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1、International Standard $ 6839 0 1 4 4Y% INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*MEX/.lYHAPOtlAfl OPAHH3AUHR l-l0 CTAHAPTbl3Al “, ., I i l,i., ._ , , , $ k ;,: I d : f/ i ,. I, ;. (, ; i; L / , , c-z . yy n, .i Anionic surface active agents - Determination of solubility in water Agents de surf
2、ace anioniques - Dj,i,# : ; : 3, 5) b” UDC 661.186: 620.1 : 541.8 Descriptors : surfactants, anionic sutfactants, tests, determination, solubility. Ref. No. IS0 6839-1982 (E) Price based on 3 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licens
3、ee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:34:19 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The
4、 work of developing Inter- national Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental,
5、in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 6939 was developed by Technical Commit
6、tee ISO/TC 91, Surface active agents, and was circulated to the member bodies in February 1992. It has been approved by the member bodies of the following countries: Australia Germany, F.R. Austria Hungary Belgium Ireland China Italy Czechoslovakia Japan Egypt, Arab Rep. of Mexico France Netherlands
7、 Poland Romania South Africa, Rep. of Spain Switzerland USSR No member body expressed disapproval of the document. 0 International Organization for Standardization, 1992 0 Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=
8、NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:34:19 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 6639-1962 (E) Anionic surface active agents - Determination of solubility in water 0 Introduction The method described in thi
9、s International Standard is one of the simplest of the methods which can be used for this pur- pose; it is sufficiently accurate and is suitable for a number of practical uses. Repetition of the test, varying the temperature of the bath within the range established by the preliminary determination,
10、until the clear solution remains clear and the cloudy solution re- mains cloudy, or the solutions change very slowly from being cloudy to clear or vice versa. 1 Scope and field of application This International Standard specifies a method of establishing the curve representing the solubility of an a
11、nionic surface active agent in water as a function of temperature, and, conse- quently, of allowing evaluation of its solubility at a given temperature. The method is applicable both to pure surface active agents and to technical products or formulations of liquid anionic sur- face active agents, pr
12、ovided that the solutions of these prod- ucts are optically clear and are not very strongly coloured. NOTE - The determination of solubility may be carried out without restriction in the temperature range from 0 to 90 C; at temperatures lower than 0 OC, the determination is possible provided that th
13、e solu- tion does not freeze. The solubility curve obtained in the case of pure products may possibly allow the Krafft temperature to be determined. 2 Reference IS0 607, Surface active agents and detergents - Methods of sample division. 3 Principle Preliminary determination on an aqueous solution of
14、 known anionic surface active agent concentration of the temperatures at which the solution changes, on heating, from being cloudy to clear and, on cooling, from being clear to cloudy. Placing in a bath, controlled at a temperature within the range established in the preliminary determination, of tw
15、o solutions of the same concentration, one being colder and cloudy and the other being warmer and clear, and noting the appearance of the two solutions at temperature equilibrium. From the surface active agent concentrations and the limiting temperatures of solubility, plotting the solubility curve.
