Effect of Blend Compositions on Processing and Mechanical Properties of Polycarbonate /

Acrylonitrile-Styrene-Acrylate Blends

Advisor : Assoc. Prof. Dr. Sarawut RimdusitCo-advisor : Dr. Ruksapong Kunanuruksapong

Polymer Engineering LaboratoryDepartment of Chemical Engineering

Faculty of EngineeringChulalongkorn UniversityBangkok 10330, Thailand

by

Sirisak Laopetcharat

1

Polycarbonate (PC)

• Polycarbonate or PC is important class of thermoplastic engineering polymer.

• PC contains carbonate groups (-O-CO-O-) in the main chain.

• The most widely used PC is base on bisphenol A.

Ref.: L. A. Utracki, “Commercial Polymer Blends,” Chapman & Hall, London, (1998) p.85.

C

CH3

CH3

O C

O

O

n

Carbonate Group

2

Properties of Polycarbonate

• High impact resistanceIzod, notched impact strength = 600-850 J m-1

• High heat resistanceMaximum working temperature = 130oC

• High transparencyLight transmittance, initial 85 % and after 3 yr 82 %

• Dimensional stabilityTensile modulus = 2.3 GPaFlexural modulus = 2.3 GPa

• Poor processability

• Notch sensitivityRef.: C. A. Harper in, “Handbook of Plastics, Elastomers, and Composites,” McGraw-Hill,New York (2002)29-30.

J. E. Mark, “Polymer Data Handbook,” Oxford University Press, Inc., 1999. 3

Acrylonitrile Styrene Acrylate (ASA)

• ASA is a two-phase thermoplastic material

combining styrene-acrylonitrile copolymer (SAN)

and acrylic rubber. 

Ref.: N. Niessner, “Polystyrenes and Styrenic Copolymers,” 2nd ed., John Wiley & Sons, Wiltshire (2003).

Acrylonitrile Styrene

O

O

Acrylate(butyl acrylate)

4

Acrylonitrile Styrene Acrylate (ASA)

• Structure is typically core-shell structure with a

cross-linking polyacrylate (usually poly(butyl

acrylate)) core and a grafted SAN copolymer shell.

Ref.: N. Niessner, “Polystyrenes and Styrenic Copolymers,” 2nd ed., John Wiley & Sons, Wiltshire (2003).

SAN matrix Graft shell of SAN

Rubber core based on alkyl acrylate

5

Acrylonitrile Styrene Acrylate (ASA)

• Structure is typically core-shell structure with a

cross-linking polyacrylate (usually poly(butyl

acrylate)) core and a grafted SAN copolymer shell.

Ref.: N. Niessner, “Polystyrenes and Styrenic Copolymers,” 2nd ed., John Wiley & Sons, Wiltshire (2003). 6

Styrene

Acrylonitrile

Rubber

Properties of ASA

• Excellent weatherability Total color difference E* = 0.8

(after exposure time 2 yr, south facing Florida)

• High toughness

• Good impact resistance Izod, notched impact strength = 250-400 J m-1

• Low notch sensitivity

• Good processability

Ref.: J.K. Fink, “Handbook of Engineering and Specialty Thermoplastics,” Vol. 1, Polyolefins and Styrenics, Wiley-Scrivener, New York (2010).L.K. Massey, “The Effects of UV Light and Weather on Plastics and Elastomers”, p.48 (2007) 7

Applications of ASA

• Automotive Sector

• Recreational Equipment Components

• Garden Equipment

• Household Sector

• Building Sector

• Marine Parts

• Outdoor Structural Parts

Ref.: http://www.viking-garden.com, http://henderson-recreation.com, http://www.aucklandglassrepair.co.nz. 8

Objectives

1. To study composition ratios between PC and ASA.

2. To investigate effect of blend compositions on dynamic mechanical and impact properties.

3. To evaluate effects of processing temperature on impact properties of PC/ASA blends.

9

Experimental Method

ASAPC

Twin screw extruder

Injection MolderSample

Processing temperature 210oC - 240oC

10Ref.: M. S. Kang, and C. K. Kim. “PC/ASA blends having enhanced interfacial and mechanical properties”, Korea-Australia Rheol J (2006) 1-8.

