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1、BRITISH STANDARD BS 7164-13: 1994 Incorporating Amendment No. 1 Chemical tests for raw and vulcanized rubber Part 13: Method for determination of total hydrocarbon content Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy
2、, (c) BSI BS 7164-13:1994 This British Standard, having been prepared under the direction of the Plastics and Rubber Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 August 1994 BSI 08-1999 The following BSI references relate to the wor
3、k on this standard: Committee reference PRM/23 Draft for comment 93/307863 DC ISBN 0 580 23331 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plastics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/23, upon w
4、hich the following bodies were represented: Institute of Water and Environmental Management Laboratory of the Government Chemist Ministry of Defence Royal Society of Chemistry Rubber and Plastics Research Association Amendments issued since publication Amd. No.DateComments 8596May 1995Indicated by a
5、 sideline in the margin Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7164-13:1994 BSI 08-1999i Contents Page Committees responsibleInside front cover Forewordii Introduction1 1Scope1 2References1 3Princip
6、le1 4Reagents1 5Apparatus1 6Sampling2 7Procedure2 8Calculation and expression of results3 9Test report3 Figure 1 Apparatus for determination of total hydrocarbon content2 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:2
7、2 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7164-13:1994 ii BSI 08-1999 Foreword This Part of 7164 has been prepared under the direction of the Plastics and Rubber Standards Policy Committee. It supersedes Section 4 of BS 903-B12:1960, which is withdrawn. Attention is drawn to BS 7164-15.1:1994
8、which also specifies a thermogravimetric method for particular listed polymers. 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 standar
9、ds will be withdrawn or deleted by amendment, as appropriate, when superseded by Parts and Sections of BS 7164.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 th
10、e user from legal obligations relating 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
11、immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, 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
12、 the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7164-13:1994 BSI 08-19991 Introduction The presence of elements in the polymer, other than carbon, hydrogen and
13、 oxygen, causes decomposition with carbonization. For this reason this method cannot be applied to acrylonitrile or chloroprene rubbers. Insofar as vulcanization has brought other elements into combination with the hydrocarbon, some carbonization results but the resultant error is small. Other sourc
14、es of error causing positive bias are associated with the fillers present in the compound and with combined sulfur. Thus clays, silicates and silicas lose moisture when heated at the temperature of pyrolysis and these losses may amount to 15 % of the filler present. Some carbon blacks similarly lose
15、 volatile matter, mainly hydrocarbon. In addition certain other materials, not removed by solvent extraction, will also pyrolyze and cause an additional weight loss; examples of such materials are lead and cobalt-salts, phenolics and other resins. 1 Scope This Part of BS 7164 describes a pyrolytic m
16、ethod for the determination of total hydrocarbon rubber in a rubber compound. This method is recommended for the following polymers: polyisoprene, natural and synthetic; polybutadiene; styrene-butadiene copolymers; butyl rubber; acrylate rubber; ethylene-propylene copolymer; ethylene-propylene terpo
17、lymer; polyethers. 2 References 2.1 Normative references This Part of BS 7164 incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed on the inside back cover. For date
18、d references, only the edition cited applies; any subsequent amendments to or revisions of the cited publication apply to this Part 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
19、any amendments. 2.2 Informative references This Part of BS 7164 refers to other publications 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
20、Principle A weighed test portion of the rubber is extracted with acetone and, if bitumen is present, with dichloromethane. The extracted rubber is pyrolyzed in a combustion boat at (550 25) C in a stream of nitrogen, cooled and weighed. The loss in mass during pyrolysis represents the rubber content
21、. 4 Reagents WARNING. All recognized health and safety precautions should be taken when carrying out this procedure. It is essential that all evaporations should be carried out in a fume cupboard (hood). 4.1 General. Use only reagents of recognized analytical grade and only distilled water conformin
22、g to grade 3 of BS 3978:1987 or water of equivalent purity. 4.2 Nitrogen, dry and containing less than 20 ppm by volume of oxygen. 4.3 Sulfuric acid solution, c(H2SO4) = 18 mol/l. 4.4 Xylene, general laboratory grade. 4.5 Acetone 4.6 Dichloromethane 4.7 Ethanol-toluene azeotrope (ETA). Mix seven vol
23、umes of absolute ethanol with three volumes of toluene. Alternatively, mix seven volumes of commercial grade ethanol with three volumes of toluene and boil the mixture with anhydrous calcium oxide under reflux for 4 h. Distil the azeotrope and collect the fraction with a boiling range not exceeding
24、1 C for use in the test. 5 Apparatus 5.1 Combustion boat, made of silica, of length 50 mm to 60 mm, with handle. 5.2 Tube furnace assembly (see Figure 1), comprising the following parts. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Un
25、controlled Copy, (c) BSI BS 7164-13:1994 2 BSI 08-1999 5.2.1 Combustion tube, made of quartz or of impervious aluminous porcelain, and fitted with means for advancing and withdrawing the combustion boat (5.1). The inside diameter of the tube shall be suitable to allow the combustion boat to enter an
26、d move easily through the tube. The tube shall be 30 cm longer than the electric tube furnace (5.2.2). One end of the tube is provided with a gas-inlet system for nitrogen, the opposite end with a suitable outlet system for the vapours produced during the pyrolysis. 5.2.2 Horizontal tube furnace, ha
