1、BRITISH STANDARDBS EN 14712:2005Surface active agents Determination of physical stability in alkaline and acid solutionsThe European Standard EN 14712:2005 has the status of a British StandardICS 71.100.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49
2、g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14712:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 19 August 2005 BSI 19 August 2005ISBN 0 580 46101 7National forewordThis
3、British Standard is the official English language version of EN 14712:2005.The UK participation in its preparation was entrusted to Technical Committee CII/34, Methods of test for Surface active agents, which has the responsibility to:A list of organizations represented on this committee can be obta
4、ined on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of
5、 the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations. aid en
6、quirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis doc
7、ument comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE
8、NORMEN 14712May 2005ICS 71.100.40English versionSurface active agents - Determination of physical stability inalkaline and acid solutionsAgents de surface - Dtermination de la stabilit physiquedans les solutions alcalines et acidesGrenzflchenaktive Stoffe - Bestimmung der physikalischenStabilitt in
9、alkalischer und saurer LsungThis European Standard was approved by CEN on 25 March 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists
10、 and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibi
11、lity of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Ital
12、y, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 20
13、05 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14712:2005: EEN 14712:2005 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle5 5 Reagents.5 6 Apparatus .6 7 Proc
14、edure .6 8 Expression of results 8 9 Test report 8 Annex A (normative) Forms for the test report 9 EN 14712:2005 (E) 3 Foreword This European Standard (EN 14712:2005) has been prepared by Technical Committee CEN/TC 276 “Surface active agents”, the secretariat of which is held by AFNOR. This European
15、 Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2005, and conflicting national standards shall be withdrawn at the latest by November 2005. According to the CEN/CENELEC Internal Regulations, the natio
16、nal standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Por
17、tugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14712:2005 (E) 4 Introduction The stability of a surface active agent in alkaline and acid solutions is its physical stability during the defined time period, as judged by its appearance. The statement “the surface active a
18、gent A has an alkaline stability of x g NaOH per litre“ means that the surface active agent A can be dissolved in a concentration of 10 g/l in an aqueous solution containing up to x g NaOH per litre to give a stable solution. Analogously the statement “the surface active agent A has an acid stabilit
19、y of y ml sulfuric acid per litre“ means that the surface active agent A can be dissolved with a concentration of 10 g/l in an aqueous solution containing up to y ml sulfuric acid per litre (with a purity of 95 % to 97 %) to give a stable solution. It should be noted that miscibility gaps can occur,
20、 i.e. the solution can be unstable at intermediate alkali or acid concentrations. The definition of a stable solution depends on the application of the surface active agent or surface active agent formulation. Thus homogeneous opalescent or turbid solutions may be considered either stable or unstabl
21、e. EN 14712:2005 (E) 5 1 Scope This European Standard specifies a method for the determination of physical stability of surface active agents in alkaline and acid solutions. It is applicable to all classes of surface active agents and also to other substances or mixtures such as polymers, complexing
22、 agents and formulations of surface active agents. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including
23、any amendments) applies. EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987). 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 alkaline stability maximum mass concentration of sodium hydroxi
24、de (purity at least of 98 %) in grams per litre at which the surface active agent can be dissolved in the alkaline solution with a mass concentration of 1 % to yield a stable solution 3.2 acid stability maximum volume concentration of sulfuric acid (purity 95 % to 98 %), in millilitres per litre, at
25、 which the surface active agent can be dissolved in the acid solution with a mass concentration of 1 % to yield a stable solution 3.3 other bases and acids other bases and acids may be used. This should be described together with the purity in the test report 4 Principle Aqueous solutions are prepar
26、ed with increasing concentrations of sodium hydroxide or sulfuric acid respectively. Then the surface active agent to be tested is mixed in these aqueous solutions. The formulations are examined visually after 24 h of storage at ambient temperature (22 3) C to see whether a stable solution resulted
27、or not. Clear homogeneous solutions are always considered stable, whereas phase separation indicates instability. Homogeneous opalescent or homogeneous turbid samples can be considered either stable or unstable depending on the surface active agent application. 5 Reagents 5.1 Water, grade 3, in acco
28、rdance with EN ISO 3696. 5.2 Sodium hydroxide, NaOH, analytical grade, preferably as an aqueous solution with a mass concentration of 30 % NaOH (this corresponds to 398 g NaOH (100 % active substance) in 1 l ; density = 1,328 g/ml at 20 C). 5.3 Sulfuric acid, H2SO4, analytical grade, preferably as a
29、n aqueous solution with a mass concentration of 25 % H2SO4(density = 1,18 g/ml at 20 C). EN 14712:2005 (E) 6 6 Apparatus 6.1 General Ordinary laboratory apparatus and the following: 6.2 Glass beakers or bottles with magnetic stirrer sticks, for storing and assessing the sample solutions. 125 ml scre
