Transcript Commodity Thermoplastics_ LDPE, HDPE, PP, PVC, PS Professor Joe Greene CSU, CHICO Polyolefin Definition • Olefins: Unsaturated, aliphatic hydrocarbons made from ethylene gas • Ethylene is.

Commodity Thermoplastics_ LDPE,
HDPE, PP, PVC, PS
Professor Joe Greene
CSU, CHICO
1
Polyolefin Definition
• Olefins: Unsaturated, aliphatic hydrocarbons made from
ethylene gas
• Ethylene is produced by cracking higher hydrocarbons of
natural gas or petroleum
• Olefin means oil forming
• Historically given to ethylene because oil was formed when
ethylene was treated with Cl.
• Now applies to all hydrocarbons with linear C::C double
bonds (not aromatic C::C double bonds)
• Polyethylene discovered around 1900, though using an
expensive process
• LDPE commercialized in 1939
2
• HDPE commercialized in 1957
Principal Olefin Monomers
• Ethylene
Propylene
H H
H
H
C C
C
C
H H
CH3
H
• Butene-1
H
H
C
C
C2H5 H
H
H
C
C
4-Methylpentene
C5H6 H
CH3
3
Several Olefin Polymers
• Poly Ethylene
Poly Propylene
H H
C C
H H
n
• PolyisoButene
H
H
C
C
C2H5 H
H
H
C
C
C5H6 H
n
CH3
H
H
C
C
CH3
H
n
PolyMethylpentene
n
4
Polymers Derived from Ethylene Monomer
X Position
Material Name
Abbreviation
H
Cl
Methyl group
Benzene ring
CN
OOCCH3
OH
COOCH3
F
Polyethylene
Polyvinyl chloride
Polypropylene
Polystyrene
Polyacrylonitrile
Polyvinyl acetate
Polyvinyl alcohol
Polymethyl acrylate
Polyvinyl fluoride
PE
PVC
PP
PS
PAN
PvaC
PVA
PMA
PVF
Note:
Methyl Group is:
|
H–C–H
|
H
Benzene ring is:
X Position
Y Position
Material Name
Abbreviation
F
Cl
CH3 (Methyl group)
COOCH3
F
Cl
CH3
CH3
Polyvinylidene fluoride
Polyvinyl dichloride
Polyisobutylene
Polymethyl methacrylate
PVDF
PVDC
PB
PMMA
5
Addition Polymerization of PE
• Polyethylene produced with low (Ziegler) or high pressure
(ICI)
• Polyethylene produced with linear or branched chains
H H
H H
H H
H H
H H
C C
C C
C C
C C
C C
H H
H H
H H
H H
H H
n
OR
H H
H H
H H
H H
H H
C C
C C
C C
C C
C C
H H
H H
H
H H
H H
n
6
Mechanical Properties of Polyethylene
• Type 1: (Branched) Low Density of 0.910 - 0.925 g/cc
• Type 2: Medium Density of 0.926 - 0.940 g/cc
• Type 3: High Density of 0.941 - 0.959 g/cc
• Type 4: (Linear) High Density to ultra high density > 0.959
Mechanical Properties
Branched Low
Density
Density
0.91- 0.925
Medium
Density
0.926- 0.94
High
Density
0.941-0.95
Linear High Density
0.959-0.965
Crystallinity
30% to 50%
50% to 70%
70% to 80%
80% to 91%
Molecular
Weight
Tensile
Strength, psi
Tensile
Modulus, psi
Tensile
Elongation, %
Impact Strength
10K to 30K
30K to 50K
50K to 250K
250K to 1.5M
600 - 2,300
1,200 - 3,000
3,100 - 5,500
5,000 – 6,000
25K – 41K
38K – 75 K
100% - 650%
100%- 965%
150K – 158
150K – 158 K
K
10% - 1300% 10% - 1300%
No break
1.0 – no
break
D50 – D60
ft-lb/in
Hardness, Shore D44 – D50
0.4 – 4.0
0.4 – 4.0
D60 – D70
D66 – D73
7
Physical Properties of Polyethylene
Physical Properties of polyethylene
Branched Low Medium Density
Density
Optical
Transparent to Transparent to
opaque
opaque
Tmelt
98 – 115 C
122 – 124 C
High
Density
Transparent to
opaque
130 – 137 C
Linear High Density
Transparent to opaque
130 –137 C
Tg
-100 C
H20 Absorption Low < 0.01
-100 C
Low < 0.01
-100 C
Low < 0.01
-100 C
Low < 0.01
Oxidation
Resistance
UV Resistance
Low, oxides
readily
Low, Crazes
readily
Resistant
below 60C
Resistant
Low, oxides
readily
Low, Crazes
readily
Resistant below
60C
Resistant
Low, oxides readily
Low, oxides readily
Low, Crazes readily
Low, Crazes readily
Resistant below 60C
Resistant below 60C
Resistant
Resistant
Oxidizing
Acids
Oxidizing Acids
Oxidizing Acids
Oxidizing Acids
