ANALYTICAL EDITION
FEBRUARY 15, 1940
OF COMMERCIAL SAPHTHENIC ACIDS TABLE 111. ANALYSES
Acid Aruba Romanian Calif. 160 Calif. 250 Mexican lustrian B. R. R. Flask and sample, 54 922 32.152 68.695 43.137 53.331 43.351 55 290 32.350 68.654 43 329 grams 68.472 43.058 77.911 8 8 . 0 8 3 65.796 40.432 52.248 29.305 65.797 40.433 50 442 40.398 52.248 29.305 65.796 40 432 Flask, grama 73.004 83.409 2.899 2,705 2.674 2.675 2.625 2.847 2.889 2.953 3.042 3.045 2 . 8 5 8 2.897 4.907 4.674 Sample, grams NaOH (0.5901, cc. 17.2 16.9 ... ... ... ... ... 27.0 27.1 ... .., 35.0 33.2 Na,OH (0.562), cc. ... ,.. 25.7 241 13:4 14.2 23.4 23.9 ... 22.4 22.9 ... ... Acid No. 205 206 280 281 158 157 255 255 285 285 247 249 228 227 Flaek and residual acid, grams 68.009 63.623 68.202 42.416 53.907 30.985 52.668 42.670 54.770 31.791 67.471 42.433 77.304 87.554 Flask. grams 65.797 61.445 65.796 40.432 52.248 29.305 50.442 40.398 52.248 29.305 65.796 40.432 73.004 83.409 R e s i d i a l acid, 1.659 1.680 2.226 2.272 2 , 5 2 2 2 486 2.212 2.178 2.406 1.984 1.675 2.001 4.300 4.145 grama 16.5 16.2 ... ... ... 23.8 23.5 ... 33.2 32.0 NaOH (0.590), 00. ii:ij ii:i5 19.8 20.2 ,.. 22.6 18.6 ... 14 8 17 7 ... ... NsOH (0.562), cc. 62.0 59.0 77.0 82.9 83.2 83.0 73.4 77.0 82:Q 81.6 58 7 69 1 Residual acid, yo 87.6 88.6 74.6 74.4 91.0 86.3 86.8 94.4 95.0 91.0 94.1 94.1 89 2 89.4 92.3 92.0 Total acid, % Acid No. of residual 212 211 238 238 296 295 280 280 302 303 245 247 277 278 acid
...
...
...
sample was 243.5 (average), while that of the check sample was 244 (average). The method therefore appears sufficiently accurate for technical work. The details of the analyses on the several samples of commercial naphthenic acids are given in Table 111.
Discussion The choice of weighing procedure given above depends mainly upon the naphthenic acid being investigated. Since commercial naphthenic acids are complex mixtures, some samples will contain acids which are appreciably volatile a t
the evaporation temperature required to remove the petroleum ether and will be lost during arid after the evaporation of the solvent. However, if the unsaponifiable matter has been completely extracted from the sample and only acid is lost during the evaporation procedure this loss may be quantitatively corrected for by the final titration. The quantitative removal of petroleum ether under the conditions used is indicated by the concordance of the acid numbers of the residual regenerated acids. PRESENTED before the Division of Paint rtnd Varnish Chemistry at the 98th Meeting of the American Chemical Sopiety, Boston, Mass.
Continuous Laboratory Method for Bodying Oiticica Oil VINCENT RIARCHESE, Columbia University, New York, N. Y., JOSEPH M,ITTIELLO, Hilo Varnish Corp., Brooklyn, N. Y., AND LINCOLN T. WORK, Columbia University, New York, N. Y. Oiticica oil was heat-bodied by a continuous method to viscosities from 3.8 to 22.7 poises employing temperatures of 540' F. (282 ' C.), 590' F. (310 ' C.), and 662" F. (350 C.), and properties of this bodied oil were measured. The apparatus consisted of a RZonel metal heating coil in a lead-antimony bath with thermocouple indication of the metal bath temperature and the outlet temperature. The oil was given a single pass through the coil, the velocity being controlled by a recirculating by-pass a t the pump; and it was quickly cooled after it had completed passage through the heating coil. Viscosities were high for low rates of flow and became substantially constant for each bodying temperature a t the higher flow rates. Acid number increased
S
IKCE oiticica oil was first introduced to the protective
coating industry in this country, its distinctive properties have been studied in comparison with other oils used in the paint and varnish industry (1-4, 6). Sorenson, Schumann, Schumann, and Mattiello ( 7 ) briefly summarized its properties in the introduction to their paper and showed its kettle-bodying characteristics both in air and in an atmosphere of carbon dioxide. I n this investigation it was found desirable to develop a continuous method of bodying for laboratory testing, and to body samples at several temperatures, the resulting oil to be subjected to tests of physical characteristics, gelation time, and livering characteristics.
