J a n . , 1921
T H E JOURNAL OF INDUSTRIAL A X D ENGINEERIXG CHEMISTRY
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ORIGINAL PAPERS NOTICE TO AUTHORS: All drawings should be made with India ink, preferably on tracing cloth. If coordinate paper is used, blue must be chosen, as all other colors blur on reduction. The larger squares, curves, etc., which will show in the finished cut, are to be inked in. Blue prints and photostats are not suitable for reproduction. Lettering should b e even, and large enough to reproduce well when the drawing is reduced to the width of a single column of THIS JOURNAL, or less frequently to double column width. Authors are requested to follow the SOCIETY'S spellings on drawings, e. g., sulfur, per cent, gage, etc. STUDIES ON T H E NITROTOLUENES. V-BINARY SYSTEMS OF O-NITROTOLUENE AND ANOTHER NITROTOLUENE' By James M. Bell, Edward B. Cordon, Fletcher H. Spry and Woodford White LNIVERSITY OF NORTH CAROLINA, CHAPELHILL, N. C. Received November 8, 1920
The third paper of this series, b y Bell and Herty,2 records t h e results of studies of t h e binary systems of t h e components: p-nitrotoluene ( M N T ) , 1,2,4-dinitrotoluene ( D N T ) , and 1,2,4,6-trinitrotoluene ( T N T ) . T h e present paper contains t h e results of work upon three binary systems in each of which o-nitrotoluene ( O N T ) is one of t h e components, and one of t h e above nitrotoluenes is t h e other component.
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two freezing points indicates t h e existence of two different crystalline forms of O N T , a n observation which we found had already been made by several investigators.' X E L T I N G P O I N T S O F T H E T W O FORMS OF ONT
The metastable form of O N T (WONT) always appears first, and frequently remains unchanged for several hours even when t h e freezing liquid is stirred vigorously. Where t h e stable form of O N T (0-ONT) was desired, von Ostromisslensky cooled t h e liquid t o -50' or -60' in solid carbon dioxide. At first the metastable form appeared, b u t after a very short time transition t o t h e stable form took place with a crackling sound. During our work a much simpler method was found, based on a n observation made i n a n a t tempt t o obtain t h e eutectic temperature for M N T and a-O?JT. All a t t e m p t s t o find this temperature failed because of t h e change of metastable O N T t o t h e stable form. T o get t h e stable form we seeded with a few crystals from liquid O N T a t about -IO' t h e eutectic mixture above described. T h e tempera(corr.) and remained t u r e immediately rose t o -4.45' constant t o complete solidification. This material was kept in a low-temperature bath for "seed" purposes.
50"
PURIFICATION OF THE NITROTOLUENES
Crude M N T was crystallized several times from hot alcohol solution, filtered by suction, and allowed t o d r y in a warm place. A constant melting point ( j 1 . 3 ' corr.) accorded well with t h e earlier work.3 I n a similar way D N T and T N T gave constant melting points of 69.5 j o(corr.) and 80.35' (corr.), respectively. Crude O N T was distilled under reduced pressure. T h e distillate was then partially frozen and t h e mother liquor decanted from t h e crystals. T h e crystals were allowed t o melt and this liquid was again partially frozen and t h e mother liquor decanted from t h e cryrtals. After several such treatments, in which t h e impurities in t h e original material are removed in t h e liquid, a constant freezing point of -10.5' was reached. Frequently a supercooling of O S T t o about -16' was observed before crystals appeared, after which t h e On several occasions thermometer rose t o -10.5'. another rise in temperature t o - 4 . 4 j 0 was noticed, accompanied by a crackling sound. T h e existence of paper is the fifth of a series dealing with the freezing points and thermal properties of the nitrotoluenes, the investigation having been undertaken a t the request of the Division of Chemistry and Chemical Technology of the National Research Council. 2 THISJOURNAL, 11 (1919), 1124. 8 In the paper by Bell and Herty (page 1125) there is a discussion of the various values for the melting point of MNT, many citations giving 54O while others are around 51 5 " . We have recently found an explanation of the discrepancy in an article by Holleman (Rec. tvav. chim , 33 (1914), 5 ) , who found a sample of the material originally used by van der Arend. The melting point given by the latter, 54', was the original of all the citations giving the higher value. From a redetermination of the melting point with the Same material as originally used, Holleman concludes t h a t the pubThis brings all the determinations Iished value 54.4' is a misprint for 5 1.4'. within a few tenths of a degree of agreement. 1 This
40" 3O0
2 0"
t
3
%
sR
IO,"
/ U0
0'
O0
- /o"
-I 0"
- 2oa
-2 0"
M NT
ONT Fic. 1
These temperatures are very close t o those found by von Ostromisslensky: -10.56' and - 4 . 1 4 ~ . The earlier results, however, are more a t varl'ance with these. Thus, von Schneider2 gives -14.8', and Lepsius, i n a private communication t o Knoevenagel, gives
* von Ostromisslensky, 2. 9 h r s i k . Chem., 67 (1906), 341; Knoevenagel, Ber., 40 (1907), 508; both of whom cite D. R . P. KI. 120, No. 158,219. 2 Z . physik. Chem., 19 (1896), 157.
