Introduction
Chemical Resistance of
Geosynthetic Polymers to
Hydrocarbons and Toxic Soil
Contaminants
Presented by Charlotte Shaw
© Industrial Textiles & Plastics Ltd.
Objective
Improve understanding of:
• Chemical resistance
• How a polymer’s chemical resistance
depends upon its molecular structure
• Chemical resistance Standards & Test
Methods
• Limitations of current test methods
• New Technologies to improve chemical
resistance
© Industrial Textiles & Plastics Ltd.
Geosynthetic Materials
polyvinyl chloride
polyisobutylene / PIB
ethylene propylene diene monomer
chlorosulphonated polyethylene [HypalonTM]
polychloroprene [NeopreneTM ]
polypropylene
low density polyethylene
high density polyethylene
ethylene interpolymer alloy
[ CoolgardTM, XR-5TM, UltraTechTM, ElvaloyTM ]
Aluminium Laminates
PVC
Butyl Rubber
EDPM
CSPE
CR
PP
LDPE
HDPE
EIA
© Industrial Textiles & Plastics Ltd.
Geosynthetic Materials
Limited Chemical Resistance
Information
• Industry practice to compile
resistance charts
• Information often sparse and
qualitative
• Do not provide any performance data
© Industrial Textiles & Plastics Ltd.
Geosynthetic Materials
Biphenyl
Benzene
Derivatives
N
D
N
D
ND
ND
ND
ND
Dichlorobenzene
ND
Acetic Anhydride
Organics
Butyl Acetate
Ethyl Acetate
Acids
Benzoic Acid
Toluene
Carbonic Acid
Ethylbenzene
Inorganics
Hydrochloric Acid
Stryene
Perchloric Acid
ND
ND
ND
Xylenes
Carbohydrates
Nitrobenzene
Acenaphthene
Aromatics
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Polycyclic
Aromatic
Hydrocarbons
(PAH)
Benzo( b)fluoranthene
Benzo(k)fluoranthene
Dibnezo(a,h)anthracene
Fluoranthene
Fluorene
Indeno(1,2,3-cd)pyrene
N
D
N
D
N
D
N
D
N
D
N
D
N
D
N
D
N
D
N
D
Carbon Dioxide
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Carbons
Carbon Monoxide
Aqueous
Chlorines
Gaseous
Calcium Carbonate
Naphthalene
Alkalis
ND
ND
ND
Calcium Hydroxide
Hydroxides
Inorganic
Compounds
Magnesium Hydroxide
Sodium Hydroxide
Bromides
Bromine (liquid)
Fluorines
Elemental
ND
Iodines
Elemental
ND
Nitrogen
Gaseous
Oxygen
Elemental
Salt
Brine
Silicone
Oil
Hexane
Hydrocarbons
Methane
Magnesium Carbonate
Sodium Carbonate
ND
Butane
Ethane
Starch
ND
Pentane
ND
Propane
ND
Copper Sulphate
Alkanes
Sulphurs
Zinc Sulphide
Aliphatics
Octane
ND
ND
Tin
Stannous Chloride
Heptane
Fats
Fatty acids
Kerosene
Animal and Vegetable
Isoprene
ND
Oils
ND
Turpentine
Cyclohexane
Amyl
Alkenes
Butene
Alkynes
Acetylene
Brominated
ND
ND
Lipids
Butyl
Bromoform
Ethyl
Carbon Tetrachloride
ND
Isopropyl
Methyl
Chloroform
Chlorinated
Halogenated
Acetaldehyde
Dichloroethane
Aldehydes
Tetrachloroethane
Benzaldehyde
ND
Formaldehyde
Trichloroethylene
Organic
Compounds
Freon 12
Fluorocarbons
Freon 22
Iodinated
Benzyl
Alcohols
Amines
Aniline
Copper Cyanide
ND
Cynides
Sodium Cyanide
ND
Iodoform
Diethyl Ether
Mineral Oil
Ethers
MTBE
ND
ND
ND
ND
ND
ND
ND
Crude Oil
Generic
Oils & Fuels
Acetone
Ketones
Petroleum Oil
Methyl Isopropyl Ketone
ND
Ferric Chloride
ND
Ferric Nitrate
ND
Diesel
Dioxan (1,4)
ND
ND
Organometallics
Morpholine
ND
ND
ND
Ferric Sulphate
Hetrocyclics
Pyridine
Carbolic Acid
Tetrahydrofuran
Phenols
Cresols
Tannic Acid
Urea
Rating Index
Resistant
Limited Effect (at elevated temperature or high concentration)
Not Resistant
ND
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No Data
PURAFLEX
EIA
HDPE
PC
LDPE
PP
Neoprene
Acetic acid
Benzene
Benzyl chloride
Compound
CSPE
Subgroup
Butyl
Group
EDPM
Category
PVC
EIA
PURAFLEX
HDPE
Membrane Material
LDPE
PC
PP
Neoprene
Compound
CSPE
Subgroup
EDPM
Group
PVC
Category
Butyl
Membrane Material
Test Methods
EN 13361 Reservoirs & Dams
EN 13362 Canals
EN 13491 Tunnels & Underground
Structures
EN 13492 Liquid Waste
EN 13493 Solid Waste
•
•
© Industrial Textiles & Plastics Ltd.