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
8
Processing Properties of Polyethylene
Processing Properties
Branched Low
Density
Tmelt
98 – 115 C
Recommended Temp
I: 300F – 450F
Range
E: 250F – 450F
(I:Injection, E:Extrusion)
Molding Pressure
5 – 15 psi
Mold (linear) shrinkage
(in/in)
0.015 – 0.050
Medium Density
Linear High Density
122 – 124 C
High
Density
130 – 137 C
I: 300F – 450F
E: 250F – 450F
I: 350F – 500F
E: 350F – 525F
I: 350F – 500F
E: 350F – 525F
5 – 15 psi
12 – 15 psi
12– 15 psi
0.015 – 0.050
0.015 – 0.040
130 –137 C
0.015 – 0.040
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Special Low Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• Very Low Density Polyethylene (VLDPE)
– Densities between 0.890 and 0.915
– Applications include disposable gloves, shrink packages,
vacuum cleaner hoses, tuning, bottles, shrink wrap,
diaper film liners, and other health care products
• Linear Low Density Polyethylene (LLDPE)
– Densities between 0.916 and 0.930
– Contains little if any branching
– Properties include good flex life, low warpage, and improved
stress-crack resistance
– Applications include films for ice, trash, garment, and produce
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bags
Special High Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• High Molecular Weight- High Density Polyethylene
(HMW-HDPE)
– Densities are 0.941 or greater
– MW from 200K to 500 K
– Properties include improved toughness, chemical
resistance, impact strength, and high abrasion resistance.
– High viscosities
– Applications include trash liners, grocery bags, industrial
pipe, gas tanks, and shipping containers
11
Special High Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• Ultra High Molecular Weight Polyethylene
(UHMWPE)
– Densities are 0.96 or greater
– MW from 3M to 6M
– Properties include improved high wear resistance,
chemical inertness, and low coefficient of friction.
– High viscosities result in material not flowing or melting.
– Processed similar to PTFE (Teflon)
– Ram extrusion and compression molding are used.
– Applications include pump parts, seals, surgical implants,
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pen tips, and butcher-block cutting surfaces.
Copolymers of Polyethylene
• Ethylene-ethyl acrylate (EEA)
– Properties range from rubbery to tough ethylene-like
properties
– Applications include hot melt adhesives, shrink wrap,
produce bags, bag-in-box products, and wire coating.
• Ethylene-methyl acrylate (EMA)
– Produced by addition of methyl acrylate monomer (40%
by weight)with ethylene gas
– Tough, thermally stable olefin with good elastomeric
characteristics.
– Applications include food packaging, disposable medical
gloves, heat-sealable layers, and coating for composite
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packaging
Copolymers of Polyethylene
• Ethylene-Vinyl Acetate (EVA)
– Repeating groups is ethylene with an acetate functional
– Part of the pendent group are highly polar.
– Vinyl acetate reduces crystallinity and increases chemical reactivity
because of high regions of polarity.
– Result:flexible polymer that bonds well to other materials
– Excellent adhesive (Elmers Glue)
– Other applications include flexible packaging, shrink wrap, auto
bumper pads, flexible toys, and tubing
H H
H H
C
C
H
H
n
C
C
H
O
m
C=O
C
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Copolymers of Polyethylene
• Ethylene-Propylene (EPM)
– Ethylene and propylene are copolymerized in random manner and
causes a delay in the crystallization.
