effect of blend compositions on processing and mechanical properties of polycarbonate /...
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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.
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