slightly with the increasing viscosity but w-as generally around 5.5 to 7. Iodine number decreased with increasing viscosity from a Falue of 170 to as low as 140. A curve of gelation time us. viscosity bears some relation to Sorenson. Schumann, Schumann, and Mattiello's curve of gelation time us. temperature. Pastes made with zinc oxide and bodied oiticica oil were subjected to the accelerated livering test and flow characteristics were defined. All samples were in the nonlivering area and showed generally good to excellent flow. The acid number-viscosity plot to differentiate livering areas from nonlivering areas is presented with data on a number of bodied oils to indicate its potential value as a criterion of livering tendencies for oils bodied under normal procedures.
-Apparatus A diagram of the apparatus is presented in Figure 1. It consisted of a container, B , which served as a reservoir for the oil, a pump, A , t o circulate the oil, valves D and C to regulate the amount of oil flowing through the coiled tube, E , an electric furnace, F , containing a lead-antimony bath in which the coil was immersed, and a container, I , cooled by water to receive the bodied oil. The heating coil was of Monel metal 0.3 em. (0.125 inch) in inside diameter and 4 meters (12 feet) long. Two thermocouples, G and H , were used to measure the temperature, the former being in the metal bath to meamre the temperature of the coil, and the latter being a t the outlet to ensure that the temperature had been obtained. Both thermocouples read the same temperature while runs mere in progress.
INDUSTRIAL AND ENGINEERING CHEMISTRY
78
I
FIGURE 1. DIAGRAM OF APPARATCS
Preparation of Samples With the oil circulating completely through the by-pass valve, C, the lead-antimony bath was brought to the required bodying temperature. When this was accomplished valve D was opened and valve C adjusted to allow the oil to flow through the Monel tube a t constant rate. Approximately 100 grams of oil were collected in the aluminum cup, I , and the time of flow was recorded along with the bath and tube temperature by means of thermocouples G and H . Maintaining the bath temperature a t the same point by means of the electric furnace, the rate of flow of oil through the Monel tube was decreased and another sample of approximately 100 grams xas taken. This process was repeated, decreasing the rate of flow for each sample, until a sufficient number of samples were obtained, or until the rate became so slow that it was difficult to obtain flow. The oil had a tendency to gel in the tube, especially for bodying temperatures a t and below 590" F. Six samples were taken a t a bodying temperature of 540" F. (282" C.), four samples a t 590" F. (310" C.), and four samples at 662" F. (350" C.). Table I gives the data for the three runs.
TABLE I. DATAON RUNS
Time Sec.
Weight of Oil Grams
1 2 3 4 5 6
52.2 86.4 205.2 229.4 373.5 268.5
131 134 139 I58 157 133
7 8 9 10
77.4 117.4 235.8 404
90 90 93 68
11 12 13 14
29.1 224.4 319.2 486.8
82 105 102 95
Sample No.
Bath Temperature ' F. C. R u n No. 1 540 282 540 282 540 282 540 282 540 282 540 282 R u n No. 2 590 310 590 310 590 310 590 310 R u n No. 3 662 350 662 330 662 350 662 350
Tube Temperature O F . C.
TemDerature of. Ingoing Oil ' C.