– Thus, the copolymer is rubbery at room temp because the Tg is
between HDPE (-110C) and PP (-20C).
– Ethylene and propylene can be copolymerized with small amounts
of a monomer containing 2 C=C double bonds (dienes)
– Results in a ter polymer, EPDM, or thermoplastic rubber, TPO
H
H
H
H
C
C
C
C
H
H
CH3
H
n
15
m
Mechanical Properties of PE Blends
Mechanical Properties of PE Blends
Ethylene-vinyl
Ethylene-vinyl
acetate
alcohol
Density
0.922 – 0.943
1.14 – 1.19
Tensile
Strength, psi
Tensile
Modulus, psi
Tensile
Elongation, %
Impact Strength
Ethyleneethyl acrylate
0.93
Ethylene-methyl
acrylate
0.942 – 0.945
2,200 – 4,000
8,520 – 11,600
1,600 – 2,100 1,650
7K – 29K
300 K – 385 K
4K – 7.5 K
300% - 750%
180%- 280%
700% - 750% 740%
No break
1.0 – 1.7
No break
12 K
ft-lb/in
Hardness, Shore D17 – D45
D27 – D38
16
Processing Properties of PE Blends
Processing Properties
Ethylene-vinyl
acetate
Tmelt
103 – 108 C
Recommended Temp
C: 200-300F
Range (C: Compression) I: 300F – 430F
(I:Injection, E:Extrusion) E: 300F – 380F
Molding Pressure
1 – 20 psi
Mold (linear) shrinkage
(in/in)
0.007 – 0.035
Ethylene-vinyl
alcohol
142 – 181 C
Ethylene-ethyl
acrylate
Ethylene-methyl
acrylate
83 C
I: 365F – 480F
E: 365F – 480F
C: 200 – 300F
I: 250F – 500F
E: 300F – 620F
1 – 20 psi
0.015 – 0.035
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Polypropylene History
• Prior to 1954 most attempts to produce plastics
from polyolefins had little commercial success
• PP invented in 1955 by Italian Scientist F.J. Natta
by addition reaction of propylene gas with a
sterospecific catalyst titanium trichloride.
• Isotactic polypropylene was sterospecific
(molecules are arranged in a definite order in
space)
• Polypropylene is similar in manufacturing
method and in properties to PE
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Chemical Structure
• Propylene
H
H
C
C
CH3
H
n
• Isotactic- CH3 on one side of polymer chain
(isolated). Commercial PP is 90% to 95% Isotactic
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
C
C
C
CH3 H
CH3 H
CH3 H
CH3 H
CH3 H
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Polypropylene Stereostatic Arrangements
•Atactic- CH3 in a random order (A- without; Tactic- order) Rubbery and of
limited commercial value.