Results and Discussion

Dynamic Mechanical Properties

0.01

0.1

1

10

30 60 90 120 150 180

PCPC/ASA1PC/ASA2PC/ASA3PC/ASA4PC/ASA5ASA

Sto

rage

Mo

dul

us

(GP

a)

Temperature oC

Storage Modulus of PC/ASA Blends at Various Compositions

Heating rate: 2C/min, Test amplitude: 30µm, Test frequency 1Hz.

13

• Storage modulus at room

temperature was found to

symmetrically increase with

an increasing PC content.

• This observation suggested

the partially miscible nature

of these polymer blends.

1.3

2.9

Loss Tangent of PC/ASA Blends at Various Compositions

Heating rate: 2C/min, Test amplitude: 30µm, Test frequency 1Hz.

14

30 60 90 120 150 180

PC PC/ASA1 PC/ASA2 PC/ASA3 PC/ASA4 PC/ASA5 ASA

Tan

Temperature oC

• Two clearly separated peak

were observed when ASA

content in the blends is

greater than 20 wt%.

• May be due to the miscibility

of SAN phase with PC at low

concentration of SAN.

Impact Properties

0

200

400

600

800

1000

0 100

No

tch

ed

Izo

d I

mp

act

Str

eng

th (

J/m

)

PC Content (wt%)

Notched Izod Impact Strength of PC/ASA Blends

SampleNotched Izod

Impact Strength (J/m)

ASA 384

PC/ASA5 546

PC/ASA4 615

PC/ASA3 684

PC/ASA2 745

PC/ASA1 771

PC 835

16

Effects of Processing Temperature on

Impact Properties

0

200

400

600

800

1000

180 200 220 240 260

PC/ASA1PC/ASA2PC/ASA3PC/ASA4PC/ASA5

Not

che

d Iz

od im

pac

t str

eng

th (

J/m

)

Processing Temperature (oC)

Effect of Processing Temperature on Impact Properties of PC/ASA Blends

18

• The notched Izod impact was

observed to show a maximum

value with an increasing

processing temperature.

• May be due to phase

separation in a LCST type of

the PC/ASA blends at high

temperature.

Conclusions

• Storage modulus at room temperature and notched Izod

impact strength of the PC/ASA blends were found to increase

steadily with the PC mass fraction.

• Tgs of PC/ASA blends exhibited two step changes and were

found to shift towards each other with increasing amount of PC

suggested the partially miscible nature of the blends.

• Processing temperature showed substantial effect on impact

property of the blends. The optimal processing temperature

tended to increase with the PC mass fraction. 19

Acknowledgements

• This research is financially supported by Innovation and

Technology Department, PTT Phenol Co., Ltd., and partly

supported by the Higher Education Research Promotion and

National Research University Project of Thailand, Office of the

Higher Education Commission (AM1076A).

20

Compare Properties of PC/ASA-997 Blends with Commercial Products

Company Grade Density (g/cm3)

Ours blend(density)

Izod impact (J/m)

Ours blend (izod impact)

MVR (cm3/10min)

MFR (g/10min)

Ours blend (MVR)

Ours blend (MFR)

LuranS   KR 2863 C 1.16 70/30

(1.16)700

684 18 -

20 23.1 KR 2861/1 C 1.15 600 14 -

Sabic

Geloy XTPM307 1.15

70/30(1.16)

640

684

16 -

20  23.1

Geloy XTPM309E 1.16 675 17 -

Geloy XTPM309 1.16 685 13 -

Geloy XTPM309E 1.16 675 17 -

Geloy FXW751SK 1.16 300 - 8.3

Geloy HRA170D 1.16 750 29 30

Geloy HRA222F 1.1780/20(1.17) 385 745 - - 17 19.4

Geloy XTPMFR15 1.1990/10(1.18) 700 771 - 30 15 17.5

Polykemi  Scanblend FS7 1.13 50/50

(1.13)450

546- 20

26 28.9 Scanblend FS7 uv4 1.13 460 - 20

14

N

Polycarbonate / Acrylonitrile Butadiene Styrene (PC/ABS)

Ref.: http://www.omnexus.com, http://www.hubert.com, http://www.performancechemicals.basf.com.

