FORD FLTM AZ 105-1-2000 TITRIMETRIC DETERMINATION OF THE PEROXIDE NUMBER OF OXIDIZED GASOLINE TEST FUELS (Replaces FLTM AZ 005-01).pdf

1、 FORD LABORATORY TEST METHOD AZ 105-01 Date Action Revisions 2000 08 22 Revised Editorial no technical change A. Cockman 2000 05 22 Editorial no technical change A. Cockman 1990 12 07 Printed copies are uncontrolled Page 1 of 6 Copyright 2000, Ford Global Technologies, Inc. TITRIMETRIC DETERMINATION

2、 OF THE PEROXIDE NUMBER OF OXIDIZED GASOLINE TEST FUELS Application This method describes a titrimetric method for determining the Peroxide Number of oxidized (“sour“) gasoline test solutions prepared using the procedure contain ed in the Appendix. The method can also be used (with certain precautio

3、ns) to measure the depletion of the Peroxide Number during the course of immersion tests using the test solution so that the need to replenish the test solution can be determined. Apparatus Required Erlenmeyer Flasks* - 250 mL with ground glass joint. Condenser* Allihn or Leibig water cooled type wi

4、th ground glass joint to fit the Erlenmeyer flasks. Measuring Cylinders* - 100 mL glass, graduated. Hot Plate, or other means of heating* Suitable for heating the Erlenmeyer flasks with fitted condensers to reflux the reagents. Burette* - 10 mL glass, graduated * - Apparatus is available from any su

5、itable laboratory equipment supplier. Reagents Required Ethanoic (Acetic) Acid - glac ial, analytical reagent grade. Potassium Iodide Solution 100 g/liter analytical reagent grade in distilled water. Store in a dark glass reagent bottle. Discard if the solution gives the equivalent of a Peroxide Num

6、ber of 2 when carrying out a blank titr ation. FORD LABORATORY TEST METHOD AZ 105-01 Page 2 of 6 Copyright 2000, Ford Global Technolog ies, Inc. Propan-2-ol (Iso-Propyl Alcohol) - analytical reagent grade. Sodium Thiosulphate Solution - 0.1 N accurately standardized aqueous solution. Ethanoic Acid/P

7、ropan-2-ol Mixture Mix 100 mL glacial ethanoic acid with 1150 mL Propan - 2 - ol. Store in a dark glass bottle. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/ - C and 50 +/ - 5 % relative humidity for not less t

8、han 24 h prior to testing and tested under th e same conditions unless otherwise specified. Procedure 1. Add 25 mL ethanoic acid/Propan - 2 - ol mixture to a 250 mL Erlenmeyer flask. 2. Add 10 mL of the Potassium Iodide solution to the flask. 3. Accurately transfer by pipette 2 mL of the oxidized ga

9、s oline test solution under test to the flask. 4. Fit the condenser to the flask and reflux gently on the hot plate for 5 minutes to release free Iodine. 5. Cool the flask in a cold water bath and wash the condenser down with 5 mL of Distilled Water. 6. R emove the condenser and titrate the contents

10、 of the flask with the standardized 0.1 N Sodium Thiosulfate until the yellow coloration just disappears. Record the volume of Sodium Thiosulfate consumed as V1. 7. Carry out a blank determination by repeating steps 1 to 6 but omit the addition of the oxidized test solution (step 3). Record the volu

11、me of Sodium Thiosulfate consumed as V2. This volume should not exceed 0.1 mL. 8. Calculate the Peroxide Number according to the following equation: Peroxide Numb er = (V1 - V2) x N x 1000 Sample Volume x 2 FORD LABORATORY TEST METHOD AZ 105-01 Page 3 of 6 Copyright 2000, Ford Global Technolog ies,

12、Inc. Where: V1 = Volume of titrant consumed by sample, mL V2 = Volume of titrant consumed by blank, mL N = Normality of standardized sodium thiosulfate solution Note: This method can be used to determine the Pe roxide Number of the oxidized gasoline test solution during the course of an immersion te

13、st. However the following precautions should be observed: 1. Most immersion tests involving elastomers will result in the test solution becoming yellowed by the extr action of additives in the rubber. This should be taken into account when the end point of the titration is established. 2. The additi

14、ves extracted from the material under test may themselves be capable of liberating free Iodine from the Iodide solution. A blank should therefore be carried out and a duplicate immersion test using the base fuel containing no hydroperoxide. Chemicals, materials, parts, and equipment referenced in th

15、is document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD AZ 105-01 Page 4 of 6 Copyright 2000, Ford Global Technolog ies, Inc. Appendix Preparation of Oxidized Gasoline Test Solutions This method o