H
H
H
CH3
H
CH3
H
H
H
CH3
C
C
C
C
C
C
C
C
C
C
CH3 H
H
H
H
H
CH3 H
H
H
•Syndiotactic- CH3 in a alternating order (Syndio- ; Tactic- order)
H
H
H
CH3
H
H
H
CH3
H
H
C
C
C
C
C
C
C
C
C
C
CH3 H
H
H
CH3 H
H
H
CH3 H
20
Addition Polymerization of PP
• Polypropylene produced with low pressure process (Ziegler)
• Polypropylene produced with linear chains
• Polypropylene is similar in manufacturing method and in
properties to PE
• Differences between PP and PE are
–
–
–
–
–
Density: PP = 0.90; PE = 0.941 to 0.965
Melt Temperature: PP = 176 C; PE = 110 C
Service Temperature: PP has higher service temperature
Hardness: PP is harder, more rigid, and higher brittle point
Stress Cracking: PP is more resistant to environmental stress
cracking
21
Advantages of Polypropylene
• Advantages
–
–
–
–
–
–
–
–
–
–
Low Cost
Excellent flexural strength
Good impact strength
Processable by all thermoplastic equipment
Low coefficient of friction
Excellent electrical insulation
Good fatigue resistance
Excellent moisture resistance
Service Temperature to 126 C
Very good chemical resistance
22
Disadvantages of Polypropylene
• Disadvantages
–
–
–
–
–
–
–
High thermal expansion
UV degradation
Poor weathering resistance
Subject to attack by chlorinated solvents and aromatics
Difficulty to bond or paint
Oxidizes readily
flammable
23
Molecular Weight Review
• Molecular Weight estimates the average length of the
polymer chain and is similar to the DP (degree of
polymerization)
– MW = (MW of mer) x DP
• Example: MW= 100,000 for PS then the DP = 1000. (PS = 104 amu)
• Example: MW= 50,000 for PE then the DP = 1800. (PE = 28 amu)
• Molecular Weight is measured by osmometry, light
scattering and solution viscosity
• Molecular Weight is characterized by Weight Average, Mw,
Mn
and Number Average, Mn. Frequency
• Polydispersity, PD
Mw
– Ratio of Mw / Mn
24
Weight
Mechanical Properties of Polypropylene
Mechanical Properties of Polypropylene
HDPE
Polypropylene LDPE
(For Comparison) (For Comparison)
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
30% to 50%
30% to 50%
80% to 91%
10K to 30K
250K to 1.5M
Range of
MWD for
processing
4,500 – 5,500
Range of MWD
for processing
Range of MWD
for processing
600 - 2,300
5,000 – 6,000
165K – 225K
25K – 41K
150K – 158 K
100% - 600%
100% - 650%
10% - 1300%
0.4 – 1.2
No break
0.4 – 4.0
R80 - 102
D44 – D50
D66 – D73
Molecular Weight 200K to 600K
Molecular Weight
Dispersity MWD
(Mw/Mn)
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
ft-lb/in
Hardness, Shore
25
Physical Properties of Polyethylene
Physical Properties of Polypropylene
HDPE
Polypropylene LDPE
Transparent to Transparent to
Transparent to opaque
Optical
opaque
opaque
175 C
98 – 115 C
130 –137 C
Tmelt
Tg
H20
Absorption
-20 C
0.01 – 0.03
Low, oxides
Oxidation
readily
Resistance
UV Resistance Low, Crazes
readily
Resistant
Solvent
below 80C
Resistance
Resistant
Alkaline
Resistance
Oxidizing
Acid
Acids
Resistance
-100 C
Low < 0.01
-100 C
Low < 0.01
Low, oxides
readily
Low, Crazes
readily
Resistant below
60C
Resistant
Low, oxides readily
Oxidizing Acids
Oxidizing Acids
Low, Crazes readily
Resistant below 60C
Resistant
26
Processing Properties of Polyethylene
Processing Properties
Polypropylene
Tmelt
175 C
Recommended Temp
I: 400F – 550F
Range
E: 400F – 500F
(I:Injection, E:Extrusion)
Molding Pressure
10 -20 psi
Mold (linear) shrinkage
(in/in)
0.010 – 0.025
LDPE
98 – 115 C
HDPE
130 –137 C
I: 300F – 450F
E: 250F – 450F
I: 350F – 500F
E: 350F – 525F
5 – 15 psi
12– 15 psi
0.015 – 0.050
0.015 – 0.040
27
Copolymers of Polypropylene
• Ethylene-propylene copolymers
– Small amount of PP can lower crystallinity of linear HDPE
• Polyallomers (block copolymers)
– Blocks of PE and PP polymers allows crystallization to take place
– Properties are similar to HDPE and PP
• Ethylene-propylene rubbers
– Random co-polymerization of ethylene and propylene prevents
crystallization of the chains by suppressing regularity of molecules
– Resulting polymers are amorphous having low Tg (between -110C
and -20C depending on % of PE and PP)
– Polymers are rubbery at room temperature
– Conventional vulcanization allows for use as commercial rubber,
thermoplastic rubbers, TPR
28
Polyolefin_Polybutylene
• History
H
H
– PB invented in 1974 by Witco Chemical
C
C
– Ethyl side groups in a linear backbone
• Description
