1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58ICS 83.060Rubber Determination of ashBRITISH STANDARDBS ISO 247:2006BS ISO 247:2006This British Sta
2、ndard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2006 BSI 2006ISBN 0 580 49484 5Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer im
3、munity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 247:2006. It supersedes BS 7164-5:1991 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/23, Test methods for rubber and no
4、n-black compounding ingredients.A list of organizations represented on PRI/23 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a INTERNATIONALSTANDARDISO247Fourth edition2006-09-15Reference numberISO 247:2006(E)Rubber Determinat
5、ion of ashCaoutchouc Dtermination du taux de cendresBS ISO 247:2006iiiiiForewordISO (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 ISOtechnic
6、al committees. Each member body interested in a subject for which a technical committee has beenestablished has the right to be represented on that committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with
7、 the InternationalElectrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft Internati
8、onal Standardsadopted by the technical committees are circulated to the member bodies for voting. Publication as anInternational Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the
9、 subject of patentrights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 247 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2,Testing and analysis.This fourth edition cancels and replaces the third edition (ISO 247:1990
10、), which has been revised to update thenormative references.BS ISO 247:2006blank1Rubber Determination of ash1ScopeThis International Standard specifies two methods for the determination of ash from raw rubbers, compoundedrubbers and vulcanizates. The methods are applicable to raw, compounded or vulc
11、anized rubbers of the M, N,O, R and U families described in ISO 1629, except that: Method A shall not be used for the determination of ash from compounded or vulcanized rubbers containingchlorine, bromine or iodine. Method B shall be used for compounded or vulcanized rubbers containing chlorine, bro
12、mine or iodine. ltshall not be used for uncompounded rubbers. Lithium and fluorine compounds may react with silica crucibles to form volatile compounds, giving low ashresults. Platinum crucibles shall therefore be used for ashing fluorine-containing and Iithium-polymerizedrubbers.This International
13、Standard does not cover the interpretation of the ash results as to the inorganic chemicalcontent of a compound or vulcanizate. This is the responsibility of the analyst, who has to be aware of thebehaviour of rubber additives at elevated temperatures.The two methods of ashing do not give identical
14、results in all cases, and it is necessary to state in the test reportthe method of ashing employed.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest
15、edition of the referenced document(including any amendments) applies.ISO 248, Rubber, raw Determination of volatile-matter contentISO 1629, Rubber and latices NomenclatureISO 1795, Rubber, raw natural and raw synthetic Sampling and further preparative procedures3 Principle3.1 Method AA weighed test
16、portion is heated in a crucible over a gas burner. After expulsion of the volatile decompositionproducts, the crucible is transferred to a muffle furnace where it is heated until all the carbonaceous matter hasbeen burnt off and constant mass is attained.3.2 Method BA weighed test portion is heated
17、in a crucible in the presence of sulfuric acid, first by means of a gas burner andthen in a muffle furnace until all the carbonaceous matter has been burnt off and constant mass is attained.BS ISO 247:200624Reagent4.1 Sulfuric acid (for method B only), analytical grade, .5 ApparatusOrdinary laborato
18、ry apparatus, plus the following:5.1 Crucible, of porcelain, silica or platinum, of capacity approximately . For raw synthetic rubbers, it ispermitted to use a crucible of minimum capacity per gram of test portion.5.2 Heat-resistant, thermally insulating board, square and of thickness approximately
19、, witha central hole to accommodate the crucible (5.1). About two-thirds of the crucible shall project below the board.5.3 Bunsen burner, or similar type of gas burner.5.4 Muffle furnace, fitted with a flue and with provision for controlling the air flow through the furnace. (Thismay be achieved by
20、adjusting the door opening.) A temperature-controlling device is required to maintain atemperature of or .6 Preparation of the test portion6.1 Test portions of raw natural rubber shall be cut from the homogenized piece prepared in accordance withISO 1795. Test portions of raw synthetic rubbers shall
21、 be cut from the dried rubber obtained after carrying outthe determination of volatile-matter content in accordance with ISO 248.6.2 Test portions of rubber compounds shall be comminuted by hand.6.3 Test portions of vulcanizate shall be sheeted or crumbed on a mill or comminuted by hand.6.4 Care sha
22、ll be taken to ensure that test portions of rubber compounds and vuIcanizates are representativeof the sample.7 Procedure7.1 Method AHeat a clean empty crucible (5.1) of appropriate size for about in the muffle furnace (5.4), maintained at, allow to cool to ambient temperature in a desiccator and we
23、igh to the nearest . Take atest portion of about of raw rubber or to of compounded rubber or vulcanizate, according to the massof ash to be expected, and weigh to the nearest . Place the weighed test portion in the crucible mountedin the hole in the heat-resistant, thermally insulating board (5.2).
24、Heat the crucible gently with the burner (5.3) ina hood for proper ventilation, taking care that the rubber does not ignite. If any material is lost due to spurting orfrothing, repeat the above procedure with a new test portion.When the rubber has decomposed to a charred mass, gradually increase the
25、 heat from the burner until thevolatile decomposition products have been substantially expelled and a dry carbonaceous residue remains.Transfer the crucible and its contents to the muffle furnace, maintained at (see, however, theNote), leaving the door of the furnace slightly open to provide suffici
26、ent air to oxidize the carbon.Continue heating until the carbon is completely oxidized and a clean ash is obtained. Remove the crucible andits contents from the furnace, allow to cool to ambient temperature in the desiccator and weigh to the nearest. Then heat the crucible and its contents again for
27、 about in the muffle furnace, maintained at(or see the Note), allow to cool to ambient temperature in the desiccatorand re-weigh to the nearest . This mass shall not differ from the previous mass by more than in thecase of raw rubbers or by more than relative to the amount of ash for compounds and v
28、ulcanizates. If this = 1,84 g/cm350 cm325 cm3100 mm 5mm550C 25C 950C 25C30 min550C 25C 0,1 mg5g 1g 5g0,1 mg550C 25C0,1 mg 30 min550C 25C 950C 25C0,1 mg 1mg1%BS ISO 247:20063requirement is not fulfilled, repeat the heating, cooling and weighing procedure until the difference between twosuccessive wei
29、ghings meets this requirement.NOTE For compounds and vulcanizates, a temperature of may be used.7.2 Method BHeat a clean empty crucible (5.1) of appropriate size for about in the muffle furnace (5.4), maintained at, allow to cool to ambient temperature in a desiccator and weigh to the nearest . Take
30、 atest portion of about to of the compound or vulcanizate and weigh to the nearest . Place the testportion in the crucible and pour about of concentrated sulfuric acid (4.1) over it so that the rubber iscompletely wetted. Place the crucible and its contents in the hole in the heat-resistant, thermal
31、ly insulatingboard (5.2) and heat gently with the burner in a hood for proper ventilation. If, during the initial reaction, themixture swells excessively, withdraw the flame to avoid possible loss of material.When the reaction becomes more gentle, increase the heat from the burner until the excess s
32、ulfuric acid isvolatilized and a dry, carbonaceous residue remains. Transfer the crucible and its contents to the muffle furnace,maintained at , and heat for about until all the carbon is completely oxidized and a clean ashis obtained. Remove the crucible and its contents from the furnace, allow to
33、cool to ambient temperature in adesiccator and weigh to the nearest . Then heat the crucible and its contents again for about inthe muffle furnace, maintained at , allow to cool to ambient temperature in the desiccator andre-weigh to the nearest .If this mass differs from the previous mass by more t
34、han relative to the amount of ash, repeat the heating,cooling and weighing procedure until the difference between two successive weighings is less than relativeto the amount of ash.8 Expression of resultsThe ash content is given, as a percentage by mass, by the formulawhereis the mass, in grams, of
35、the test portion;is the mass, in grams, of the empty crucible;is the mass, in grams, of the crucible and ash.9 Test reportThe test report shall include the following particulars:a) all details required for full identification of the piece or sample tested;b) a reference to this International Standar
36、d;c) the method employed method A or method B;d) the temperature used, and the reason for its choice if was used for method A;e) the ash determined for the product tested, as a percentage by mass;f) the date of the test.950C 25C30 min950C 25C 0,1 mg1g 5g 0,1 mg3,5 cm3950C 25C 1h0,1 mg 30 min950C 25C
37、0,1 mg1%1%m2m1m0 100m0m1m2950CBS ISO 247:2006BS ISO BSI389 Chiswick High RoadLondonW4 4AL247:2006BSI British Standards InstitutionBSI 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 inc
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