1、- MIL-PRF-23942A W 9999906 2052656 059 Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Air Warfare Center AircraftDivision, Code414100B120-3, Highway 547, Lakehurst, NJ 08733-5
2、100, by using the self addressed StandardizationDocument Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. . SENSITIVE MIL-PRF-23942A(AS) 30 SeDtember 1997 SUPERSEDING 19 August 1964 MIL-P-23 942(AS) PERFORMANCE SPECIFICATION POLYBUTADIENE, LINEAR, CARBOXYL TERM
3、INATED This specificationis approved for use by the Naval Air Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1. i Scorn. This specification establishes the requirements for two types of carboxyl terminated line
4、ar polybutadiene used in the mantacture of solid propellant grains. 1.2 Classification. The carboxyl terminated linear polybutadieneis of the following types: Type I - Low acid content Type II - High acid content 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified
5、 in sections 3 and 4 of this specification. This section does not include documents in other sections of this specificationor recommended for additional information or as examples. While every effort has been made to ensure the completeness of Uiis list, document users are cautioned that they must m
6、eet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. AMSC NIA FSC 1336 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Licensed by Information Handling ServicesProvided by IHSNot for ResaleNo repro
7、duction or networking permitted without license from IHS-,-,- MIL-PRF-23942A 99999Ob 2052b57 T95 m 2.2 Non-Government Dublications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are t
8、hose listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited in the solicitation(see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM-D240 - Heat of Combustion of Liqui
9、d Hydrocarbon Fuels by Bomb Calorimeter Standard Test Method for (DoD adopted). ASTM-D 1 159 - Bromine Number of Petroleum Distillates and Commercial Aliphatic Olefm by Electrometic Titration, Test Method for OD adopted). ASTM-D1218 - Refractive Index and Refractive Dispersionof Hydrocarbon Liquids
10、Test Method for OD adopted). ASTM-D1298 - Density, Relative Density (Specific Gravity), or API Gravity of Petroleum and Liquid Petroleum Products by Hydrometer Method, Standard Practice for (DoD adopted). ASTM-E275 - Describing and Measuring Performance of Ultraviolet, Visible, and Near-Infrared Spe
11、ctrophotometers, Standard Practice for (Application for copies should be addressed to the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.) 2.3 Order of mecedence. In the event of a conflict between the text of this document and the references cite
12、d herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection in a
13、ccordance with 4.3. 3.2 Chemical and phvsical reuuirements. The chemical and physical requirements of the carboxyl-terminated linear polybutadiene, Types I and II, shall be in accordance with table I. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,
14、-NIL-PRF-23942A = 9999906 2052658 921 3.3 Workmanship. The material furnished under this specification shall be a uniform product free from foreign contaminates. It shall be manufactured in accordance with standard manufacturingprocedures of the industry. TABLE I. Chemical and pvsical rauirements. C
15、haracteristic Viscosity, poise at 77F Viscosity ratio, 77“F/1 O0 OF Specific gravity, 60 60F index of refiaction, 250 Carboxyl content, weight (wt.) percent Unsaturation type, Cis (percent of total) Trans (percent of total) Vinyl (percent of total) Volatiles, wt. percent Moisture, wt. percent Antiox
16、idant, wt. percent Insoluble in trichloroethylene, wt percent Ash, ignited, wt. percent Heat ofcombustion, British Thermal Units Tu) per pound mass, net Requirement Type I 200 1.5 0.890 1.5 14 1.10 25 35 15 - - 1 .o - - - 17,900 3 Vlaximum 100 1 .O 1.925 1.519 1.40 45 55 25 1 .o 0.05 1.5 0.2 0.05 18
17、,400 Type II 230 1.5 D.890 1.5 14 1.60 25 35 20 - - 1 .o - - 17,900 daXiInum !50 5 .O 1.925 1.519 1.90 45 55 30 1 .o 0.05 1.5 0.2 0.05 18,400 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-23942A = 9999906 2052b59 8b8 4. VERIFICATION 4.1 C
18、lassificationof inswctions. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.3) b. Conformance inspection (see 4.4) 4.2. Lot size. A lot shall consist of material produced by one manufacturer in one continuous operation employing not more tha
