《BS-EN-1890-1999.pdf》由会员分享，可在线阅读，更多相关《BS-EN-1890-1999.pdf（10页珍藏版）》请在三一文库上搜索。
1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1890:1999 The Europ
2、ean Standard EN 1890:1999 has the status of a British Standard ICS 71.100.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Surface active agents Determination of cloud point of non-ionic surface active agents obtained by condensation of ethylene oxide Licensed Copy: sheffiel
3、dun sheffieldun, na, Mon Oct 30 04:53:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 August 199
4、9 BSI 08-1999 ISBN 0 580 32287 4 BS EN 1890:1999 Amendments issued since publication Amd. No.DateComments National foreword This British Standard is the English language version of EN 1890:1999. It supersedes BS 6829-4.1:1991 which is withdrawn. The UK participation in its preparation was entrusted
5、to Technical Committee CII/34, Methods of test for surface active agents, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor rel
6、ated international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document ma
7、y be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Stan
8、dards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. The BSI copyright notice
9、 displayed throughout this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 04:53:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung
10、Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1890:1999 E EUROPEAN STANDARDEN 1890 NORME EUROPE ENNE EUROPA ISCHE NORM March 1999 ICS 71.100.40 Descriptors: surfactant
11、s, non-ionic surfactants, ethylene oxide, tests, measurements, cloud point English version Surface active agents Determination of cloud point of non-ionic surface active agents obtained by condensation of ethylene oxide Agents de surface De termination du point de trouble des agents de surface non i
12、oniques obtenus par condensation doxydes de thyle ne Grenzfla chenaktive Stoffe Bestimmung des Tru bungspunktes nichtionischer, durch Anlagerung von Ethylenoxid hergestellter grenzfla chenaktiver Stoffe This European Standard was approved by CEN on 13 February 1999. CEN members are bound to comply w
13、ith the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secreta
14、riat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officia
15、l versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Mon
16、 Oct 30 04:53:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 1890:1999 BSI 08-1999 Foreword This European Standard has been prepared by Technical Committee CEN/TC 276, Surface active agents, the Secretariat of which is held by AFNOR. This European Standard shall be given the status of a nat
17、ional standard, either by publication of an identical text or by endorsement, at the latest by September 1999, and conflicting national standards shall be withdrawn at the latest by September 1999. Annex A is informative. According to the CEN/CENELEC Internal Regulations, the national standards orga
18、nizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Forewo
19、rd2 Introduction3 1Scope3 2Normative references3 3Terms and definitions3 4Principle4 5Reagents4 6Apparatus4 7Preparation and storage of samples4 8Procedure4 9Expression of results6 10Precision6 11Test report7 Annex A (informative) Bibliography7 Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30
20、04:53:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 1890:1999 BSI 08-1999 Introduction Solutions of non-ionic surface active agents obtained by the reaction of ethylene oxide with a hydrophobic base molecule, in water or in mixtures of water and organic solvents become turbid at a given te
21、mperature as the temperature increases and finally separate into two liquid phases. The process is reversible and the system becomes homogeneous again upon cooling. The temperature at which the solution becomes clear upon cooling is determined as the cloud point. This temperature is characteristic f
22、or a particular surfactant. This temperature increases with the amount of ethylene oxide chemically combined in the surfactant molecule for a given composition of solvents. This phenomenon is not limited to ethoxylated surfactants and the cloud point can be determined also for other non-ionic compou
23、nds. The knowledge of the cloud point of non-ionic surfactants obtained by the reaction of ethylene oxide with hydrophobic bases is important for their use. For a given base molecule, the cloud point is indeed a simple measure of the amount of the combined ethylene oxide. Moreover, the cloud point s
24、uggests directly the temperature at which many functional surfactant properties change dramatically. The curve of cloud point versus degree of ethoxylation is asymptotic, therefore molecules containing high amounts of ethylene oxide show only small differences in their cloud point. In these cases th
25、e cloud point loses its significance. Methods D and E of this European Standard are based on methods described in ISO 1065 and DIN 53917 respectively. The test principle is the same and test conditions are similar but more exactly defined. 1 Scope This European Standard specifies methods for the det
26、ermination of the cloud point of solutions of non-ionic surface active agents obtained by the reaction of ethylene oxide with a hydrophobic base molecule. This standard primarily applies to surfactants obtained by reaction of ethylene oxide with hydrophobic base molecules, such as fatty alcohols, fa
27、tty acids, long-chain alkylphenols, fatty amines, fatty acid esters of sugar derivatives among other ethoxylated non-ionic surfactants, which are by far the most commonly used. NOTE Other non-ionic surfactants containing other structural units, such as propylene oxide-ethylene oxide block copolymers
28、, have distinctive behaviours that make the determination of the cloud point more difficult. This leads sometimes to a continuous turbidity over a temperature range of several degrees or even to the occurrence of two cloud points at significantly different temperatures. 2 Normative references This E
29、uropean Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publicati
