No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information...
-
Upload
macey-jarrell -
Category
Documents
-
view
216 -
download
0
Transcript of No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information...
![Page 1: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/1.jpg)
No. 1 of 19
Polymers for Geosynthetics
by
Dr. Don Bright
The Tensar Corporation
The information presented in this document has been reviewed by the Education Committee of the International Geosynthetics Society and is believed to fairly represent the current state of practice.
However, the International Geosynthetics Society does not accept any liability arising in any way from use of the information presented.
![Page 2: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/2.jpg)
Presentation
• Polymers• Principal polymers in Geosynthetics• Principal polymer chemical configurations• Polymerization• Molecular weight & its importance• Elements of deterioration and degradation• Controlling impact of deteriorative elements
![Page 3: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/3.jpg)
Polymers: By Definition
• Polymers are macromolecular structures formed by the chemical union (polymerization) of many (poly) repeat mono units (mers) of a specific chemical configuration.
• The polymerization process results in a long molecular structure of the monomer unit.
![Page 4: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/4.jpg)
H H H H H H H H H H H H H H H H H H
| | polymerization | | | | | | | | | | | | | | | | C = C = - C - C - C - C - C - C - C - C - C - C - C - C - C - C - C - C - | | | | | | | | | | | | | | | | | | H H H H H H H H H H H H H H H H H H
Monomer Polymer
Polymer Chains
![Page 5: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/5.jpg)
Polymers By Classification
• Polymers are either inorganic or organic with the latter being the more predominant.
• Inorganic polymers comprise only a few compounds.
• Organic polymers are principally derivatives of petroleum.
• Organic polymers are classified as natural, semisynthetic, or synthetic.
![Page 6: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/6.jpg)
Classification Of Polymers
• Inorganic– Siloxanes– Silicones– Sulfur Chains
• Organic– Natural Polymers
• Polysaccharides
• Insulin
• DNA
– Semisynthetic Polymers
• Rayon
• Cellulose Acetate
– Synthetic Polymers
![Page 7: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/7.jpg)
Synthetic Polymers
• Synthetic polymers are subdivided into principal categories:
– Thermoset Polymers
– Thermoplastic Polymers
![Page 8: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/8.jpg)
Thermoset Resins
• Are polymers, that once are fully cured, cannot be resoftened with heat and reprocessed.
• Examples– Epoxies– Phenolics– Rubbers– Elastomers
![Page 9: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/9.jpg)
Thermoplastic Resins
• Are polymers that can be resoftened repeatedly with heat and reprocessed.
• Examples– Polyolefins– Vinyl polymers– Polyesters– Engineering polymers– Fluorocarbons
![Page 10: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/10.jpg)
Examples Of Polyolefins
• Polyethylene
• Polypropylene
• Polybutylene
![Page 11: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/11.jpg)
Examples Of Vinyl Resins
• Poly(vinyl chloride) – Rigid Grade: Pipe– Plasticized Grade: Geomembrane – Plastisol Grade: Coating
• Poly(vinyl dichloride) [clear food wrap]
• Poly(vinyl butyral) [Windshield Laminate]
![Page 12: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/12.jpg)
Examples Of Polyesters
• Poly(ethylene terephthalate) (PET)– Geotextiles– Geogrids– Tire Cord Tread Belting
![Page 13: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/13.jpg)
Examples Of Engineering Resins
• Polyamide [NylonTM]
• Polycarbonate [LexanTM]
• Poly(methy methacrylate) [PlexiglassTM]
![Page 14: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/14.jpg)
Examples Of Fluorocarbons
• Polytetrafluroethylene [PTFE Plumbers Tape]
• Polychlorotrifluoroethylene [wire coating]
![Page 15: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/15.jpg)
Grades Of Polyethylene(ASTM D 1248)
• Low Density Polyethylene (LDPE) 0.910 < Density < 0.925
• Medium Density Polyethylene (MDPE) 0.926 < Density < 0.940
• High Density Polyethylene (HDPE) 0.941 < Density < 0.965
![Page 16: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/16.jpg)
Grades Of Polypropylene
• Homopolymer
• Impact Copolymer (with > 7% PE in PP)
• Random Copolymer (with < 7% PE in PP)
![Page 17: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/17.jpg)
Chemical Configurations
Polyethylene
H H
| |
-- -- C - C -- --
| |
H H
Polypropylene
H H
| |
-- --- C -- C --- --
| |
H CH3
![Page 18: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/18.jpg)
PE & PP Polymerization
• Addition Polymerization
• A Random Process
• Broad Molecular Weight Distribution
![Page 19: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/19.jpg)
Broad Molecular Weight Distribution
|_____________________| |__ short__|
chain length
|_______________________long chain length___________________|
|___intermediate chain length__|
