INDUSTRIAL AND ENGINEERING CHEMISTRY
1042
with bicarbonate (or possibly carbonate) radicals. The resulting product was fully oil-soluble and, as is shown in Tables V to VIII, it retains substantial acid neutralizing power, although it is possibly less vigorous in its reaction than a hydroxy soap of equivalent acid neutralizing capacity. The neutralizing action is assumed to be of the type Ba(DNNS)HCO$
+ HCL
Ba(DSNS)Cl
4- HzO
+ CO,
The bicarbonate half soap has the great advantage of complete Etorage stability in diester as well as in petroleum oils. Under crankcase conditions the hydroxyl-containing soaps would be expected to revert rapidly to the carbonated form. It is reasmring to ncte that such carbonated inhibitors will retain substantial acid-getting properties, particularly for traces of strong acids such as hydrochloric or hydrobromic. ACKNOWLEDGMENT
The authors acknowledge with pleasure the cooperation of King Organic Chemicals, Inc., Nor--alk, Conn., in making available a supply of purified dinonylnaphthalenesulfonic acid, and in preparing certain research samples of the sodium and barium soaps of this acid in conformity v i t h the suggestions of this laboratory. Lyophilized preparations of sodium and barium dinonylnaphthalene sulfonates mere prepared by John G. Honig of this laboratory, whom the authors wish to thank. LITERATURE CITED
(1) Archibald, hI. A,, in “Science of Petroleum,” Vol. IV, p. 2840, London, Oxford University Press, 1938. (2) Aseeff, P. A , Mastin. T. If7., and Rhodes, A., U. 8. Patents 2,616,904,2,616,905,2,616.906 (1952).
Vol. 46,No. 5
(3) Baker, H. R., “Corrosion of Brass-Retainer Ball Bearings,” Naval Research Laboratory, NRL Rept. 3918 (December 1951). (4) Baker, H. R., “Synthetic Oil-Soluble Sulfonate Rust Inhibitor,” Naval Research Laboratory, NRL Letter R e p t . 3270-308,Sl (Aun. 7. 1951). (5) Baker7H. R., Jhnes, D. T., and Zisman, W. A , , IKD.ENG.CHEM. 41,137 (1949). (6) Baker, H. R., and Zisman, W. A., Ibzd., 40 2338 (1948). (7) Baker, H. R., and Zisman, W. $., Lubrzeation Eng., 7, 117 (1951). (8) David, 1%’. W., J . Inst. Petroleum,35, 563 (1949). (9) Eckert, G . W., U. S. Patent’2,610,946(1952). (10) Edgar, J. A., Plantfeber, J. M.,and Bergstrom, R. F., S B E Quart.Trans., 3,381 (1949). (11) Federal Specification VV-L-791, Method 531.1. (12) Ibid., Method 532.1. (13) Honig, J. G., and Singleterry, C. R., “Physical-Chemical Properties of Oil-Soluble Soaps. I. Sodium Phenylstearate in Benzene,” accepted for publication in J . Phgls. Chem. (14) Kaufman, S., and Singleterry, C. R., “Micelle Formation by Sulfonates in Non-polar Solvents,” Naval Research Laboratory Report, to be published. (15) Mertes, R. W., U. S. Patent 2,501,731 (1947). (16) RIurphy, C. XI., Saunders, C.E., and Smith, D. C., IND.ENG. CHEM.,42,2462 (1950). (17) Pilot, S. v., Sereda, J., and Saankowski, W., Petroleum Z., 29, l(1933). (18) Pritsker, G. G., A-atZ. Petroleum A’ews, 37, R-793 (1945). (19) Sperling, R., IND.ERG.CHEM.,40, 890 (1948). (20) Van Ess, R. P., and Sipple, H. E., U. 9. Patent 2,585,520 (1952). (21) Williams, C. G., Inetitute of Automobile Engineers, “Collected Researches on Cylinder Wear,” 1940. (22) Zuidema, H. H., “Performance of Lubricating Oils,” ACS Monograph 113, pp. 144-53, Kew Yoyk, Reinhold Publishing Corp., 1952. RECEIVED for review September 8, 1953.
BCCEPTED February 2, 1954.