30、w-top jars are recommended. NOTE Within the series the same type of beakers or bottles should be used. 6.3 Magnetic stirrer. 6.4 Beaker, for the preparation of the stock solution of the surface active agents. 6.5 Analytical balance, accurate to 0,01 g. 7 Procedure 7.1 General An aqueous stock soluti
31、on of the surface active agent to be tested shall be prepared with a mass concentration of 100 g/l. If surface active agent trade products are used, relate the mass concentration of 100 % active substance. 7.2 Alkaline stability Pour and mix the corresponding amount of water (5.1) and of sodium hydr
32、oxide (5.2), preferably as a sodium hydroxide solution with a mass concentration of 30 % NaOH, into a series of beakers or bottles, for example 125 ml screw-top jars, (6.2) according to Table 1. Table 1 Series of solution of sodium hydroxide Jar Water Quantity of NaOH solution Concentration of (6.2)
33、 (5.1) (mass concentration of 30 %) NaOH g or ml g ml g/l A 87,5 3,3 2,5 10 B 80,0 13,3 10 40 C 70,0 26,7 20 80 D 60,0 40,0 30 120 E 50,0 53,3 40 160 F 40,0 66,7 50 200 G 30,0 80,0 60 240 H 20,0 93,3 70 280 I 10,0 106,7 80 320 J 0 120,0 90 360 Then pipette 10 ml or weigh 9,9 g of the stock solution
34、of the surface active agent into each beaker, for example the 125 ml jars, to prepare a test solution of the surface active agent with a mass concentration of 10 g/l. (The density of the stock solution is normally about 0,993 g/ml at 20 C). If the stock solution is inhomogeneous, do not EN 14712:200
35、5 (E) 7 use it but fill the corresponding mass of the surface active agent calculated to 100 % active substance directly in the beakers. Mix the test samples with the stirrer sticks on the magnetic stirrer (6.3) for about 5 min at about 400 min-1. Allow the test samples to stand at ambient temperatu
36、re (22 3) C for 24 h and then evaluate them. Gentle stirring or shaking is recommended, as slight phase separation is often difficult to detect otherwise. Turbid test samples shall be poured out in a second beaker to test, if any sediment was formed in the first beaker. Evaluate the NaOH concentrati
37、ons between the stable test samples and the unstable ones in a second series after testing this first series. The volumes and equivalent mass concentrations of the components of the first and the second series are given in Table A.1. NOTE The test may be carried out at other temperatures. If, for ex
38、ample, temperature controlled storage chambers are used, this should be noted in the test report. 7.3 Acid stability Pour and mix the corresponding amount of water (5.1) and sulfuric acid (5.3) into a series of beakers or bottles, for example 125 ml screw-top jars, (6.2) according to Table 2. Table
39、2 Series of solution of sulfuric acid Jar Water Quantity of sulfuric acid solution (5.3) Resulting volume (6.2) (5.1) (mass concentration of 25 %) concentration of sulfuric acid (100 % a.s.) g or ml g ml ml/l A 89,6 0,5 0,4 1 B 88,0 2,4 2,0 5 C 86,0 4,7 4,0 10 D 82,0 9,4 8,0 20 E 74,0 18,9 16,0 40 F
40、 66,0 28,3 24,0 60 G 58,0 37,8 32,0 80 H 50,0 47,2 40,0 100 I 42,0 56,6 48,0 120 J 34,0 66,1 56,0 140 Then pipette 10 ml or weigh 9,9 g of the stock solution of the surface active agent into each beaker, for example the 125 ml jars, to prepare a test solution of the surface active agent with a mass
41、concentration of 10 g/l. (The density of the stock solution is normally about 0,993 g/ml at 20 C). If the stock solution is inhomogeneous, do not use it but fill the corresponding mass of the surface active agent calculated to 100 % active substance directly in the beakers. Mix the test samples with
42、 the stirrer sticks on the magnetic stirrer (6.3) for about 5 min at about 400 min-1. Allow the test samples to stand at ambient temperature (22 3) C for 24 h and then evaluate them. Gentle stirring or shaking is recommended, as slight phase separation is often difficult to detect otherwise. Turbid
43、test samples shall be poured out in a second beaker to test, if any sediment has been formed in the first beaker. EN 14712:2005 (E) 8 Evaluate the sulfuric acid concentrations between the stable test samples and the unstable ones in a second series after testing this first series. The volumes and eq
44、uivalent mass concentrations of the components of the first and the second series are given in Table A.2. NOTE The test may be carried out at other temperatures if, for example, temperature controlled storage chambers are used, this should be noted in the test report. 8 Expression of results Use the
45、 score list according to Table 3 for the evaluation of the appearance of the test sample. Table 3 Evaluation of the test sample Score Appearance of the test sample 1 homogeneous clear 2 homogeneous opalescent 3 homogeneous turbid 4 macroscopic phase separation A liquid which is not clear, but throug
46、h which objects can be recognized, is rated as “opalescent“. An example is a liquid with 100 formazine nephelometric units. A liquid which is not clear, and through which objects can not be recognized, is rated as “turbid”. An example is a liquid with 1 000 formazine nephelometric units. In some cas
47、es a phase separation of a test sample is not or hardly visible by the naked eye. Therefore clear test samples shall be stirred or shaken, as mentioned in 7.2 or 7.3. If the test sample now shows turbidity, it is rated as “macroscopic phase separation“. A turbid test sample which shows a sediment wh
48、en poured out of the beaker is rated as “macroscopic phase separation“. According to this score list, the alkaline stability of a surface active agent is the highest NaOH concentration, in grams per litre, of that solution which is stable. Analogously, the acid stability of a surface active agent is
49、 the highest sulfuric acid concentration, in millilitres per litre, of the solution which is stable. Clear homogeneous test samples are always considered stable, whereas phase separation indicates instability. Homogeneous opalescent or homogeneous turbid test samples may be considered either stable or unstable, depending on the surface active agent application. The definition of stability used shall be included in the test report. 9 Test report The test report shall be made using the forms according to Annex A. EN 14712:2005 (E) 9 Annex A (normativ