|____________| |__________________________|
|___________________________________|
|_________________| |________________________________________|
![Page 20: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/20.jpg)
Chemical Configuration
Poly(ethylene terephthalate) (PET)
H H | |
- C - C - O - C - - C - O -
| | || || H H O O
![Page 21: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/21.jpg)
PET Polymerization
• Condensation Polymerization
• Generation of water molecules
• Narrow Molecular Weight Distribution
![Page 22: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/22.jpg)
Narrow Molecular Weight Distribution
|____________________Longest Chain Length @ 2X _________________|
|_Shortest Chain Length @ 1X _|
Molecular Weight Distribution Ratio 2:1
![Page 23: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/23.jpg)
Environmental ExposureNeed To Consider
• Weathering
• Chemical degradation– Oxidation– Hydrolysis
• Biological degradation
![Page 24: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/24.jpg)
Weathering
• Exposure to:– Ultraviolet light– Temperature– Oxygen– Humidity– Airborne Agents
• Chemical• Biological
![Page 25: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/25.jpg)
Consequences Of Weathering
• Product Deterioration– Physical Properties
• Density, Appearance, Integrity– Mechanical Properties
• Tensile Strength and Creep Resistance• Polymer Degradation
– Molecular Breakdown– Lower Molecular Weight– Free Radical Group Formation
![Page 26: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/26.jpg)
Protection From Weathering
• Polyolefins– Addition of Carbon Black and/or– UV Stabilizer Package
• Polyester– UV Stabilizer Package or– Protective Coating with UV Stabilizer
Package
![Page 27: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/27.jpg)
Effect of Carbon Black on Resistance to UV Lightfor Polyethylene and Polypropylene
0
25
50
75
100
0 1 2 3 4 5 6
Carbon Black Content (Wt %)
Per
cen
t of P
rote
ctio
n (%
)
Polyethylene
Polypropylene
![Page 28: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/28.jpg)
Oxidative Degradation
• Degradation of a polymer through its reaction with oxygen
• Dependent upon:– Product exposed surface area– Product manufacturing process– In-use environment oxygen
concentration• Susceptible geosynthetic polymers
– Polyolefins: PE and PP
![Page 29: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/29.jpg)
Consequences Of Oxidation
• Product deterioration– Physical properties
• Density, appearance, integrity– Mechanical properties
• Tensile strength and creep resistance• Polymer degradation
– Molecular breakdown– Lower molecular weight– Free radical group formation
![Page 30: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/30.jpg)
Controlling Oxidation
• Antioxidant: inhibitor of oxidation process
• Polymer and product configuration dictates:– Antioxidant package
• Chemical composition• Mechanism of prevention
– Concentration / loading
![Page 31: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/31.jpg)
Hydrolytic Degradation
• Molecular breakdown due to reaction of a specific monomeric chemical structure with water or water vapor
• Susceptibility is dependent upon– Molecular Weight, MW– Carboxyl End Groups, CEG
• Susceptible Geosynthetic Polymers– Polyesters (PET)
![Page 32: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/32.jpg)
Consequences Of Hydrolysis
• Product deterioration– Physical properties
• Density, appearance, integrity– Mechanical properties
• Tensile strength and creep resistance• Polymer degradation
– Molecular breakdown
– Reduces molecular weight (MWn)
– Increases carboxyl end groups (CEG)
![Page 33: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/33.jpg)
Controlling Hydrolysis
• Selection of molecular weight (MWn)– Coated geogrids & high strength geotextiles :
MWn > 25,000– Non Woven Geotextiles: MWn < 20,000
• Selection of carboxyl end groups (CEG)– Coated geogrids & high strength geotextiles :
CEG < 30– Non Woven Geotextiles: 40 < CEG < 50
• In-use environment 3 < ph < 9
![Page 34: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/34.jpg)
Biodegradation
• Micro-organisms – Bacteria, fungi, algae
• Physical degradation• Molecular deterioration
• Macro-organisms– Rodents, insects
• Physical degradation
![Page 35: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/35.jpg)
Controlling Biodegradation
• Not a concern for the molecular weight grades of PE, PP, PET, and PVC used in geosynthetics.
• Microorganisms are known to attack and digest additives used to plasticize some base polymers.
![Page 36: No. 1 of 19 Polymers for Geosynthetics by Dr. Don Bright The Tensar Corporation The information presented in this document has been reviewed by the Education.](https://reader035.fdocuments.net/reader035/viewer/2022062619/551814fd5503469d318b45e6/html5/thumbnails/36.jpg)
Summary
• Polymers• Principal polymers in Geosynthetics• Principal polymer chemical configurations• Polymerization• Molecular weight & its importance• Elements of deterioration and degradation• Controlling impact of deteriorative elements