1、 FORD LABORATORY TEST METHOD AJ 106-02 Date Action Revisions 2001 01 16 Revised Editorial no technical change A. Cockman 2000 03 21 Editorial no technical change A. Cockman 1990 04 30 Printed copies are uncontrolled Page 1 of 6 Copyright 2001, Ford Global Technologies, Inc. MOLYBDENUM DISULFIDE, LIT
2、HIUM SOAP, AND POLYETHYLENE IN GREASES Application This procedure is used to determine the molybdenum disulfide, lithium soap, and polyethylene content in greases that are generally used for wheel bearings. Refer to FLTM AJ 150-02 when only molybdenum disulfide and/or polyethylene content must be de
3、termined and the grease contains no other solid lubricants or fillers. Apparatus Required Analytical Balance Precision +/- 0.1 mg Extraction Apparatus, Soxhlet, Ground Glass Joint Includes flask, extraction tube and Allihn Condenser Tubing 6.4 mm I.D. Flask 250 mL Tube and Flask Joint 24/40 Thimbles
4、, Extraction Cellulose Single thickness, 33 x 80 mm Hot Plate Variable temperature Tall Form Beaker 300 or 400 mL Separatory Funnel, Squibb 500 mL; ground glass stopper No. 19 or equivalent Weighing Bottle FORD LABORATORY TEST METHOD AJ 106-02 Page 2 of 6 Copyright 2001, Ford Global Technologies, In
5、c. Mortar and Pestle Crucible, Gooch, Porcelain (Coors Series 27007) 35 mL capacity Boiling Chips “Boileezers“ B-365 or equivalent Laboratory Refrigerator Capable of maintaining 7 +/- 2 C The above apparatus may be obtained at any reputable laboratory equipment supply house. Materials Required Glass
6、 Microfiber Filters Whatman 934-AH, 2.4 cm Filter Paper Whatman No. 42 and No. 541 or equivalent. pH Test Paper Hydrion pH test paper or equivalent. Petroleum Ether or N-Hexane Reagent grade. Caution: Low flash point. 30 % Glacial Acetic Acid/70 % Toluene Solution Reagent grade. Caution: Corrosive A
7、mmonium Sulfide (46-52 %) Technical grade. Nitric Acid Concentrated (69.5 %). Caution: Corrosive Sulfuric Acid Concentrated (95 %). Caution: Corrosive Isopropyl Alcohol Reagent grade. Caution: Low flash point FORD LABORATORY TEST METHOD AJ 106-02 Page 3 of 6 Copyright 2001, Ford Global Technologies,
8、 Inc. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Dr
9、y an extraction thimble containing a fluted Whatman No. 42 ashless filter paper in an oven at 70 +/- 2 C for 30 minutes. 2. After cooling to ambient in a desiccator, determine the weight of the thimble and filter paper by difference using a tared weighing bottle. Weight of thimble and filter paper =
10、 A 3. Thoroughly mix the grease, place 10 - 15 g onto the filter paper and replace in thimble. Determine the weight of the thimble, filter paper and grease by difference using a tared weighing bottle. Weight of thimble, filter and grease = B 4. Make a cap from the bottom of another thimble. Place th
11、e cap inside the thimble to cover the filter paper and grease. 5. Place the thimble containing the filter paper, grease and cap in a Soxhlet extraction tube. 6. Fill the flask that is to be used with the Soxhlet tube approximately two-thirds full with petroleum ether. Include a half dozen boiling ch
12、ips. 7. Reflux until the petroleum ether in the Soxhlet tube is clear and water white. (Usually 48 h is sufficient.) Additional petroleum ether should be added to maintain the solvent level throughout the refluxing period. 8. Transfer the petroleum ether extract to a 250 mL, low form, Griffin beaker
13、. Evaporate the ether using a steam bath, no air stream, for 2 h (ether odor must be absent). Place beaker in forced air oven at 104 C for 15 +/- 2 minutes. Retain this extract for determining the base fluid requirements of the grease. . Flash and Fire Points (ASTM D 92) . Viscosity (ASTM D 445) . V
14、iscosity (ASTM D 2270) . Pour Point (ASTM D 97) 9. Remove the thimble containing the filter paper and the grease insolubles and place into a 300 mL tall form beaker and dry on a steam bath under a hood for two h. FORD LABORATORY TEST METHOD AJ 106-02 Page 4 of 6 Copyright 2001, Ford Global Technolog
15、ies, Inc. 10. Place the 300 mL beaker containing the thimble, filter paper, grease insolubles and cap into an oven at 70 +/- 2 C and dry to a constant weight. (Do not include the cap in the weighing.) Determine the weight by difference in a tared weighing bottle. Weight of thimble, filter paper and
16、grease insolubles = C 11. % grease insolubles = C - A x 100 B - A 12. Grind the insolubles from the grease with a mortar and pestle for determination of molybdenum disulfide, polyethylene, and lithium soap content. Note: Emission, spectrographic and infrared analyses should be run to confirm the pre