Define mechanical performance and
Defines chemical resistance testing to:
EN 14414 & EN 14415
Test Methods
EN 14414 Chemical Resistance to
Leachates and Aggressive Chemicals
• Method A – Acids
• Method B – Alkalis
• Method C – Hydrocarbons
(diesel fuel, paraffin, lubricating oil)
• Method D – Synthetic leachate
EN 14415 Resistance to Leaching
• Method A – Hot water
• Method B – Alkalis
• Method C – Organic solvents
(methanol, isopropanol & glycol)
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Test Methods
EN 14414 and EN 14415 Test Procedure
• Immersion test
• 50 ºC for 56 days
• Visual inspection
• Measurements of Tensile Strength &
Elongation variances
• Pass criterion is merely
residual strength >75%
* Test Procedures equivalent to
ASTM D5322 within EPA method 9090
and ASTM D5747.
© Industrial Textiles & Plastics Ltd.
Chemical Resistance - Characterised
Molecular structure characteristics
• Molecular Weight
- Chain length is directly related to
polymer strength
• Molecular Weight Distribution
- Relationship between the number of
species and the molar mass
• Crystallinity
- Ratio of amorphous regions to
crystalline regions within the polymer’s
structure
• Polarity
- Distribution of electrons
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Chemical Resistance - Materials
HDPE
LDPE
PP
PVC
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Chemical Resistance - Materials
Polymer
HDPE
LDPE
PP
PVC
Crystallinity %
55-65
30-45
40-45
0
Tensile Strength
Good
Fair
Good
Poor
Brittle Deformation
Poor
Good
Fair
Excellent
Chemical Resistance
Good
Fair
Good
Poor
Non-Polar
Non-Polar
Non-Polar
Polar
Polarity
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Chemical Resistance - Polarity
Polar & Non-polar Chemicals
• Normally an atom has an even distribution of electrons in the
orbits
• If more end up on one side that the other in a molecule, there is
a resulting electrical field in that area
Polar
Non-polar
H 2O
CO2
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Chemical Resistance - Solubility
General rule
• Polar + Polar
= Soluble
• Non-polar + Non-polar = Soluble
• Polar + Non-polar
= Not Soluble
e.g. Water (Polar) + Oil (Non-Polar)
Why is this significant?
Methanol (Polar)
Hydrocarbons (Non-polar)
HDPE (Non-polar)
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Geosynthetic Materials
PVC
Butyl Rubber
EDPM
CSPE
CR
PP
LDPE
HDPE
EIA
polyvinyl chloride
Polar
polyisobutylene / PIB
Non-Polar
ethylene propylene diene monomer
Non-Polar
chlorosulphonated polyethylene
Polar
[HypalonTM]
polychloroprene [NeopreneTM]
Polar
polypropylene
Non-Polar
low density polyethylene
Non-Polar
high density polyethylene
Non-Polar
ethylene interpolymer alloy
Polar
[ CoolgardTM, XR-5TM, UltraTechTM, ElvaloyTM ]
© Industrial Textiles & Plastics Ltd.
Chemical Resistance
Solubility Parameters
• Graphical representation
• Green Sphere = polymer
• Red Satellites = challenge chemicals
δD Dispersion
Solubility Parameter
δH Hydrogen Bonding
Solubility Parameter
δP Polar Solubility
Parameter
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The closer the challenge chemical is to the
polymer
• > Solubility
• > Permeation rate
Key Points – Materials & Tests
Common Geosynthetic Materials
• Limited chemical resistance of monopolymer membrane materials
Current Test Methods
• Immersion testing measures a
membrane’s Resilience, i.e. the effect
of the challenge chemical on the
membrane’s physical characteristics
• Limited scope of challenge chemicals
• Lack of Quantitative chemical
resistance data, i.e. no measure of
performance.
