T h e feed concentration used above is much higher than that normally found in most waste waters. Drinking water standards on organics are not very definite; many potable water supplies: however, have a total organic content of only a few parts per million. Even though waters containing 300 p.p.m. of detergents may not be potable, still the data reported above on the extent of detergent removal in one step, and the corresponding product rate obtainable using the CA4-NRC-18type membranes in the reverse osmosis process, may be of practical interest from the points of view of water pollution control and water renovation. Conclusions
For a full development of this membrane separation technique for studying the solution properties of surface active substances, it is necessary to work with pure compounds and mixtures of known composition, and identify the chemical nature of the solutes in the membrane permeated and nonpermeated solutions. Data on the properties of concentrated nonionic detergent solutions are generally lacking in the literature. Most useful results are likely to emerge when this separation technique is combined with other physicochemical studies covering a wide range of surface active substances in aqueous and nonaqueous solutions. Acknowledgment
T h e authors are grateful to W . S . Peterson, A . E. McIlhinney, and Neil H. Scheel for their help in building the
equipment; and to .4. G. Baxter and Lucien Pageau for their valuable assistance in the progress of these investigations. Literature Cited
( 1 ) Becher, P., J . CollotdScz. 16,49 (1961). (2) Ibzd., 17, 325 (1962). (3) Becher, P.. Clifton, N. K., Ihzd., 14, 519 (1959) ( 4 ) Levich, V. G., “Physicochemical Hydrodynamics,” p. 390, Prentice-Hall, Englewood Cliffs, N. J., 1962. (5) Loeb, S., SouriAjan, S., Aduan. Chem. Ser., No 38, 117 (1963 ). ( 6 ) Loeb, S., Sourirajan, S., U. S. Patent 3,133,132 (May 12, 1964). ( 7 ) Rosch, M., Kollozd Z . 147,78 (1956). ( 8 ) Schick, M . J., Atlas, S. M., Eirich, F. R., J . Phys. Chem. 66,1326 (1962). (9) Schott. H.. Zhzd.. 68. 3612 (1964) (10) Shinoda, K., Nakagawa, T., Tamamushi, B.-I.. Isemura. T., “Colloidal Surfactants,” p. 117. Academic Press, New York, 196’3 .. ._
(11) Zbid., p. 252. (12) Sirianni, A. F., Coleman, R. D., Can. J . Chem. 42, 682 (1964). 2, 51 (13) Sourirajan, S.) IND. ENG. CHEM. FUNDAMENTALS (1963). (14) Ihzd.. 3, 206 (1964). 4, (15) Sourirajan, S., IND.ENG. CHEM.PROD.RES. DEVELOP. 201 (1965). (16) Sourirajan, S.. J . Appl. Chem. 14, 506 (1964). (17) Sourirajan, S., ’Vuture 199, 590 (1963). (18) Ibzd., 203, 1348 (1964). (19) Souriraian. S.. Govindan. T. S.. First Intenrational Svmposium on Water Desalination, Washington, D. C., Paper SWD/41 (October 1965). J . Chem. Phys. 11, 72 (1943). (20) Stewart, G. W., ~I
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RECEIVED for review May 4; 1965 .\CCEPTED January 7, 1966 Issued as N. R. C. No. 8895.
SORPTION OF DIMETHYL METHYLPHOSPHONATE VAPOR ON AN AMBERLYST CATION EXCHANGE RESIN W. M . G R A V E N , l J . D. PATON, AND S. W
WELLER
Aeronutronzc Division, Philco Corp. , Newport Beach, Calif.
A macroreticular, sulfonic acid cation exchanger (Amberlyst-15) exhibited a capacity for and efficiency of removal of dimethyl methylphosphonate vapor from a humidified air stream which were comparable to those of an equal volume of activated charcoal. Several tests were made to determine the process by which the resin removed the organophosphorus vapor from the air stream. N A
recent air purification project some interesting and
I unexpected observations were made when a n ion exchange resin was used to remove a n organophosphorus vapor from a humidified air stream. T h e resin exhibited a capacity for and efficiency of removal of dimethyl methylphosphonate ( D M M P ) which were comparable to those of a n equal volume of activated charcoal. Rohm and Haas recently announced a series of ion exchange resins having a macroreticular structure characterized by a high degree of porosity and considerable rigidity (7). T h e characteristics of one of these resins, Amberlyst-15, have been described (2). A sample of Amberlyst-15: a sulfonic acid cation exchanger, was obtained from the manufacturer and used in tests for removal of D M M P from a stream of humidified air. With this resin, as with activated charcoal, the D M M P I
34
Present address, Aerospace Corp., Los Angeles, Calif. I & E C PRODUCT RESEARCH A N D DEVELOPMENT
ultimately passed through the bed a t approximately inlet concentration, although for a n initial period no D M M P was detected in the effluent stream. In the test an air stream containing 1.7 mg. of D M M P and 8.2 mg. of H20 per liter was passed at a flow rate of 4.8 liters per minute through a 25-m1. bed of resin (initially dry and weighing 14.3 grams), which was maintained at a constant temperature of approximately 70’ C . to prevent condensation. T h e effluent from the bed was analyzed at approximately 15minute intervals for D M M P with a Perkin-Elmer Vapor Fractometer equipped with a flame ionization detector and a capillary column coated with Carbowax-4000.