19、n one lot of each ingredient and with no change in formulation or process. If manufacture is by batch process, batches may be combined to form a lot provided not more than one lot of each ingredient and no change in formulationor process is used. 4.3 First article inspection. When required (see 6.2)
20、, the first article inspection shall consist of all the tests required for conformance inspection. 4.4 Conformance insrxction. Conformance inspection shall consist of all the performance tests specified in 4.5. 4.4.1 Conformance satnluiq. Each lot shall be sampled as specified in the contract or ord
21、er (see 6.2). All samples shall be selected at random from each lot. There shall be no defects. 4.5 Performance tests. All tests shall be performed to determine conformance with table I. 4.5.1 Viscositv at 77F and 100F. The apparatus and procedures for the determinationof viscosity at 77F and 100F s
22、hall be as follows: 4.5.1.1 Aaratus. a. Brookfield viscometer, Model RVF, Brookfield Engineering Laboratories, or equivalent. b. Constant temperature water baths, maintainedat 77F and 100F. 4.5.1.2 Procedure. a. Remove the handle and mount the viscometer on a ring stand. Carefully attach the Brooldi
23、eldNo. 7 spindle. If a different spindle or speed is used, consult the chart accompanying the instrument for the multiplying factor. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-lIL-PRF-23942A 9999906 2052660 58T b. Pour the sample into a 600-mi
24、lliliter(mL) beaker, place in the water bath at 77F or 100“F, and stir with a thermometer until the sample comes to the test temperature. Do not stir air bubbles into the sample. c. Lower the viscometer on the ring stand until the surface of the sample is in the narrow section of the spindle. Level
25、the viscometer and operate at 20 revolutionsper minute (rpm) for determinationsin the 1 O0 to 2,000 poise range. During operation maintain the spindle depth in the sample so that the polymer level climbs midway up the narrowest section of the spindle. d. Obtain a series of readings until the value i
26、s constant. 4.5.2 Calculations. Using the No. 7 spindle at 20 rpm, and reading the O to 1 O0 scale, calculate the viscosities as follows: Viscosity at 77“F, poises = (20)(scalereading) Viscosity at 1 OOF, poises = (SO)(scale reading) If a different spindle or speed is used, consult the chart accornp
27、anyingthe instrument for the multiplying factor. Convert the resulting centipoises to poises by dividing by 1 OO. Calculate the ratio of the viscosities at 77F and 1 00F as follows: viscosity ratio, 770 /1 OOOF = Viscositv at 77F. mises Viscosity at 1 OOF, poises 4.5.3 SDecific mvitv. The specific g
28、ravity shall be determinedin accordance with ASTM-D 1298. 4.5.4 Index of rehction. The index of refraction shall be determined in accordance with ASTM-D12 1 8. 4.5.5 Carboxvl content. The procedures for the determinationof carboxyl content shall be as follows: - 4.5.5.1 Aaratus. a. Buret. b. 250-mL
29、Erlenmeyer flask or equivalent. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- flIL-PRF-23942A 99999Ob 2052bbL 4Lb c. Magnetic stirrer. 4.5.5.2 Reagents and materials. a. Foil. b. Nitrogen. c. Pyridine, reagent grade. d. Sodium methylate, standar
30、d, 0.2 normal (N). Dissolve4.6 grams (g) of clean metallic sodium in reagent grade methanol and dilute to one liter with the same solvent. Standardize against standard O. 1N HC1 using thymol blue indicator. e. Sodium methylate, 0.02N standard. Dilute 100.0 mL of the 0.2N standardized sodium methylat
31、e to exactly one liter with methanol. f. Thymol blue indicator. Dissolve 0.3 g thymol blue in 1 O0 mL of methanol. 4.5.5.3 Procedure. 4.5.5.3.1 Test stxcimenorezlaration. Weigh, in duplicate, 0.4 to 0.6 g of polymer sample into a previouslytared 250 mL Erlenmeyer flask (see 6.4. i). Add 50 mL of pyr
32、idine and a magnetic stirring bar. Cover the flask with foil to help exclude atmospheric carbon dioxide and dissolve the sample by stirring magnetically. 4.5.5.3.2 Titration. Insert the sodium methylate buret tip and the nitrogen flush tube into the flask by puncturingthe foil. Flush the flask with
33、nitrogen, and maintain a slow flow of nitrogen into the flask during the titration. Add ten drops of thymol blue solution and titrate to a blue end point with 0.02N sodium methylate solution prepared above. Repeat the titration procedure using 50 mL of pyridine as a blank. 4.5.5.4 Calculations. Carb
34、oxyl content shall be calculatedas follows: - Carboxyl content, wt. percent = f A-BI 0 ( 45-02) x 100 (1 ,oww Where: A = mL of sodium methylate required for sample. B = mL of sodium methylate required for blank. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license f
