The Chemical Resistance of Geosynthetic Polymers to ...sclf.co.uk/conference/2011/5 Shaw.pdf · Chemical Resistance of Geosynthetic Polymers to Hydrocarbons and Toxic Soil Contaminants

IntroductionIntroduction

Chemical Resistance of Geosynthetic Polymers to Hydrocarbons and Toxic Soil Contaminants

Presented by Charlotte Shaw

© Industrial Textiles & Plastics Ltd.

Presented by Charlotte Shaw

ObjectiveObjective

� 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

Geosynthetic MaterialsGeosynthetic Materials

� PVC polyvinyl chloride� Butyl Rubber polyisobutylene / PIB� EDPM ethylene propylene diene monomer� CSPE chlorosulphonated polyethylene [HypalonTM]� CR polychloroprene [NeopreneTM ]� PP polypropylene


� PP polypropylene� LDPE low density polyethylene� HDPE high density polyethylene� EIA ethylene interpolymer alloy

[ CoolgardTM, XR-5TM, UltraTechTM, ElvaloyTM ]� Aluminium Laminates


� Limited Chemical Resistance Information• Industry practice to compile

resistance charts• Information often sparse and

qualitative


• Do not provide any performance data


Category Group Subgroup Compound

Membrane Material

PV

C

But

yl

ED

PM

CS

PE

Neop

rene

PP

PC

LDP

E

HD

PE

EIA

PURA

FLEX

Aromatics

Benzene Derivatives

Benzene

Benzyl chloride ND

ND ND

BiphenylND

ND ND

Dichlorobenzene ND

Toluene

Ethylbenzene

Stryene

Xylenes

PolycyclicAromaticHydrocarbons(PAH)

Nitrobenzene

Acenaphthene ND

ND ND ND ND ND ND ND ND ND

Anthracene ND


Benzo(a)anthracene ND


Benzo(a)pyrene ND


Benzo( b)fluorantheneND


Benzo(k)fluorantheneND


Dibnezo(a,h)anthracene ND


Fluoranthene ND


FluoreneND


Indeno(1,2,3-cd)pyreneND


Naphthalene ND

Butane ND

Ethane ND ND ND ND

Category Group Subgroup Compound

Membrane Material

PV

C

But

yl

ED

PM

CS

PE

Neo

pren

e

PP

PC

LDP

E

HD

PE

EIA

PURA

FLEX

Acids

Organics

Acetic acid

Acetic Anhydride

Butyl Acetate

Ethyl Acetate

Inorganics

Benzoic Acid

Carbonic Acid

Hydrochloric Acid

Perchloric Acid ND ND ND

Carbohydrates Starch

InorganicCompounds

CarbonsCarbon Dioxide

Carbon Monoxide

Chlorines Aqueous

Gaseous

Alkalis

Calcium Carbonate

Magnesium Carbonate

Sodium Carbonate

Hydroxides

Calcium Hydroxide

Magnesium Hydroxide

Sodium Hydroxide

Bromides Bromine (liquid)

Fluorines Elemental

Iodines Elemental

Nitrogen Gaseous

Oxygen Elemental


Hydrocarbons

Aliphatics

Alkanes

Hexane

Methane ND

Pentane ND

Propane ND

Octane ND

Heptane

Kerosene

Isoprene ND ND

Cyclohexane

Alkenes Butene ND ND

Alkynes Acetylene

Halogenated

Brominated Bromoform

Chlorinated

Carbon Tetrachloride ND

Chloroform

Dichloroethane

Tetrachloroethane

Trichloroethylene

Fluorocarbons Freon 12

Freon 22

Iodinated Iodoform

Generic Oils & Fuels

Mineral Oil

Crude Oil

Petroleum Oil

Diesel

Hetrocyclics

Dioxan (1,4) ND ND

Morpholine ND ND ND

Pyridine

Tetrahydrofuran

Oxygen Elemental

Salt Brine

Silicone Oil

Sulphurs Copper Sulphate

Zinc Sulphide ND

Tin Stannous Chloride

OrganicCompounds

Lipids

Fats Fatty acids

OilsAnimal and Vegetable

Turpentine

Alcohols

Amyl

Benzyl

Butyl

Ethyl

Isopropyl

Methyl

Aldehydes

Acetaldehyde

Benzaldehyde ND

Formaldehyde

Amines Aniline

Cynides Copper Cyanide ND

Sodium Cyanide ND

Ethers Diethyl Ether

MTBE ND ND ND ND ND ND ND

Ketones Acetone

Methyl Isopropyl Ketone ND

Organometallics

Ferric Chloride ND

Ferric Nitrate ND

Ferric Sulphate

Phenols

Carbolic Acid

Cresols

Tannic Acid

Urea

Rating Index

Resistant

Limited Effect (at elevated temperature or high concentration)

Not Resistant

ND No Data

Test MethodsTest Methods

� EN 13361 Reservoirs & Dams� EN 13362 Canals� EN 13491 Tunnels & Underground

Structures� EN 13492 Liquid Waste� EN 13493 Solid Waste


� EN 13493 Solid Waste

• Define mechanical performance and• Defines chemical resistance testing to:

EN 14414 & EN 14415


� 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


• Method D – Synthetic leachate

� EN 14415 Resistance to Leaching• Method A – Hot water• Method B – Alkalis• Method C – Organic solvents

(methanol, isopropanol & glycol)


� EN 14414 and EN 14415 Test Procedure• Immersion test • 50 ºC for 56 days• Visual inspection• Measurements of Tensile Strength &

Elongation variances


Elongation variances• Pass criterion is merely

residual strength >75%

* Test Procedures equivalent to ASTM D5322 within EPA method 9090 and ASTM D5747.