A minimum concentration of D M M P corresponding to about 0.1% of the inlet concentration could be detected in the effluent stream under these conditions. No D M M P was observed in the effluent for a period of 4 hours. as demonstrated by the results shown in Figure 1. A comparative test was
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Figure 1. Comparative removal of DMMP from a humidifled air stream by resin and by charcoal Bed volume 25 ml.; bed t e m p e r a t u r e 70“ C.; 4.8 liters air/min.; 1.7 mg. DMMPlliter air; 6.2 mg. HzO/liter air
carried out with the same volume (10.7 grams) of activated charcoal. Under similar conditions no D M M P was observed in the effluent from the charcoal bed for about 6 hours, as shown in Figure 1. However, in both cases after 10 hours the effluent D M M P concentration was approximately 98$, of the inlet value. No D M M P was desorbed from either a n Amberlyst-15 resin bed or a n equal volume of activated charcoal, each of which initially contained an amount of D M M P approximately equivalent to one-half its capacity, by a 507, R H fresh air stream flowing a t a rate of 4.5 liters per minute for 26 hours. Some additional studies were made in a n attempt to determine the process by which the resin removed D M M P from the air stream. At the conclusion of a run, such as that shown in Figure 1, the “spent” resin bed was extracted with acetone. Infrared analysis of the acetone extract showed that 5.43 grams of D M M P had been recovered. A graphical integration of a plot of effluent D M M P us. time indicated that 5.32
grams of D M M P should have been retained on the resin bed. There appeared to be complete recovery, within experimental error, and hence no chemical change in the sorbed DMAMP. Direct titration of the unused, washed resin with standard base showed that the capacity of the Amberlyst-15 resin was 3.91 meq. of acid per gram. After the run shown in Figure 1 the spent resin bed was extracted with water. T h e capacity of the used resin bed was redetermined and found to be 3.83 meq. of acid per gram of resin. Such close agreement with the result obtained with the unused resin suggested that no permanent change in the resin had occurred. As a further check on this point the used resin was recharged with acid, washed, and subjected to a repetition of the test with a 507, R H air stream containing 1.7 mg. of D M M P per liter at a flow rate of 4.8 liters per minute. T h e original ability of the resin to remove D M M P had returned, since no D M M P appeared in the effluent from the bed until after 5 hours on stream Although no hydrolysis of the ester appeared to have occurred, as indicated by the complete recovery of the D M M P from the resin by acetone extraction, an approximate correlation existed between the amount of D M M P retained by the resin (5.4 grams or 44 mmoles) and that which would be expected on the basis of the resin capacity (14 x 3.9 or 55 meq.) if one D M M P molecule were absorbed by each exchange site of the resin. Some of the D M M P molecules may have occupied more than one exchange site, or the entire resin bed may not have been completely utilized because of the relatively high rate of “throughput” of the air stream. It is less likely that a purely physical adsorption on the surface of the Amberlyst-15 resin accounts for its behavior toward D M M P , since the resin shows approximatelv the same capacity for D M M P as does an equal volume of activated charcoal, although the surface area of the charcoal is more than 20-fold greater than that of the resin (40 to 50 sq. meters per gram for Amberlyst-15 us. 1200 to 1400 for activated charcoal). literature Cited
( 1 ) Kunin, R., Meitzner, E., Bortnick: N., J . .4m. Chem. SOC.84 305 (1962). (2) Kunin, R.,Meitzner, E. F.: Oline, J. A , , Fisher, S..4., Frisch, N., IND.ENG. CHEM.PROD.RES.DEVELOP. 1, 140 (1962).
RECEIVED for review August 9, 1965 ACCEPTED December 22, 1965
ISOCYANURATE S Y N T H E S E S VIA T R I ET HY LEN ED I A M I N E - C O C A T A L Y S T CO M BI N A T I O N S .
B E I T C H M A N , Houdry Process and Chemical Co., .Marcus Hook, Pa.
are a class of compounds which have high
catalysts. A number of references on isocyanate trimerization have been cited in review articles on isocyanate chemistry (7, 9 ) . In an attempt to prepare copolymers of isocyanates and olefin oxides by the action of triethylenediamine (sold commercially under the name DABCO by the Houdry Process and Chemical Co., a Division of Air Products and Chemicals,
6U R T 0 N D SOCYANGRATES
I thermal stability and, as such, have potential applications in the development of high temperature polymers (70) or in the modification of better known polymers, such as polyurethanes (2-7. 72). Many procedures have been described for preparing isocyanurates. the most common being the trimerization of isocyanates by the action of various
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