Retarding Changes in Turpentine during Storage ~
W. C. SMITHAND H. P. HOLMMY, Bureau of Chemistry and Soils, Washington, D. C.
T
HE marked tendency of as to the best c o n d i t i o n s for Turpentine can be stored in large metal tanks t u r p e n t i n e to undergo storage and was advised to have f o r 4 years or longer without serious changes progressive changes on the interior of the tanks well taking place i f the tanks are kept well filled, aging, becoming viscous, less shellacked, to draw off accumuif the turpentine is protected f r o m the air, if lated water from the bottom of volatile, turbid, and discolored, separated water is .frequently removed, and if and developing a sharp odor, has each tank a t least once a month, prevented producers from storand to keep the tanks well filled. provision is made to precent corrosion of the ing turpentine for more than a T h e s e recommendations were metal. This is probably the most practical few months and has also precarefully followed. Before being method of storing large quantities of turpentine. vented consumers from stocking filled, the tanks were thoroughly The changes in iurpentine can also be remore than a few months’ supply. cleaned and given two coats of tarded by adding certain chemical substances. Undoubtedly oxidation is largely g a r n e t s h e l l a c . The tanks, responsible for these changes in which mere 10 feet in diameter, Calcium oxide in the f o r m of granulated quick turpentine, since it keeps better were filled w i t h i n 0.5 f o o t of lime should prove to be a practical preservative in full and tightly closed conthe top, leaving only sufficient f o r turpentine f o r 2 or 3 years. Solid acid tainers than in partly filled or air space for expansion in sodium sulfite might prove io be a practical open containers. The presence warm weather, and were fitted presercatii!e of turpentine f o r 5 years. of water, which is always diswith check valves to r e l i e v e solved to a slight extent in fresh inner p r e s s u r e . W a t e r and gum spirits, apparently hastens these changes in turpentine, sludge were pumped each month from drain wells a t the as does also exposure to light and heat and cont,act with lower ends of the slightly inclined tanks. At intervals of 3 or 4 months representative samples were taken from seven corrodible metals. Dupont and Crouzet (3) found that the rate of absorption of the tanks and sent to Mellon Institute to be examined of oxygen by pinene, the chief constituent of turpentine, is by fellows of the Pine Institute of America. The effect of accelerated by temperature, light, and the presence (traces) 15 to 18 months of storage on the properties of the turpentine of oxidized products of turpentine and other prooxidants, was reported by Burnett and Salzberg ( 2 ) . The tests showed including ferric chloride, iodine, potassium iodide, and the that, although some changes were noticeable, the turpentine resinates of cobalt, iron, lead, chromium, and nickel. Hydro- was entirely satisfactory for general commercial use and quinone, gallic acid, pyrogallic acid, activated carbon, and complied with A. S. T. &I. specifications, but it did not meet stannous chloride were found to have an antioxidizing effect the requirements of German specifications in regard to upon turpentine. The theory of autoxidation and anti- bromine number and evaporation residue. Samples from two of the tanks containing turpentine of oxidants has been advanced by Moureu and Dufraisse ( 5 ) . Kingzett and Woodcock (4) have shown that the oxidation relatively low specific gravity and from two others containof turpentine is accompanied by the production of material ing turpentine of higher specific gravity were taken a t apquantities of formic acid, acetic acid, and aldehydes. The proximately 6-month intervals and sent to this bureau for acids in oxidized turpentine attack certain metals, forming examination. The first tests were made Sovember 2 , 1927, salts which are somewhat soluble in turpentine. The copper from 2 to 5 months after the turpentine had been stored, salts color turpentine green, and the iron salts impart a and the last tests on turpentine taken from the storage tanks reddish color. Iron is attacked readily by turpentine when mere made on Sovember 13, 1929 (three samples), and on April 4, 1930 (one sample). Late in 1929 and early in 1930 water is present. I n order to prevent changes in turpentine, it must be the tanks were drained, and the bulk of the turpentine was stored out of contact with air, water, reactive metals, and used in regular production of shoe polishes. At this time light, or it must contain an effective antioxidant. Schorger the turpentine Tvas reported to be perfectly satisfactory for (6) showed that turpentine stored in closed iron drums and this purpose, although it had been in storage for more than wooden barrels changed very little in boiling point, specific 2 years. At the time the tanks mere emptied, some of the turpentine gravity, and refractive index during 18 months. T’eitch from each of three tanks was transferred to newly shellacked, and Grotlisch ( 8 ) , in giving certain precautions to be ob served in storing turpentine, stated that it can be stored for clean, galvanized iron drums in which the turpentine was 12 to 18 months without marked change in composition and stored under conditions duplicating as nearly as possible properties. They recommended that storage tanks be kept those of the tank storage. Samples representing the turpentine in the drums were taken a t 6-month intervals and full, any withdrawals being replaced by fresh stock. sent to this bureau for examination. The results of periodical STORAGE WITHOCT ADDITIOK O F PRESERVATIVES tests on turpentine from the various tanks are shown in An opportunity to study the effects of storage on large Table I. Table I shows that there were no material changes in the quantities of turpentine over a long period was presented early in 1927. A firm manufacturing shoe polishes, and one turpentines during the period of tank storage, but that of the largest industrial consumers of turpentine, undertook changes mere progressive beginning with the transfer to the storage of a 2-year supply in a number of horizontal drums. The slight variations in specific gravity and certain cylindrical steel tanks, each having a capacity of 24,000 other constants of the samples taken during tank storage gallons. A representative of the firm consulted this bureau are believed to be largely due to the method of packaging 716
July, 193%
TABLE I. TESTSON TURPENTINE REFR.4CTIVE STORAQE
TInE Months Tank storage
5 11 16
23 29 Tank and drum storage
40 45
Si+
;;
+
Limits of A. S. T. M. specification
..
