Module 6: Chemical Resistance

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Darrell French
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1 Module 6: Chemical Resistance 1

2 Viton versus Other Elastomers classification according to ASTM 2000D Service temperature versus Oil No Heat resistance Service Temperature ( C) IIR EPDM SBR Natural Rubber Acsium Neoprene (CR) VMQ Hypalon (CSM) AEM (Vamac ) FVMQ ACM HNBR ECO NBR Kalrez (FFKM) Viton (FKM) A Not required B 140 C 120 D 100 E 80 F 60 G 40 H 30 J 20 K 10 Oil Resistance Class (% volume swell in ASTM No. 3 Oil after 70 hours) Chemical resistance Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 2

3 Uniqueness of FKM Fluoroelastomers High ratio of fluorine-to-hydrogen Very strong carbon-fluorine bond Absence of unsaturation (i.e., double bonds) Specialty monomers Excellent oil and fluids resistance Excellent heat (200 C+) resistance Low temperature flexibility Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 3

4 Viton - Chemical Resistance Excellent hydrocarbons (solvents, fuels ) Very good chlorinated solvents mineral acids aromatic solvents oxidizing fluids Fair to good hot aqueous fluids like acids and steam Critical chemical attack strong bases strong organic acids, aldehydes ammonia and amines high volume swell low molecular weight ether, ester and ketones Viton Extreme TM or Kalrez preferred Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 4

5 Viton - Relative Performance Standard Products Specialty Products Viton product A B F GBL-S* GF-S * GLT-S * GBLT-S * GFLT-S * TBR-S * Extreme ETP-S * Extreme Curing system bisphenol bisphenol bisphenol peroxide peroxide peroxide peroxide peroxide bisphenol peroxide Fluorine content 66% 68.5% 69.5% 68% 70% 64% 66% 67% 60% 67% Heat resistance Chemical resistance* * All Viton products have outstanding thermal properties BEST Base resistance BEST BEST Low temperature BEST properties Compression set resistance Relative cost of polymer BEST low low low low low medium medium medium low high BEST Excellent Very good Good Fair poor * S indicates products made with Advanced Polymer Architecture ** Consult the Chemical Resistance Guide at or contact your Viton specialist. Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 5

6 Viton - Selection Guide is available on Internet Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 6

7 Selection Based on Application Needs Base resistance: Best resistance to aggressive amine based anti-corrosion additives? YES NO Hydrocarbon resistance (automotive fuels, etc.)? High resistance to oxygenated-fuels (MeOH, MTBE), steam, acids? YES NO YES NO ETP-S TBR-S Low temperature flexibility better than -20 C? Low temperature flexibility better than -20 C? GFLT-S YES NO YES NO GFLT-S F GLT-S A B AL GBLT-S GF-S GBL-S red for Viton made with APA («-S» for APA technology) Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 7

8 Swell in Fuel Mixtures Influence of oxygenated additives 80 volume swell 168h, 23 C (%) Viton A Viton B Viton F NBR ECO FVMQ 0 Fuel C + MTBE* + Methanol* + Ethanol* (hydrocarbon) (ether) (alcohol) (alcohol) * 10% level blended with reference ASTM Fuel C Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 8

9 Superior Fluids Resistance 168 hr ATF (150 C) (transmission fluid) Toluol (40 C) (aromatic alcohol) MTBE/Toluol (23 C) (92:8) (ether/aromatic alcohol) MEK (23 C) (ketone) KOH (100 C) (30%) (Base) Volume swell % A-401C GF TBR ETP Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 9

10 Resistance to Methylene Chloride (23 C) Volume Increase (%) Viton A types Viton GF-S types Kalrez Exposure Time (hrs.) Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 10

11 Resistance to 95% Sulfuric Acid 2 Months Exposure Volume Swell ( %) Viton A types Viton GF-S types Kalrez Temperature ( C) Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 11

Degradation resulting from Oil Immersion

Degree of Base Resistance required Engine

bearing Suggested Polymer bisphenol cured

500 hrs ESSO Dexron III ATF B-651C, 1000

Cecilia 20 5W40 engine oil GF-600S, 1000

Mobile Axle lube TBR-605CS, 1000 hrs ESSO

Axle lube Viton is a registered trademark

12 Degradation resulting from Oil Immersion which polymer to choose? Degree of Base Resistance required Engine Gear box and Transmission Axle & Wheel bearing Suggested Polymer bisphenol cured B-651C un-aged B-651C, 500 hrs Shell Helix Ultra 0W40 engine oil B-651C, 500 hrs BP Cecilia 20 5W40 engine oil B-651C, 500 hrs ESSO Dexron III ATF B-651C, 1000 hrs Mobile Axle lube GF-600S, 1000 hrs BP Cecilia 20 5W40 engine oil GF-600S, 1000 hrs ESSO Dexron III ATF GF-600S, 1000 hrs Mobile Axle lube TBR-605CS, 1000 hrs ESSO Dexron III ATF TBR-605CS, 1000 hrs Mobile Axle lube Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 12

13 Chemical Resistance of Elastomers Chemical resistance of elastomers depends on chemical structure. Within a class of elastomers such as Viton fluoroelastomer, chemical resistance within different families will depend on monomer composition, fluorine content and vulcanization system Several factors must be considered when selecting an elastomer for a rubber part in service: Service temperature (the higher the temperature the higher the effect of a given chemical on the polymer) Service conditions (static vs. dynamic application) Polymer type (within a class of polymers, several families with different chemical resistances are often available) Compound formulation (optimization of some properties may adversely affect others such as fluid resistance) Curing system (bis-phenol or peroxide) Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 13

14 Chemical Resistance Guide on-line The CRG is a ressource to help you choose the best elastomer for your application. Access to our on-line Chemical Resistance Guide (CRG) is available through the DuPont Performance Elastomers web site at detailed information about our product line may also be found. Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 14

15 The information set forth herein is furnished free of charge and is based on technical data that DuPont Performance Elastomers believes to be reliable. It is intended for use by persons having technical skill, at their own discretion and risk. Handling precaution information is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safety hazards. Since conditions of product use and disposal are outside our control, we make no warranties, express or implied, and assume no liability in connection with any use of this information. As with any material, evaluation of any compound under end-use conditions prior to specification is essential. Nothing herein is to be taken as a license to operate or a recommendation to infringe on patents. While the information presented here is accurate at the time of publication, specifications can change. Check for the most up-to-date information. Caution: Do not use in medical applications involving permanent implantation in the human body. For other medical applications, discuss with your DuPont Performance Elastomers customer service representative and read Medical Caution Statement H DuPont is a trademark of DuPont and its affiliates. Viton, Viton Extreme, Kalrez, Hypalon and Acsium are trademarks or registered trademarks of DuPont Performance Elastomers. Copyright 2006 DuPont Performance Elastomers. All Rights Reserved. Viton is a registered trademark of DuPont Performance Elastomers. AST January 2006 Module 6 Page 15

Module: 4 Viton - Selection Guide

Module: 4 Viton - Selection Guide Monomers used in Viton VF 2 HFP TFE H 2 C=CF 2 (59% fluorine) vinylidenefluoride F 2 C=CF-CF 3 (76% fluorine) hexafluoropropylene F 2 C=CF 2 (76% fluorine) tetrafluoroethylene