEX-S (UBE)

• KAPTON (DuPont)

• KEVLAR (DuPont)

N N

O

O O

O

O O

n

N

O

O

O

C

CH3

CH3

O

N

O

O

n

N

O

O

N

O

O

O

n

N

O

O

N

O

O

n

N N

O

O O

O

O

n

n

C

O

C

O

HN

HN

• A form of energy that is emitted from a source and travels in the form of waves or particles through a medium, eg air or a vacuum.

NonNonNonNon----Ionizing radiationIonizing radiationIonizing radiationIonizing radiation : microwaves, IR, radio frequenciesIonizing radiationIonizing radiationIonizing radiationIonizing radiation : α, β, neutron, electron, gamma, X-ray, UV

Non-ionizing radiation Ionizing radiation

Radio frequencies Heat GammaMicrowaves X-rays

Infra red Ultraviolet

Visiblelight

What is Radiation ?What is Radiation ?What is Radiation ?What is Radiation ?

---- The electromagnetic spectrumThe electromagnetic spectrumThe electromagnetic spectrumThe electromagnetic spectrum

Electron Beam ProcessElectron Beam ProcessElectron Beam ProcessElectron Beam Process• Electron beam process creates useful

changes in material properties and performance, such as polymer crosslinkingand chain scissioning.

• Electron beam process is also widely used for medical device sterilization, cosmetics sterilization, and pharmaceutical sterilization.

Electron Beam Curing ProcessElectron Beam Curing ProcessElectron Beam Curing ProcessElectron Beam Curing Process• Nonthermal, nonautoclave curing

method that uses high-energy electrons to initiate polymerization and cross linking reactions.

Comparison of radiation and Comparison of radiation and Comparison of radiation and Comparison of radiation and thermal curing thermal curing thermal curing thermal curing

Environmentally hazardous materials

Fire hazard

Adhesion to different substrate

Damage to sensitive substrate

Chemical resistanceSpeed

Space requirementsRunning costs

Energy consumption

OOXOOHealth &

Safety

XO

XOXO

Technical

XOXOXOXO

Commercial

ThermalUVEBFactor

O : Advantage : Intermediate X : Disadvantage

ExperimentalExperimentalExperimentalExperimental• Materials

– Polyimide film (Kapton HN, 5mil, DuPont)

• Irradiation– Electron beam– Nitrogen atmosphere– Energy of 1.14 MeV, 4 mA– Total radiation dose : 0.2~3.8 x 104 kGy

CharacterizationCharacterizationCharacterizationCharacterization• Dynamic Mechanical

Analyzer (DMA)– Storage/loss modulus– Tan delta

• Tensile properties– Tensile strength– Young’s modulus

• Thermogravimetricanalysis (TGA)– Decomposition temp.– Residue

• Electrical properties– Dielectric constant– Conductivity– LCR meter17.25

17.2517.2517.2517.25

Typical DMA curves of PITypical DMA curves of PITypical DMA curves of PITypical DMA curves of PIββββ2222 relaxationrelaxationrelaxationrelaxation Glass relaxationGlass relaxationGlass relaxationGlass relaxation

0 100 200 300 400 500

500

1000

1500

2000

2500

3000

3500

4000

30

40

50

60

70

80

90

100

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

Ta

n d

elta

Lo

ss m

od

ulu

s (M

Pa

)S

tora

ge

mo

du

lus (

MP

a)

Temperature (oC)

Tan delta curves of PITan delta curves of PITan delta curves of PITan delta curves of PI

100 200 300 400

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

Ta

n d

elt

a

Temperature (oC)

Control

1.5 x 104 kGy

Relaxation temperatureRelaxation temperatureRelaxation temperatureRelaxation temperature

100

110

120

130

140

150

1.5 x 104

0.5 x 104

1.0 x 104

ββββ2 relaxation

Glass relaxation

Radiation dose (kGy)

Tem

pera

ture

(oC

)

0.0400

410

420

430

440

450

Te

mp

era

ture

(oC

)

Values of tan delta (Glass relaxation)Values of tan delta (Glass relaxation)Values of tan delta (Glass relaxation)Values of tan delta (Glass relaxation)

0.046

0.048

0.050

0.052

0.054

0.056

Ta

n d

elt

a

Radiation dose (kGy)

0.0 0.5 X 104 1.0 X 10

41.5 X 10

4

Mechanical PropertiesMechanical PropertiesMechanical PropertiesMechanical Properties

0

5

10

15

20

1.5 x 104

1.0 x 104

0.5 x 104

Radiation dose (kGy)

Ten

sil

e s

tren

gth

(kg

f/m

m2)

0

80

120

160

200

240

280

320

Mo

du

lus (k

gf/m

m2)

Thermal stabilityThermal stabilityThermal stabilityThermal stability

a Thermal decomposition temperature (on-set) from TGA measurement, scan rate: 10 oC/min, N2 protectionb Temperature at 5% weight loss from TGA measurementc Temperature at 10% weight loss from TGA measurement

58.10580.82557.89570.671.5

59.80582.10560.08571.251.0

60.79583.04562.42571.170.4

61.41583.50563.58571.420

Residue

(%)

T10

(oC)c

T5

(oC)b

Td

(oC)a

Radiation

dose

(x10-4 kGy)

200 300 400 500 600 700 800

60

70

80

90

100

Weig

ht

(%)

Temperature (oC)

Control

0.4 X 104 kGy

1.0 X 104 kGy

1.5 X 104 kGy

Electric propertiesElectric propertiesElectric propertiesElectric properties

-2 0 2 4 6 82.6

2.8

3.0

3.2

3.4

control 8,000 kGy 15,000 kGy

25,000 kGy 33,000 kGy 38,000 kGy

Die

lec

tric

co

ns

tan

t

log f

-2 0 2 4 6 810

-17

10-15

10-13

10-11

10-9

10-7

10-5

Control

8,000 kGy

15,000 kGy

25,000 kGy

33,000 kGy

38,000 kGyC

on

du

ctiv

ity (

ΩΩ ΩΩ-1cm

-1)

log f

SummarySummarySummarySummary• Polyimide films show extensive radiation resistivity• Irradiation leads to decrease in the β2 relaxation

temperature and the thermal decomposition temperature

• The tensile strength decrease insignificantly and Young’s modulus tends to increase slightly with dose

• A significant change of the dielectric constant is observed after electron beam irradiation

• Polyimide is sufficiently endurable to survive the high energy irradiation and temperature fluctuations present in space environments

Brownian movement (motion)Brownian movement (motion)Brownian movement (motion)Brownian movement (motion)• Brownian motionBrownian motionBrownian motionBrownian motion is the random movement of

particles suspended in a liquid or gas or the mathematical model used to describe such random movements, often called a particle theory.

• The mathematical model of Brownian motion has several real-world applications. An often quoted example is stock market fluctuations. Another example is the evolution of physical characteristics in the fossil record

LRC meterLRC meterLRC meterLRC meter

PI filmPI filmPI filmPI film

Stainless steelStainless steelStainless steelStainless steel

Cylindrical instrumentCylindrical instrumentCylindrical instrumentCylindrical instrument

TerminologyTerminologyTerminologyTerminology

• Glass transition temperature– When an amorphous polymer is heated, the

temperature at which it changes from a glass to the rubbery form is called the glass transitionglass transitionglass transitionglass transition

– SSSSegmental motion occurringegmental motion occurringegmental motion occurringegmental motion occurring

• Secondary beta relaxation– The rotation or oscillation of functional groupsrotation or oscillation of functional groupsrotation or oscillation of functional groupsrotation or oscillation of functional groups

occur