30、ons apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN ISO 862, Surface active agents Vocabulary (ISO 862:1984 + Corrigendum 1:1993). EN ISO 3696, Water for analytical laboratory
31、use Specification and test methods (ISO 3696:1987). ISO 607:1980, Surface active agents and detergents Methods of sample division. 3 Terms and definitions For the purposes of this standard, the definitions given in EN ISO 862 and the following apply. 3.1 cloud temperature temperature above which aqu
32、eous solutions of certain non-ionic surface active agents become heterogeneous by the separation into two liquid phases (coacervation) EN ISO 862 NOTE 1 The value of the cloud temperature depends on the concentration of the solution. NOTE 2 The temperature at which the system becomes homogeneous upo
33、n cooling is called temperature of clarification. The cloud temperature and the temperature of clarification do not need to coincide for reasons concerned with the measurement procedure. However, for practical reasons, the temperature of clarification is conventionally called the cloud point. 3.2 cl
34、oud point critical lower phase-separation temperature (lower consolute temperature) above which the system is a cloudy solution and a further temperature rise results in two immiscible phases that are in equilibrium NOTE 1 The cloud point is measured as the temperature falls. NOTE 2 The cloud point
35、depends on the number of ethylene oxide units linked to the base molecule and on their statistical distribution. It is also very sensitive to the presence of electrolytes and other organic substances in the aqueous solution. Therefore it should operate under well-established conditions. 3.3 temperat
36、ure of clarification temperature at which the mixture of two liquid phases of aqueous solution of certain non-ionic surface active agents exhibiting a cloud temperature, becomes homogeneous on cooling EN ISO 862 NOTEThe temperature of clarification is often determined as cloud point. Licensed Copy:
37、sheffieldun sheffieldun, na, Mon Oct 30 04:53:12 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 1890:1999 BSI 08-1999 4 Principle The surfactant solution is heated until it is completely cloudy. Then it is slowly cooled with constant stirring while measuring the temperature. The temperature at
38、 which the turbidity disappears and the solution becomes homogeneous is recorded as the cloud point. Depending on the nature of the surfactant and the purity of the materials the solution can become completely clear or slightly opalescent, but in this case a definite change from the cloudy solution
39、is observed. 5 Reagents During the test, unless otherwise stated, use only reagents of recognized analytical grade. 5.1 Water, according to grade 3 in EN ISO 3696 or water of at least equivalent purity. 5.2 Diethylene glycol mono-n-butylether, (special quality) C4H9-O-CH2-CH2-O-CH2-CH2-OH (also comm
40、ercially known as butyldiglycol). 5.2.1 Specifications The butyldiglycol (BDG) shall have the following: minimum purity: 99,5 %; density at 20 8C: (0,9520,002) g/ml; refractive index: nD20= (1,4310,001); water content: 0,1 %. NOTEImpurities present in diethylene glycol mono-n-butylether and differen
41、ces in concentration of its 25 % as mass fraction aqueous solution affect the cloud point to some extent. For arbitration purposes samples of diethylene glycol mono-n- butylether shall be exchanged between laboratories. 5.2.2 Butyldiglycol/water, solution at mass fraction of 25 %. Dissolve 250 g of
42、butyldiglycol (5.2.1) with 750 g of water. 5.3 Sodium chloride aqueous solutions. 5.3.1 50,00 g NaCl per litre solution in water. 5.3.2 100,00 g NaCl per litre solution in water. 6 Apparatus 6.1 Calibrated thermometer, graduated in 0,1 8C, with a range appropriate to the temperature to be measured o
43、r a calibrated electronic measuring instrument with digital display. 6.2 Conical flask, capacity 250 ml, with glass or plastic stopper. 6.3 Test tube, capacity 30 ml. 6.4 Conventional heating appliance (see also Figure 1). 6.5 Beaker, capacity 250 ml, containing a transparent heat-transfer fluid. 7
44、Preparation and storage of samples Prepare and store the sample of the surface active agent in accordance with ISO 607. 8 Procedure 8.1 Selection of test procedure Five methods of cloud point determination are described; select from those given in 8.2 to 8.6, the most appropriate method for the part
45、icular surfactant under test, depending upon the temperature at which the solution of the test sample becomes turbid. NOTEThe temperature at which the solution of a surfactant becomes turbid depends on the percentage by mass of ethylene oxide which it contains (see Figure 2). The choice between meth
46、ods B, C, D and E is based on the sharpness of the cloud point and the sensitivity of the method. It should be noted that the methods B and C and methods D and E will produce different cloud point results and so the method used should be fully noted when reporting any results. 8.2 Method A: Water so
47、lution NOTE 1 Method A is used when an aqueous solution of 1 g of sample plus 100 g of water becomes turbid at a temperature between 10 8C and 90 8C. Weigh 1,0 g of the sample (see clause 7) to the nearest 0,01 g into the conical flask (6.2), add 100,0 g of water, stopper the flask and stir until th
48、e sample has dissolved to form a clear solution. Pour about 15 ml to 25 ml of this solution into the test tube (6.3). Put the thermometer (6.1) into the tube, place the tube in the beaker (6.5) and heat under slow stirring with the thermometer until it is completely opaque. NOTE 2 The opacity appear
49、s as bands that thicken and results in turbidity. The temperature of the solution should not exceed by more than 10 8C the temperature at which the opacity appears. Allow to cool slowly in the air while stirring. Read the temperature at which the opaque bands disappear. Repeat the determination, using a fresh solution, until at least two results differ from each other by not more than 0,5 8C. NOTE 3A fresh solution is used to avoid loss of water due to evaporation. 8.3 Method B: Salt solution of NaCl at 50 g/l NOTEMethod B