16、 4 Reagent During the determination, use only distilled water or water of equivalent purity. 5 Apparatus Usual laboratory equipment, and 5.1 Test tubes, made of borosilicate glass, of diameter 20 mm and length 200 mm. 5.2 Precision thermometers, complying with the re- quirements of IS0 653. 5.3 Ther
17、mostatically controlled water bath, capable of being controlled at -5 “C to + 90 OC, to within + 0,l OC, with a transparent cell. 6 Sampling The laboratory sample of anionic surface active agent shall be prepared and stored in accordance with the instructions given in IS0 607. 7 Procedure 7.1 Test p
18、ortion Weigh, to the nearest 0,Ol g, the quantity of laboratory sample corresponding to one of the surface active agent concentra- tions to be studied concentrations usually between 1 and 50 % bnlm)l then prepare approximately 100 ml of solution. If the solution contains dispersed impurities, it is
19、advisable to filter it after heating to a temperature higher than that at which it is cloudy. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:34:19 MDTNo reproduction or net
20、working permitted without license from IHS -,-,- IS0 6839-1982 (El This procedure shall not involve any alteration of the surface active agent concentration. 7.2 Preliminary determination Transfer approximately 10 ml of the test solution (7.1) to a test tube (5.1) and heat it directly over a flame u
21、ntil the solution becomes clear. Allow to cool slowly in the ambient environment until it becomes cloudy, then slowly raise the temperature again, stir- ring the solution with a thermometer (5.21, and, as soon as the solution becomes clear, note the temperature it,). Allow to cool slowly, stirring t
22、he solution with the ther- mometer, and, as soon as the solution becomes cloudy, note the temperature Ct,). The temperature range thus determined is generally of the order of 10 OC. 7.3 Determination of the limiting temperature of solubility Set the thermostatically controlled bath (5.3) at a temper
23、ature within the range defined by the preliminary determination (7.2) and keep it constant to within 0,l OC. Fill two test tubes (5.1) with the solution (7.11, stopper them, adjust their temperatures so that the solution in one becomes clear and the solution in the other becomes cloudy, and then pla
24、ce them in the thermostatically controlled bath. When the temperatures of the two solutions are equal to that of the water bath, note whether the two solutions are clear or cloudy. If both solutions are clear, lower the temperature of the water bath by a few degrees Celsius if both solutions are clo
25、udy, raise it to a slightly higher temperature and repeat the above test. Carry out a third test, or more if necessary, controlling the bath at a temperature deduced from the previous tests, until the change in appearance of the solutions (cloudy to clear or clear to cloudy) occurs very slowly or th
26、e clear solution remains clear and the cloudy solution remains cloudy. A maximum observa- tion period of 2 to 3 h may be adopted. Note the temperature at which this occurs to the nearest 0.1 “C, as the limiting temperature of solubility. If the ap- pearance of the solutions remains unchanged, take t
27、he temperature immediately below that at which the two solutions remained cloudy. NOTE - The speed with which the limpidity and cloudiness are re- versed is a function of the temperatures tt and f2 determined in 7.2 in relation to that of the bath. 7.4 Plotting the solubility curve Repeat the above
28、procedures (7.1,7.2 and 7.31, using different quantities of test portion so as to cover the range of concentra- tions to be studied. Plot the solubility curve as a function of the concentrations and corresponding limiting temperatures of solubility. This curve makes it possible to - deduce the solub
29、ility of the surface active agent at a given temperature; - determine, if required, the Krafft temperature. 8 Expression of results 8.1 Method of calculation Express the solubility of the anionic surface active agent in water, for a given temperature, as a percentage by mass. 8.2 Precision Comparati
30、ve analyses on samples of three different surface active agents, carried out in eight laboratories, have provided the information given in the table. 9 Test report The test report shall include the following information : a) all the information necessary for the complete iden- tification of the samp
31、le and details of the treatment of the test portion (and, if required, the temperature to which the solution was heated before filtration); b) the reference of the method used (reference to this In- ternational Standard); c) the results obtained and the method of expression used : - temperature (t,)
32、 at which the solution becomes cloudy for the concentration being studied; - temperature (t2) at which the solution becomes clear for the concentration being studied; - limiting temperature of solubility for the concentra- tion being studied; d) if necessary, the solubility curve (and the Krafft tem
33、perature, if required); e) details of any operations not specified in this Inter- national Standard or regarded as optional, together with details of any incidents likely to have affected the results. Copyright International Organization for Standardization Provided by IHS under license with ISO Lic
34、ensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:34:19 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8839-1982 (El Table Surface active agent Sodium laurate, purity 96.4 % Sodium lauryl sulphate, purity 99 % Sodium alkane sulphonate, purity 98
35、 % Concentration % hlml 2.5 5 10 20 30 2,5 5 10 20 30 40 41 42 43 45 Mean observed limiting temperature of solubility OC 24 27,7 31,7 366 42,7 14 15,3 17 19,8 22,1 13,5 17.7 23 34,7 57,5 Standard deviation of reproducibility OC 2 I,7 2 13 It6 12 I,6 12 I,3 I,4 I,5 1 23 3 3,5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:34:19 MDTNo reproduction or networking permitted without license from IHS -,-,-