Cation Exchange Materials from Cotton and Polyvinyl Phosphate GEORGE C. DAULI, J. DAVID REID, AND ROBERT RI. REINIPARDT Southern Regional Research Laboratory, New Orleans, Las
T
HE production of ion exchange fabrics by chemical modifica-
tion of cotton cellulose has been reported by several B-orkers ( 9 , 7 , 11, 16, I“), and the ion exchange characteristics of these fabrics have been studied a t this laboratory by Hoffpauir and Guthrie (9). An ion exchanger in the form of fabric is convenient €or laboratory use; no special apparatus is necessary, a piece of cloth being merely stirred with the liquid for a time and removed. Phosphorylated cotton is more promising than other ion exchange fabrics with respect to its cation exchange capacity and p H range (11). This modified cotton v a s used by Hoffpauir and Guthrie (8) as a cation exchanger in the laboratory preparation of highly purified oilseed proteins. Coppick ( 2 ) phosphorylated cotton cloth by padding with an aqueous solution of phosphoric acid containing urea, then drying and curing a t around 140” C. The product has been characterized as a dibasic acid phosphate of cellulose (17 ) . Korever, phosphorylation of cotton cellulose hss been limited t o about one acid group per three anhydroglucose units because of the attendant excessive degradation of the cloth. As the phosphorylation reaction causes the degradation, a previously highly phosphorylated material might be used to react with cotton t o give a product with equivalent cation exchange capacity and reduced degradation. I n the present work it was postulated that excessive degrada1
Present address, Courtaulds (Alabama), Ioc., Mobile, Ala.
tion and strength loss might be overcome by first phosphorylating a polyhydric alcohol and then making this product react with cotton to give a cation exchanger of higher capacity. PREPARATION OF POLYVINYL PHOSPHATES
Polyvinyl alcohol was selected ae being a representative poiyhydric alcohol which also possessed the capacity of further condensation by cross-linking m ith itself. This reaction is catalyzed by phosphoric acid and heat (IO) and yields a product which is insoluble in water. Since this work started, Ferrel, Olcott, and Fraenkel-Conrat (6)have reported the phosphorylation of polyvinyl alcohol in 3 days at room temperature with phosphorus pentoxide and phoephoric acid. The product contained 20% phosphorus; of this orthophosphate residues were attached to about one fourth of the vinyl units, metaphosphates to about one third, and no phoephorup was contained in the remainder. Using the same method, Katohalfiky and Eisenberg (12) have phosphorylated polyvinyl alcohol fibers. Kosolapoff ( I S ) has patented a method of preparing polyvinyl arylphosphates by reaction of polyvinyl alcohol with an arylphosphoryl halide such as diphenylphosphoryl chloride or phenylphosphoryi dichloride. Several known methods of phosphorylating alcohols were adapted to the phosphorylation of polyvinyl alcohol to obtain
INDUSTRIAL AND ENGINEERING CHEMISTRY
May 1954
products with varying amounts of substitution and solubilities ranging from water-soluble to water-insoluble. PHOSPHORUS OXYCHLORIDE METHOD. Sixteen grams of phosphorus oxychloride (11) in 50 ml. of dioxane was added to 4.5 grams of dry, powdered low-viscosity polyvinyl alcohol (I). The hydrogen chloride formed in the reaction was removed by vacuum. The product of this reaction was a gray powder, insoluble in organic solvents, and containing chlorine. I t was probably polyvinyl phosphoryl chloride or dichloride (111). When added to water, it turned yellow-orange, swelled considerably, but did not dissolve. After several washings with hot water, a chlorine-free product (IV) containing 14.72% phosphorus was obtained. This corresponds to a substitution of about one phosphate per three vinyl groups. [-CHz-CHOH--]n
+ POCls
I
I11
I
I11
11
+ 2Hz0
4
+ HCl
[-CHz-CH-]n
+
[-CH2-CH-],
bl/OH
+ 2 HCI
1043
Phosphorus oxychloride had been used by Reid and Mazzeno (16) to phosphorylate cellulose in the presence of pyridine and a substitution of about 1 phosphate per 1.5 anhydroglucose units was obtained. Accordingly, 50 grams of dry, low-viscosity polyvinyl alcohol (I) was phosphorylated with 85 ml. of phosphorus oxychloride (11) in 500 ml. of anhydrous pyridine. The product was washed with pyridine, filtered, and then added to water and stirred. -4portion settled out and the water was decanted. The solid portion was washed with acetone, filtered, and dried in vacuum. It contained 14.7% phosphorus. The decanted liquid portion was allowed to stand and more solid material settled out. After filtering the solid material was washed with acetone and dried as before. It contained 15.2% phosphorus. Both products were light yellow in color and insoluble in water after drying. PHOSPHORIC ACID METHOD. Low-viscosity polyvinyl alcohol (I) was phosphorylated with phosphoric acid (V) in the presence of phosphorus pentoxide as described by Ferrel (5), except that the ratio of alcohol to acid was 1 to 2 instead of 1 to 100. This treatment gave a product which contained only 8% phosphorus and was only partially soluble in water.
