BS ISO 124-2014 Latex rubber Determination of total solids content《乳胶 橡胶 总固体含量的测定》.pdf

1、BSI Standards PublicationBS ISO 124:2014Latex, rubber Determinationof total solids contentBS ISO 124:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 124:2014. Itsupersedes BS ISO 124:2011 which is withdrawn.The UK participation in its preparation was entru

2、sted to TechnicalCommittee PRI/50, Rubber - Raw, natural and synthetic, includinglatex and carbon black.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are r

3、esponsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 80286 7ICS 83.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStanda

4、rds Policy and Strategy Committee on 31 March 2014.Amendments issued since publicationDate Text affectedBS ISO 124:2014 ISO 2014Latex, rubber Determination of total solids contentLatex de caoutchouc Dtermination des matires solides totalesINTERNATIONAL STANDARDISO124Seventh edition2014-03-15Referenc

5、e numberISO 124:2014(E)BS ISO 124:2014ISO 124:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All 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, includi

6、ng photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested 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 74

7、9 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 124:2014ISO 124:2014(E) ISO 2014 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Principle 14 Apparatus . 15 Sampling 16 Procedure. 26.1 General . 26.2 Heating at atmospheric pressure (70

8、C and 105 C) Natural and synthetic rubber latex 26.3 Heating at atmospheric pressure (up to 160 C) Synthetic rubber latex 26.4 Heating at reduced pressure Synthetic rubber latex 27 Expression of results 38 Precision . 39 Test report . 3Annex A (informative) Drying conditions for synthetic latices at

9、 atmospheric pressure 4Annex B (informative) Precision statement 5Bibliography 8BS ISO 124:2014ISO 124:2014(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

10、normally carried out through ISO technical 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

11、in the work. ISO collaborates closely with 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

12、 the different approval criteria needed for 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 d

13、ocument may be the subject of patent rights. 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

14、org/patents). Any trade name used in this 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 WT

15、O principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.This seventh editio

16、n cancels and replaces the sixth edition (ISO 124:2011) which has been technically revised to introduce the following modifications: the introduction has been deleted; the scope has been extended to cover field latex; Subclause 6.1 now states the preferred method in case of dispute; the precision da

17、ta in Annex B have been updated to cover field latex.iv ISO 2014 All rights reservedBS ISO 124:2014INTERNATIONAL STANDARD ISO 124:2014(E)Latex, rubber Determination of total solids contentWARNING Persons using this International Standard should be familiar with normal laboratory practice. This Inter

18、national Standard does not purport to address all of the safety problems, 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 national regulatory conditions.1 ScopeThis International Standard spe

19、cifies methods for the determination of the total solids content of natural rubber field and concentrated latices and synthetic rubber latex. These methods are not necessarily suitable for latex from natural sources other than the Hevea brasiliensis, for vulcanized latex, for compounded latex, or fo

20、r artificial dispersions of rubber.2 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 refere

21、nced document (including any amendments) applies.ISO 123, Rubber latex Sampling3 PrincipleA test portion of the latex is dried to constant mass under specified conditions, either at atmospheric pressure or under vacuum. The total solids content is determined by weighing before and after drying to co

22、nstant mass.NOTE The determination of the residue after drying for a specific period of time is the subject of ISO 3251.14 ApparatusUsual laboratory equipment, and in particular, the following.4.1 Flat-bottomed dishes, lipless, of diameter approximately 60 mm.4.2 Ovens, capable of being maintained a

23、t 70 C 5 C, 105 C 5 C, or at another selected temperature between 100 C and 160 C accurate to 5 C.4.3 Vacuum oven, capable of being maintained at 125 C 2 C and at a pressure below 20 kPa1).4.4 Analytical balance, capable of being read to 0,1 mg.5 SamplingCarry out sampling in accordance with one of

24、the methods specified in ISO 123.1) 1 kPa = 1 kN/m2. ISO 2014 All rights reserved 1BS ISO 124:2014ISO 124:2014(E)6 Procedure6.1 GeneralFor natural rubber latex, proceed in accordance with 6.2; and for synthetic rubber latex proceed in accordance with 6.2, 6.3, or 6.4. Perform the determination in du

25、plicate.In case of dispute, heating the latex at 70 C is the preferred method.6.2 Heating at atmospheric pressure (70 C and 105 C) Natural and synthetic rub-ber latexWeigh, to the nearest 0,1 mg, a dish (4.1). Pour into the dish 2,0 g 0,5 g of latex and determine the exact mass (m0) by weighing to t

26、he nearest 0,1 mg. Gently swirl the contents of the dish to ensure that the latex covers the bottom. If desired, approximately 1 cm3of distilled water or water of equivalent purity can be added and mixed with the latex by swirling.Place the dish in the oven (4.2) so that it is horizontal, and heat i

27、t at 70 C 5 C for 16 h, or at 105 C 5 C for 2 h, or until the test portion has lost its whiteness.NOTE 1 The disappearance of whiteness is the first indication of dryness. Dry latex film is translucent.Remove the dish from the oven and allow it to cool to ambient temperature in a desiccator. Remove

28、the dish and weigh.Return the dish to the oven for 30 min at 70 C 5 C or 15 min at 105 C 5 C. Remove the dish and allow it to cool to ambient temperature in a desiccator as before and reweigh.Repeat the drying procedure for periods of 30 min or 15 min, as appropriate until the loss in mass between t

29、wo successive weightings is less than 0,5 mg.Record the mass of the dried latex (m1).If after heating at 105 C 5 C, the dried deposit becomes excessively sticky, repeat the determination at 70 C 5 C.NOTE 2 Stickiness is symptomatic of oxidation of some rubbers when exposed to air at too high a tempe