16、utlines the procedure for preparing oxidized (“sour“) gasoline test solutions for use in the determination of their effec ts on elastomeric, plastic, and metallic materials and components. The procedure covers the preparation of solutions with Peroxide Numbers of PN 60, 90, and 180 using a mixture o

17、f a t - Butyl Hydroperoxide (70 % aqueous solution), soluble Copper ion (0.01 m g/L) and a base fuel consisting of 80 % ASTM Fuel C, 15 % Methanol and 5 % 2 - methyl propan - 2 - ol (t - Butyl Alcohol). Other base fuels and Peroxide numbers may be used as required by the Engineering Materials Specif

18、ication. It should be noted that some base fuels may give rise to separation of the aqueous phase of the hydroperoxide solution. Apparatus Required Bottles 1000 mL wide mouth polyethylene bottles with screw caps* Volumetric Flasks 1000 mL - glass* Pipettes 10 mL glass - graduated* Measuring Cylinder

19、s 100 mL glass - graduated* *Available from any suitable laboratory equipment supplier. Materials Required t-Butyl Hydroperoxide 70 % aqueous solution - density 0.935 g/mL Source: Lucidol Division Luperox GmbH Penn - Walt Corp. Postfach 1354 1740 Military Road D - 8870 Guenzburg Buffalo,NY 14240 U.S

20、.A. West Germany AKZO Chemicals Division 1 - 5 Queens Road Hersham, Waltham - on - Thames Surrey KT12 5NL UK FORD LABORATORY TEST METHOD AZ 105-01 Page 5 of 6 Copyright 2000, Ford Global Technolog ies, Inc. Copper Ion Concentrate Nuodex NuXtra 12 % Copper by weight Source: Tenneco Chemica ls Inc. Ce

21、ntral Laboratory Services Intermediates Division Ford Motor Company P.O. Box 2 15 000 Century Drive Turner Place Commerce Park North Poscataway, NJ U.S.A. Dearborn, MI 48121 U.S.A. Materials Laboratory 13/100 Ford Research and Enginee ring Center Laindon, Basildon Essex SS15 6EE UK 2.2.4 - Trimethyl

22、 Pentane (iso-Octane)* Reagent grade. CAUTION: Low flash point Toluene* Reagent grade. CAUTION: Low flash point 2-MethylPropan-2-ol (t-Butyl Alcohol)* Reagent grade. CAUTION: Low fla sh point * - Reagents are available from any suitable laboratory chemical supplier. Procedure CAUTION: This procedure

23、 must be carried out under a fume hood. Eye protection and disposable plastic gloves must be worn. 1. Preparation of Test Fluids A. Base Fuel Mixture (a) Prepare ASTM Fuel C by mixing equal volumes of 2,2,4 - trimethyl Pentane and Toluene. Store in dark glass bottle. (b) Mix ASTM Fuel C, Methanol an

24、d 2 - MethylPropan - 2 - ol in the ratio 80:15:5 by volume to make the base fuel. Store in a dark glass bottle. FORD LABORATORY TEST METHOD AZ 105-01 Page 6 of 6 Copyright 2000, Ford Global Technolog ies, Inc. B. Copper Ion Stock Solution (1 mg/liter) (a) Add 10 mL of 12 % copper ion concentrate (de

25、nsity 0.95 g/mL) to 990 mL of Base Fuel to produce 1000 mL of 1 140 mg/mL copper ion solution “Cu - 1“. Store in a dark glass bottle. (b) Add 100 mL of “Cu - l“ to 1040 mL of Base Fuel to produce 0.1 mg/mL copper ion solution “Cu - 2“. Store in a dark glass bottle. (c) Add 10 mL of “Cu - 2“ to 990 m

26、L Base Fuel to produce 1.0 mg copper ion solution “CSS“. Store in a dark glass bottle. C. Preparati on of Oxidized Gasoline Test Solutions (a) Use the following mixtures to produce oxidized gasoline test solutions of the required working strengths. Store in polyethylene bottles in the dark for no lo

27、nger than 4 weeks. Check the Peroxide Number immediate ly after mixing and before subsequent use by means of the titrimetric test method described in the Appendix. For ease of mixing, add the peroxide and Copper ion solution to 500 mL Base Fuel in a 1000 mL Volumetric Flask then make up to 1000 mL shaking wel l to dissolve the water content of the hydroperoxide. Desired Peroxide 70 % t - Butyl Copper ion Base Number Hydroperoxide soln. “CSS“ Fuel PN mL mL 60 8.3 10 Fill to 1000 mL 90 12.4 10 Fill to 1000 mL 180 24.8 10 Fill to 1000 mL Note: 1 Peroxide Number (PN) = 1 millimole/liter