I
+ H3P04
PzOh
IV
+ H20
-+
v
0-P-OH
Iv This equation shows the idealized reaction, forming the singly bound phosphorus compound. By a similar mechanism, doubly and triply bound phosphorus compounds may be formed. When high-viscosity polyvinyl alcohol was treated with phosphorus oxychloride in chloroform, with cooling, a product was obtained which when hydrolyzed was a yellow, granular material, insoluble in water. When placed in a glass tube, it allowed the passage of water freely, which indicated its possible use in a cation exchange column. This material had a maximum cation exchange capacity of 4516 m. eq. per kg. by the titration method (14) or 4845 m. eq. per kg. in the presence of sodium chloride (1,6). These results compare favorably with commercial cation exchange resins. Hoffpauir and Guthrie (9) determined cation exchange capacity of phosphorylated cotton in the presence of excess sodium chloride a t various hydrogen ion concentration, and expressed the result as a percentage of the maximum capacity. Figure 1 shows the curve obtained when the cation exchange capacity of insoluble polyvinyl phosphate was determined by Hoffpauir’s method. The curve is typical of that of a dibasic acid, except that the first break is a t G7.5% of capacity instead of a t 50%. This indicates a certain amount of doubly bound phosphorus; the first portion of the curve represents the first acid group of the singly. esterified material and the single acid group of the doubly esterified material. This sample of polyvinyl phosphate contained 13.4% phosphorus and, by calculation, the titration accounts for 36.4% of that amount as singly bound and 39.1% as doubly bound phosphorus. The remaining 24.5% may have been triply bound or possibly some of the phosphorus was bound as the metaphosphate as postulated by Ferrel and his coworkers (6). -(-CHr-CH-)n-
-(-CHz-CH-)fi-I
d I
O=P-OH
dI
--(-CHz-CH-)nSingly bound phosphorus
Doubly bound phosphorus
-(-CHZ-CH-)n-I
b I
O=p-O--.
I
0
I
-(-CH2--CH-)n-‘-f Triply bound phosphorus
When a mixture of 100 grams of low-viscosity polyvinyl alcohol and 350 grams of 85% orthophosphoric acid was allowed to stand in a vacuum desiccator over phosphorus pentoxide for 3 days a t room temperature, a product soluble in water and containing only 2.4% phosphorus was obtained. Warming a similar mixture of polyvinyl alcohol and orthophosphoric acid gave a black, insoluble product of comparably low phosphorus content. PHOSPHORIC ACID-UREANETHOD.Completely water-soluble (3) with high phosphorus contents were obtained by reaction of low-viscosity polyvinyl alcohol (I) with phosphoric acid (V) and urea (VI).
-
KHz I + V + 2
”,
\
/c=O
VI
[-CH$-CH-]
I
n
ll I/ + NH2-C-NH-C-XH2
+ HzO
0
VI1
VI11
In a typical preparation, 300 grams of 85% orthophosphoric acid and 175 grams of urea were mixed and warmed until dissolved. To this was added 100 grams of low-viscosity polyvinyl alcohol dissolved in 300 ml. of water. Much of the excess water was removed by heating a t 110’ C. for 3 hours in a circulating air oven, with occasional stirring. The mass was then heated a t 150’ for 15 minutes in an enamel pan. Ammonia was evolved as the urea decomposed and the white mass expanded to several times its original volume. On cooling, the mass became brittle. I t was dissolved in 300 ml. of water and urecipitated by pouring s l o d y into alcohol being agitated in a Waring Blendor. The product was dried in a vacuum oven a t GOo C.. ground to a I powder, and extracted for 4 hours’Gith alcohol in a Soxhlet apparatus to remove the impurities.
L-
H
I CH, I 1
The yield based on polyvinyl alcohol was 94’%. The Droduct was readily soluble in water but insoluble in organic solvents. It was a white solid having a phosphorus content of 19.6% and a nitrogen content of 9.8%. The analyses correspond to a monoammonium salt of polyvinyl phosphoric
.
