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Also, since neither the sand nor the rod end-point indicators worked satisfactorily, the touch method was used, one experienced observer making the determinations. The adsorption characteristics of the woods for the various constituents of the paints naturally affected the drying times considerably and produced results differing from those on glass. However, the effects of the adverse conditions on the drying rate were the same. The retarding tendency of humidity and low temperature is evident from Table VI, but the average time differences are not so great as on glass, which can also be attributed t o the adsorption factor of the wood. I n two cases, cypress and redwood with paints €3 and E, there was a distinct increase in the retarding effect of the adverse condition.
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At best, excessive moisture and low temperature, particularly the latter, contribute to poor painting conditions, and this retarding effect can readily be intensified by poor lumber. These findings will take on an added significance when durability data on paints dried under controlled, adverse drying conditions become available. Literature Cited (1) Gardner, Paint Mfrs. Assocn. U. S., Tech. Circ. 70 (1919). (2: Miller, Trans. Am. Inst. Chem. Eng., 13, Pt. I, 379 (1920). (3) Nelson, Schmutz, and Gamble, Proc. Am. SOC.Testing Malerials, 26, Pt. I1 (1926). (4) Sanderson, Zbid., 26, Pt. 11, 407 (1925). ( 5 ) Schmutz and Gamble, IND.ENG.CHEM.,Anal Ed , 1, 83 (1929). (6) Waele, de J. SOL.Chem. I n d . , 39, 49 (1920).
Action of Refining Reagents on Pentamethylene Sulfide in Naphtha Solution’ P. Borgstrom, R. W. Bost, and J. C. McIntire UNIVERSITY O F hyORTH CAROLINA, CHAPEL HILL,N. C.
Pentamethylene sulfide has been studied in three HE ring sulfides came only be told by further work. naphthas and with various reagents. It is almost into p r o m i n e n c e i n The results of the experiments completely removed by sulfuric acid, by mercuric salts, connection with petroreported in this paper, where by refluxing with permanganate, and by washing leum products when Mabery the solvent used is not a pure with sodium hypochlorite. It is removed to some a n d Q u a y l e (6) identified known hydrocarbon, may be extent by silica gel, by treatment with aluminum “thiophanes” in C a n a d i a n influenced by the solvent in a trichloride, and by extracting with liquid sulfur dipetroleum. Since that time manner that is not apprecioxide. Metallic sodium does not seem to affect i t many have been prepared and ated a t the present time. appreciably. their properties g i v e n b y Table I gives a comparison In behavior pentamethylene sulfide resembles the chemists. Study of them in of the behavior of alkyl sulalkyl sulfides more than thiophene. a naphtha, h o w e v e r , h a s fides, pentamethylene sulfide, been-very rare. Youtz and and thiophene with different Perkins (8) prepared tetramethylethylene sulfide and studied reagents as compiled from the literature. The behavior of the its behavior with sulfuric acid, silica gel, and methyl and mer- sulfides and thiophenes for many reagents is reported as varicuric iodides. They found that it was largely removed by able, because of the difference in the structure of the sulfide sulfuric acid, partially by silica gel, and sIightIy by methyl or thiophene treated. Conclusions drawn from the behavior of one member of the group are questionable, as pointed out and mercuric iodides. Thiophene has had much more attention than the poly- by Youtz and Perkins (8). With certain reagents there is no methylene sulfides, Wood, Lowy, and Faragher (?) state reaction for all types. Also the behavior of a naphtha conthat thiophene is not removed by hypochlorite, copper taining 0.1 per cent added sulfur may differ widely from that oxide, sodium plumbite, sodium plumbite and sulfur; that it of one containing 0.5 per cent added sulfur. Most of the data decomposes when heated with aluminum trichloride, and that in the literature are based on the higher concentration, while it forms soluble thiophene sulfonic acid. Birch and Norris the work done with the pentamethylene sulfide is with a (1) have confirmed the results that thiophene