CH2
H
– Linear isotactic material
– Upon cooling the crystallinity is 30%
CH3
– Post-forming techniques can increase crystallinity to 55%
– Formed by conventional thermoplastic techniques
• Applications (primarily pipe and film areas)
– High performance films
– Tank liners and pipes
– Hot-melt adhesive
– Coextruded as moisture barrier and heat-sealable packages 29
Properties of Polybutylene
Mechanical Properties of Polybutylene
Polybutylene Polypropylene LDPE
HDPE
(For Comparison) (For Comparison)
0.908 -.917
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
30% to 50%
30% to 50%
30% to 50%
80% to 91%
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
4,000
4,500 – 5,500
600 - 2,300
5,000 – 6,000
10K – 40K
165K – 225K
25K – 41K
150K – 158 K
300% - 400%
100% - 600%
100% - 650%
10% - 1300%
No break
0.4 – 1.2
No break
0.4 – 4.0
D44 – D50
D66 – D73
ft-lb/in
Hardness
Shore D55 – D65 R80 - 102
30
Polyolefin_Polymethylpentene (PMP)
• Description
H H
– Crystallizes to 40%-60%
C C
– Highly transparent with 90% transmission
– Formed by injection molding and blow molding
CH2 H
• Properties
H3C-CH-CH3
– Low density of 0.83 g/cc; High transparency
– Mechanical properties comparable to polyolefins with higher
temperature properties and higher creep properties.
– Low permeability to gasses and better chemical resistance
– Attacked by oxidizing agents and light hydrogen carbon solvents
– Attacked by UV and is quite flammable
• Applications
– Lighting elements (Diffusers, lenses reflectors), liquid level
31
– Food packaging containers, trays, and bags.
Properties of Polymethylpentene
Mechanical Properties of Polymethylpentene
Polymethyl- Polypropylene LDPE
HDPE
pentene
(For Comparison) (For Comparison)
0.83
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
40% to60%
30% to 50%
30% to 50%
80% to 91%
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
4,000 – 5,000
4,500 – 5,500
600 - 2,300
5,000 – 6,000
160K – 200K
165K – 225K
25K – 41K
150K – 158 K
100% - 400%
100% - 600%
100% - 650%
10% - 1300%
0.4 – 1.0
0.4 – 1.2
No break
0.4 – 4.0
R80 – R100
R80 - 102
D44 – D50
D66 – D73
ft-lb/in
Hardness
32
PVC Background
• Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB
– Polyvinyls were invented in 1835 by French chemist V. Regnault
when he discovered a white residue could be synthesized from
ethylene dichloride in an alcohol solution. (Sunlight was catalyst)
– PVC was patented in 1933 by BF Goodrich Company in a process
that combined a plasticizer, tritolyl phosphate, with PVC
compounds making it easily moldable and processed.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is made by suspension process (82%), by mass
polymerization (10% ), or by emulsion (8%)
– All PVC is produced by addition polymerization from the vinyl
chloride monomer in a head-to-tail alignment.
– PVC is amorphous with partially crystalline (syndiotactic) due to
structural irregularity increasing with the reaction temperature.
33
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
PVC and Vinyl Products
• Rigid-PVC
– Pipe for water delivery
– Pipe for structural yard and garden structures
• Plasticizer-PVC or Vinyl
–
–
–
–
Latex gloves
Latex clothing
Paints and Sealers
Signs
34
PVC and PS Chemical Structure
• Vinyl Groups (homopolymers produced by addition polymerization)
– PVC
- poly vinylidene - polyvinylalcohol (PVOH)
chloride (PVDC)
H H
H H
H Cl
C C
C C
C C
H Cl
n
H Cl
– polyvinyl acetate (PVAc)
H OH n
n
- PolyStyrene (PS)
H H
H
H
C C
C
C
H OCOCH3
n
H
n
35
Mechanical Properties of Polyvinyls
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PVC (rigid)
1.30-1.58
PVC (Flexible)
1.16-1.35
PVB
1.05
PVDC
1.65-1.72
6,000 - 7,500
1,500 -3,500
500 - 3,000
3,500 - 5,000
350K – 600K
160K –240K
40% - 80%
200%-450%
150% - 450%
160% -240%
0.4 - 22
Range
Range
0.4 - 1
Shore D65-85
Shore A50-100
M60-65
50 -100
70-250
190
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT 264 psi
140 F -170F
130F -150F
36
Physical Properties of Polyvinyls
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
PVC (rigid)
Transparent
PVC (Flexible)
Transparent
PVB
Transparent
PVDC
Transparent
75 – 105 C
75 – 105 C
49
172C
75 -105C
75-105C
49
-15C
0.04-0.4% (24h)
0.15-0.75% (24h)
0.09-0.16% (24h)
0.1% (24h)
good
good
good
good
Poor
Poor
Poor
good
Soluble in
Acetone, and
Cyclohexanol.