540 540 540 540 534 530
282 282 282 282 279 277
60 60 60 60 60 60
590 590 594 580
310 310 312 304
60 60 60 60
660 662
349 350 350 330
60 60 60 60
662
662
Results of Bodying Tests Table I1 gives the rate, time, viscosity, iodine number, acid number, and gelation time for all the bodied samples, Standard test methods were used for viscosity, iodine num-
VOL. 12, NO. 2
ber, and acid number, and the gelation time was measured by the Browne heat test a t 540" F. (282" C.). The results expressed in Table I1 may be compared in terms of pairs of variables. For example, the oil bodied a t 662" F. (350" C.) attains a viscosity of 6.7 poises a t the comparatively high rate of flow of 2.8 grams per second and maintains essentially that viscosity until t h e rate is decreased below 0.5 gram per second, Tvhence it rises rapidly to a viscosity of 22.7 poises a t a flow rate of 0.2 gram per second. The oil bodied a t 540" F. (282" C.) has the same form for its curve of viscosity against rate of flow, but a t all times is appreciably below the curve for the higher temperature. The curve for the intermediate temperature falls between these two curves. A better basis for comparison is a plot of seconds per gram against viscosity and that is shown in Figure 2 . T h e rapid development of viscosity for a given time of exposure a t the high temperature is clearly distinguished from the slower development a t the lower temperature. The essentially constant value for acid number over t h e whole range of viscosities is especially pointed out. A t low viscosity the curves begin with a n acid number of 5.6, and acidity is developed less readily a t the high temperature than at the low temperature. Other comparisons can be made from the data, but these are the more outstanding. TABLE 11. RESULTSOF BODYING TESTS Sample No,
Rate G./sec. R a w oil 2.53 1.56 0.678 0.688 0.420 0,0496
7 8 9 10
1.16 0.766 0.393 0.168
11 12 13 14
2.83 0.468 0.320 0.195
Heating Iodine Time Viscosity KO. Sec. Poises R u n No. 1, 540' F. (282" C.) .... 3.85 170 4.86 157 9.02 5.30 161 14.8 33.8 LO1 l5G 153 33.3 4.90 5.30 1GO 54.5 1 3 , 5 0 462 147 R u n Xo. 2, 590' F. (310" C.) 19.7 6.11 1.53 29.9 5.50 164 58.0 5.81 160 136 6.98 I52 R u n KO.3, 662'F. (350' C.1 8.09 6.70 lj3 48.9 7.98 155 11.8 151 71.6 117 22.7 140
Acid No.
Gelation Time
5.6 5.6 5.6 5.7 5,s 5.8 5,9
20.5 20.7 19.2 19.8 20.3 20.2 18.7
5.7 5.9 5.9 6.3
18.3 19.4 19.9 18.8
5.8 6.2 6.5 7.0
22.9 24.2 29.7
Mi n .
19.9
The viscosity in poises plotted against gelation time in minutes for the several samples of the three oils is shown in Figure 3. Sorenson, Schumann, Schumann, and Mattiello (7) have shown the plot of temperature against gelation time and find that gelation time decreases as temperature rises from 400" to 540" F., but increases markedly from there to 600" F. The results shown in Figure 3 represent another cross section of the same phenomenon.
Flow Characteristics Made by Incorporating Zinc Oxide into Bodied Oil Zinc oxide pastes were made by using 52.8 grams of pigment and 20 grams of oiticica oil. The pigment was incorporated into the bodied oils by grinding on a three-roller laboratory mill with constant setting of the rolls. The pastes were passed through the mill three times and consistency was observed as the pigment-oil mixt,ure flowed on the skirt of the mill. All pastes, after being ground, were divided into two parts and placed in a separate capsule box. One box was kept a t room temperature and the other was kept in an oven at 180" F. for examination at definite intervals. The pastes were heated to 180" F. to accelerate livering in accordance with the procedures of Mattiello and Work ( 5 ) .