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
1344
acid (VII) R-it,h a subst,itution of 3 phosphoric acid groups per 4 vinyl groups (theoretical phosphorus 19.9% and nitrogen 9.0%). Several products made by the above method had phosphorus contents up to 21.50j0, which is close to a substitution of 1 phosphorus per vinyl group. This is probably as completely substituted a material as it is possible to obtain, since polyvinyl alcohol, ivhich is prepared by "completely hydrolyzing" polyvinyl acetate, is known t o contain approximately 57, of residual acetate groups (16). Allso,terminal groups of the polymer chains rearrange on hydrolysis to form an aldehyde group which would not be phosphorylated. Less substituted products were prepared by lowering t,he ratio of phosphoric acid and urea to polyvinyl alcohol.
Vol. 46, No. 5
phosphate would therefore precipitate more readily and have a lower phosphorus content. It may be safely assumed that little if any hydrolysip took place under the conditions described.
T.4BI.E
I. STABILITY O F I'OLYYISYL
PHOSPHATE (SODIUAr 3.41.T)"
P Content after % H o u r Treatment, % R o o m temperatuse 12.9 13.9 11.8 12.9 12.0 13.0 Phospliorus content of unheated sample was 1 4 6 % .
~
60' C .
Solution G.1.V sodium hydroxide 1S sodium hydroxide 0.1:V sodium chloride 1 IT sodium chloride
13.3
14 R
13.4 14.6 13.3 14.5
APPLICATION OF SOLUBLE POLYVINYL PHOSPHATE TO COTTON
01
I
I
I
1
I
I
I
30
40
50
60
70
80
90
30
X CAPACITY
Figure 1. Relation of pH to Per Cent Cation Exchange Capacity of Polyvinyl Phosphate
The ammonium salt) of polyvinyl phosphate (1711) was coiivcrted to the free acid (11') by acidification with hydrochloric acid. The free acid \vas separat,ed x-ith acetone and purified by passage through a column containing a cation acceptor, Amberlite IR-1OOH. Electrometric titration shoved this material to be a typical dibasic acid ivith most of the phosphorus singly bound. When the free acid X I S heat,ed, cross linking and/or condenaatiori took place to insolubilize the product. Jones (10) has found phosphoric acid to be an effective condensing agent in insolubilizing polyvinyl alcohol through cross linking, and i t is evident that the substituent phosphoric acid groups of polyvinyl phoephat'e also cause such cross linking. The ammonium salt requires longer periods at higher temperatures to become innolub!e. These insoluble products are cation exchange resins n-ith high capacity. The stability of soluble polyvinyl phosphate toward mild hydrolysis was determined by preparing the sodium salt of poly\Tiny1 phospha,te containing 14.5% phosphorus and dissolving '2.5-gram samples of this salt in 50-mi. portions of O.1N and 1-V solutions of sodium hydroxide, sodium chloride, and hydrochloric acid. The solutions were allowed to stand a t room temperature for 2 hours. -4nother set of samples in like solutions of the same concentrations mas heated a t 60" C. for the same period. ill1 samples were then adjusted to a p H of 9 and precipitated with acetone. The products contained from 11.8to 14.6% phosphorus. Table I showa t h a t there is no regularity in the variations in phosphorus content,. It thus appears, Lhat some fractionation had taken place during the acetone precipitation. This could be due to the fact t h a t polyvinyl alcohol is less soluble in acetone than polyvinyl phosphate and the lower substituted polyvinyl
TTYO methods of applying polyvinyl phosphate to cotton iihric to obtain the maximum retention of the desirable physical proprrties of the fabric were investigated. In one method, some of the cellulosic hydroxyls are esterified; in the other, the p o l ~ - ~ i l l y l phosphate is condensed by cross linking on the cotton (4). Determining to what extent each of these two reactions ta,ICrs place would be extremely difficult, if not impossible. However, an experiment was run t'o determine the conditions needed Cor condensation and esterification. Cotton, nylon, cellulose acetate, and glass fiber tapes were padded to about 100% take-up of aqueous solut,ion containing 10% polyvinyl phosphate and 30% urea, heated in an oven a t 150" for 15 minutes, and then xashed and dried. The cotton tape had gained 7.8% in weight; the cellulose acetate had' not changed; t'he nylon had gained only 0.7%) and the glass only 0.9%. Hoivever, when like-treated tapes were heated for 1 hour, the cotton gained 12.0%,, the cellulose acetate 13.9%, the nylon 1 l . O % , and the glass 10.4%. This indicates that the 15-minute cure was sufficientfor the polyvinyl phosphate to react with the cellulosic hydroxyls and that a longer cure caused condensation. When two samples of polyvinyl phosphate were heated a t 150" for 15 minutes and 1 hour, respectively, the 15-minute sample dissolved readily in wtt,er while the 1-hour sample \vas insoluble.