Partially in
Toluene
Excellent
Soluble in
Acetone, and
Cyclohexanol.
Partially in
Toluene
Excellent
Dissolved in ketones
and esters
good
Excellent
good
good
good
good
good
$0.27
$0.27
$
$1.62
37
Processing Properties of Polyvinyls
Tmelt
Recommended Temp
Range
(I:Injection, E:Extrusion,
C: Compression)
Molding Pressure
Mold (linear) shrinkage
(in/in)
PVC (rigid)
75 – 105 C
PVC (Flexible)
75 – 105 C
I: 300F – 415F I: 320F – 385F
C: 285F-400F C: 285F - 350F
10-40 kpsi
8-25 kpsi
0.002 – 0.006
0.010 – 0.050
PVB
49
PVDC
172C
I: 250F – 340F
C: 280F-320F
I: 300F – 400F
C: 260F-350F
E: 300F-400F
0.5-3kpsi
5 - 30 kpsi
0.005 - 0.025
38
PS Background
• PS is one of the oldest known vinyl compounds
– PS was produced in 1851 by French chemist M. Berthelot by passing benzene
and ethylene through a red-hot-tube (basis for today)
– Amorphous polymer made from addition polymerization of styrene
– Homopolymer (crystal): (2.7 M metric tons in 1994)
• Clear and colorless with excellent optical properties and high stiffness.
• It is brittle until biaxially oriented when it becomes flexible and durable.
– Graft copolymer or blend with elastomers- Impact polystyrene (IPS):
• Tough, white or clear in color, and easily extruded or molded.
• Properties are dependent upon the elastomer %, but are grouped into
– medium impact (Izod<1.5 ft-lb), high impact (Izod between 1.5 to 2.4
ft-lb) and super-high impact (Izod between 2.6 and 5 ft-lb)
– Copolymers include SAN (poly styrene-acrylonitrile), SMA (maleic anhydride),
SBS (butadiene), styrene and acrylic copolymers.
– Expandable PS (EPS) is very popular for cups and insulation foam.
• EPS is made with blowing agents, such as pentane and isopentane.
39
• The properties are dependent upon cell size and cell size distribution
Mechanical Properties of PS, ABS, SAN
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PS
1.04
ABS
1.16-1.21
SAN
1.07
5,000 - 7,200
3,300 - 8,000
10,000 -12,000
330K-475K
320K-400K
475K-560K
1.2% - 2.5%
1.5%-25%
2%-3%
0.35-0.45
1.4-12
0.4-0.6
M60-75
R100-120
R83, M80
50 -83
65- 95
65-68
169F - 202F
190F - 225F
214F - 220F
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT
264 psi
40
Physical Properties of PS, ABS, SAN
PS
Transparent
ABS
Transparent
SAN
Transparent
100 C
125C
120C
75 -105C
110 -125C
120C
0.01-0.03% (24h)
0.2-0.6% (24h)
0.15-0.25% (24h)
good
good
good
fair
fair
fair
Solvent
Resistance
Soluble in
Acetone, Benzene,
Toluene and
Methylene
dichloride
Dissolved in ketones
and esters
Alkaline
Resistance
Acid
Resistance
Excellent
Soluble in
Toluene and
Ethylene
dichloride,
Partially in
Benzene
Excellent
Poor: attacked by
oxidizing agents
Poor: attacked by
oxidizing agents
$0.41
$0.90
Optical
Tmelt
Tg
H2 0
Absorption
Oxidation
Resistance
UV Resistance
Cost $/lb
Poor: attacked by
oxidizing agents
good
$0.87
41
Processing Properties of PS, ABS, SAN
Tmelt
Recommended Temp
Range
(I:Injection, E:Extrusion)
Molding Pressure
Mold (linear) shrinkage
(in/in)
PS
100 C
ABS
125C
SAN
120C
I: 350F – 500F
E: 350F- 500F
C: 300F - 400F
I: 380F – 500F
C: 350F - 500F
I: 360F – 550F
E: 360F -450F
C:300F - 400F
5 - 20 kpsi
8-25 kpsi
5-20 kpsi
0.004 – 0.007
0.004 – 0.008
0.003 – 0.005
42
Section Review
• Major Topics
– Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is produced by addition polymerization from the vinyl chloride monomer
in a head-to-tail alignment.
