April, 1946 (6) (7) (8) (9) (10) (11)
INDUSTRIAL AND ENGINEERING CHEMISTRY
Fargher, R. G . , and Probert, M. E., Ibid., 14, T49-65 (1923). Ibid., 14, T53 (1923). Ibid., 15, T337-46 (1924). Ibid., 15, T419-33 (1924). Hilditch, T . P., Fette u . Seijen, 43, 97-100 (1936).
Hilditch, T. P., “Industrial Chemistry of Fats and Waxes”, 2nd ed., p. 55, New York, D. Van Nostrand Co., 1941. (12) Ibid., p. 60. (13) Ibid., p. 87.
41 5
(14) Lane, N. J., J. Am. Chem. SOC.,15, 110 (1893). (15) Leys, A,, J . pharm. chim., 3, 577 (1912). (16) Lewkowitsch, J., “Chemical Technology and Analysis of Oils. Fats, and Waxes”, 6th. ed., Vol. 1, p. 416, London, Macmillan co.,,1921. (17) Ibzd., p. 428. (18) Ibid., pp. 459-63. (19) Matthews, J. M., “Textile Fibers”, 4th ed., pp. 468-75, New York, John Wiley & Sons, 1924.
Solubilitv in Common Solvents J
T
HE solubility of cotton wax was studied by Fargher with reference to complete removal of the wax from the fiber (I), but because of the limited quantities of wax available, no attempt was made to obtain solubility curves. Pickett (2) suggested that solubility-temperature curves be determined by dissolving weighed amounts of wax in 100 grams of solvent, heating to dissolve wax, cooling, and recording the cloud point as the saturation temperature. This method allows the least soluble constituents to dictate the cloud point, and it is impossible to observe accurately the cloud points of dark colored solutions like those of cotto’n wax. A wide range of representative solvents were chosen, including those commonly employed industrially as wax solvents: benzene, toluene, xylene, turpentine, chloroform, carbon tetrachloride, carbon disulfide, Skelly solvent C, methyl, ethyl, n-propyl, nbutyl alcohol, tert-butyl, and isoamyl alcohols, acetone, diethyl ether, ethyl acetate, and glacial acetic acid. All were reagent grade. Cotton wax was placed in 250-ml. flasks with 200 grams of solvent. The flask was put into a thermostatically controllcd water
bath a t the desired temperature, and agitated or shaken until equilibrium was reached between the solvent and the wax (generally 2-4 hours). This time was increased to 8 hours in order to ensure complete penetration of the solvent into the granulated wax. Care was taken that a large excess of wax is present a t all times. Then samples were siphoned off into closed, tared weighing bottles and weighed, the solvent was evaporated a t 105’ C., and the remaining wax was weighed. The temperature range of the bath, which had both heating elements and cooling coils, was controllable from 0 ” to 95” C. However, since most of the boiling points of the solvents were considerably lower than 95 C., the upper limit of the bath was no handicap. No solubility values were determined above 70” C., the melting point of Cotton wax. A minimum of ten temperatures a t which the solubility of the wax was experimentally measured were rhosen for each solvent between 0 ” and 70’ C.; thus, there were always ten points from which to plot the curve. The solubility is expressed as grams of wax per 100 grams of solvent. The solvents can be broken down into two general groups. I n one (Figure 1) the cotton wax was readily soluble (more than
I
0 TEMPERATURE -‘C.
10
20
30
‘
40
T E M P E RAT U R E
Figure 1. Curves for Solvents in Which Cotton Wax Is Readily Soluble
-
50 C.
I
60
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 38. No. 4
-W P
N
m
W
d
N
I 0
10
I
I
20
30
I.
1
40
50
1
I
60
70
10
0
T E M P E R ATUR E - * C .
Figiire 2.
CurTes for Soheill+ i t 1 Whivh
100 barns of solvent a t 55' (3.). The solvents in the latter group wemed to exert some selectivity in dissolving the different components present in cotton wax. SOLIEIIT FR4CTION4TIO\
The solvents of the group which exhibited poor bolubility and widences of selective solution or extraction of certain components o f the wax were the subject of further investigation. Information thus obtained would be desirable and useful from R purifying and inanufacturing viewpoint.
SOLVEKT FRACTIOS-\.L'IOS O F COTTON \ v A X 801. Fraction, c,, 44 61 89 95 55
Solvent Methanol Ethanol n-Propanol n-Butanol Acetone
InToi. Fraction, % 56 39
I? 45
OF SOLVENT-EXTRACTED FRACTIONS OF T \FILE 11. PROPERTIES
COTTOSW A X Melting Point,
Solvent Methanol
Fraction Sol. Insol.
n-Propanol
Sol. Insol. Sol.
n-Butanol
Sol.
Ethanol
.icetone
c.
M g . KOH/Gram __ Saponification value
Acid
63
value 16.5 44.9 20.3 30.3 20.4
69
26:3
62
2i:7 53.0
66 79 63
55
Insol.
> 100
Insol. Sol. Insol.
> 130 60
30
40
50
60
70
TEMPERATURE- ' C
'10 grams per 100 grams of bolvent at 5.5' C.); in the othw gioup (Figure 2) the wax was difficultly soluble (less than 20 grams pcr
TABLEI.
20
50.0 97.0 60.4 99.3 64.3 145.3 69.2 150.5 62.1 63.3