SP. GR.
INDEX :20° C . )
DISTILLINQ BELOW 170' C (760M M . )
2 8
13 20 26 30 Tank and drum storage
36
SPECIFIC ROTATION COLOR GRADE (200 C . )
%
....
94.5 94 94.5 93.5
.... ....
ww
0.8708 0.8703 0.8700 0.8708 0.8706
1.4721 1.4716 1.4714
0.8710 0.8732 0.8743 0.8760 0.8771
1.4714 1.4722 1.4722 1.4722 1.4727
92 89 89
-1.94 -1.78 -1.94
0.875
1.478
90
....
Standard
....
..
....
FROM TANK 15
Tank storage
717
I N D U S T R I A L '4 N D E N G I N E E R I N G C H E M I S T R Y
..*.
0.8674 0.8677 0.8682 0.8680 0.8674 0.8676
1.4720 1.4712 1.4714 1.4712
0.8692 0.8702 0.8724 0.8729 0.8767
1.4712 1.4718 1.4719 1.4720 1.4728
....
ww
.... ....
Standard Standard Standard
....
1 shade off 1 shade off 1 shade off 1 shade off 2 shades off
0.0
95.5 96 96.5 96.5
....
WW
-7.75
95:5
-10.72
ww ww ww ww
..
.... ....
....
.... ....
ww
Standard Standard Standard Standard Standard
Failed to comply with t h e specifications i n EVAPN. RESIDEE these respects and the other had reached the % maximum specific gravity allowed. After 1:is 1.26 4 years of storage the 1.37 1.39 e v a p o r a t i o n residue had reached the point 1.75 2.18 where s h o e p o l i s h e s 2.63 3.47 made from the turpen3.58 tines were inclined to .. be tacky, although the odor of the polishes was 0:66 not objectionable. 0.75 0.67 0.67 0.66 1.29 1.61 2.30 2.77 3.14
STORAGE WITH
PRESERVATIVES
Experiments w e r e -9.46 93:5 : i f also made, on a small -9.42 90.5 54 -9.85 scale, t o determine 89 60 whether c h a n g e s i n .... Standard ,. 90 0.875 1,478 Limits of A. S. T . M . specifiaation . . FBOM TANK 16 turpentine during ..., ww 97 Tank storage 2 0.8656 .... s t o r a g e c a n be preU 0:57 96.5 0.8677 .... . . . . ww 0.53 ww 97 -0.52 vented or retarded by 13 0.8678 1.4716 97 0.46 .... ww ww 0.8678 1.4707 20 adding chemical 0.39 .... 0.8670 1.4710 26 agents. Storage tests .... Standard 0.8682 1.4712 ... . 0.77 37 Tank and drum storage on turpentine mixed 1.04 Standard .... 0.8700 1.4712 1.86 .. $3.58 0.8727 1.4716 Standard w i t h different m a t e2.19 +3.58 92 0.8725 1.4716 54 2.40 91 1 ;hade off +3.72 0.8750 1.4720 60 rials having a reducing 90 0.875 1.478 .... Standard action, others having a Limits of A . S. T. M . specification . . FROM TANK 19 dehydrating a c t i o n , 96 0.8650 .... .... ww Tank storage and still o t h e r s hav96 0.8680 .... WW O:k7 .... 97 0.52 0.8678 1.4716 ww li +1.05 ing a combined reduc97 0.63 0.8678 1.4707 .... ww 21 .. 0.59 0.8670 1.4710 .... ww ing and dehydrat27 ing action were 90 0.875 1.478 Standard Limit6 of A. S. T. M.specifioation . . started in September, 1927. Portions of an the samples. Some of the samples were shipped in incom- authentic sample of water-white gum spirits of turpentine pletely fdled and others in completely filled cans. The con- were placed in 1-pint (0.55-liter) glass-stoppered bottles, stants of turpentine were found to change perceptibly while and other portions in 4-ounce (llgcc.) oil sample bottles standing for several days in a partly filled, although well- closed with cork stoppers, in contact with the various mastoppered, can. Possibly the samples were not perfectly terials to be tested for preservative effect. The bottles representative of the contents of the tanks, but this is not were kept on an open shelf in the laboratory, exposed to likely since the samples were composites of portions taken diffused daylight and direct light from electric bulbs. Durfrom the top, middle, and bottom of each tank. ing the first part of the storage period the bottles were shaken At the time the last tests were made on samples from the once a week, but during the greater part of the time they tanks, the turpentine had been in storage 26 to 31 months stood undisturbed. On account of their small volumes it and all samples still complied with A. S. T. M. specifications was not possible to examine these samples periodically as ( I ) as regards specific gravity, refractive index, percentage