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1、BRITISH STANDARD BS EN 13926:2003 Surface active agents Alkoxylated derivatives Determination of hydroxyl value N-methyl imidazole method The European Standard EN 13926:2003 has the status of a British Standard ICS 71.100.40 ? Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00
2、 2006, Uncontrolled Copy, (c) BSI BS EN 13926:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 20 March 2003 BSI 20 March 2003 ISBN 0 580 41461 2 National foreword This British Standard is the official English language version of EN 13926
3、:2003. 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 obtained on request to its secretary. Cross-references The British Stan
4、dards 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 the BSI Electronic Catalogue or of British Standards Online. Thi
5、s 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 enquirers to understand the text; present to the responsible inte
6、rnational/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 pages This document comprises a front cover, an inside front cover, the EN
7、title page, pages 2 to 13 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c)
8、BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13926 March 2003 ICS 71.100.40 English version Surface active agents - Alkoxylated derivatives - Determination of hydroxyl value - N-methyl imidazole method Agents de surface - Drivs alkyloxyls - Dtermination de lindice dhydroxyle - Mthode la
9、N-mthylimidazole Grenzflchenaktive Stoffe - Alkoxylierte Derivate - Bestimmung der Hydroxylzahl - N-Methylimidazol- Verfahren This European Standard was approved by CEN on 29 November 2002. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for g
10、iving 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 Management Centre or to any CEN member. This European Standard exists in three official vers
11、ions (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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cz
12、ech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG M
13、anagement Centre: rue de Stassart, 36 B-1050 Brussels 2003 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13926:2003 E Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13
14、926:2003 (E) 2 Contents page Foreword3 1Scope 4 2Normative references 4 3Term and definition4 4Principle4 5Reagents.4 6Apparatus .5 7Sampling.5 8Procedure .5 9Expression of results 6 10Precision.8 11Test report 8 Annex A (informative) Results of interlaboratory test9 Annex B (informative) Example fo
15、r potentiometric operating parameters.11 Annex C (informative) Example for a typical titration curve and its derivative .12 Bibliography13 Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13926:2003 (E) 3 Foreword This document (EN 13926:2
16、003) 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 national standard, either by publication of an identical text or by endorsement, at the latest by September 2003, and con
17、flicting national standards shall be withdrawn at the latest by September 2003. Annexes A, B, and C are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cze
18、ch Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy,
19、(c) BSI EN 13926:2003 (E) 4 1 Scope This European Standard specifies a method for the determination of hydroxyl value of aliphatic and alicyclic hydroxyl compounds such as polyols, sorbitan esters, plasticisers and surface active agent alcohols and alkoxylates with hydroxyl values greater than 20 mg
20、 KOH/g. 2 Normative references This European 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
21、or revisions of any of these publications 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 (including amendments). ISO 607, Surface active agents and detergents Methods of sample di
22、vision. ISO 4314, Surface active agents Determination of free alkalinity or free acidity Titrimetric method. 3 Term and definition For the purposes of this European Standard, the following term and definition apply. 3.1 hydroxyl value I(OH) number of milligrams of potassium hydroxide needed to neutr
23、alize the acetic acid required to esterify the hydroxyl groups in 1 g of the material, or the number of milligrams of potassium hydroxide corresponding to the hydroxyl groups in 1 g of the material 4 Principle A known mass of test sample is esterified with an excess of acetic anhydride/tetrahydrofur
24、an solution using N-methyl imidazole as a catalyst. The excess of acetic anhydride is hydrolysed and then the formed acetic acid istitrated potentiometrically with ethanolic potassium hydroxide standard volumetric solution. The hydroxyl value is calculated from the difference in titration volumes of
25、 a blank test and the test sample. 5 Reagents 5.1General During the analysis, unless otherwise specified, use only reagents of recognized analytical grade and have been checked in advance as to not interfere with the analytical results. WARNING Tetrahydrofuran and N-methylimidazole being hazardous c
26、hemicals, all the operations shall be conducted under a well ventilated fume hood. 5.2Tetrahydrofuran, C4H8O. 5.3Acetic anhydride, C4H6O3. 5.4N-methyl imidazole, C4H6N2. 5.5 Potassium hydrogen phthalate, C8H5O4K, w(C8H5O4K) = 99 % dried at (105 1) C. Licensed Copy: sheffieldun sheffieldun, na, Mon O
27、ct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13926:2003 (E) 5 5.6Ethanol, C2H5OH. 5.7Potassium hydroxide standard volumetric solution in ethanol, c(KOH) = 0,5 mol/l. Weigh 66,0 g of potassium hydroxide with a purity of 85 % (m/m) to the nearest 0,1 g and dissolve it in 250 ml freshly
28、 boiled water. Then transfer the solution into a 2 l volumetric flask and complete to the mark with ethanol (5.6). Allow the solution to stand for 24 h before standardization. 5.8Acetylation reagent Carefully mix 92 ml of tetrahydrofuran (5.2) and 8 ml of acetic anhydride (5.3). This solution is sta
29、ble for up to one month. 6 Apparatus 6.1General Ordinary laboratory apparatus and the following. 6.2Potentiometer, comprising a titrator with a combined glass/calomel electrode, automatic burette assembly and a magnetic stirrer. 6.3Water bath, capable of maintaining a temperature of (45 1) C. 6.4Air