does not react 0.1 per cent solution. with hypochlorite. Faragher, Morrell, and Monroe ( 4 ) state on Alkyl Sulfides, Ring Sulfides, that thiophene, which they used as their example of residual Table I-Action of Refininga nAgents d Thiophene sulfur, is not appreciably removed by acidified cadmium PENTAMETAYLENB REAGENTALKPLSULFIDES4 SULFIDE THrOPHENE4 chloride, metallic mercury, alcoholic sodium plumbite, reducHgNOs.Hz0 Removed (4) Removed None removed (4) tion with glacial acetic acid and zinc, or with mercurous ni- HzSO4 (25 Ibs. Largely Completely Largely removed (7, 8 ) per bbl.) removed (g) removed trate. Faragher, Morrell, and Comay (3) showed that thio- AlClr Variable ( 8 ) Nearly comVariable (7, 8 ) phene can be passed through a heated tube a t 496.11’ C. pletely removed Silica gel Variable (6, 8 ) Nearly corn25 per cent removed@) (925” F.) and 871.5” C. (1600” F.) without loss of sulfur, in pletely removed Completely None removed ( 1 , 7 ) fact, with a slight increase owing to decomposition of hydro- Hypochlorite Variable ( I ) removed carbons. Youtz and Perkins (8) studied the substituted a As reported in the literature. Italic numbers in parentheses refer thiophene with sulfuric acid, aluminum trichloride, silica gel, to “Literature Cited.” and fuller’s earth, which showed varying degrees of efficiency Table I1 gives the percentages of sulfur found by the lamp in removal. method after treatment of the naphtha solution of pentaThis paper discusses the behavior of pentamethylene sulfide in three naphthas. Whether this sulfide shows the same methylene sulfide. When naphthas 3 and 7 were treated with reaction as other ring sulfides and whether the reactions of mercuric acetate and mercurous nitrate (monohydrate) part this one in the naphthas used are typical for all naphthas can of the original sulfur of the naphtha was removed. When these naphthas were treated with a sulfuric acid wash (25 2 Received October 8, 1929. This work is being continued as Project pounds per barrel) a small amount of the sulfur was removed No. 41 of the American Petroleum Institute Research entitled “The Prepafrom naphtha 2 and much more from naphthas 3 and 7. I n ration and Properties of Thiophanes.”
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general, it seems that it is slightly harder to remove the sulfide from naphtha 2 than from naphtha 3 or 7, although the difference is not appreciable. Table 11-Sulfur
.
Found by Lamp Method after Treatment with Varioue Reagents rSUI,FURIN----CONDITION OB SULFUR Naphtha 2 Naphtha 3 Naphtha 7 Per cent Per cent P e r cent Found in naphtha (blank) 0.010 0,026 0,036 Added 0,125 0,118 0,109 Blank and added 0.135 0.144 0,145 Found 0.133 0.139 0,145 After treatment with: HPSOI(3.8 Ibs. per bbl.) 0.060 0.064 0.069 HzSOI (7.6 lbs. per bbl.) 0.018 0.033 0.012 His04 (3.8 4- 3.8) o:ois 0,021 0 009 HzSOI (25 Ibs. per bb!.) 0,011 0,013 HgAcr wash 0 014 0.018 0.031 HgClz wash 0.012 0.038 0 012 HgNOs.Hi0 wash o:ois 0.021 0.130 Re%uxwith sodium metal 0.138 0.134 Shaking with silica gel 0.026 0.036 0.042 0,048 Extracting with liquid $01 0,060 0.064 Reflux with AlCla 0 039 0,052 0,090 Reftux and distillation from AICls 0,015 0.045 0.069 0 007 KMnO4 0.012 Hypochlorite wash 0:024 0:037 Blank after treatment with: HI SO^ (25 lbs. per bbl.) 0.008 0.011 0,013 HgAci wash 0.015 0.029 ... 0.015 0.019 HgNOs.Hz0 wash KMnO4 0,007
...
Experimental
Naphtha 2, taken from a natural gas well, was thoroughly washed with sulfuric acid, water, alkali, and water. Naphthas 3 and 7 were used as received from the oil companies. The constants are given in Table 111. The solutions were made up by weight, the sulfide being weighed in a small bulb. Table 111-Physical Characteristics of Naphthas DBTERMINATION NAPHTHA 2 NAPHTHA 3 NAPHTHA 7 Gravity, A. P. I. at 60' F . , 66.3 54.8 49.3 Color, Saybolt. , 28 25f Sulfur, per cent. O:OLO 0.026 0.036 Assay distillation: O F. Per cent Per cent Per cent 170 202 Over 293 332 390 404 Dry 14 120 .. 31 130 .. .. 57 140 .. 66 150 '3 79 .. 160 34 88 170 65 io 179 .. 94 .. 180 86 20 184 30 .. 188 190 96 93'.5 40 .. 194 98 200 96:7 50 .. 201 60 210 70 222 80 240 90 298 .. 92 Total 9 s :0 1 4 Residue 1.6 4 1 Loss 0.4 Neg. Neg. Doctor test Neg.
. . .. . ... .. .
+
..
..
..
..
..