T4BLE
11. c: \ T I 0 9 J ~ X C H O G ECH4RkCTERIBTICS O F C O r T O N CLwm TREATED WITH POLYVINYL PHOSPHATX~
Sanigle KO, 1 2 3 4 5
6 7 8 9
10
pII 2.2 2.7 2.9 3.3 4.0 6.3 8.8 10.1 10.6 10.9
Cation Exchange Capacity, .\Ieq./Kg. 1188 1233 1323 1397 1466 1718 2048 2694 2732 2740
Salt Formb,
% 43 45 48 51 53 63
77 98 99.7
100
Contained 20.3% phosphosufi. b Xxpreased as percentage of total cation exchange capacity.
0
Cotton cloth, padded to 100% take-up with a solution containing 30 grams of polyvinjl phosphate (phosphorus content of 20.3%), 30 grams of urea, and 40 ml. of aater, was dried a t 105" for 10 minutes, then cured a t 140"for 15 minutes. The wtihed product had a phosphorus content of 4.8% and a total ?.ition exchange capacity of 3200 m. eq. per kg. determined by adtling excess standard alkali and back-titrating an aliquot vr.ith stiin(lar(1 hydrochloric acid (14). Ten approximately 1-gram samples of this treated cloth were accurately weighed, cut into 1-cm.-square pieces, and placed in 250-ml. volumetric flasks, to each of which had been added 50 ml. of 1 M sodium chloride solution The pW of each solution ~ ~
a 3
May 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
1045
COAMPARISON OF COTTON TREATED WITH URE.4-POLYVINY L PHOSPHATE AND UREA-PHOSPHATE
I2
To compare the results of treating cotton with polyvinyl phosphate mith those of the urea-phosphate treatment, solutions of 0.5, 1.0, and 1.5N orthophosphoric acid and polyvinyl phosphate, both containing excess urea, were padded on cotton thread, dried at 105’ for 20 minutes, and cured a t 140” for 20 minutes. The polyvinyl phosphate used had a phosphorus content of 18.7%. After washing and drying, the samples were analyzed for phosphorus content and breaking strength. Results are shown in Table 111. The strength losses were of the same magnitude for each pair of samples, increasing with increased substitution; however, the samples treated with polyvinyl phosphate had four times the phosphorus content of those treated with phosphoric acid. I n other words, with equivalent loss of the strength of the cotton it is possible to get a much greater degree of phosphorylation with polyvinyl phosphate than with phosphoric acid.
10
8
2 n. $ 6
n. 4
2
CONCLUSIONS 0
0
-
1000
2000.
adjusted by adding known quantities of standard hydrochloric acid and sodium hydroxide solutions to obtain a p H range of 2.2 to 10.9, then carbon dioxide-free distilled water was added to bring the level of liquid in the flasks to the 250-ml. mark. The pamples were allowed to stand with occasional shaking for 16 hours to equilibrate. The p H of each solution was determined v i t h a glass electrode and a 50-ml. aliquot was titrated to the phenolphthalein end point to determine the cation exchange capacity. Moisture was determined on a separate sample of cloth and found to be 5.2%. Exchange capacities of the ten samples were calculated on a moisture-free basis and are shown in Table I1 for the various pH’s. When these results are plotted, a curve is obtained which is typical of a dibasic acid, similar to those obtained with insoluble polyvinyl phosphate (Figure 1) and cellulose phosphate (9). Six samples of 48-square cotton cloth were padded to about 100% pickup with various aqueous solutions of polyvinyl phosphate with a phosphorus content of 19.6%. The solutions contained from 5 to 30’% polyvinyl phosphate and an equal amount of urea. The samples were dried at 105’ C. for 10 minutes, cured a t 140’ C. for 15 minutes, m-ashed, acidified with 2% hydrochloric acid, washed with distilled water, and dried. The total cation exchange capacity of each sample was determined by adding excess standard alkali and back-titrating an aliquot i t ith standard hydrochloric acid as before. Capacities ranged from 420 to 2470 m. eq. per kg. and when plotted against pickup (Figure 2) show a straight-line relationship. Figure 2 indicates the reproducibility of the method of preparation of these ion exchange materials.
