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1、BRITISH STANDARD BS EN ISO 14896:2001 Incorporating Corrigendum No. 1 Plastics Polyurethane raw materials Determination of isocyanate content The European Standard EN ISO 14896:2001 has the status of a British Standard ICS 83.080.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT
2、LAW BS EN ISO 14896:2001 This British Standard, having been prepared under the direction of the Sector Policy and Strategy Committee for Materials and Chemicals, was published under the authority of the Standards Policy and Strategy Committee on 4 September 2001 BSI 13 March 2002 ISBN 0 580 38062 9
3、National foreword This British Standard is the official English language version of EN ISO 14896:2001. It supersedes BS EN ISO 9369:1997 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/42, Fibre reinforced thermosetting plastics and prepregs, whic
4、h has the responsibility to: 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 may be found in the BSI Standards Catalogue under
5、 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 Standards are responsible for their correct app
6、lication. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers 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;
7、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 ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 9, a blank page, the Annex ZA page and
8、 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 13760 Corr. No. 1 13 March 2002 Incorporation of Annex ZA EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14896 August 2001
9、 ICS 83.080.10Supersedes EN ISO 9369:1997 English version Plastics - Polyurethane raw materials - Determination of isocyanate content (ISO 14896:2000) Plastiques - Matires premires des polyurthannes - Dtermination de la teneur en isocyanate (ISO 14896:2000) Kunststoffe - Polyurethanrohstoffe - Besti
10、mmung des Isocyanatanteils (ISO 14896:2000) This European Standard was approved by CEN on 15 June 2001. 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.
11、 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 versions (English, French, German). A version in any other language made by translation un
12、der 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, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxe
13、mbourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CENAll rights of exploitation in any form and by any
14、means reserved worldwide for CEN national Members. Ref. No. EN ISO 14896:2001 E I NESO 41:6982001 (E) 2 CORRECTED 2002-02-06 Foreword The text of the International Standard from Technical Committee ISO/TC 61 “Plastics“ of the International Organization for Standardization (ISO) has been taken over a
15、s a European Standard by Technical Committee CEN/TC 249 “Plastics“, the secretariat of which is held by IBN. This document supersedes EN ISO 9369:1997. 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
16、 by February 2002, and conflicting national standards shall be withdrawn at the latest by February 2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic,
17、 Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO 14896:2000 has been approved by CEN as a European Standard without any modi
18、fications. NOTE Normative references to International Standards are listed in annex ZA (normative). EN ISO 14896:2001 2 INTERNATIONAL STANDARD ISO 14896 First edition 2000-09-01 Reference number ISO 14896:2000(E) OSI 2000 Plastics Polyurethane raw materials Determination of isocyanate content Plasti
19、ques Matires premires des polyurthannes Dtermination de la teneur en isocyanate EN ISO 14896:2001 ii EN ISO 14896:2001 ISO 98410002:6)E( ISO 0002 All rithgs rreseved iii ContentsPage 1Scope .1 2Normative references .1 3Terms and definitions 1 4Principle 2 5Application 2 6Interferences .2 7Sampling .
20、2 8Test conditions 3 9Reagents 3 10Apparatus .3 11Method A Toluene/dibutylamine with aqueous HCl 4 12Method B Toluene/TCB/DBA with methanolic HCl .6 EN ISO 14896:2001 ISO :69841(0002)E iv ISO 0002 All rithgs rreseved Foreword ISO (the International Organization for Standardization) is a worldwide fe
21、deration of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical com- mittees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that c
22、ommittee. International organizations, governmental and non-governmental, in liai- son with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in ac
23、cordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attentio
24、n is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 14896 was prepared by Technical Committee ISO/TC 61,Plastics, Subcom
25、mittee SC 12, Thermosetting materials. This first edition cancels and replaces ISO 9369:1997, which has been technically revised. An International Standard dealing with the analysis of refined aromatic diisocyanates and their prepolymers has been published (see ISO 9369). Method A of this Internatio
26、nal Standard incorporates the methodology of ISO 9369, therefore ISO 9369 will be deleted after publication of this International Standard. Method B of this International Standard is based on Test Method C of ASTM D 5515-91,Standard Test Method for Polyurethane Raw Materials Determination of the Iso
27、cyanate Content of Aromatic Isocyanates. EN ISO 14896:2001 ANRETNIITOLAN TSDNADRAISO 98410002:6)E( ISO 0002 All rithgs rreseved 1 Plastics Polyurethane raw materials Determination of isocyanate content CAUTION Persons using this International Standard should be familiar with normal laboratory practi
28、ce. This International Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health practices and to ensure compliance with any national regulatory cond
29、itions prior to use. 1Scope This International Standard specifies two methods for the measurement of the isocyanate content of aromatic iso- cyanates used as polyurethane raw materials. Method A is primarily applicable to refined toluene diisocyanate (TDI), methylene-bis-(4-phenylisocyanate) (MDI) a