30、-cooler, with a length of 1 m. 6.5Analytical balance, with an accurate to 0,000 1 g. 7 Sampling Sample the material to be tested and store in accordance with ISO 607. 8 Procedure 8.1 Standardization of the ethanolic potassium hydroxide standard volumetric solution Weigh approximately 1 g of dried po
31、tassium hydrogen phthalate (5.5) to the nearest 0,1 mg into a 150 ml beaker and dissolve it in 80 ml of freshly boiled water. Immerse the electrode and a magnetic stir bar into the beaker, stir and titrate with the potentiometer (6.2) with the ethanolic potassium hydroxide standard volumetric soluti
32、on (5.7). Record the volume Vo of the ethanolic potassium hydroxide standard volumetric solution (5.7) at the first inflection point. Carry out the standardization in triplicate. 8.2 Test portion Calculate the quantity of the laboratory sample to be weighed, m, expressed in grams, by the equation (1
33、): ()EOH 168 I m =(1) Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13926:2003 (E) 6 where I(OH)Eis the expected hydroxyl value, in milligrams KOH per gram of the material. 8.3 Determination Fill the calculated mass of the test portion
34、(8.2), m, weighed to the nearest 0,1 mg and not exceeding 10 g into a clean dry 150 ml stoppered conical flask. Introduce with a pipette 10 ml of the acetylation reagent (5.8). Add 2 ml of N-methyl imidazole (5.4) into the flask and dissolve the test portion. Stop up the flask or connect the air coo
35、ler (6.4). Place the flask in a water bath (6.3) at 45 C for 15 min. At the end of the reaction time, add 10 ml of water (taking care of washing the stopper or the air-cooler). Homogenise and allow to stand for 2 min. Introduce the electrode and a magnetic stir bar into the flask, add enough ethanol
36、 to cover the tip of the electrode. Titrate with the potentiometer (6.2) with the ethanolic potassium hydroxide standard volumetric solution (5.7) and note the volume (V1) at the first inflection point. Perform the laboratory sample analysis in duplicate. 8.4 Blank tests Carry out two blank tests at
37、 the same time at the determination, using the same reagents, but without the test portion and note the volume at the first inflection as V2. 9 Expression of results 9.1 Standardisation factor of the ethanolic potassium hydroxide standard volumetric solution The standardisation factor, f, of the eth
38、anolic potassium hydroxide standard volumetric solution (5.6) is calculated by the equation (2): cMV wm f = 0 00 10 (2) where mois the mass of potassium hydrogen phthalate (5.5), in grams; wois the purity of potassium hydrogen phthalate (5.5), in percent (m/m); Vois the volume of the ethanolic potas
39、sium hydroxide standard volumetric solution (5.7) used for the standardisation (8.1), in millilitres; Mis the molar mass of potassium hydrogen phthalate (5.5), M (C8H5O4K) = 204,23 g/mol; cis the concentration of the ethanolic potassium hydroxide standard volumetric solution (5.7), c(KOH) = 0,5 mol/
40、l. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13926:2003 (E) 7 Take as the standardization factor the mean of three titrations performed according to 8.1. 9.2 Hydroxyl value The experimental hydroxyl value, I(OH)o, in milligrams of K
41、OH per gram of the test portion, is calculated by the equation (3): ()() m fcVVI o 1156 OH 12 , =(3) where V2is the mean volume of the ethanolic potassium hydroxide standard volumetric solution (5.7) used for the blank tests (see 8.4), in millilitres; V1is the volume of the ethanolic potassium hydro
42、xide standard volumetric solution (5.7) used for the determination (see 8.3), in millilitres; cis the concentration of the ethanolic potassium hydroxide standard volumetric solution (5.7), c(KOH) = 0,5 mol/l; fis the mean of standardisation factor of ethanolic potassium hydroxide the standard volume
43、tric solution (5.7) from 9.1; mis the mass of the test portion (see 8.3), in grams. For samples containing free acidity, the hydroxyl value, I(OH), is calculated by the equation (4): ()()AVII o +=OHOH(4) where ()oI OHis the experimental hydroxyl value, in milligrams of KOH per gram of the test porti
44、on; AVis the acidity value of the sample in accordance with ISO 4314 or equivalent, in milligrams of KOH per gram of the test portion. For samples containing free alkalinity, the hydroxyl value, I(OH), is calculated by the equation (5): ()()BVII= o OHOH(5) where I(OH)ois the experimental hydroxyl va
45、lue, in milligrams of KOH per gram of the test portion; BVis the alkalinity value of the sample in accordance with ISO 4314 or equivalent, in milligrams of KOH per gram of the test portion. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN
46、13926:2003 (E) 8 10 Precision 10.1 Repeatability limit The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will not exceed
47、the repeatability limit, r, in more than 5 % of cases. Typical precision data obtained in a ring test are given in annex A. 10.2 Reproducibility limit The absolute difference between two independent single test results, obtained using the same method on identical test material in different laborator
48、ies by different operators using different equipment, will not exceed the reproducibility limit, R, in more than 5 % of cases. Typical precision data obtained in a ring test are given in annex A. 11 Test report The test report shall include the following information: a) all information necessary for
49、 the complete identification of the sample; b) a reference to this European Standard; c) the test results; d) details of any operations not specified in this European Standard, and any operations regarded as optional, as well as any incidents likely to have affected the results. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 02:16:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13926:2003 (E) 9 Annex A (informative) Results of interlaboratory te
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