1、BS ISO 26603:2017Plastics Aromaticisocyanates for use in theproduction of polyurethanes Determination of total chlorineBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 26603:2017 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of
2、 ISO 26603:2017. It supersedes BS ISO 26603:2008 which is withdrawn. The UK participationinitspreparation wasentrusted to TechnicalCommittee PRI/42,Fibre reinforced thermosetting plastics andprepregs.Alistoforganizations represented on this committeecanbeobtainedonrequest to itssecretary.Thispublica
3、tiondoes not purport to include allthe necessaryprovisions of a contract. Usersare responsibleforitscorrectapplication. The British Standards Institution 2017. Published by BSI StandardsLimited 2017ISBN978 0580 96210 3ICS83.080.10Compliancewitha British Standard cannot confer immunityfromlegal oblig
4、ations.ThisBritish Standard waspublishedunder the authority of theStandardsPolicy and StrategyCommittee on 31March2017.Amendments/corrigenda issued since publicationDate Text affectedBS ISO 26603:2017 ISO 2017Plastics Aromatic isocyanates for use in the production of polyurethanes Determination of t
5、otal chlorinePlastiques Isocyanates aromatiques utiliss pour la production de polyurthannes Dosage du chlore totalINTERNATIONAL STANDARDISO26603Second edition2017-03Reference numberISO 26603:2017(E)BS ISO 26603:2017ISO 26603:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017
6、, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. P
7、ermission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 26603:2017ISO 26603:2017(E)
8、Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 24.1 Test Method A 24.2 Test Method B 25 Interferences 26 Sampling 27 Test Method A Total chlorine by oxygen bomb 27.1 Reagents 27.2 Apparatus 37.3 Procedure 47.4 Calculation 57.5 Precision and bias 67
9、.5.1 Precision 67.5.2 Bias 68 Test Method B Total chlorine by Schniger oxygen flask 68.1 Reagents 68.2 Apparatus 68.3 Procedure 78.4 Calculation 88.5 Precision and bias 88.5.1 Precision 88.5.2 Bias 89 Test report . 8Bibliography 9 ISO 2017 All rights reserved iiiContents PageBS ISO 26603:2017ISO 266
10、03:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for
11、which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on al
12、l matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. Th
13、is document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any
14、 or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of
15、users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the followi
16、ng URL: www .iso .org/ iso/ foreword .html.The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 12, Thermosetting materials.This second edition cancels and replaces the first edition (ISO 26603:2008), of which it constitutes a minor revision. The changes compared to th
17、e previous edition are as follows: a key has been added to Figure 1.iv ISO 2017 All rights reservedBS ISO 26603:2017ISO 26603:2017(E)IntroductionIsocyanates are typically produced by phosgenation of an aromatic amine using chlorine-substituted benzenes (e.g. o-dichlorobenzene) as reaction solvents.