27、ving suitable inside diameter to allow the combustion tube (5.2.1) to enter the heated section of the furnace. The furnace is electrically heated and thermostatically maintained at (550 25) C, with a temperature-indicating meter. 5.2.3 Silica glass rod with hook, of length sufficient to reach throug
28、h the combustion tube (5.2.1) and inlet tube (5.2.4), and of diameter sufficient to make tight contact with the rubber tube in the inlet tube. 5.2.4 Inlet tube, with side tube for nitrogen supply and with a short length of rubber tubing in which the silica glass rod (5.2.3) is held in an air-tight j
29、oint but allows the rod to slide in and out of the combustion tube (5.2.1). The tubing used for the gas inlet system shall be made of plasticized PVC or other material having a low permeability to oxygen and water vapour. Flow meters and flow controllers for nitrogen or oxygen are required. 5.2.5 Va
30、pour absorption equipment, consisting of rubber tubing, for the connection of the outlet system of the combustion tube (5.2.1) with a trap for readily condensable vapours, and two gas-washing bottles containing xylene (4.4). 5.3 Extraction apparatus, conforming to BS 7164-3:1992. 5.4 Dessicator 5.5
31、Oven, capable of maintaining a temperature of 100 C. 5.6 Standard laboratory apparatus 6 Sampling Cut a test sample of at least 1.5 g from the laboratory sample. 7 Procedure 7.1 Prepare the test sample by passing the rubber six times between the rolls of a laboratory mill set to a nip not exceeding
32、0.5 mm. Cut from the sheet a test portion having a mass of approximately 0.1 g to 0.5 g. If it is not possible to pass the sample through the mill, the sample may be cut into pieces with sides measuring less than 1 mm. 7.2 Weigh the test portion to the nearest 0.1 mg. Record this mass (m0). Wrap the
33、 test portion in filter paper and extract with acetone (4.5) for 4 h or until the solvent in contact with the test portion is colourless. If bitumen is present in the compound, extract with dichloromethane (4.6) for 4 h or until the solvent in contact with the test portion appears colourless. Uncure
34、d compounds cannot be extracted with dichloromethane. ETA (4.7) may be used instead of the acetone and dichloromethane. NOTEExtraction with dichloromethane is only necessary if materials not completely soluble in acetone, such as bitumen, are present. Extraction can be facilitated by comminuting the
35、 test portion before weighing. To do this, pass it through a mill with minimum clearance between the rolls. Figure 1 Apparatus for determination of total hydrocarbon content Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Co
36、py, (c) BSI BS 7164-13:1994 BSI 08-19993 7.3 Remove the extracted test portion from the paper and dry in an oven (5.5) controlled at (100 3) C until the solvent is completely removed. 7.4 Quantitatively transfer the dried test portion to the combustion boat (5.1) and weigh (m1). Place the boat in th
37、e combustion tube (5.2.1) near the nitrogen inlet system. 7.5 Close the tube with the entry fitting and connect to the nitrogen (4.2) supply. Introduce the combustion tube into the furnace (5.2.2) heated to (550 25) C keeping the boat in the cool part of the combustion tube. Connect the opposite end
38、 of the tube to the vapour absorption equipment (5.2.5). 7.6 Pass the nitrogen through the tube at approximately 200 cm3/min for 5 min or more to eliminate the air contained in the combustion tube. 7.7 Reduce the rate of nitrogen flow to about 100 cm3/min and move the boat slowly into the heated zon
39、e of the combustion tube over a period of approximately 5 min. 7.8 Leave the boat in the hot zone for a further 10 min in order to complete the pyrolysis. 7.9 Withdraw the boat to the cold part of the tube and allow to cool for 10 min, while still maintaining the flow of nitrogen. 7.10 Transfer the
40、boat to the desiccator (5.4), complete the cooling and weigh to the nearest 0.1 mg. Record this mass (m1). 7.11 Carry out the determination in duplicate. 8 Calculation and expression of results The polymer content C in % (m/m) is calculated using the following equation: where NOTE 1The test portion
41、may be taken from previously extracted material. In this case a correction for solvent extract level is made to obtain m0. NOTE 2Any non-extractable matter volatile at 550 C inherent in the carbon black (as purchased) will be lost during the pyrolysis in nitrogen. The final result for the mass perce
42、ntage of carbon black will therefore be lower by this amount. In cases where the carbon black type and origin are known, a suitable correction can be made. 9 Test report The test report shall include the following information: a) reference to this British Standard; b) identification of the test samp
43、le; c) the mean of the two results obtained; d) any unusual features noted during the determination; e) any operation not included in this British Standard or any operation regarded as optional. m0is the mass of the test portion (in g); m1is the mass of the combustion boat plus extracted test portio
44、n (in g); m2is the mass of the combustion boat and its contents after heating in nitrogen (in g). C m1m2 m0 - -100= Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 blank Licensed Copy: London South Bank Unive
45、rsity, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7164-13:1994 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 7
46、164, Chemical tests for raw and vulcanized rubber. BS 7164-3:1992, Methods for determination of solvent extract. Informative references BSI publications BRITISH STANDARDS INSTITUTION, London BS 903, Physical testing of rubber1). BS 1673, Methods of test for raw rubber and unvulcanized compounded rub
47、ber1). BS 5923, Methods for chemical analysis of rubber1). BS 7164, Chemical tests for raw and vulcanized rubber. BS 7164-15, Method for thermogravimetric determination of the composition of vulcanizates and uncured compounds. BS 7164-15.1:1994, Butadiene, ethylene-propylene copolymer and terpolymer
48、, isobutene-isoprene, isoprene and styrene-butadiene rubbers1). 1) Referred to in the foreword only Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:34:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7164-13: 1994 BSI 389 Chiswick High Road London W4 4AL BSI
49、British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inacc
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