35、rom IHS-,-,-MIL-PRF-23742A 9Ob 2052662 352 MIL-PRF-23 942A(AS) N = Normality of sodium methylate. W = Weight of sample in grams. 45.02 = molecular weight of the carboxyl group, COOH. Duplicate determinations shall not differ from the mean by more than *0.05 percent carboxyl in the range of O. 1 to 5
36、.0 weight percent. 4.5.6 Unsaturationdetermination. The determinationof unsaturation shall be as follows: 4.5.6.1 Aunaratus. a. Infrared spectrophotometer. Use a double beam instrument. Although a Perkin-Elmer Model 21 or its equivalent is preferred, one of the less expensive instruments such as Inf
37、iacord or the IR-5 may be used with some sacrifice in reproducibility. ASTM-E275 may be used to compare the performance of the equivalent spectrophotometerunit to the Perkin-Elmer Model 21. b. Sample cells. Use two matched pairs of cells with sample cell thickness of 1,500 and 500 micrometers (p). B
38、uild these cells in a laboratory if no commercial product is available. Directions for preparationof the cells are given in 4.5.6.3a c. Accessory equipment. (1) Vacuum desiccator (2) Vacuumpump (3) 25-mL volumetric flasks 4.5.6.2 Reagents and materials. Unless otherwise specified below, all reagents
39、 shall conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society (ACS). a. Carbon disulfide. b. Antioxidant. Phenyl-B-naphthylamine (PBNA). 4.5.6.3 Procedure. a. Preparationof sample cells. Use pairs of infrared cells. One cell, of known thick
40、ness, serves as the sample cell, while the other should be of the thickness to compensate for the carbon disulfide solvent in the sample cell. If built in a laboratory, first build a sample cell of the latter thickness, and then build several cells 2.5 percent thinner. Obtain differential spectra be
41、tween a 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-23942A U 999990b 2052bb3 299 2.5 percent polybutadiene solution in the sample cell and pure carbon disulfide in the reference cells. Examine the carbon disulfide absorption bands at 4.
42、35, 4.65 and 1 1.65 pn (see 6.4.2). 4.5.6.3.1 Preziarationof solutions. 4.5.6.3.1.1 Regulartmcedure. a. Prepare a stock solution of solvent by dissolving O. 1 g of PBNA or other antioxidant in a 2-kg (5-pound) bottle of carbon disulfide. b. Tare a 25-mL volumetric flask to the nearest O. 1 mg. Add 0
43、.625 g of polymer to the flask and reweigh the flask to *O. 1 mg. Care should be taken to prevent the polymer from sticking to the lip or neck of the flask where solvent will not reach it. Add stock carbon disulfide to 2/3 final volume. Allow to stand, with occasional shaking until the polymer is di
44、ssolved. c. Check the solution thoroughly for gel. Gel occurs in two forms: “tight gel“ which is visible as definite particles and a “loose gel“ which may be detectable only by the slight difference in rehctive index from the surrounding solution. When gel is present discard the solution and use the
45、 alternate procedure of 4.5.6.3.1.2. When no gel is present, make the solution up to final volume and shake well before sampling for scanning (see 4.5.6.3.2). 4.5.6.3.1.2 Alternatetxocedure. Thisprocedureshall beused insteadofthat in4.5.6.3.1.1 for those samples which are found in the regular proced
46、ure to contain gel. a. Weigh 1.3 g of polymer into a small bottle and add 50 mL of stock carbon disulfide. Allow to stand with occasional shaking until the polymer is dissolved. Examine the solution carefully for gel. If any is present, remove it by filtration. b. Tare a small (25 mL) vial to the ne
47、arest O. 1 mg. At the time the infrared cells are filled, withdraw 10.0 mL of the solution with a pipet and place in the tared vial. Place the vial in a hood and allow the solvent to evaporate. Remove the last traces of solvent overnight in a vacuum desiccator. Weigh the vial to the nearest O. 1 mg
48、and subtract the tare weight to obtain the weight of the solids. The concentration of the solution in g/L is 1 O0 times the weight of the residue in grams. 4.5.6.3.2 Scanning of samdes. Calibrate the instrument for electrical balance and the 1 O0 percent T line. Set the zero percent T line to coinci
49、de with that of the chart paper. When these checks are completed, the instrument is ready for scanning. a. Make the polymer solution up to the final volume and shake thoroughly. Fill the 1,500-w sample cell. Fill the reference cell with the same stock carbon disulfide used to make the solution. 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
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