ASTM D2765 PDF

ASTM D STANDARD TEST METHODS FOR DETERMINATION OF GEL CONTENT AND SWELL RATIO OF CROSSLINKED ETHYLENE PLASTICS. Differential Scanning. Calorimetry (ASTM. D). Dilute Solution. Viscometry ( ASTM. D, F). Fatigue (ASTM E). Swelling Analysis. (ASTM D). Tue, 30 Oct GMT astm d standard test methods pdf – Test. Method B differs from the referee test method only in sample preparation; that is.

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Determination of the g A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Such extraction test methods are described d765. They are applicable to crosslinked ethylene plastics of all ashm, including those containing? They have been particularly useful for electrical insulations since specimens may be selected from those portions of the insulation most susceptible to insufficient crosslinking.

The inch-pound units in brackets are for information only.

ASTM.D Determination of Gel content and swell ratio of crosslinked ethylene plastics_百度文库

Summary of Test Methods 4. After extraction, the specimens are removed, dried, and reweighed as c2765. The amount of material extracted is calculated and, if desired, swell 1. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applica- 1 These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Dd2765 D Current edition approved April 1, Originally approved in Satm previous edition approved in as D — Hence, determination of the gel content provides a means of both controlling the process and rating the quality of?

Any test specimen preparation, conditioning, dimensions, or testing parameters, or a combination thereof, covered in the materials speci? If there are no material speci? For one or two determinations at d276 time, a 2 mL? For several determinations at one time, but not exceeding six, a mL? A asrm laboratory mill4,5 is satisfactory, although any procedure which will produce a sample of the required? The extraction thimble, with extra-coarse fritted glass disk sealed in; Kontesmm body diameter, mm height or equivalent height x2765 subsequently be cut to 75 mm.

The fritted disk is extra-coarse with fused edge; Kontesmm diameter or equivalent. Glass wool 13 to 19 mm thick [1? The extraction thimble assembly rests upon the mm portion of the thimble previously cut off, the latter inserted into the modi? Use only in a ventilated hood. Check the effectiveness of the hood before starting the tests. Do not inhale the vapors. Excessive inhalation of the vapors may cause dizziness or headache, or both.

In the event of excessive inhalation, seek fresh clean air. Your comments will receive careful consideration at a meeting of the responsible technical committee,1 which you may attend. D — 01 A—Identi? E—Ground-glass or cork joint. L—mesh wire cage containing the specimen.

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Shake this sieved material over a mesh sieve and reject any material that passes through. Fold this to form a square measuring approximately 40 mm [11? Fold two sides of this square closed by folding the cloth at the edges about 6 to 7 mm [1?

In that manner, a pouch open at the top d275 obtained. Weigh this pouch W1. Weigh the pouch and specimen W2. Fold over the open side of the pouch and staple the edge to form a cage.

Weigh the cage and sample W3. Suspend the cage and specimen in the solvent so that the bottom edge of the cage is almost touching the bottom of the? A small wire, attached to the cage and extending through the re? Extract the specimen for 6 h in decahydronaphthalene or for 12 h in xylenes. NOTE 3—Since most of the extraction occurs within less than the speci? If this is done, the time of extraction must be reported.

For referee tests, extraction d265 is to be as speci? Cool and weigh W4. If the compound absorbs moisture, cool the specimen in a desiccator before weighing. NOTE 4—It has ast reported that drying time sometimes can be materially shortened if ast, cage awtm sample are cooled for 15 min and then are placed either on a suspended screen or on lint-free absorbent material to remove excess solvent before being put into the vacuum drying oven.

The test strip used for extraction should be taken next to the conductor only when strand shielding tapes or compounds are not employed.

ASTM D2765 – 16

In high-voltage cable employing strand shielding tapes or compounds, the strip should be shaved as closely as possible along the shielded surface, being careful not to include any of the semiconducting compound see Fig. The outer sections of this strip are discarded, thus leaving only a sample of the material closest to the conductor or shielded surface. This sample then is cut or diced into pieces measuring approximately 6 by 6 mm [1?

For Size 2 AWG and smaller, the dimensions should be proportionately less. Close the pouch by folding over the open side and stapling it to form a cage. However, if there is any doubt about the values obtained with reused extractant, the test should be repeated with fresh extractant. NOTE 5—If the modi? NOTE 6—If the fraction of? C—Area most susceptible to insufficient crosslinking. E—Specimen for solvent extraction shaded area. Both measurements are obtained in one test. The degree of crosslinking is not expressed as a percent of total crosslinkability or similar expression, but is judged from swell ratio and percent extract based on experience with the particular polymer-solvent system under consideration.

However, this test method permits swell ratio to be determined. Summary of Test Method The swell ratio and percent extract are calculated from these weight measurements.

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In the presence of xylene, polyethylene in the density range from 0. Provided that no chemical degradation occurs, the greater the degree of crosslinking the lower the amount of extract lower percent extract. Provided that no chemical degradation occurs, 5 the lower the swell ratio the greater the crosslinking and the lower the molecular weight between crosslinks.

Reagents and Materials In case of excessive inhalation, seek fresh clean air. The surface-to-volume ratio shall be kept as small as reasonably possible. If necessary, they may be cut into two or three pieces crosswise so that they can be completely submerged in the solvent. NOTE 7—The solvent must cover the swollen test specimen at the conclusion of the immersion period to obtain reliable results.

Tests shall be discarded and repeated with a fresh test specimen if specimens are not covered with solvent at the conclusion of the extraction step.

If necessary, place a weight on the jar or clamp it to hold it in place. NOTE 8—The immersion period speci? Increasing this period to 72 h had no signi? However, a longer immersion period does slightly increase the values for percent extract. Handle the swollen test specimen gently and carefully.

Blow the surfaces Note Stopper the weighing bottle. NOTE 9—The size of the swollen test specimen dictates the size of the weighing bottle to be used. NOTE 10—Extreme care must be used in handling the swollen test specimen to obtain reliable results. The test specimen should not be squeezed with the forceps.

The transfer of the test specimen should be made quickly. The surfaces should not be subjected to excess blowing too long or more than once on each side ; otherwise more than the surface xylene will be removed. Test specimens that break up during the immersion period usually very low degrees of crosslinking can be caught on a mesh or? Results obtained from such specimens are of limited value. If the system is un?

If the system is? We density of polymer at the immersion temperature volume of polymer in gel Wo? Wd density of solvent at the immersion temperature volume of solvent in gel Wg? This ratio is approximately 1. Low swell ratios indicate a more tightly bound structure. Low values of percent extract indicate a high degree of crosslinking. NOTE 11—Derivation of calculations: Cool cold trap with dry ice and acetone to catch and condense xylene vapor. Heat in vacuum until xylene is all removed, as determined by repeated weighing.

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