The pentamethylene suUide was prepared by heating pentamethylene dihalide with sodium sulfide in absolute alcohol. After refluxing, the reaction product was diluted with water and then extracted with ether. The ether extract was dried and distilled, the fraction retained boiling a t 140-141O C. The yield was about 45 per cent purified product. ANALYsIs-The official A. S. T. M. lamp sulfur method was used. Subtracting the blank, the recovery was 98.4 per cent for naphtha 2, 95.8 per cent for naphtha 3, and 100 per cent for naphtha 7. This shows that this sulfur compound can be determined by this method with a remarkable degree of accuracy. SULFURIC ACID (SP. GR. 1.84)-The results in Table I1 for all the naphthas except those treated with sulfuric acid a t the rate of 25 pounds per barrel were obtained by vigorously shaking the naphtha and acid for 10 minutes, decanting into a clean separatory funnel, and washing thoroughly with water. The results on those treated with sulfuric acid a t the rate of
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25 pounds per barrel were obtained by shaking for 3 minutes as described by Youtz and Perkins (8). The first acid wash became highly colored in the case of naphthas 3 and 7, while the second acid wash was faintly colored only, as was the first acid wash for naphtha 2. These results show that two washings with 3.8 pounds per barrel are more efficient than one with 7.6 pounds. This treatment removed as much sulfur as was added and part of that present in the naphtha itself in the case of naphthas 3 and 7. Salts such as mercuric chloride and mercurous nitrate have often been used in removing sulfur compounds (6). Using saturated mercuric chloride (2 volumes of naphtha to 1 of the mercuric chloride solution) gave nearly complete removal of the sulfide. A heavy precipitate was formed and the double compound could not be washed with water because of decomposition. With a mercuric acetate (0.5 At), using the same volume as for mercuric chloride, less sulfur was found in naphthas 3 and 7 than in the blank. Using mercurous nitrate monohydrates (3) there was an appreciable loss of the blank for naphthas 3 and 7. The results for naphtha 2 show that pentamethylene sulfide can be almost completely removed. METALLICSODIUM-Ten grams of metallic sodium were used per 100 cc. of naphtha and the mixture refluxed for 3 hours. I n naphthas 3 and 7 the sodium was molten and a bright surface was always visible. There was a reddish brown sediment in the naphtha, the most for naphtha 7, less for naphtha 3, and a trace for naphtha 2. The sodium was not molten in naphtha 2, although there was rapid refluxing, and the sodium did not have a b i g h t surface. On analysis the loss of sulfur for naphtha 2 was 4 per cent, for naphtha 3, 5 per cent, and for naphtha 7,lO per cent. SILICAGEL (6, @-Twenty grams of silica gel (medium size) per 100 cc. of naphtha were shaken for 2 hours in a shaking machine. The solution was poured off from the silica gel and analyzed. Subtracting the blank, 13, 9, and 6 per cent of the sulfur remained for naphthas 2, 3, and 7, respectively . LIQUID SULFURDIOXIDE @)-The sulfur dioxide was distilled into the naphtha until the volume was increased 50 per cent. The naphtha and liquid sulfur dioxide were thoroughly stirred and allowed to separate. The naphtha was decanted and washed with dilute sodium hydroxide to remove the dissolved sulfur dioxide and then 3 times with water. Subtracting the blank, 30, 29, and 26 per cent of the sulfur remained in the case of naphthas 2, 3, and 7. ALUMINUMTRICHLORIDE (?)-One gram of aluminum chloride per 100 cc. of naphtha was refluxed for 4 hours. Half of the resulting solution was poured off,thoroughly washed, dried, and analyzed. The remainder was distilled through a short column practically to dryness. Naphtha 2 gave off a small amount of hydrogen sulfide during refluxing, while naphthas 3 and 7 gave large amounts. After the first refluxing there was a dark-red residue in the case of naphthas 3 and 7 and a heavy red oily layer in the case of naphtha 2. On distillation, naphthas 3 and 7 gave a large amount of hydrogen sulfide, while naphtha 2 gave a small amount. The residue in the flask for naphthas 3 and 7 was charred. Subtracting the blank, 23, 22, and 50 per cent of the sulfur compound remained in the naphtha from refluxing. After distillation 4, 16, and 30 per cent of the sulfur remained for naphthas 2, 3, and 7. The sulfide can be oxidized to a sulfone which is water soluble. Therefore on refluxing with one-half its volume of potassium permanganate (0.3 M) for 3 hours, washing, and drying, no odor of the sulfide was present. On analysis, naphtha 2 had 0.007 per cent sulfur, even less than the original naphtha.
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Sodium hypochlorite, in the concentrations recommended be used for an Oxidizing by Birch and (I), can were agent. 2o cc. of sodium added to 20 cc. of the naphtha solution in a separatory funnel and shaken for 15 minutes. The naphtha was washed 3 times with water and then analyzed for its sulfur content. The removal of the pentamethylene sulfide from the threenaphthas was practically complete.
Literature Cited (1) Birch and Norris, J . Chem. So