17、sence of molybdenum, lithium, and polyethylene. Determination of Molybdenum Disulfide 1. Weigh accurately a 0.4 to 0.5 g sample of grease insolubles into a 500 mL tall form beaker. Weight of grease insolubles = D 2. Add 25 mL of concentrated sulfuric acid and heat on a hot plate to dense white fumes
18、. Remove from the hot plate and cool. 3. Cautiously add 5 mL of concentrated nitric acid dropwise and heat under a hood on a hot plate to dense white fumes. Continue the nitric acid fuming procedure until all organic matter is destroyed. The solution should be very pale yellow or straw. 4. Cool, add
19、 100 mL of distilled water and filter the solution through No. 541 filter paper into a 400 or 500 mL tall form beaker to remove any remaining particulate impurities. Rinse the filter paper several times with distilled water into the same beaker. (Usually filtration is not necessary since no insolubl
20、e matter is present.) 5. Add 3 to 5 drops of phenolphthalein indicator and then add concentrated ammonium hydroxide (stirring the solution with a glass stirring rod) until the solution is slightly basic (add 5 or 6 drops excess beyond the end point). 6. Add 5 mL ammonium sulfide. 7. While using pH t
21、est paper, acidify (carefully) with dilute (1:1) sulfuric acid (add 1 or 2 mL excess beyond the end point). There should be a precipitate present. 8. Boil gently under a hood, until no odor of sulfide is detected and cool. FORD LABORATORY TEST METHOD AJ 106-02 Page 5 of 6 Copyright 2001, Ford Global
22、 Technologies, Inc. 9. Prepare a Gooch crucible using a glass microfiber filter, dry at 104 C and then place in a 540 C furnace for 1 h. Cool, desiccate and weigh. Weight of the prepared Gooch crucible = E 10. Filter the solution from step 8 through the weighed Gooch crucible. Wash the crucible seve
23、ral times with distilled water and discard the solution. 11. Place the crucible in a 540 C furnace for 2 h. Cool, desiccate and weigh. Note: The molybdenum is now in the form of molybdenum trioxide. Weight of molybdenum trioxide and crucible = F % molybdenum disulfide = F - E x 1.112 x % grease inso
24、lubles D (1.112 is the conversion factor for molybdenum trioxide to molybdenum disulfide.) Determination of Lithium Soap and Polyethylene in Grease 1. Weigh accurately a 0.4 to 0.5 g sample of grease insolubles into a 300 or 400 mL tall form beaker. Weight of grease insolubles = G 2. Add 200 mL of g
25、lacial acetic acid/toluene solution. (30 % acetic acid/70 % toluene) 3. Heat on a hot plate until dissolution of the soap portion of the insolubles is complete. (Usually 10 to 15 minutes at a light boil.) 4. Remove from the hot plate, cover, and allow the solution to cool in a refrigerator for 24 h
26、at 7 +/- 2 C. (There should be a suspension of polyethylene and a precipitate of molybdenum disulfide. The lithium soap, which has been converted to a fatty acid and lithium acetate, will remain in solution.) 5. Prepare a Gooch crucible using a glass microfiber filter, dry at 104 C and then place in
27、 a furnace at 540 +/- 10 C for 1 h. Cool, desiccate and weigh. Weight of the prepared Gooch crucible = I 6. Filter the solution from step 4 at 7 +/- 2 C followed by a 1:1 distilled water/isopropyl alcohol solution at 23 +/- 2 C to remove any residual acetate. FORD LABORATORY TEST METHOD AJ 106-02 Pa
28、ge 6 of 6 Copyright 2001, Ford Global Technologies, Inc. 7. Transfer the filtrate into a separatory funnel. Separate the toluene layer (top layer) and wash twice with distilled water, discarding the water/isopropyl layer and the water washes. (The discarded water/isopropyl layer contains the acetic
29、acid and lithium acetate. The toluene layer contains the fatty acid.) 8. Transfer the toluene layer from the separatory funnel to a weighed 250 mL beaker. Weight of beaker = H 9. Evaporate the beaker to dryness on a steam bath followed by drying in a 70 C convection oven to remove any residual moist
30、ure. Allow the beaker to cool in a desiccator and weigh. Weight of beaker and fatty acid = J % Lithium Soap = J - H x 1.078 x % grease insolubles G 1.078 is the conversion factor for the fatty acid (stearic acid) to lithium hydroxystearate soap. 10. Dry the crucible (from step 6) in an oven at 104 C
31、 for 1 h, desiccate and weigh. Weight of crucible, molybdenum disulfide, and polyethylene = K 11. Place the crucible in furnace at 540 C for 2 h, desiccate, and weigh. Weight of crucible and molybdenum trioxide = M % polyethylene = (K - I) - 1.112 (M - I) x (% grease insolubles) G Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
