ASTM_D_7129_-_05.pdf

Designation:D 7129 05Standard Test Method forDetermination of Ammonia Trapping in a Grafted BatterySeparator1This standard is issued under the fixed designation D 7129;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of the abilityof a material to capture ammonia.1.2 This test method is intended primarily for testing graftedpolyolefin materials used as a battery separator,although othermaterials could be tested.1.3 The values stated in SI units are to be regarded as thestandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesE 438 Specification for Glasses in Laboratory ApparatusE 1272 Specification for Laboratory Glass Graduated Cyl-inders3.Terminology3.1 Definitions:3.1.1 For definitions on other textile terms in this testmethod,refer to Terminology D 1234.Summary of Test Method4.1 A predetermined amount of separator and ammoniumhydroxide is added together in a KOH solution.The specimensare conditioned under a controlled temperature for 24 h.Afterthe solution is cooled,the solutions are distilled to determinethe amount of ammonia the separator retained.4.2 Results are calculated as mol/g using the appropriateequations.5.Significance and Use5.1 Nickel metal hydride(Ni-MH)cells can exhibit highself-discharge rates.Nitrate impurities in the positive electrodecan be reduced to ammonia on the negative electrode.Thiscauses rapid self-discharge.Technical publications have re-ported a link between the separator ammonia trapping capa-bilities and the cells charge retention.Grafted polyolefinseparators can absorb or trap these impuritieshence,reduc-ing self-discharge rates.The level of ammonia trapping fromthis method gives an indication of the efficiency of a separatorto trap these contaminates,thus helping a battery self discharge(charge retention).A higher value should provide a cell withgreater charge retention.6.Apparatus6.1 Flask,Erlenmeyer,wide mouth,250 mL capacity with ascrew cap.6.2 Flask,Erlenmeyer,wide mouth,500 mL capacity.6.3 Cylinder,Graduated,Class A,250 mL capacity.NOTE1The tolerance on the accuracy of the graduations in Specifi-cation E 1272 for this apparatus is 61.4 mL.If greater accuracy isrequired for a test result,the graduated trap(s)should be calibrated.6.4 Pipette,Volumetric,Class A,10 mL capacity.NOTE2The tolerance on the accuracy of the graduations in Specifi-cation E 438 for this apparatus is 60.02 mL3.If greater accuracy isrequired for a test result,the graduated trap(s)should be calibrated6.5 Pipette,Volumetric,Class A,3-mL capacity.NOTE3The tolerance on the accuracy of the graduations in Specifi-cation E 438 for this apparatus is 60.01 mL.If greater accuracy isrequired for a test result,the graduated trap(s)should be calibrated.6.6 Distillation Unit,Micro or macro Kjeldhal apparatus.6.7 Oven.7.Reagents7.1 Ammonium Hydroxide,0.3M(NH4OH),ACS grade.7.2 Hydrochloric Acid,0.1M(HCL),ACS grade.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.19 on Dielectric Sheet and Roll Products.Current edition approved March 1,2005.Published March 2005.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.7.3 Methyl Red,ACS grade.7.4 Potassium Hydroxide Solution,8MPrepare a suffi-cient quantity of KOH solution for the testing programimmediately at hand as follows.7.5 To a 1500-cm3(mL)beaker add 800 to 850 cm3(mL)ofdistilled water.Slowly add 448 g of potassium hydroxidepellets,certified ACS grade,to the beaker.Allow cooling toroom temperature.7.6 Potassium Hydroxide,0.1M(KOH),ACS grade.(WarningFollow appropriate safe handling procedureswhen using acids or bases.)8.Conditioning8.1 Determine sampling based on grafting process.Then cuttest specimen to a weight of 2.00 6 0.05 g.8.1.1 Cut specimen into 1-cm2pieces.8.1.2 Place cut pieces into Erlenmeyer flask as stated in 6.1.8.2 Measure out 120 mL of KOH solution as stated in 7.3.8.2.1 Add to the Erlenmeyer flask containing the cut speci-men.8.3 Using the 3 mL volumetric pipette,add 3 6 0.01 mL ofammonium hydroxide to the Erlenmeyer flask and immediatelycap the