18、ISO 15028 is used to determine the hydrolyzable chlorine content of the isocyanates. The test methods in this document are used to determine the total chlorine content of aromatic isocyanates. The difference between the total chlorine content and the hydrolyzable chlorine content is a measure of the
19、 reaction solvents left in the product, and therefore is a useful tool for assessing product quality. ISO 2017 All rights reserved vBS ISO 26603:2017BS ISO 26603:2017Plastics Aromatic isocyanates for use in the production of polyurethanes Determination of total chlorineSAFETY PRECAUTIONS Persons usi
20、ng this document should be familiar with normal laboratory practice, if applicable. This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure complianc
21、e with any regulatory requirements.1 ScopeThis document specifies the determination of the total chlorine content of aromatic isocyanates used in the preparation of polyurethanes. The difference between the total chlorine content and the hydrolyzable chlorine content (see ISO 15028) is a measure of
22、the process solvents left in the product. Both test methods are applicable to a variety of organic compounds, including aliphatic isocyanates, but the amount of sample used might need to be adjusted. These test methods can be used for research or for quality control.NOTE This document is technically
23、 equivalent to ASTM D466103.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the ref
24、erenced document (including any amendments) applies.ISO 3696, Water for analytical laboratory use Specification and test methodsISO 6353-2, Reagents for chemical analysis Part 2: Specifications First seriesISO 6353-3, Reagents for chemical analysis Part 3: Specifications Second series3 Terms and def
25、initionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t
26、 p :/ www .iso .org/ obp3.1isocyanateorganic compound containing one or more NCO groups3.2polyurethanepolymer prepared by the reaction of an organic di- or polyisocyanate with compounds containing two or more hydroxyl groups3.3hydrolyzable chlorineorganic or inorganic chlorine compounds formed in th
27、e production of isocyanates that react with methanol under the conditions of ISO 15028 to liberate hydrogen chlorideINTERNATIONAL STANDARD ISO 26603:2017(E) ISO 2017 All rights reserved 1BS ISO 26603:2017ISO 26603:2017(E)3.4total chlorineinorganic and organically bound chlorine present in isocyanate
28、s that is converted to titratable chlorides under the combustion conditions of the test4 PrincipleIn each test method, the organic matter in the sample is destroyed by combustion with oxygen, thus converting the organically combined chlorine to ionic chloride. The chloride is determined potentiometr
29、ically by titration with silver nitrate (AgNO3) solution.4.1 Test Method ACombustion of the sample is done in a pressurized oxygen bomb.4.2 Test Method BCombustion is done at atmospheric pressure in a Schniger oxygen flask.NOTE For information on the Schniger flask, see Reference 6.5 InterferencesTh
30、iocyanate, cyanide, sulphide, bromide, iodide or other substances capable of reacting with silver ion, as well as substances capable of reducing silver ion in acid solution, will interfere with the determination.6 SamplingSince organic isocyanates react with atmospheric moisture, take special precau
31、tions in sampling. Usual sampling methods, even when conducted rapidly, can expose the isocyanate to moisture and cause contamination of the sample with insoluble ureas; therefore, blanket the sample with a dry inert gas (e.g. nitrogen, argon or dried air) at all times.WARNING Organic isocyanates ar
32、e hazardous when absorbed through the skin, or when the vapours are breathed.CAUTION Provide adequate ventilation and wear protective gloves and eyeglasses.7 Test Method A Total chlorine by oxygen bomb7.1 Reagents7.1.1 Purity of reagentsReagent-grade chemicals shall be used in all tests. Other grade
33、s may be used, provided that it is first determined that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of ISO 6353-2 and ISO 6353-3.7.1
34、.2 Purity of waterUnless otherwise indicated, references to water shall be understood to mean grade 2 water as defined by ISO 3696.2 ISO 2017 All rights reservedBS ISO 26603:2017ISO 26603:2017(E)7.1.3 Ethyl alcohol, conforming to ISO 6353-2.7.1.4 Nitric acid (diluted). While stirring vigorously, add
35、 100 ml of nitric acid (HNO3,specific gravity 1,42) to 100 ml of water cooled in an ice bath.7.1.5 Oxygen, free of combustible materials and halogen compounds.7.1.6 Silver nitrate, standard solution (0,01 M). Prepare a 0,01 M silver nitrate (AgNO3) solution and check frequently enough to detect chan
36、ges of 0,000 5 M, either gravimetrically or potentiometrically, using standard hydrochloric acid (HCl).7.1.7 Sodium carbonate solution (50 g/l). Dissolve 135 g of sodium carbonate decahydrate (Na2CO310H2O) in water and dilute to 1 l.7.2 Apparatus7.2.1 Weighing bottle and balance, suitable for weighi
37、ng a liquid sample by difference to the nearest 0,5 mg.7.2.2 Oxygen bomb apparatus. A corrosion-resistant steel reactor capable of being pressurized to 40 atmospheres of pure oxygen, followed by electrical ignition of the sample by use of an internal fuse wire. The bomb shall be capable of withstand
38、ing the pressure build-up caused by the combustion of the sample. Parr Bomb No. 1108 is a suitable device (see Figure 1). Equivalent apparatus may be substituted with appropriate changes in the procedure.7.2.3 Fuse wire, iron-nickel-chromium, No. 34 B and S gage.7.2.4 Titrimeter, automatic (preferre
39、d) or manual, equipped with a silver/silver chloride electrode pair and a 10 ml capacity microburette.7.2.5 Bubble counter, a 100 ml graduate and delivery tube, or a bent “L” glass tube connected to a piece of rubber tubing. The graduate is filled to the 50 ml mark with water to which 3 ml of 0,1 M
40、AgNO3and 1 drop of concentrated nitric acid have been added. Any turbidity that develops indicates that HCl gas is being lost when venting the bomb. ISO 2017 All rights reserved 3BS ISO 26603:2017ISO 26603:2017(E)Key1 ignition wire2 sample pan3 oxygen fill port4 oxygen vent portFigure 1 Parr oxygen
41、bomb7.3 Procedure7.3.1 Make certain that the bomb, oxygen lines, and fittings are free of oil and grease.WARNING Small quantities of either oil or grease may cause a violent explosion.When the bomb is used repeatedly, a film may form on its inner surface. Remove this film by rotating the bomb on a l
42、athe at about 300 r/min and polishing the inside surface with Grit No. 2/0 or equivalent paper coated with light machine oil, then with a paste made from grit-free chromic oxide and water. This procedure will remove all but very deep pits while polishing the surface. Before using the bomb, wash it w
43、ith soap and water to remove residual cutting oil or paste. Bombs with pitted surfaces should not be used because they will retain chlorine from sample to sample.7.3.2 Weigh a 0,9 g sample by difference to 0,000 5 g into the combustion capsule.WARNING A severe safety hazard exists if more than 1 g o
44、f sample is used.7.3.3 Fit a 100 mm, iron-nickel fuse wire (7.2.3) onto the two electrodes. Place the combustion capsule on the loop electrode and adjust the fuse wire in the capsule so that it is under the surface of the sample but does not touch the capsule. Place about 5 ml of Na2CO3solution (7.1
45、.7) in the bomb and, with a small rubber spatula, wet the interior surface of the bomb, including the head, as thoroughly as possible. Put the bomb head in the bomb cylinder and the contact ring on top of the bomb head, screwing the cap down finger-tight. Close the outlet valve securely with the spe
46、cial wrench provided and open the main oxygen cylinder slightly. Place the bomb in its bench-mounted holder and tighten the holder with a suitably sized hex wrench. Attach the union on the oxygen-filling connection to the inlet valve of the bomb. Admit oxygen slowly (to prevent blowing the sample fr
47、om the cup) to 20 to 25 atmospheres (2,03 MPa to 2,53 MPa). Close the operating valve of the oxygen cylinder and observe the pressure on 4 ISO 2017 All rights reservedBS ISO 26603:2017ISO 26603:2017(E)the bomb gage. If a leak is indicated by a gradual pressure drop, inspect and tighten all connectio
48、ns. Do not continue with the test until the leak is stopped and the bomb holds pressure. Release the pressure from the oxygen tank and disconnect the bomb. Place the valve thumb nut on the oxygen inlet valve and tighten finger-tight.WARNING Exercise extreme caution from this point on until the bomb
49、has been fired, cooled, and bled free of oxygen.7.3.4 Pull the plug to the bomb ignition unit. Fill the bomb ignition receptacle three-quarters full of water. Submerge the bomb in the centre of the ignition receptacle and visually inspect it for oxygen leaks. If the needle valve is not gas tight, tighten the packing gland slightly. Do not fire the bomb until all leaks are repaired. Allow cooling water to circulate around the bomb the entire time the bomb is in the receptacle.WARNING A serious
