1、BRITISH STANDARD BS 7164-22.1: 1994 Chemical tests for raw and vulcanized rubber Part 22: Determination of chlorine content Section 22.1 Parr bomb method UDC 678.763:543:546.13BS7164-22.1:1994 This British Standard, having been prepared under the directionof the Plastics and Rubber Standards Policy
2、Committee, waspublished underthe authorityofthe Standards Boardand comesintoeffect on 15August1994 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference PRM/23 Draft for comment 93/309891 DC ISBN 0 580 2332 6 X Committees responsible for this British Stand
3、ard The preparation of this British Standard was entrusted by the Plastics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/23, upon which the following bodies were represented: Institute of Water and Environmental Management Laboratory of the Government Chemist Ministry of D
4、efence Royal Society of Chemistry Rubber and Plastics Research Association Amendments issued since publication Amd. No. Date CommentsBS7164-22.1:1994 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6
5、Sampling 1 7 Procedure 1 8 Calculation and expression of results 2 9 Test report 2 List of references Inside back coverBS7164-22.1:1994 ii BSI 08-1999 Foreword This Section of 7164 has been prepared under the direction of the Plastics and Rubber Standards Policy Committee. It supersedes Section 3 of
6、 BS 903-B12:1960, which Section is withdrawn. BS 7164 rationalizes all the methods that deal with chemical analysis of raw, compounded and vulcanized rubber, some of which have previously been published in BS 903, BS 1673 and BS 5923. Relevant Parts of those standards will be withdrawn or deleted by
7、 amendment, as appropriate, when superseded by Parts and Sections of BS 7164. This British Standard calls for the use of substances that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations rela
8、ting to health and safety at any stage. 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. S
9、ummary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside
10、 front cover.BS7164-22.1:1994 BSI 08-1999 1 1 Scope This Section of BS 7164 describes a fusion method for the determination of chlorine. This method is applicable to the determination of total chlorine in neoprene. 2 References 2.1 Normative references This Section of BS 7164 incorporates, by dated
11、or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the c
12、ited publication apply to this Section of BS 7164 only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 2.2 Informative references This Section of BS 7164 refers to other publicatio
13、ns that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Principle Extraction of a weighed test portion of the rubber with light petroleum or metha
14、nol is carried out. The extracted rubber is decomposed by fusion with sodium peroxide in a Parr bomb. The chlorine is converted to sodium chloride which is determined by titration with silver nitrate. 4 Reagents WARNING. All recognized health and safety precautions should be taken when performing th
15、is method of analysis. It is essential that all procedures should be carried out in a fume cupboard (hood). 4.1 General. Use only reagents of recognized analytical grade and only distilled water conforming to grade 3 of BS 3978:1987 or water of equivalent purity. 4.2 Silver nitrate solution, c(AgNO
16、3 ) = 0.025 mol/l. 4.3 2, 7- dichlorofluorescein indicator solution Dissolve 0.2 g 2, 7-dichlorofluorescein in 100 cm 3industrial methylated spirits. 4.4 Nitric acid solution, c(HNO 3 ) = 16 mol/l. 4.5 Dilute nitric acid solution. Dilute one volume of4.4 with four volumes of water. 4.6 Fusion mixtur
17、e. Prepare a mixture of 3 parts of sodium peroxide and 1 part of sodium carbonate. 4.7 Sucrose 5 Apparatus 5.1 Parr bomb, the design and construction of which shall be such as to resist any pressure likely to occur during the reaction. The Parr bomb apparatus should be complete with a lid, gasket an
18、d union, and the metal and gasket shall be resistant to chemical attack by the reaction mixture. WARNING. A suitable fusion guard should be used during the firing of the bomb. A short metal cylinder, two or three times the diameter of the bomb and about twice the height, is suitable. 5.2 Oven, capab
19、le of maintaining a temperature of100 C. 5.3 Standard laboratory equipment 6 Sampling Cut a test portion from the laboratory sample. 7 Procedure 7.1 Weigh a test portion of approximately 0.1 g of the sample to the nearest 0.1 mg. Record this mass(m 0 ). Wrap the test portion in filter paper and extr
20、act with light petroleum or methanol in accordance with BS 7164-3:1992. 7.2 Remove the extracted test portion from the paper and dry in an oven (5.2) controlled at(100 3) C until the solvent is completely removed. 7.3 Place in the fusion cup of the bomb 6 g of the fusion mixture (4.6) to which 0.5 g
21、 of sucrose has been added. 7.4 Break the dry test portion into small pieces, add to the mixture in the fusion cup and mix well. 7.5 Assemble the bomb and fire in accordance with the manufacturers instructions. 7.6 Cool the bomb in cold water and open. 7.7 Wash the contents of the bomb into a beaker
22、, cool and filter. 7.8 Neutralize the filtrate with nitric acid (4.4) and then make just acid with dilute nitric acid (4.5). 7.9 Titrate the chloride with silver nitrate solution using the p-chlorofluorescein indicator. 7.10 Carry out a duplicate analysis. 7.11 Carry out a blank firing of the bomb t
23、o confirm the absence of chlorine in the reagents used. If a blank is found titrate the solution and subtract this value from that obtained in the determination.BS7164-22.1:1994 2 BSI 08-1999 8 Calculation and expression of results The chlorine content C in% (m/m) is calculated using the following e
24、quation: where NOTEThe test portion may be taken from previously extracted material. In this case a correction for the solvent extract may be made to obtain m 0 . 9 Test report The test report shall include the following information: a) reference to this British Standard; b) identification of the te
25、st sample; c) the mean of two results obtained; d) any unusual features noted during the determination; e) any operation not included in this BritishStandard or any operations regarded as optional. v is the volume of silver nitrate solution required to neutralize the test solution (incm 3 ); m 0 is
26、the mass of the test portion (in g). C v 0.088 m 0 - =BS7164-22.1:1994 BSI 08-1999 List of references (see clause 2) Normative references BSI publications BRITISH STANDARDS INSTITUTION, London BS 3978:1987, Specification for water for laboratory use. BS 7164, Chemical tests for raw and vulcanized ru
27、bber. BS 7164-3:1992, Method for determination of solvent extract. Informative references BSI publications BRITISH STANDARDS INSTITUTION, London BS 903, Physical testing of rubber 1) . BS 1673, Methods of test for raw rubber and unvulcanized compounded rubber 1) . BS 5923, Methods for chemical analy
28、sis of rubber 1) . 1) Referred to in the foreword onlyBS 7164-22.1: 1994 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international le
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