was done in the case of the turpentine stored in tanks. The distilling below 170" C., and color. One lot of turpentine materials tested for preservative effect included the followhad changed from water-white to standard in color; the ing : others were still water-white. AGENTSHAVINQBOTH The first samples taken after the transfer to the drums had REDUCINQ AND DBREDCCINQ AQENTS DERYDRATINQ AQmNTS HYDRATINO ACTION greater specific gravity, color, and evaporation residue than Calcium oxide Metallic sodium char the last samples from the storage tanks, and succeeding Bone Oxalic acid Calcium chloride, granular Metallic calcium Calcium sulfate, monoM i x t u r e of calcium chloride samples showed progressive changes. Apparently the con- Stannoua Acid sodium sulfite hydrate oxide and bone char tact with air during the transfer to the drums started chemi- Metallic zinc Metallic magnesium, cal changes which continued after the turpentine was put powdered into the drums. The ratio of surface to bulk of turpentine Hydroquinone Pyrocatechol was unquestionably greater in the drums than in the tanks, Pyrogallol &Naphthol and this may have increased the rate of change. Four years after they had been put in storage, the three I n the case of the organic reducing agents, 1 per cent of lots of turpentine stored in drums still complied with A. S. T. M. specifications except in the color of one sample. Six months the estimated weight of turpentine was added. In other later one lot of turpentine from drums failed to comply with cases usually 5 per cent was added. Turpentine to which A. S. T. M. specifications as regards specific gravity and per- nothing was added was stored in a glass-stoppered bottle centage distilling below 170" C., as well as color, and one under the same conditions to which the other samples were year later, when the last tests were made, two of the samples exposed.
-
c
e...
..
'718
IN DUSTR IA L AN D EN G I N E ER IN G CH E M ISTR Y
After 2.5 years of storage the materials which appeared to be most effective in retarding changes in gum spirits of turpentine were powdered calcium oxide and powdered magnesium. The turpentine stored in contact with these materials was water-white, had the sweet odor of fresh gum spirits, and showed no evidence of change. Bone char prevented the development of the sharp odor of oxidized turpentine, but the turpentine acquired a yellowish color. Some of the organic reducing agents also prevented a change in odor but discolored the turpentine. After 5 yearq of storage the turpentine to which no preservative had been added vias turbid, viscous, discolored, and had a sharp odor. It had a specific gravity of 0.905, an acid number of 5 . 5 , and the evaporation residue [from 10 cc. in a flat dish 3 inches (7.6 em.) in diameter] after three 1-hour periods of drying in an electric oven at 97" t o 100" C. was 12.8 per cent by weight. Turpentine stored with calcium oxide had the best color of any of the samples (almost waterwhite) and an odor almost like that of fresh gum spirits, but the specific gravity and evaporation residue were much higher than for fresh gum spirits, the specific gravity being 0.003 higher than allowed in A. S.T. M. specifications. The best preservatives, as indicated by specific grarity and evaporation residue, as well as odor, were acid sodium sulfite, hydroquinone, and pyrogal!ol. The last two produce dark colors in turpentine which would necessitate redistillation or limit the use of the turpentine to dark-colored products like shoe polish. The turpentine which had been stored for 5 years in contact with these materials had a specific gravity of 0.870 to 0.871 (within the A. S. T. 11.specification limits) and eraporation residue of 0.8 to 1.1 per cent. The turpentine stored with acid sodium sulfite was only slightly darker than standard and was very fragrant. I t did not give a test for sulfur by the copper strip test.