Performance measured by Permeation
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Permeation
2
1
3
1 Sorption
2 Diffusion
3 Desorption
Partitioning of the
chemical to the liner
governed by
Henry’s Law :
Migration on a molecular
scale through the barrier
expressed by
Fick’s first Law :
Partitioning
between the
chemical and the
outer surface of
the barrier
Cg = Sgf*C
f = -Dg* (dcg / dz)
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Permeation
Permeation Test Method
• Each challenge chemical exposed to
the sample in a permeation cell
• Sweep gas to mass spectrometer
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Permeation Comparisons - materials
Polychloroprene (CR) 1.5mm
CSPE 1.5mm
PVC 1.5mm
EPDM 1.5mm
Butyl 1.5mm
HDPE 1.5mm
Puraflex 0.45mm
0.00E+00
2.00E+02
Puraflex
0.45mm
Vinyl Chloride
Methyl Isopropyl Ketone (MIK)
Hexane
Fluorene
Benzene
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1.67E-01
9.43E+00
1.56E-06
3.23E-06
3.52E-04
4.00E+02
6.00E+02
8.00E+02
1.00E+03
1.20E+03
1.40E+03
HDPE 1.5mm Butyl 1.5mm EPDM 1.5mm PVC 1.5mm CSPE 1.5mm
1.84E+03
8.05E+02
5.37E+02
1.41E+02
5.69E+02
6.15E+03
2.68E+03
1.79E+03
4.69E+02
1.90E+03
4.92E+03
2.15E+03
1.43E+03
3.75E+02
1.52E+03
6.15E+03
2.68E+03
5.59E+02
4.69E+02
1.90E+03
6.15E+02
2.69E+02
1.79E+02
4.69E+01
1.90E+02
Polychloropre
ne (CR)
1.5mm
4.92E+03
2.15E+03
5.01E+02
3.75E+02
1.52E+03
Aluminium Laminates
7 days
14 days
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Aluminium laminates often sold as ‘barrier’
membranes
• Products are generally Aluminium
laminated to LDPE or Bitumen
• Developed as a Methane barrier
• Fails EN 14414 A (sulphuric acid)
• Unsuitable for moist soils, acidic soils or
wherever there is any risk of acid rain
Aluminium oxidises rapidly
• Increases ‘wicking’
• Delamination of membrane
• Barrier properties negated
Technology
Barrier Technology
• Extruded multi-layer composite
• Incorporates Polar and Non-polar layers
(> 5 layers and > 5 polymers)
• Chemical Resistant core
• Thermally weldable
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Technology
Composite construction
Polar and Non-polar polymers
Resistant to Non-Polar and Polar challenge
chemicals
Polar (Methanol)
Non-Polar (Hydrocarbons)
Non-polar
Polar
Non-polar
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Installation
Installation
• Compatible with existing installation
methods
• Conventional geosynthetic membrane
welding equipment
• Typically a Leister Twinny S hot air
wedge welder
• BS EN 13067 Qualified Installers
recommended
• Rapid 4m/min installation
• Protected in accordance with
EN 13719
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Puraflex Testing Summary
Passes Industry Chemical Resistance
Tests
• Immersion Tests
• ASTM D5322 test method is common
to EPA Method 9090, ASTM D5647,
EN BS 14414 & EN BS 14415
• EN BS tests limited to ‘cocktail’
immersion tests (only 3 Hydrocarbons)
Additional Puraflex Test Data
• Immersion tests for further
Hydrocarbons (as identified in risk
assessment)
and
• Permeation data for 200 hydrocarbons
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Puraflex Permeation Modeller
Permeation Modeller Software
• Specifically written for environmental
consultants, hydro-geologists &
geotechnical engineers
• Upload soil analysis concentrations
• Enter variables
• Output permeation rates
• Risk Assessment Models (e.g.CLEA)
© Industrial Textiles & Plastics Ltd.
References
ASTM D5322. Laboratory Immersion Procedures for evaluating the Chemical
Resistance of Geosynthetics to liquids.
ASTM D5747. Tests to Evaluate Chemical Resistance of Geomembranes to
Liquids.
CLAIRE Report. The soil generic assessment criteria for human health risk
assessment.
Bromwich.D.W The design of permeation cells for testing chemical protective
clothing (1999). Phd Thesis – Griffith University.
EN 14414 Geosynthetics – Screening test method for determining chemical
resistance for landfill applications (2004).
EN 14415 Geosynthetics barriers – Test methods for determining the resistance
to leaching (2004).
Lampman.S.W. Characterization and failure analysis of plastics (2003). ASM
International.
Method 9090A. Compatibility test for Wastes and Membrane Liners.
Sangam.H.P. & Rowe.R.K. Migration of dilute aqueous organic pollutants
through a HDPE geomembrane (2001). Geotextiles and Geomembranes, 19 pp
329 – 357.
Scheirs.J. A guide to polymeric geomembranes: A practical approach (2009).
Wiley.
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Thank you !
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