– PVC is partially crystalline (syndiotactic) with structural irregularity increasing
with the reaction temperature.
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
X1
– Vinyls have (CH2CX2) repeating link
– PS is Amorphous and made from addition polymerization
– PC is amorphous and made from condensation polymerization
– Effects of reinforcements on PP and PS
43
Homework Questions
6. Four typical Physical Properties of PVC are Optical = _______,
Resistance to moisture= ______ , UV resistance= _____, solvent
resistance=_______
7. The Advantages of PP are ________, ________, _______, and
__________.
8. The Disadvantages of PP are ________, ________, _______, and
__________.
9. Glass fiber affects PP by (strength) ________, (modulus)________,
(impact)_______, (density) __________, and (cost) ____________.
10. Two Blends PVC are ___________, and __________.
44
Section Review
• Major Topics
– Isotactic, atactic, sydiotactic polypropylene definitions
– Differences between PP and PE
– Molecular Weight definition and forms (Weight Average,
Mw, and Number Average, MA )
– Polydispersity definition and meaning
– Relation between Molecular weight and Degree of
Polymerization (DP)
– Mechanical, physical, and processing properties of PP,
Polybutylene, and polymethylpentene
– PP is produced with linear chains
45
Section Review
• Key Terms and Concepts
–
–
–
–
–
–
–
–
Polyolefin
Molecular weight
Number average molecular weight, weight average MW
Polydispersity
Polymer shrinkage
Polymer blends
Tensile Modulus
Izod Impact Strength
46
Homework Questions
1. Define Polyvinyls, PS, PP, HDPE, chemical structure.
2. Compare the density PVC, PVB, PS, and PVDC which is higher/lower than PP.
3. Compare the density of HDPE, LDPE, UHMWPE, LLDPE to PP?
4. What is the tensile strength of PP with 0%, 30% glass fibers? What is the tensile
modulus?
5. Plot tensile strength and tensile modulus of PVC, PS, PP, LDPE and HPDE to look
like:
50
Tensile
Strength,
10
Kpsi
xHDPE
xLDPE
200
500
Tensile Modulus, Kpsi
47
Homework Questions
1. Define Polypropylene chemical structure
2. Does commercial PP have Isotactic, atactic, sydiotactic form.
3. If MW of PP is 200,000, what is the approx. DP?
4. Polydispersity represents the distribution of _______and _____
5. Density of PP is _____ which is higher/lower than HDPE.
6. PP mechanical properties are higher/lower than LDPE and HDPE
7. Plot tensile strength and tensile modulus of PP, LDPE and HPDE to
look like the following
50
Tensile
Modulus,
10
Kpsi
xHDPE
xLDPE
2
5
Tensile Strength, Kpsi
48
Homework Questions
8. Four typical Physical Properties of PP are Optical = _______,
Resistance to moisture= ______ , UV resisance= _____, solvent
resistance=_______
9. The Advantages of PP are ________, ________, _______, and
__________.
10. The Disadvantages of PP are ________, ________, _______, and
__________.
11. Glass fiber affects PP by (strength) ________, (modulus)________,
(impact)_______, (density) __________, and (cost) ____________.
12. Five polyolefins are ________, ________, _______, ______, and
__________.
49