Chemical Resistance Chemical Resistance -- CharacterisedCharacterised

� Molecular structure characteristics• Molecular Weight

- Chain length is directly related to polymer strength

• Molecular Weight Distribution- Relationship between the number of


- 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

Chemical Resistance Chemical Resistance -- MaterialsMaterials

LDPEHDPE


PP PVC

Chemical Resistance Chemical Resistance -- MaterialsMaterials

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

Polarity Non-Polar Non-Polar Non-Polar Polar

Chemical Resistance Chemical Resistance -- PolarityPolarity

� 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


H2O CO2

Polar Non-polar

Chemical Resistance Chemical Resistance -- SolubilitySolubility

� 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?


� Why is this significant?

Methanol (Polar) Hydrocarbons (Non-polar)

HDPE (Non-polar)


� PVC polyvinyl chloride Polar� Butyl Rubber polyisobutylene / PIB Non-Polar� EDPM ethylene propylene diene monomer Non-Polar� CSPE chlorosulphonated polyethylene Polar

[HypalonTM]� CR polychloroprene [NeopreneTM] Polar


� CR polychloroprene [NeopreneTM] Polar� PP polypropylene Non-Polar� LDPE low density polyethylene Non-Polar� HDPE high density polyethylene Non-Polar� EIA ethylene interpolymer alloy Polar

[ CoolgardTM, XR-5TM, UltraTechTM, ElvaloyTM ]

Chemical ResistanceChemical Resistance

� Solubility Parameters• Graphical representation• Green Sphere = polymer• Red Satellites = challenge chemicals

� The closer the challenge chemical is to the


� The closer the challenge chemical is to the polymer

• > Solubility• > Permeation rate

δD Dispersion Solubility ParameterδH Hydrogen Bonding Solubility ParameterδP Polar Solubility Parameter

Key Points Key Points –– Materials & TestsMaterials & Tests

� Common Geosynthetic Materials• Limited chemical resistance of mono-

polymer membrane materials� Current Test Methods

• Immersion testing measures a membrane’s Resilience, i.e. the effect of the challenge chemical on the


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

PermeationPermeation

21 3


1 SorptionPartitioning of the chemical to the liner governed by Henry’s Law :

Cg = Sgf*C

2 DiffusionMigration on a molecular scale through the barrier expressed by Fick’s first Law :

f = -Dg* (dcg / dz)

3 DesorptionPartitioning between the chemical and the outer surface of the barrier

PermeationPermeation

� Permeation Test Method• Each challenge chemical exposed to

the sample in a permeation cell• Sweep gas to mass spectrometer


Permeation Comparisons Permeation Comparisons -- materialsmaterials

HDPE 1.5mm

Butyl 1.5mm

EPDM 1.5mm

PVC 1.5mm

CSPE 1.5mm

Polychloroprene (CR) 1.5mm


0.00E+00 2.00E+02 4.00E+02 6.00E+02 8.00E+02 1.00E+03 1.20E+03 1.40E+03

Puraflex 0.45mm

HDPE 1.5mm

Puraflex 0.45mm

HDPE 1.5mm Butyl 1.5mm EPDM 1.5mm PVC 1.5mm CSPE 1.5mmPolychloropre

ne (CR) 1.5mm

Vinyl Chloride 1.67E-01 1.84E+03 6.15E+03 4.92E+03 6.15E+03 6.15E+02 4.92E+03

Methyl Isopropyl Ketone (MIK) 9.43E+00 8.05E+02 2.68E+03 2.15E+03 2.68E+03 2.69E+02 2.15E+03

Hexane 1.56E-06 5.37E+02 1.79E+03 1.43E+03 5.59E+02 1.79E+02 5.01E+02

Fluorene 3.23E-06 1.41E+02 4.69E+02 3.75E+02 4.69E+02 4.69E+01 3.75E+02

Benzene 3.52E-04 5.69E+02 1.90E+03 1.52E+03 1.90E+03 1.90E+02 1.52E+03

Aluminium Laminates Aluminium Laminates

� 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)7 days


• 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

14 days

TechnologyTechnology

� Barrier Technology • Extruded multi-layer composite• Incorporates Polar and Non-polar layers

(> 5 layers and > 5 polymers)• Chemical Resistant core• Thermally weldable


• Thermally weldable

TechnologyTechnology

� 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

Installation Installation

� Installation• Compatible with existing installation

methods• Conventional geosynthetic membrane

welding equipment• Typically a Leister Twinny S hot air

wedge welder


wedge welder• BS EN 13067 Qualified Installers

recommended• Rapid 4m/min installation• Protected in accordance with

EN 13719

PuraflexPuraflex Testing Testing SummarySummary

� 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’


• 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

PuraflexPuraflex Permeation ModellerPermeation Modeller

� Permeation Modeller Software • Specifically written for environmental

consultants, hydro-geologists & geotechnical engineers

• Upload soil analysis concentrations• Enter variables


• Enter variables• Output permeation rates • Risk Assessment Models (e.g.CLEA)

ReferencesReferences

� ASTM D5322. Laboratory Immersion Procedures for evaluating the ChemicalResistance of Geosynthetics to liquids.

� ASTM D5747. Tests to Evaluate Chemical Resistance of Geomembranes toLiquids.

� CLAIRE Report. The soil generic assessment criteria for human health riskassessment.

� Bromwich.D.W The design of permeation cells for testing chemical protectiveclothing (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 pp329 – 357.

� Scheirs.J. A guide to polymeric geomembranes: A practical approach (2009).Wiley.

Thank you !Thank you !


Documents

The Chemical Resistance of Geosynthetic Polymers to ...sclf.co.uk/conference/2011/5 Shaw.pdf · Chemical Resistance of Geosynthetic Polymers to Hydrocarbons and Toxic Soil Contaminants