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-9.4' and -3.6', the former figure being later revised t o 4 . 9 5 O. The d u Pont Company has kindly furnished us with results on t h e binary system MNT-ONT, in which t h e freezing point for M N T accords well with our determination, but t h e freezing point for O N T is given We are now unable t o explain t h e rather as -3.3'. large difference between these results ranging from -3.3' to - 4 . 4 5 O . I n our work we purified several different lots of O N T b y t h e method described above, which is also t h e patented method cited above, and obtained a constant freezing point unaltered by further crystallizations.
TABLE 11-BINARY SYSTEM:
DINITROTOLWENE-O-MITROTOL~E~S
Per cent by Weight DNT ONT 0 100 5.6 9.9 18.2 30 40 50
Vol. 1 3 , No. I
Freezing Point
Solid Phase
-4.450
94.4 90.1 81.8
8-ONT -10.5 19.50 29.19 39.39 48.36 55.46 62.55 69.55.
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70 80 90 100
'
DNT
eutectic are -11.45' and 2 1 per cent D N T . We were able t o follow t h e curve for t h e metastable O X T for a short distance and have represented i t by an unbroken line in t h e figure, t h e continuation as a dotted BINARY SYSTEM: MKT-ONT~ portion representing unstable conditions. The unThe freezing points and compositions of t h e mixbroken portion of this line is plotted from two detertures for this system are given in Table I and Fig. I. minations in which t h e metastable O N T was used as TABLEI-BINARY S Y S T B M P - ~ I T R o T o ~ , u E N R - o - N I T n o T ~ L ~ ~ ~ ~ ~seed and did not change over t o t h e stable form before Per cent by Weip;ht Freezing the determination was complete. MNT ONT Point Solid Phase 0 10 20 30
100 90 80 70
40
GO
50 60 70 80 90 100
50 40
-4.4S0'
-8.2 -12.8 -6.13 6.22 16.84
30
3"::;;
20 10 0
39.27 45.68 51.3
'
8-OST
; 1 .
}
MXT
In t h e figure the points are observed t o fall on two curves, one representing mixtures from which M N T is separating and t h e other representing mixtures from which P-ONT is separating. The eutectic temperand 26 per cent ature and composition are -15.73O M N T . We were able also t o obtain one point on t h e curve where W O N T is t h e solid phase. This curve begins a t t h e freezing point for t h e metastable O N T and is roughly parallel t o the curve for t h e stable O N T . In t h e diagram t h e unbroken lines represent conditions which it was possible t o attain, t h e unstable conditions appearing as dotted lines. A study of this system has already been made by Holleman and Vermeulen,2 although their paper was not found until t h e present work was completed. I t is interesting t h a t they were able t o follow t o t h e eutectic point t h e curve for a - O N T , and give for t h e eutectic temperature -20.6 '. The unpublished results of t h e du Pont Company and t h e results of Holleman and Vermeulen are in general in close accord with t h e present results. Our curve for M N T lies slightly higher t h a n t h e d u Pont curve, which in t u r n is slightly above t h e curve of Holleman and Vermeulen. The three sets of results for t h e O N T curve also show differences, as t h e curves cross at a slight angle. The as - 1 5 . 7 3 ~ ~ eutectic temperature is given as -14.6', and as -16.4O, t h e first b y Holleman and Vermeulen a n d t h e last by t h e d u Pont chart.
0'
-IO0
/--- .ONT
DNT
FIQ. 2
B I N A R Y S Y S T E M : DNT-ONT3
T h e d a t a for this system are represented in Table II and in Fig. P. In this case, like t h e preceding system, there are two curves crossing in a eutectic point. The temperature and composition for t h e
* Experimentill
work by F. H. Spry. Rec. traw. chim., 88 (1914). I . a Experimental work by E. B. Cordon.
