Acardites

It is prepd by the action of methylamine on 4-chloro-l-nitrobenzene (Ref 5) by the action of methyl iodide (Ref 6), or methyl sulfate on 4-nit roaniline (Ref 7) or by the hydrolysis of 4-nitro-N-methylformanilide with hot coned aq HC1 (Ref 8). In a study of the effect of nitric acid concn on the prods of the nitration of N,N-dimethylaniline to form Tetryl, it was isolated in low yield by the action of nitric acid, d 1.046g/cc, plus Na nitrite on N,N-dimethylaniline (Ref 10). A eutectic mixt with N-ethyl-4-nitroaniline has been patented as a stabilizer for NC (Ref 12). Studies at NPF indicate that 4-nitro-N-methyl-aniline is superior to Centralite, 2-nitrodiphenyl-amine, or Acardite in stabilizing. NC Refs 1) Beil 12, 586, (295) 1125 ... 

Single base NC propints were used in rifles and in the shape of tubes in some cannons. As gelatinizer for such propint an ether-ale mixture was often used, and as stabilizer diphenyl-amine (DPhA). Some NC—NG proplnts, gelatinized by acetone, contd small amts of organic nitrates. As stabilizer they used DPhA and later Centralite or Acardite. They were surface-treated by Centralite or by aromatic nitrocompds. Such NC—NG proplnts were used in large caliber cannons (Ref 44, p 252)... 

Acardite or asym-Diphenylurea, described in Vol 1 of Encycl (Ref 24, p A47-R), was developed in Germany under the name of Akardit. It has been used, accdg to Belgrano (Ref 31, p 218) as a stabilizer in some Italian smokeless propellants... 

At that time the composition was improved by the addition of a small amount of graphite which acts as a lubricant and so facilitates extrusion. In many cases centralite was replaced either by Acardite or by phenylethylurethane or diphenyl-urethane. In Japan formyldiphenylamine was applied. 

No. Purpose Nitroce llulose c o <30 o Sh Nitrodiglycol Nitroguanidine DNT Nitronaphthalene Centralite Acardite Ethylphenylurethane Diphenylurethane Hydrocellulose Graphite Magnesium oxide Potassium sulphate Dimensions Calorific value (kcal/kg)... 

Nitroc S2. Nitrogen % f- V) o Nitrodiglycol Nitrotriglycol 1 Nitroguanidine j 1 Nitronaphthalene 1 i Centralite Acardite Ethylphenylurethane j Diphenylurethane Butyl phthalate... 

Acardites are compds developed in Germany as stabilizers-gelatinizers for NC in smokeless propellants. There are three acardites of which Acardite I was developed first... 

ReudlerfRef 3), studied the nitration of Acardite I and obtained asym-dinitrodiphenyl-ureas and asym-tetranitrodiphenylure a... 

Analytical procedures for acardites are briefly described following Acardite III... 

Acardite II was proposed in Germany as a stabilizer-gelatinizer in NC smokeless propellants. As a stabilizer, it was considered superior to Acardites III I and as a gelatinizer inferior to Acardite III but superior to Acardite l(Ref 3)... 

Acardites, Analytical Procedures. Following methods are based on Refs 1,2,3 5 ... 

Method 1 (when only acardite I is present and no urethanes, DPhA or centralites) a)Extract with chloroform or methylene chloride(5—lOg) a finely divided propellant using a Soxhlet... 

Note According to Dalbert Tranchant(Ref 3), the above direct bromination of acardite I is not as convenient as their method, which consists essentially of a)saponification of acardite (extracted from propellant) by boiling with 3N NaOH soln for 2 hrs HaN CO WfR.1 +nn feTH. NH.rH. +ro... 

Method 2(when acardite 1 and a centralite are present) a)Extract the finely ground sample of propellant, as in Method 1, evaporate the solvent and weigh the dry residue (wt 1), which is equal to centralite acardite b) Treat the residue with aq AcOH at pH ca 4. This will hydrolize the centralite, leaving acardite I intact c)Wash the residue with w, dry, and weigh(wt 2). Wt 2 is equal to acardite 1 and wt 1 — wt 2 is equal to centralite a) Det mp of acardite 1 and if ca 189°, no further analysis is necessary e)If mp is not Ig0°. detn the amt of acardite either by direct bromination, proc(d)of Method 1 or by the method of Dalbert Tranchant(Ref 3)... 

Method 3(when acardite II centralites are present) a)Extract with chlf or methylene chloride ca lOg of finely divided propellant, evap the solvent and weigh the dried extract (wt 1 - centralite + acardite II) b)Treat the extracted material with aq AcOH at pH ca 4 and filter the mixt through cared sintered glass crucible. Rinse the residue, dry it to const wt and weigh(wt 2 = acardite II and wt 1 — wt 2 centralites) c)Continue. the analysis as described in procedures (c) to (g) of Method 4... 

Method 6(when acardite III alone is present as stabilizer and gelatinizer) Procs a) to e)— same as in Method 4 f)In order to establish that the sample contains acardite III and not acardite 11, treat the solnfafter removal of N gas) with chromic mixt(KaCr207 + Ha S04) in order to oxidize ethanol to acetaldehyde. Treat the oxidized soln with fuchsin, previously... 

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