FEBRUARY 15. 1940 The Binney-Smith flowmeter was used to define most of the flow characteristics. The instrument consists of eight semicircular metal tubes which are soldered together so as to form a metallic table (35 X 20.2 cm., 14 X 8.81 inches) having eight parallel grooves and graduated in tenths of inches from 0 to 14 inches. At the starting point a metal strip is attached along the eight outside surfaces of the instrument so as t o enable the operator t o scrape from the knife the material being tested. In order t o control the angle of the instrument, an adjustment screw is used on a scale which is calibrated in degrees. Through the use of the Binney-Smith flowmeter, the flow characteristics may be defined as follows: V E F , very excellent flow E F . excellent flow VGF, very good flow GF, good flow F F , fair flow P F , poor flow-
ANALYTICAL EDITION
79
TABLE111. FLOW CHARACTERISTICS OF ZIXC OXIDEPASTES Character of Sample Paste T h e n KO. Viscosity Ground Poises
Qualitative and Flowmeter Ratings of Pastes Hours Indicated 2 hours 4 hours 8 hours Inches Inches Inches Oil Bodied a t 540' F. (282' C.) 3.85 B T'EF 6:lOb YEF 7:25b 4.86 T'EF 8:30b VEF 7:50b ;(' 5,30 VEF 7:30b VEF 6:50b 5.01 VGF, SB VEF 83056 YEF ll:O5b 4.90 VGF, SB YEF 9:35b VEF 13:05b 5.30 VGF, SB VEF 12:45b VEF ll:45b 13.50 VEF 12.0 VGF, SB VEF 8.6 Oil Bodied a t 590' F. (310' C.I 7 6.11 VGF, SI3 F F 2.22 VEF ll:5Ob VEF 13:40b 8 5,50 VGF, S B G F 3.36 VEF 15:lOb VEF 10:40b 9 5.81 VGF, SB F F 2.45 EF 7.7 VEF 11.7 10 6.98 VGF. SB F F 2.53 YGF 6 . 2 EF 8.1 Oil Bodied a t 662' F. (350' C.) 11 g,70 VGF, S B G F 3.95 VEF 10.3 VEF 13.9 12 t.98 VGF, SB FF 2.25 EF 1.0 VGF 6 . 0 13 11.8 VGF, SB F F 1.45 EF 7.2 GF 4.3 14 22.7 F F 1.10 VGF, SB VGF 6.9 GF 5.2 a Poor flow directly from mill; b u t t e r s on standing. b hlinutes and seconds required for paste t o flow 35 om. (14inches).
;$,
I n c h e s in 20 .lfinutes 8 . 5 or more 8.5 to 7 7 t o 5.5 5.5to 3 3 to 1 1 to 0
These measurements were made with the flowmeter table tilted a t an angle of 40" and a t a temperature of 60" F., using a paste volume of 2.4 cc. Additional terms used for classifying flow characteristics are: B, buttery; SB, slightly buttery. T h e flow Characteristics of the zinc oxide pastes made from oils bodied a t different temperatures are presented in tabular form in Table 111. These pastes showed no tendency to liver after heating for 24 hours a t 180" F. Nattiello and TTork (6) have shown that the livering tendencies of kettle-bodied linseed oil may be defined as being o n one side of a line on acid number-viscosity coordinates while the nonlivering area is on the other side of the linethat is, in the region of the lower acid number. Within experimental accuracy, the livering line when peacock blue is used is identical with that obtained when-zinc oxide is used. Supplemental exueriments in extraction of acid and in adding this acid to other oil further confirmed the general significance of the livering line as a function of the acid number and visc o s i t y . Homever, oil bodied when carbon dioxide was bubbled through i t did not conform to the line, and furthermore, other compounds than those entering the acid number may have an VISCOSITY - POtSES effect on livering. FIGURE 2 Severtheless. the
after Heating a t 180' F. for
12 hours Inches VEF VEF 1-EF VEF VEF VEF 13F
24 hours Inches
7:20b 7:30b 6:35b 8:45b 10:15b 15:jOb
7.4
V E F 7:40b VEF 8:45b VEF /:4Ob VEF 8:lOb S'EF 10:lOb VEF 12:23b EF 8.4
VEF 8:05b 'JEF 14:30b WEF 9.4 ';EF S.5
VEF 8:30b VEF 13:40b VEF 11.1 VEF 9.6
'JEF 11.8 GF 3.75 I'F 2.6 I'F 1.6
V E F 10.3 FF 2.7 GF 3.4 GF 4.1
20
J
I 18
20 22 G ELATION
24 TlME
26
28
30
- MIffUT€S
FIGURE 3 livering line established for linseed oil has been further tested with kettle-bodied fish oil (a),and the results of this investigation on continuous bodying of oiticica oil are incorporated in Figure 4. The oiticica oils were all nonlivering and their acid number-viscosity points fell in the nonlivering area shown in Figure 4.
