1、 FORD LABORATORY TEST METHODBP 155-01Date Action Revisions 2006 08 15 Activated K. Nasser Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 1 of 4 CROSS-LINK DENSITY OF ELASTOMERS Application This method is used to determine the cure state of Elastomer using a method
2、 involving solvent swell of the elastomer. Apparatus Required Vials - 20 ml capacity borosilicate scintillation vials with screw caps. Polyethylene weighing vial with cap. Oven - Air circulating, capable of maintaining 105 C, conforming to ISO 188/ASTM E 145 type IIA normal oven 150 + 50 air changes
3、 per hour. Analytical Balance - Capable of measuring out to 0.1 mg (0.0001 g). Razor Blades, Pipettes Materials Required Solvent Combinations for Cure State Measurements Elastomer Solvent Solvent Gravity, g/ml ACM Methyl Ethyl Ketone 0.8054 AEM Methyl Ethyl Ketone 0.8054 NBR Methyl Ethyl Ketone 0.80
4、54 HNBR Methyl Ethyl Ketone 0.8054 VMQ Cyclohexane 0.7739 FKM Acetone 0.7908 EPDM Toluene 0.8669 CR Toluene 0.8669 IR Toluene 0.8669 NR Toluene 0.8669 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、/- 5% relative humidity for not less than 24 hours prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHODBP 155-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 2 of 4 Procedure 1. Cut three specimens from mat
6、erial to be swollen. Each specimen should be roughly 0.1000 g to 0.2000 g in weight. Tare balance and record this weight as “Initial Weight“ in the laboratory book. 2. Place each specimen in a separate, numbered 20 ml scintillation vial. Record the numbers for the given material on the data sheet ne
7、xt to the description column. 3. Add approximately 10 ml swelling solvent to the vials using pipettes, and cap quickly. A list of appropriate swelling solvent is listed above. Ensure the total specimen is submerged in solvent. 4. Allow the specimens to swell for 96 hours at room temperature. Check s
8、pecimens after 1 hour to ensure that the total specimen is still submerged in solvent. Add more solvent if needed. 5. Tare the small polyethylene vial and the snap cap on the balance. 6. Remove each swollen specimen from the swelling solvent. Quickly blot off the excess solvent with a tissue and imm
9、ediately place the swollen specimen in the tarred vial. Recap the vial. 7. Re-weigh the vial plus the swollen specimen to the nearest 0.1 mg (0.0001 g) using the balance. Record the value as the “Swollen Weight“. 8 Return the swollen specimen to its numbered scintillation vial. 9. Using a pipette, f
10、orce air into the polyethylene vial to remove any solvent left in the vessel. 10. Re-tare the vial with its cap and repeat steps 6-9 for each specimen. 11. After all the swollen weights have been measured, dry the vial with the swollen specimen in an oven at 105 C +/- 1 C for a minimum of 4 hours. 1
11、2. Re-weigh the dried specimens and record the weight as “Dried Weight“. Remember to tare the balance before the weight is taken. 13. Perform the calculations for V2M and the percent of extraction for each specimen. Refer to the Calculation section below. 14. Calculate the average of the three speci
12、mens of V2M and record this as “State of Cure“ value. Refer to the Calculation section below. 15. Calculate the standard deviation of the three V2M specimens. If the standard deviation exceeds 0.007 then the material should be retested. 16. Calculate the “Percent of Extraction“. Refer to the Calcula
13、tion section below. FORD LABORATORY TEST METHODBP 155-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 3 of 4 Calculations Volume Fraction Elastomer Swell V2M = Volume Fraction Elastomer at Swollen Equilibrium V2M = (I x F)/GE (1 x F)/GE + (S D)/GS Where: I = Init
14、ial Weight D = Dried Weight F = Weight Fraction Elastomer in the Compound* GE = Specific Gravity of the Elastomer* S = Swollen Weight GS = Specific Gravity of the Swelling Solvent *Supplier provided data for Specific Gravity of the Material and Weight Fraction Elastomer should be used, if available.
15、 If this method is to be used for specification (process or material) development then supplier data is mandatory. If supplier data is not available and not mandatory (as defined above) then on a separate and un-used (has not been exposed to fluids/greases) sample, perform the following techniques t
16、o obtain the values: Weight Fraction Elastomer - Central Lab TGA method minus toluene plasticizer extraction Specific Gravity of the Elastomer - use a published book value Example I = 0.1460 grams D = 0.1434 grams F = 0.6250 (62.50%) GE = 1.810 g/cc S = 0.3566 grams GS = 0.7908 g/ml V2M = (0.1460 x
17、0.6250)/1.810 (0.1460 x 0.6250)/1.810 + (0.3566 0.1434)/0.7908 V2M = 0.158 State of Cure State of Cure = (V2Ma + V2Mb + V2Mc) 3 Where: State of Cure = (Higher number means higher cure) V2Ma = V2M for specimen a V2Mb = V2M for specimen b V2Mc = V2M for specimen c FORD LABORATORY TEST METHODBP 155-01P
18、rinted copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 4 of 4 Percent of Extraction P = (I D) X 100% I Where: I = Initial Weight D = Dried Weight P = Percent Extraction Example I = 0.1460 grams D = 0.1434 grams P = (0.1460 0.1434) X 100 % =1.78% 0.1460 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.