30、nd their prepolymers. Method B is applicable to refined, crude or modi- fied isocyanates derived from toluene diisocyanate, methylene-bis-(4-phenylisocyanate) and polymethylene polyphenylisocyanate. It can also be used for isomer mixtures of toluene diisocyanate, methylene-bis-(4-phenyl- isocyanate)
31、 and polymethylene polyphenylisocyanate. Other aromatic isocyanates may be analysed by this method if precautions are taken to verify suitability. It is not applicable to blocked isocyanates. 2Normative references The following normative documents contain provisions which, through reference in this
32、text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publica- tions do not apply. However, parties to agreements based on this International Standard are encouraged to investi- gate the possibility of applying the m
33、ost recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain reg- isters of currently valid International Standards. ISO 385-1:1984,Laboratory glassware Burettes Part 1: Gener
34、al requirements. ISO 648:1977,Laboratory glassware One-mark pipettes. ISO 3696:1987,Water for analytical laboratory use Specification and test methods. ISO 4787:1984,Laboratory glassware Volumetric glassware Methods for use and testing of capacity. ISO 4788:1980,Laboratory glassware Graduated measur
35、ing cylinders. ISO 6353-1:1982,Reagents for chemical analysis Part 1: General test methods. ISO 6353-2:1983,Reagents for chemical analysis Part 2: Specifications First series. ISO 6353-3:1987,Reagents for chemical analysis Part 3: Specifications Second series. ISO 14898:1999,Plastics Aromatic isocya
36、nates for use in the production of polyurethane Determination of acidity. 3Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 1 EN ISO 14896:2001 ISO :69841(0002)E 2 ISO 0002 All rithgs rreseved 3.1 polyurethane a polymer prepared by the
37、 reaction of an organic di- or polyisocyanate with compounds containing two or more hydroxyl groups NOTEPolyurethanes may be thermosetting, thermoplastic, rigid or soft and flexible, cellular or non-cellular. 3.2 assay the percent by mass of a specific isocyanate present in a sample 3.3 isocyanate c
38、ontent NCO content the percent by mass of the NCO groups present in a sample 3.4 amine equivalent the mass of sample that will combine with 1 gram-equivalent of dibutylamine 4Principle 4.1Method A The isocyanate sample is reacted with an excess of dibutylamine in toluene to form the corresponding su
39、bstituted urea. After cooling to room temperature, acetone is added as a cosolvent, then the reaction mixture is back-titrated with standardized aqueous HCl using potentiometric or colorimetric end point determination. 4.2Method B The isocyanate sample is reacted with an excess of dibutylamine in a
40、toluene/trichlorobenzene solvent to form the corresponding substituted urea. After cooling to room temperature, the reaction mixture is diluted with methanol and back-titrated potentiometrically or colorimetrically with methanolic hydrochloric acid. 5Application These test methods can be used for re
41、search or for quality control purposes to characterize isocyanates used in polyurethane products. 6Interferences Phosgene, the carbamyl chloride of the isocyanate, hydrogen chloride and any other acidic or basic compounds will interfere. In refined isocyanates, these impurities are usually present i
42、n such small amounts that they do not affect the determination; however, some crude or modified isocyanates may contain acidities of up to approximately, so the value reported for the NCO content of unrefined isocyanates should preferably be designated as “corrected” or “uncorrected” for acidity. 7S
43、ampling Since organic isocyanates react with atmospheric moisture, take special precautions in sampling (see warning). Usual sampling methods (for example, sampling an open drum with a thief), even when conducted rapidly, can cause contamination of the sample with insoluble ureas; therefore, blanket
44、 the sample with a dry inert gas (e.g. nitrogen, argon or dried air) at all times. WARNING Organic isocyanates are hazardous when absorbed through the skin, or when the vapours are breathed. Provide adequate ventilation and wear protective gloves and eyeglasses. 0,3 % 2 EN ISO 14896:2001 ISO 9841000
45、2:6)E( ISO 0002 All rithgs rreseved 3 8Test conditions Since isocyanates react with moisture, keep the laboratory humidity low, preferably belowrelative humidity. 9Reagents Use reagent-grade chemicals in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the spe
46、cifications of ISO 6353-1, ISO 6353-2 and ISO 6353-3. Other grades may be used, provided that it is first de- termined that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determi- nation. Unless otherwise indicated, references to water shall be und
47、erstood to mean grade 3 water as defined in ISO 3696. 9.1Acetone (method A). 9.2Toluene, dried over type 4A molecular sieve. 9.3di-n-butylamine solution,(method A). Diluteof di-n-butylamine to 1 litre with toluene. 9.4di-n-butylamine solution,(method B). Diluteof di-n-butylamine to 1 litre with tolu
48、ene. 9.5Aqueous hydrochloric acid,(method A). Prepareaqueous hydrochloric acid and standardize frequently enough to detect changes of. 9.6Methanolic hydrochloric acid,(method B). Preparehydrochloric acid in methanol and standardize frequently enough to detect changes of. NOTEIn order to have homogen
49、eous solutions, it is recommended that methanolic HCl be used in this procedure. If desired, aqueous HCl can be used; however, turbidity will be encountered in some titrations. It is recommended thattoof methanol be added to the reacted product to minimize the formation of two layers. Experience has shown that, if the mixtures are agitated vigorously, inhomogeneity can be tolerated without adversely affecting the results. 9.7Bromophenol blue indicator solution, for colorimetric titration:aqueous