Conclusions T h e continuous method of bodying has Idistinct advantages over the batch method and gives similar results. The highest viscosity to which oiticica oil was bodied, in
INDUSTRIAL AND ENGINEERIKG CHEhIISTRY
8Q
VOL. 12, NO. 2
Gelation time Taries with viscosity or degree of bodying as well as with the temperature a t which the oil is bodied. Critical livering curves for both zinc oxide and peacock blue with bodied linseed oils were plotted, and these curves also appear to hold for bodied oiticica and fish oils.
Literature Cited (1) Brown, W. B., and Farmer, E. H., Biochem. J., 29, 631-9 (1935). (2) Gardner, H. -4.Jr., Paint Varnish Production
M g r . , KO. 6, 16, 18, 30 (1936). (3) Kappelmeier, C. P. A , , Fettchem. Umschau. 42 146-52 (1935). (4) McKinney, R. S., and Jamieson, G. S., Oil &. SOUP,13, NO. 1. 10-11 (1936).
f5) Mattiello. J.. and Work. L. T.. Xatl. Paint. Varnish and Lacquer Assoc., Sci. Sect., Circ. 502 (March, 1936). (6) Morrell, R. S., and Davis, W. R., J . Oil Colour Chem. Assoc., 19, No. 195, 359-62 (1936). (7) Sorenson, S. O., Schumann, C. J., Sehumann, J. H . , and Mattiello, J., IKD.ESG.CHEW,30, \
viscosfTY-
P O / S P S
FIGURE 4. LIVERING TENDENCIES OF OIL the cases studied, was 2 2 . i Doises, and the time required to reach this viscosity at 6620 F: (350" c.)was minutes.
,
211-16 (1938).
(8) F o r k , L. T., Swan, C., Wasmuth, A., and Mattiello, J., Ibid., 28, 1022 (1936). PRESENTED before t h e Division of Paint and Varnish Chemistry a t the Y i t h Meeting of the American Chemiral Society, Baltimore, hld. ~
Determination of Pyrethrin I Linearity of Results by Mercury Reduction Method D. A. HOLADAI-
~ V J. D
J . T. GRAHA\I. Food and Drug Administration, Washington, D. C.
ILCOXON (4) proposed a method for the determination of pyrethrin I, based on the reduction of the mercuric sulfate in DenigPs reagent to the mercurous condition, followed by precipitation as mercurous chloride and titration with potassium iodate. T h a t the reduction of the mercuric sulfate is nonlinear was implied by Wilcoxon when he specified limits of 50 to 70 mg. of pyrethrin I, between which his method should be used. Martin ( 3 ) pointed out that different sized aliquots of the same solution analyzed by Wilcoxon's procedure gave different percentages of pyrethrin I. Holaday ( 2 ) called attention to errors in the Kilcoxon method due to the presence of unsaturated organic compounds t h a t titrate with the iodate solution along with the mercurous chloride. H e proposed a modification in which these unsaturated compounds were removed by washing with alcohol or acetone, followed by chloroform, and this modification has been adopted by the Association of Official Agricultural Chemists as a tentative method (1). The present investigation was undertaken to determine whether this modification was subject to the same nonlinearity. Pyrethrum extract, obtained by extracting the powdered flowers with petroleum ether and evaporating off the solvent, was used for the work. Twenty grams of this extract were dissolved in petroleum ether, the solution was filtered, the petroleum ether was evaporated, and the residue was saponified with alcoholic sodium hydroxide. The alcohol was removed by boiling and the aqueous solution was treated with barium chloride and filtered. Excess barium was precipitated in the filtrate with sulfuric acid, the barium sulfate was filtered off, and the clear filtrate was made slightly alkaline and diluted to 1 liter. From this stock solution aliquots were taken for analysis. Each
1 Pyrethrin I,ny.
FIGURE 1
/25