Vol. 26, No. 7
Schiff ( 7 ) found that the characteristic pungent odor of American turpentine can be removed by treatment wibh acid sodium sulfite solution but soon returns on exposure of the turpentine to the air. From results of the present writers it appears that solid acid sodium sulfite not only removes the pungent odor of turpentine but is also effective in retarding the changes which ordinarily result from aging. .~CKSOWLEDGMEST
The authors wish to acknowledge the privilege accorded to the Bureau of Chemistry and Soils by the Gold Dust Corporation of studying the changes in turpentine during long-time commercial st'orage in tanks and drums, and particularly the assistance of E. T. Narceau of t,hat firm, to whom t'heg are indebted for all the samples taken during the period of storage. The conditions for large-scale tank storage were suggested by F. P. Veitch of the Bureau of Chemistry and Soils.
LITERATURECITED (1) Am. Soc. Testing Materials, S t a n d a r d s , Pt. 11, 11. 300. Sgecifications D13-26 (1930). ( 2 ) I3urnett and Salzberg, paper presented before 32nil Annual Meeting, . h i . Soc. Testing hIaterials, J u n e 94 to 28, 1999, , o . 58, 101-5 (1029!. (3) Dupont and C'rouset. Bull. i'inrt. p i i ~ S (4) Kingzett anti Woodcock, J . SOC.('hem. I d . .29, T S 1 t l S 1 0 ) . ( 5 ) Moureu and Dufraisse. ('hemi.yti..ij & Imlu.~tru,47, 519 (1928) ; ( ' h e m . Rex.. 3. 113 ( l W G ! . (6) Schorger. J. ITD: EXG.(:HE.;',, 6, 541 (1914;. (7) Schriff, C'henL.-Zfg., 20, 361 (1898). (8) T'eitch and Grotlisch, U. S. D e p t . . b r . , Bull. 898 i 1 0 9 1 l RECEIVEDApril 2 , 1934. Presented as part of the joint Byiiipiisiuiii u i i Kava1 Stores befor e the Divisions of .lgricultural and Food Cheniistry and of Industrial and Engineering Chemistry at t h e 37th Meetins of the Aiiierican Chemical Society, St. Petershurg, Fla., 1 I a r c h 25 t o 30, 1934.
Use of Rosin for Soap Manufacture .~RCHIBALD CAMPBELL, 3239
Stettinius 24ve., Cincinnati, Ohio
O S I S has been an important constituent of soaps in the United States for many years, and, although it has . been replaced to a considerable extent by other fats and oils, it is still extensively used in many grades of American household soaps.
PROPERTIES OF ROSIXSOAPS Common rosin a t temperatures below 60" F. is a hard, brittle, vitreous solid, while a t higher temperatures it becomes tacky, sticky, and somewhat plastic. The composition is variously given as abietic acid with some abietic anhydride and other rosin acids, and as a mixture of rosin acids. Gum rosin is prepared from the distillation of crude gum turpentine and wood rosin is obtained by extraction from pine tree stumps and waste pine wood by the use of solvents. Both types of rosin always contain 1-arying amounts of nonsaponifiable substances, probably derived from the raw materials and also formed by decomposition due to heating during the process of refining and processing. To the writer's knowledge, wood rosin has not been extensiT7ely used by soap manufacturers up t o the present time. Experience shows that it does not make a soap of as good quality as that derived from gum rosin. Gum rosin is insoluble in water and, like the fatty acids, is freely soluble in alcohol. It is graded according to color. The grades are designated by letters of the alphabet beginning
with the darkest and extending to the palest. The gradeb from G t o N are principally used in the soap industry. These grades, eqpecially G and H rosins, seem to produce somewhat harder soaps than the paler grades WG and WW. Gum rosin reacts readily with caustic alkalies, carbonated alkalies, and oxides of the heavy metals to form soaps. The rosin soaps of the heavy metals are semi-solid, tacky substances that find extensive use in the manufacture of lubricants. Rosin soaps of the alkali metals are very soft, viscous, sticky, and tacky, and have the characteristic aromatic, piney odor of gum rosin; they are freely soluble in water, produce a free copious lather, and have pronounced detergent properties. They are used in the production of hard and soft soaps, never by themselves but always in combination with other fats and oils. Soda soaps of pure rosin do not become hard enough to be used as commercial hard soaps; potash soaps of pure rosin do not acquire the necessary consistency and firmness to be used as commercial soft soaps. Rosin soaps do not rinse freely or completely; they leave the washed articles with a tacky feel and a rosin odor, indicating nonsaponifiable materials, and/or hydrolysis of rosin soap, or both. These tacky, sticky substances, being insoluble in mater, have a marked tendency t o adhere to the washed fabrics and to resist the action of rinsing, thus destroying the fluffiness and softness of garments and rendering them hard