• Excellent impact resistance

• Excellent heat resistance

• Dimensional stability

• Good processability

• Poor weatherability

Acrylonitrile StyreneButadiene

Oxidation (UV radiation)

• Loss of impact

• Discoloration

ABS

4

ASA

ABS

Ref.: N. Niessner, “Polystyrenes and Styrenic Copolymers,” 2nd ed., John Wiley & Sons, Wiltshire (2003). 6

OO

n

n

Polybutyl acrylate

Polybutadiene

Impact Strength of ASA and ABS after Outdoor Application

S. Rimdusit, S. Damrongsakkul and et al. (2011)

• Impact property enhancement of PVC-wood composites using acrylonitrile styrene acrylate

PVC/ASA (50:50wt%)

PVC

PVC/ASA (50:50wt%)

PVC

Results:

• PVC/ASA blend showed negligible

change in color and much lower E*

compared to that of the neat PVC.

1 2 3 4 month

Natural Weathering Test, Rayong Province, Thailand, time period 120 days

7

S. Rimdusit, S. Damrongsakkul and et al. (2011)

• Impact property enhancement of PVC-wood composites using acrylonitrile styrene acrylate

Results:PVC/ASA • The drastic change is called a percolation.

• The result is shown synergetic in

PVC/ASA blend.

PVC/ASA blends at various ASA content ranging from 0 wt% to 50 wt%

brittle fracture ductile fracture

30-40 %wt ASA

10

Ref.: S. Rimdusit and et al., “Impact property enhancement of PVC-wood composites using acrylonitrile styrene acrylate” (2011).

C. M. Benson and R. P. Burford (1995)

• Morphology and Properties of Acrylate Styrene Acrylonitrile /Polybutylene Terephthalate Blends

Results:

• Impact resistance decrease when

processing temperature is increased.

• When increasing the content of ASA,

impact strength exhibits more impact

energy resistance.

ASA 40/PBT 60

ASA 50/PBT 50

ASA 60/PBT 40

Twin screw extruder, processing temperature range 230-270 oC

13

Ref.: C.M. Benson and R.P. Burford, “Morphology and Properties of Acrylate Styrene Acrylonitrile /Polybutylene Terephthalate Blends”, J Mater Sci, 30, 573-582 (1995).

S. Rimdusit, S. Damrongsakkul and et al. (2011)

• Impact property enhancement of PVC-wood composites using acrylonitrile styrene acrylate

Results:PVC/ASA

100:0

90:10

80:20

70:30

60:40

50:50

0:100

• ASA content greater than 30 wt%

showed two clearly separated peaks.

• PVC/ASA blends was partially

miscible.

14

Ref.: S. Rimdusit and et al., “Impact property enhancement of PVC-wood composites using acrylonitrile styrene acrylate” (2011).

Brittle material

Toughening Mechanisms

Small number of (large) cracks

Low energy absorption

Toughened material

Many (small) cracks

High energy absorption

Ref.: Niessner, N. and Gausepohl, H. Polystyrene and Styrene Copolymers–An Overview. in: Scheirs, J. and Priddy, D. (eds.) Modern Styrenic Polymers: Poly Styrenes and Styrenic Copoltmers. Vol1. 2nd ed. Wiltshire : John Wiley & Sons, 2003.

rubber particle

9

Impact Strength of Thermoplastics

Polymer Impact Strength (J/m)

PS 13 – 25

PP 20 – 75

Polyamide 66 30 – 55

PBT 40 – 55

POM 60 – 120

PE (High density) 30 – 200

PP (40% GF filled) 75 – 110

ABS (Medium Impact Strength) 130 – 320

ASA 80 - 330

Ref: James, E. M. “Physical Properties of Polymers Handbook” American Institute of Physics, New York,1996.