Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T08:57:50.230Z Has data issue: false hasContentIssue false
  • English
  • Français

Crystallization of Phenmedipham from Aqueous Emulsions

Published online by Cambridge University Press:  12 June 2017

Robert F. Norris
Robert F. Norris*
Affiliation:
Dep. of Botany, Univ. of California, Davis, Ca. 95616
Get access Rights & Permissions [Opens in a new window]

Abstract

Crystallization of methyl m-hydroxycarbanilate m-methyl-carbanilate (phenmedipham) occurred from aqueous emulsions of the commercial formulation when dilutions exceeded one part of the formulation to 30 parts water. Dilutions greater than 1 to 30 accelerated crystallization and increased the quantity of phenmedipham that crystallized out. Mechanical agitation increased the rate of crystallization during the first 12 hr after initial mixing. Low water temperature increased the rate of crystallization and total amount of phenmedipham that crystallized out. Phenmedipham crystallization was not altered by water hardness or pH over the range 4.0 to 8.0. Simulated refilling of a partially empty spray tank before adding formulated phenmedipham produced considerable crystallization, whereas adding formulated phenmedipham before adding water minimized crystallization. The solvent used in the commercial formulation to dissolve phenmedipham is partially soluble in water. The partitioning of this solvent into the aqueous phase of the emulsion explains crystallization of phenmedipham.

Type
Research Article
Information
Weed Science , Volume 21 , Issue 1 , January 1973 , pp. 6 - 10
Copyright
Copyright © 1973 Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Weed Society of America. 1970. Herbicide handbook. W. F. Humphrey Press, Inc., Geneva, New York. 368 p.Google Scholar
2. Denbigh, K. 1966. The principles of chemical equilibrium. 2nd Edition. Cambridge University Press, New York. 494 p.Google Scholar
3. Francis, A. W. 1963. Liquid-liquid equilibriums. Interscience Publishers. New York. 288 p.Google Scholar
4. Hammet, L. P. 1970. Physical organic chemistry. 2nd Ediition. McGraw-Hill Book Company, New York. 420 p.Google Scholar
5. Prausnitz, J. M. 1969. Molecular thermodynamics of fluid-phase equilibria. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. 523 p.Google Scholar
6. Stephen, H., and Stephen, T. 1963. Solubilities of inorganic and organic compounds. Vol. 1. Binary systems, part 1. The MacMillan Company, New York. 960 p.Google Scholar