BINARY
SYSTEM: T N T - O N T ~
The d a t a for this system are given in Table 111 a n d in Fig. 3 . It was possible in this case t o follow out curves both for W O N T and for P - O N T t o their respective eutectic points with T N T , t h e eutectic €or T N T
2
Experimental work by W. White,
Jan.,1 9 2 1
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TAWE 111-BINARY SYSTEM:'I'RINITROTOLUENX$-O-NITROTOLUENE THE PREPARATION AND ANALYSIS OF A CATTLE FOOD Per cent by Weight Freezing CONSISTING OF HYDROLYZED SAWDUST' TNT ONT Point Solid Phase 0 100 -4.450 By E. C. Sherrard and G. W. Blanco 8-ONT 4.77 95.23 9.17 90.83 FORESTPRODUCTS LABORATORY, U. S. DEPARTMENT o s AQRICU~TURE. 15.28 84.72 -8.7 MADISON, WISCONSIN 0 100 -10.35 95.23 a-ONT -12.00 4.77 Although t h e Forest Products Laboratory has con90.83 -13.3 9.17 -0.2 25 75 sidered for some time t h e advisability of invescigating 10.2 1 70 30 40 60 25.7 t h e nutritive value of hydrolyzed sawdust, it was not 50 50 until t h e severe drouth, which occurred last year i n 60 40 TNT 70 30 t h e Northwest, called our attention t o t h e pressing 80 20 65.1 10 73.0 90 need of such a material t h a t t h e investigation was 100 0 80.35
a n d P-ONT falling a t -9.7' and 19.j per cent T N T , a n d t h e eutectic for T N T a n d a-ONT falling a t -1 5.6' a n d 1 6 per cent T N T . I n obtaining these freezing points we used the seed of t h e stable O N T i n every mixture.
undertaken. The product described in this paper was prepared b y this laboratory, and fed t o three dairy cows b y t h e Wisconsin College of Agriculture with highly gratifying results. While t h e experiment is yet in the preliminary stages, i t is deemed advisable t o describe t h e process of manufacture and present t h e analysis of t h e original and digested sawdust. PREPARATION OF MATERIAL
too
O0
-f oo
TNT
ONT F I ~ 3.
.
SUMMARY
I n this Paper we have given t h e d a t a for three binary systems of t h e nitrotoluenes, one of these nitrotoluenes having two crystal forms. I n one case i t was possible t o follow t h e freezing-point curve for t h e metastable form right t o t h e eutectic point.
The sawdust was eastern white pine obtained from a mill in Minnesota, and was representative of t h e waste obtained from mills cutting this species. N o effort was made t o remove bark or other foreign substances t h a t ordinarily are present in this material. The sawdust was treated in t h e same way as for t h e production of ethyl alcohol from wood; t h a t is, i t was digested with 1.8 per cent sulfuric acid for 1 5 or 2 0 min. under a steam pressure of about 1 2 0 lbs. per sq. in. Sufficient water was added along with the sawdust t o raise t h e ratio of water t o dry wood t o about 1.251. After the steam pressure had been blown off t o atmospheric pressure, t h e treated sawdust was removed from the digester, and a large portion of t h e acid liquor removed b y means of t h e centrifuge. The centrifuged material was then placed in towers, and the remainder of the sugar and sulfuric acid extracted with hot water. T h e leach water was mixed with the centrifuged liquor, and t h e whole almost neutralized with calcium carbonate. After t h e sludge had settled, the liquor was decanted or, if necessary, filtered, and evaporated under reduced pressure t o the consistency of a thick sirup. The leached material from t h e towers was screened through a 6-mesh screen t o remove the larger uncooked pieces of wood, a n d the screenings dried by spreading on the floor i n a thin layer. The air-dried hydrolyzed dust was then mixed with the sirup referred t o above, and t h e whole dried t o about 1 2 per cent moisture. Early in t h e experiment, when we were dependent upon t h e air drying of the finished product, considerable loss of sugar was experienced. For instance, in Cook No. 139, 21.2 per cent of t h e d r y weight of t h e original wood was converted into sugar. The final wood meal, however, contained only 16.39 per cent of sugar calculated upon t h e dry weight of t h e product. This loss of almost 5 per cent sugar was partly due t o t h e mechanical treatment and partly t o a slow fermentation of t h e sugar in t h e moist product during the early stages of drying. Table I shows t h e decrease of sugar 1 Presented before the Division of Industrial and Engineering Chemistry at the 60th Meeting of the Amerisan Chemical Society, Chicago, Ill., September 6 to 10, 1920.
