1、BSI Standards PublicationBS ISO 15028:2014Plastics Aromaticisocyanates for use in theproduction of polyurethanes Determination of hydrolysablechlorineBS ISO 15028:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 15028:2014. Itsupersedes BS ISO 15028:2004 wh
2、ich is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/42, Fibre reinforced thermosetting plastics andprepregs.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all t
3、he necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 81990 2ICS 83.080.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standa
4、rd was published under the authority of theStandards Policy and Strategy Committee on 31 March 2014.Amendments issued since publicationDate Text affectedBS ISO 15028:2014 ISO 2014Plastics Aromatic isocyanates for use in the production of polyurethanes Determination of hydrolysable chlorinePlastiques
5、 Isocyanates aromatiques pour utilisation dans la production de polyurthannes Dtermination du chlore hydrolysableINTERNATIONAL STANDARDISO15028Second edition2014-02-15Reference numberISO 15028:2014(E)BS ISO 15028:2014ISO 15028:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 20
6、14All 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. Permission can be request
7、ed from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 15028:2014ISO 15028:2014(E) ISO 2014 All ri
8、ghts reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Interference . 26 Sampling 27 Test conditions . 28 Reagents 29 Apparatus . 210 Procedure. 311 Expression of results 312 Precision and bias . 312.1 Precision . 312.2 Bia
9、s 413 Test report . 4Bibliography 5BS ISO 15028:2014ISO 15028:2014(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 technica
10、l committees. Each member body interested in a subject for 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 wit
11、h the International Electrotechnical Commission (IEC) on all 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 f
12、or the different types of ISO documents should be noted. This 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 right
13、s. ISO shall not be held responsible for identifying any 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
14、document is information given for the convenience of 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 WTO principles in the Technical Barriers to T
15、rade (TBT) see the following URL: Foreword - Supplementary information.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 15028:2004), which has been technically revised.iv IS
16、O 2014 All rights reservedBS ISO 15028:2014ISO 15028:2014(E)IntroductionNo International Standard for the determination of hydrolysable chlorine in isocyanates has been published. The main sources of hydrolysable chlorine in isocyanates are carbamoyl chloride and dissolved phosgene from the manufact
17、uring process. Both of these compounds react with alcohols and water, forming ureas, carbamates, carbon dioxide and hydrochloric acid. These acidic materials neutralize basic catalysts used in polyurethane production, thus adversely affecting processing properties. This test method is based on and i
18、s technically equivalent to ASTM D 4663. ISO 2014 All rights reserved vBS ISO 15028:2014BS ISO 15028:2014Plastics Aromatic isocyanates for use in the production of polyurethanes Determination of hydrolysable chlorineSAFETY STATEMENT Persons using this document should be familiar with normal laborato
19、ry 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 compliance with any regulatory requirements.1 ScopeThis Internati
20、onal Standard specifies a method for the determination of the hydrolysable-chlorine content of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or mixtures of the two. This test method may also be applied to other isocyanates of suitable solubility, such as crude or refined polymeric isocyanates.2
21、 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendme
22、nts) applies.ISO 385, Laboratory glassware Burettes ISO 648, Laboratory glassware Single-volume pipettesISO 3696:1987, Water for analytical laboratory use Specification and test methodsISO 4787, Laboratory glassware Volumetric instruments Methods for testing of capacity and for useISO 6353-2, Reagen
23、ts for chemical analysis Part 2: Specifications First series3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1polyurethanepolymer prepared by the reaction of an organic di- or polyisocyanate with compounds containing two or more hydroxyl groups3.2
24、hydrolysable chlorineorganic or inorganic chlorine compounds formed in the production of isocyanates that react with methanol under the conditions of the test to liberate hydrogen chloride4 PrincipleThe hydrolysable chlorine reacts with methanol, liberating hydrogen chloride. The titratable chloride
25、s are then determined potentiometrically using a standard silver nitrate solution.INTERNATIONAL STANDARD ISO 15028:2014(E) ISO 2014 All rights reserved 1BS ISO 15028:2014ISO 15028:2014(E)5 InterferenceThiocyanate, cyanide, sulfide, bromide, iodide and other substances capable of reacting with silver
26、 ions, as well as substances capable of reducing silver ions in acid solution, will interfere with the determination.6 SamplingSince organic isocyanates react with atmospheric moisture, take special precautions in sampling. Usual sampling methods (for example sampling an open drum with a thief), eve
27、n when conducted rapidly, can 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 are hazardous when absorbed through the skin, or when the vapours are breathed in. Pro
28、vide adequate ventilation and wear protective gloves and eyeglasses.7 Test conditionsSince isocyanates react with moisture, keep the laboratory humidity low preferably below 50 % relative humidity.NOTE If the relative humidity is greater than 50 % relative humidity, work quickly to minimize exposure
29、 of the sample to the air.8 ReagentsReagent-grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of ISO 6353-2. Other grades may be used, provided that it is first determined that the reagent is of sufficiently h
30、igh purity to permit its use without lessening the accuracy of the determination.Unless otherwise indicated, references to water shall be understood to mean grade 2 water as defined by ISO 3696:1987.8.1 Concentrated nitric acid, HNO3, specific gravity 1,42, conforming to ISO 6353-2.8.2 Methanol, CH3
31、OH, conforming to ISO 6353-2.8.3 Silver nitrate, standard solution (0,01 M).Standardize with standard hydrochloric acid, either gravimetrically or potentiometrically, frequently enough to detect changes of 0,000 5 M.9 Apparatus9.1 Titrator, automatic (preferred) or manual, equipped with a silver/sil
32、ver chloride electrode pair and a 50 ml burette, the latter conforming to ISO 385.9.2 Pipette, 50 ml, one-mark, conforming to ISO 648.9.3 Beakers, 400 ml, conforming to ISO 4787.9.4 Magnetic stirrer, equipped with an inert stirring bar, or equivalent stirrer.9.5 Laboratory balance, capable of weighi
33、ng out test portions to within 0,01 g.2 ISO 2014 All rights reservedBS ISO 15028:2014ISO 15028:2014(E)10 Procedure10.1 Weigh (by difference to the nearest 0,01 g) 9 g to 11 g of the sample (or 18 g to 22 g of the sample if the hydrolysable-chlorine content is expected to be less than 0,01 %) from a
34、sampling weighing bottle into a clean, dry 400 ml beaker. Add 50 ml of methanol and stir. Stir continually while the reaction starts, at which point the beaker will become warm and crystals may form on the sides of the beaker (see the Note). Fill the beaker half-full with water (add the water quickl
35、y to keep the reactants from solidifying and to minimize the loss of HCl) and boil gently for 30 min.NOTE Some isocyanates will not react readily and slight warming may be necessary to initiate the reaction. Other isocyanates may react, as indicated by warming of the reactants, but may not form crys
36、tals.10.2 Wash the sides of the beaker with water and remove and rinse the stirring bar, adding the rinsings to the beaker. Cool the beaker in an ice bath to about 10 C and add 10 drops of HNO3. Titrate potentiometrically with 0,01 M AgNO3(8.3) using a silver/silver chloride electrode pair (see 9.1)
37、 with stirring. If the chloride content is greater than 0,2 %, use 0,1 M instead of 0,01 M AgNO3solution.Statistical data were developed in a round robin in which cooling to 10 C was used. Other laboratories report that cooling to about 20 C is sufficient. A temperature of 20 C may be used if it is
38、established that the results do not differ statistically from results obtained with cooling to 10 C.11 Expression of resultsCalculate the hydrolysable chlorine, as a percentage by mass, as follows:Hydrolysable chlorine = 3,55 V c/m whereV is the volume of AgNO3solution required to titrate the test p
39、ortion, in ml;c is the exact concentration of the AgNO3solution, in mol/l;m is the mass of the test portion taken, in g;3,55 is a constant combining the atomic mass of chlorine (35,5), the conversion from mg to g (1 000), and the conversion to percent (100).12 Precision and bias12.1 PrecisionThe pre
40、cision statement is based on a limited round robin conducted among three laboratories; therefore, this test method should not be used as a referee test method in cases of dispute.12.1.1 RepeatabilityIt is estimated that duplicate results obtained by the same analyst using the same equipment on the s
41、ame day should be considered as suspect if they differ by more than 0,000 5 % at hydrolysable-chlorine concentrations of 0,001 % to 0,2 %.12.1.2 ReproducibilityIt is estimated that results reported by different laboratories should be considered as suspect if they differ by more than 0,003 % hydrolys
42、able chlorine. ISO 2014 All rights reserved 3BS ISO 15028:2014ISO 15028:2014(E)12.2 BiasBias is the difference between the expectation of the test results and an accepted reference value. There are no recognized standards by which to estimate the bias of this test method.13 Test reportThe test repor
43、t shall include the following information:a) a reference to this International Standard;b) all details necessary to identify the product analysed (such as manufacturer, product type, lot or notebook numbers and date of manufacture, as required);c) the result obtained, expressed as % hydrolysable chl
44、orine to the nearest 0,001 % hydrolysable chlorine;d) the date of the analysis;e) any incident or detail not stipulated in this International Standard which may have influenced the result.4 ISO 2014 All rights reservedBS ISO 15028:2014ISO 15028:2014(E)Bibliography1 ASTM D 4663, Standard Test Method
45、for Polyurethane Raw Materials Determination of Hydrolyzable Chlorine of Isocyanates ISO 2014 All rights reserved 5BS ISO 15028:2014ISO 15028:2014(E) ISO 2014 All rights reservedICS 83.080.10Price based on 5 pagesThis page deliberately left blankBSI is the national body responsible for preparing Bri
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