Polyvinyl phosphate has been prepared by several methods using phosphorus oxychloride, phosphorus pentoxide, 01 thophosphoric acid, and urea-phosphate. All except the lattei gave mixed esters containing singly, doubly, and possibly triply bound phosphorus, and most of these treatments gave products n-hich a w e either water-insoluble or only partially soluble. The uieaphosphate treatment gave a completely I\ ater-soluble product r\Tith a high content of substantially singly bound phosphorus. Insoluble polyvinyl phosphate may be used as an effective ration exchange resin with capacity equivalent to that of the commercial resins. The soluble polyvinyl phosphate may react with cotton and/or be condensed on cotton cloth to give a convenient cation exchange material with high capacity. With equivalent strength losses, four times as much phosphorus can be fixed on the cotton with the urea-polyvinyl phosphate as with the urea-phosphate treatment. The soluble compound can also be made t o condense on such substances as nylon, cellulose acetate, and glass fibers. LITERATURE CITED
(I) Bregman, J. I., “Characterization of Cation Exchange Resins,” M.S. thesis, Polytechnic Institute of Brooklyn, 1947. (2) Coppick, S., and Hall, W. P.,in “Flameproofing Textile Fabrics,”
ed. by R. W. Little, pp. 179-90, New York, Reinhold Publishing Corp., 1947. ( 3 ) Daul, G. C., and Reid, J. D. (to U. S. Dept. of Agriculture), U. S. Patent 2,608,360 (Sept. 2, 1952). (4) Ibid.,2,610,953 (Sept. 16, 1952). (6) Ferrel, R. E., Olcott, H. S., and Fraenkel-Conrat, H., J . Am. Chem. SOC., 70,2101-7 (1948). (6) Gregor, H. P., and Bregman, J. I., Ibid., 70, 2370-3 (1948). (7) Guthrie, J. D., Textile Research J., 17, 625-9 (1947). (8) Hoffpauir, C. L., and Guthrie, J. D., J . Biol. Chem., 178, 207-12 (1949). (9) Hoffpauir, C. L., and Guthrie, J. D., Tertile Research J., 20, 61720 (1950). ( 1 0) Jones, I.,Brit. Plastics, 16.77-80 (1944). (1 . 1) , Jurcrens, J. F., Reid. J. D., and Guthrie. J. D., !fertile Research J:, i8,42-4 (1948). (12) Katchalsky, A,, and Eisenberg, H., Nature, 166, 267 (1950). (13) Kosolapoff, G. M. (to nionsanto Chemical Co.), U. S. Patent 2,495,108 (Jan. 17, 1950). T.IBLE 111. PHOSPHORYLATION OF COTTONWITH POLYVINYL (14) Kunin, R., Anal. Chem., 21,87796 (1949). PHOSPHATE AND WITH PHOSPHORIC ACID (15) Mason, J. P., and Manning, J. F., “Technology of Plastics and reated with Cotton Treated with Resins,” p. 296, New York, D. Van Sostrand Co., 1945. hosphate Urea-Polyvinyl Phosphate (16) Reid, J. D., and Marreno, L. ’Ar., Jr., IND.ENC.CHEM.,41, Breaking Phosphorus Breaking 2828-31 (1949). content, strength, content, strength, Sormaliby a 9% Ib. 70 lb. (17) Reid, J. D., IMazseno, L. IF7., Jr., and Buras. E. M., J r . , Ibid.. 41,2831-4 (1949). 8.6 8.6 0 (control) 0133 5,7 f.’17 5.6 0.70 5.2 2.85 4.9 0 . 9 6 4 . 4 4 . 2 7 4.3 1.5 a Sorniality of polyvinyl phosphate computed from its phosphorus content.
0.5 1 .o
RECEIVEDfor review J u n e 19, 1983. ACCEPTEDJanuary 28, 1954. Presented in part at the Fifth Southwest Regional Meeting, AMERICAN CHEMICAL SOCIETY, Oklahoma City, Okla., December 8 t o 10, 1949. Mention of trade products doea not imply their endorsement by the Department of Agriculture over similar products not mentioned.