30、rature.6.3 Heating at atmospheric pressure (up to 160 C) Synthetic rubber latexBy agreement between the interested parties, the drying process can be carried out at temperatures up to 160 C to shorten drying times.NOTE The maximum drying temperature for CR latex is 130 C, while any rubber latex exce

31、pt CR in Table A.1 can be dried at up to 160 C.Proceed in accordance with 6.2, but heat the dish containing the latex at for instance 130 C 5 C for 40 min or 160 C 5 C for 20 min (see Annex A). After allowing to cool in a desiccator and weighing, repeat the drying for periods of 10 min until the los

32、s in mass between two successive weightings is less than 0,5 mg.6.4 Heating at reduced pressure Synthetic rubber latexWeigh, to the nearest 0,1 mg, a dish (4.1). Pour into the dish 1,0 g 0,2 g of latex and weigh to the nearest 0,1 mg. Add approximately 1 cm3of distilled water or water of equivalent

33、purity and mix by swirling, ensuring that the latex covers the bottom of the dish.Place the dish in the vacuum oven (4.3) so that it is horizontal. Reduce the pressure slowly to avoid foaming and splattering, and heat at 125 C for 45 min to 60 min at a pressure below 20 kPa. Release the vacuum slowl

34、y, remove the dish from the oven and allow to cool in a desiccator. Remove the dish 2 ISO 2014 All rights reservedBS ISO 124:2014ISO 124:2014(E)and weigh. Repeat the above drying procedure for periods of 15 min until the loss in mass between two successive weighings is less than 0,5 mg.7 Expression

35、of resultsCalculate the total solids content, TSC, expressed as a percentage mass fraction of the latex, using Formula (1):TSCmm=10100 (1)wherem0is the mass of the test portion before drying, expressed in g;m1is the mass of the final dried material, expressed in g.The results of the duplicate determ

36、inations shall not differ by more than 0,2 % mass fraction.NOTE Over a large number of determinations, the vacuum method (6.4) tends to give marginally lower values, but does not differ by more than 0,1 % mass fraction.8 PrecisionSee Annex B.9 Test reportThe test report shall include the following:a

37、) a reference to this International Standard (i.e. ISO 124:2014);b) details of the drying method and temperature used;c) all details necessary for identification of the test sample;d) the average value of the results and the units in which they have been expressed;e) details of any unusual features

38、noted during the determination;f) details of any operation not included in this International Standard or in the International Standard to which reference is made, as well as any operation regarded as optional. ISO 2014 All rights reserved 3BS ISO 124:2014ISO 124:2014(E)Annex A (informative) Drying

39、conditions for synthetic latices at atmospheric pressureA.1 Suitable drying conditions for various synthetic latices have been determined, i.e. conditions which give a constant mass. These are summarized in Table A.1. The conditions given for each latex are not to be considered as required condition

40、s, but as recommended conditions for the measurement of total solids content.A.2 Chloroprene rubber (CR) latex should not be heated at more than 130 C, because of possible decomposition.Table A.1 Drying conditions at 130 C and 160 CLatexaDrying timemin130 C 160 CX-SBR 40 20CR 30 Not applicablebVP 40

41、 20SBR 40 20X-SBR (with antidegradant) 40 20NBR (with antidegradant) 40 20X-NBR 40 20X-NBR (with antidegradant) 40 20X-MBR 40 20a“X-” means “carboxylated”.bSee A.2.4 ISO 2014 All rights reservedBS ISO 124:2014ISO 124:2014(E)Annex B (informative) Precision statementB.1 The precision data presented in

42、 Tables B.1, B.2, and B.3 were obtained in separate interlaboratory test programmes (ITPs) carried out at different times employing the test methods specified in 6.2 and 6.3, respectively.B.2 The precision was determined in accordance with ISO/TR 9272.2Refer to ISO/TR 92722for terminology and other

43、statistical details.B.3 The precision details in this annex give an estimate of the precision of these test methods with the materials used in the particular ITP as described below. The precision parameters should not be used for acceptance/rejection testing of any group of materials without documen

44、tation that the parameters are applicable to those particular materials and the specific test protocols that include these test methods.B.4 The precision results are given in Tables B.1, B.2, and B.3. The precision is expressed on the basis of a 95 % confidence level for the values established for r

45、epeatability, r, and reproducibility, R.NOTE Bias is not applicable. In test method terminology, bias is the difference between an average test value and the reference (or true) test property value. Reference values do not exist for this test method, since the value (of the test property) is exclusi

46、vely defined by the test method. Bias, therefore, cannot be determined for this particular test method.B.4.1 The results contained in Table B.1 are average values and give an estimate of the precision of this test method as determined in an ITP in 2012, in which seven laboratories performed triplica

47、te analyses on three samples, FL/1, FL/2, and FL/3, which were prepared from fresh field natural rubber latex. The bulk latex of each sample was homogenized and stirred prior to being sub-sampled into 1 l bottles labelled FL/1, FL/2, and FL/3. Each participating laboratory was required to carry out

48、the test using these three samples on the dates which had been given to the participants in the ITP.B.4.2 The results contained in Table B.2 are average values and give an estimate of the precision of this test method as determined in an ITP in 2010, in which 10 laboratories performed triplicate ana

49、lyses on two samples, A and B, which were prepared from high-ammonia natural-rubber latex concentrate. The bulk latex was strained and then homogenized by thorough blending and stirring prior to being sub-sampled into 1 l bottles labelled A and B. Thus, essentially, samples A and B were the same and treated as such in the statistical computations. Each participating laboratory was required to carry out the test using these two samples on the dates which