 |
|||
|
Page Title:
Determination of the Graphite Content |
|
||
| ||||||||||
|
|  MIL-C-48115A(PA)
RDX, maintaining each portion in contact with the residue for
approximately five minutes before applying suction. Stir occa-
sionally to break up any lumps and wash down the sides of the
crucible with each 20 mi portion of chloroform to insure complete
removal of the calcium resinate. Aspirate the residue until
the odor of chloroform is no longer detectable, place the
crucible and contents in a drying oven at 100 degrees Centigrade
(oC) to 105oC for one half hour, cool in a desiccator and weigh.
Repeat the above extraction, drying and weighing procedures with
individual 20 ml portions of chloroform until the loss in weight
on subsequent extractions total less than 0.003 gm. Calculate
the loss in weight of the crucible plus contents to percent
calcium resinate on a moisture-free basis as follows:
Where:
A = loss in weight of the crucible plus contents
W = weight of specimen on a moisture-free basis
4.5.2.2 Determination of the Graphite Content - Extract
the residue remaining after calicum resinate (See 4.5.2.1) has
been removed with two 20-ml portions of dimethyl formamide,
maintaining each portion in contact with the residue for approxi-
mately five minutes with intermittent stirring before applying
suction. Wash the crucible and contents with a minimum of three
20-ml portions of acetone, maintaining each portion in contact
with the residue for approximately one minute with. continuous
stirring before applying suction until the following qualitative
test for RDX in the acetone washings is negative. Transfer the
acetone filtrate to a 25 ml beaker, evaporate to dryness on a
steam bath and add several drops of a solution of chromotrophic
acid in 36 normal (N) sulfuric acid. The formation of a reddish-
brown color as compared to a pink color obtained by a blank pre-
pared in an identical manner, indicates the presence of RDX.
Aspirate the residue until the odor of acetone is no longer
detectable, place the crucible and contents in a drying over at
100 degrees to 105 degrees C for one half hour, cool in a desic-
cator and weigh. Calculate the weight of the residue in the
crucible to percentage of lubricant in the sample on a moisture-
free basis as follows:
Where:
A = increase in weight of empty tared crucible
W = weight of sample on a moisture-free basis
11
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals