《BS EN 1241-1998 Adhesives. Determination of acid value.pdf》由会员分享，可在线阅读，更多相关《BS EN 1241-1998 Adhesives. Determination of acid value.pdf（8页珍藏版）》请在三一文库上搜索。
1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1241:1998 The Europ
2、ean Standard EN 1241:1998 has the status of a British Standard ICS 83.180 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Adhesives Determination of acid value Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This Briti
3、sh Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 July 1998 BSI 1998 ISBN 0 580 29639 3 BS EN 1241:1998 Amendments issued since publication Amd. No.DateText affec
4、ted National foreword This British Standard is the English language version of EN 1241:1998. The UK participation in its preparation was entrusted to Technical Committee STI/52, Adhesives, which has the responsibility to: aid enquirers to understand the text; present to the responsible European comm
5、ittee 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. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-refe
6、rences The British Standards which implement international or European publications referred to in this document may 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 Catalogu
7、e. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards 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 compris
8、es a front cover, an inside front cover, the EN title page, pages 2 to 4, an inside back cover and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN European Committee for Standardization Comite Europe en de Normalisation Eur
9、opa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1241:1998 E EUROPEAN STANDARDEN 1241 NORME EUROPE ENNE EUROPA ISCHE NORM February 1998 IC
10、S 83.180 Descriptors: Adhesives, components, chemical tests, determination, acidity, acid number, procedure English version Adhesives Determination of acid value Adhe sifs De termination de lindice dacidite Klebstoffe Bestimmung der Sa urezahl This European Standard was approved by CEN on 2 January
11、1998. CEN members are bound to comply with 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 obtaine
12、d 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 translation under the responsibility of a CEN member into its own language and notified to the Central Secreta
13、riat has the same status as the official 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
14、 Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 1241:1998 BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 193, Adhesives, the secretariat of which is held by AENOR. This European Standard shall be g
15、iven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 1998, and conflicting national standards shall be withdrawn at the latest by August 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizati
16、ons 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 Foreword2 1S
17、cope3 2Normative references3 3Definition3 4Principle3 5Safety3 6Reagents3 7Apparatus3 8Procedure3 9Calculation and expression of results4 10Test report4 Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ? Page 3 EN 1241:1998 BSI 1998 1 Scope T
18、his standard specifies a method for determination of the acid value of adhesives, adhesive components, their basic constituents, and related products. In some cases, notably when unsaturated polyesters with free anhydrides are present, somewhat lower than theoretical acid values are found, due to th
19、e formation of acid esters which precipitate and, are therefore, not determined. 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 publicatio
20、ns are listed hereafter. For dated references, subsequent amendments to 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. EN 923, Adhesives
21、 Terms and definitions. EN 1066, Adhesives Sampling. EN 1067, Adhesives Examination and preparation of samples for testing. ISO 385-1, Laboratory glassware Burettes Part 1: General requirements. ISO 648, Laboratory glassware One-mark pipettes. ISO 1042, Laboratory glassware One-mark volumetric flask
22、s. 3 Definition For the purposes of this standard, the definitions in accordance with EN 923 and the following definition apply: acid value the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of the test product under the test conditions 4 Principle A weighed quantity of
23、 product is dissolved in a mixture of solvents and the product titrated with a standardized ethanolic solution of potassium hydroxide using a suitable indicator. 5 Safety Persons using this standard shall be familiar with normal laboratory practice. This standard does not purport to address all safe
24、ty problems, if any, associated with its use. It is the responsibility of the user to establish safety and health practices and to ensure compliance with any European and national regulatory conditions. 6 Reagents 6.1 Solvent mixture: mix two parts of toluene by volume, analytical grade, and one par
25、t of ethanol by volume, analytical grade. 6.2 Thymol blue (mass concentration b = 0,1 %) indicator solution: dissolve 0,1 g of Thymol blue in ethanol, analytical grade, and dilute to 100 ml. 6.3 Potassium hydroxide (KOH), 0,1 mol concentration, in ethanol, analytical grade. The solution shall be anh
26、ydrous and as free from carbon dioxide as possible. NOTEOptionally 0,1 mol concentration in sodium hydroxide solution can be used, if required. 6.4 Acetone, analytical grade, containing less than 0,1 % (volume fraction) of water. 6.5 Nitrogen 7 Apparatus All volumetric glassware shall be class A, in
27、 accordance with ISO 385-1, ISO 648 or ISO 1042 as appropriate. 7.1 Analytical balance, with scale divisions of 0,1 mg. 7.2 Conical flasks, capacity 250 ml, with large neck. 7.3 Burette, capacity 50 ml, graduated in 0,05 ml divisions. 7.4 Magnetic stirrer 7.5 Source of nitrogen gas 7.6 Pipettes, one
28、 mark, capacity 50 ml. 7.7 Apparatus for potentiometric titration, optional, for example, for dark coloured solutions. 8 Procedure Take a sample of the product to be tested in accordance with EN 1066. Examine and prepare this sample for testing in accordance with EN 1067. Weigh, to the nearest 1 mg,
29、 a test portion in the range of 0,5 g to 3,0 g1 mg, the quantity depending on the acid value expected. Place this test portion in one of the flasks (see 7.2) and add 50 ml of the solvent mixture (see 6.1), using a pipette (see 7.6). NOTE 1Depending on the nature of the product under test other suita
30、ble solvents, e.g. dimethyl-formamide, or solvent mixture can be used provided the product is dissolved completely without chemical reaction. For water-borne adhesives no solvent is required and aqueous standard volumetric potassium hydroxide solution free from carbon dioxide may be used. To avoid a
31、n excess of carbon dioxide, particularly to products having a low acid number, all products covered with nitrogen gas should be dissolved. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ? Page 4 EN 1241:1998 BSI 1998 Shake until the product
32、 has completely dissolved, warming if necessary on a water bath with a condenser on the flask. If the solubility is poor, or if solution is incomplete after 5 min, prepare another solution by dissolving another test portion in a mixture of 50 ml of the solvent mixture (see 6.1) and 25 ml acetone (se
33、e 6.4). Record this change in procedure in the test report. Cool the solution to (232) 8C. Add 5 drops of thymol blue solution (see 6.2). Place the flask on the magnetic stirrer and bubble into the solution a stream of nitrogen. Titrate with the potassium hydroxide solution (see 6.3) from the burett
34、e (see 7.3) to the endpoint where the colour remains blue for 20 to 30 s. Record the volume, V1, of KOH solution (see 6.3) used, in millilitres. Carry out a blank determination using 50 ml of the solvent mixture (see 6.1) or 50 ml of the solvent mixture (see 6.1) and 25 ml acetone (see 6.4) as descr
35、ibed above and titrate to obtain the same blue coloration as obtained when the product was present. Record the volume, V2, of KOH solution (see 6.3) used, in millilitres. NOTE 2Potentiometric titration is an option. 9 Calculation and expression of the results 9.1 Calculation Calculate, for each test
36、, the acid value, Av, from the equation: Av= 56,1 3 M 3 (V12 V2) m where: V1is the volume, in millilitres, of KOH solution (see 6.3) used to neutralize the solution of the product; V2is the volume, in millilitres, of KOH solution (see 6.3) used in the blank determination; Mis the molarity of the KOH
37、 solution (see 6.3); mis the mass, in grams, of the test portion. 9.2 Expression of results Take as the result the mean of at least two determinations, rounded to the nearest whole number. 10 Test report The test report shall include: a) a reference to this European Standard; b) a complete identific
38、ation of the sample; c) identification of the solvent used for solution preparation, i.e. toluene/ethanol or toluene/ ethanol/acetone and the end point detection used (by an indicator or potentiometry); d) test results, the individual acid values and their mean; e) any special features noted during
39、the determination; f) any operations not specified in this European Standard and all incidents that may have affected the results; g) date of test. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ? blank Licensed Copy: sheffieldun sheffieldu
40、n, na, Sat Oct 28 09:00:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ? BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
41、 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. R
42、evisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or
43、 ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subsc
44、ribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel: 020 8996 9001. Fax: 020 8996 7001. In response to orders for international standards, it is BSI policy t
45、o supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Var
46、ious BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the
47、 purchase price of standards. For details of these and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bod
48、ies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free
49、 use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel: 020 8996 7070. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28