1、BRITISH STANDARD BS2782-4: Method470B: 1999 ISO3451-2: 1998 Methods of testing plastics Part4: Chemical properties Method470B: Determination of ash of polyalkylene terephthalates ICS83.080.20BS2782-4:Method 470B:1999 This BritishStandard, having been prepared under the directionof the Sector Committ
2、eefor Materials andChemicals, waspublished under the authorityof the Standards Committee and comesintoeffecton 15 April1999 BSI03-2000 ISBN 0 580 32220 3 National foreword This BritishStandard reproduces verbatim ISO3451-2:1998 and implements it as the UK national standard. It supersedes BS2782-4:Me
3、thod470B:1991 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpre
4、tation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The BritishStandards which i
5、mplement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not p
6、urport 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. Summary of pages This document comprises a front cover, an inside fron
7、t cover, pages i and ii, theISO title page, pagesii to iv, pages1 to3 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 front cover. Amendments issued since publication Amd. No.
8、Date CommentsBS2782-4:Method 470B:1999 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO3451-2 1ii blankBS2782-4-470B:1999 ii BSI 03-2000 Contents Page Foreword iii 1 Scope 1 2 Normative reference 1 3 Principle 1 3.1 Unfilled materials 1 3.2 Filled and glass-f
9、ibre reinforced materials 1 3.3 Flame-retardant materials reinforced with glass fibre 1 4 Reagents (method C or method A in the presence of DBB) 1 5 Apparatus 2 6 Procedure 2 6.1 Test portion 2 6.2 Unfilled materials 2 6.3 Filled and glass-fibre reinforced materials 2 6.4 Materials reinforced with g
10、lass fibre containing flame-retardant antimony trioxide and/or other volatilizable additives 2 7 Expression of results 3 8 Precision 3 9 Test report 3 Table 1 Mass of test portion 2 Table 2 Precision data for filled PET 2 Descriptors: Plastics, polyalkylene terephthalate, analysis methods, combustio
11、n analysis, ash determination.BS 2782-4-470B:1999 BSI 03-2000 iii Foreword ISO (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 technical
12、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 with
13、the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the m
14、ember bodies casting a vote. International Standard ISO3451-2 was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC5, Physical-chemical properties. This second edition cancels and replaces the first edition (ISO3451-2:1984), which has been technically revised. ISO3451 consists of t
15、he following parts, under the general title Plastics Determination of ash: Part1: General methods; Part2: Poly(alkylene terephthalate) materials; Part3: Unplasticized cellulose acetate; Part4: Polyamides; Part5: Poly(vinyl chloride).iv blankBS 2782-4-470B:1999 BSI 03-2000 1 WARNINGThis part of ISO34
16、51 may involve hazardous chemicals, materials and operations. This part of ISO3451 does not purport to address the safety problems associated with its use. It is the responsibility of the user to establish proper safety and health practices and determine the applicability of regulatory limitations p
17、rior to use. 1 Scope This part of ISO3451 specifies methods for determination of the ash of poly(ethylene terephthalate), poly(butylene terephthalate) and copolymers of the two, both filled and unfilled. The general procedures given in ISO3451-1 are followed. For unfilled materials method A or metho
18、d C of ISO3451-1:1997 is used. For filled and glass-fibre reinforced materials methodA of ISO3451-1:1997 is used. For glass-fibre filled materials, containing flame retardant, antimony trioxide, and/or other, volatilizable additives, for instance pigment zinc sulfide, a modification is incorporated
19、to remove these as volatile bromine component(s). 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this part of ISO3451. At the time of publication, the edition indicated was valid. All standards are subject to revision,
20、 and parties to agreements based on this part of ISO3451 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO3451-1:1997, Plastics Determination of
21、ash Part1: General methods. 3 Principle 3.1 Unfilled materials Direct calcination by burning the organic matter and treating the residue at a high temperature until constant mass is reached (ISO3451-1:1997,methodA). If the material contains metal halides and/or metals (especially in the presence of
22、halogenated material) which are liable to evaporate during burning of the organic matter, calcination after sulfation can be applied (ISO3451-1:1997,method C). This procedure is carried out by heating the organic matter together with concentrated sulfuric acid up to a temperature where fuming and su
23、bsequent burning of the organic matter occurs, and finally treating the residue at a high temperature until constant mass is reached. 3.2 Filled and glass-fibre reinforced materials Direct calcination, by burning the organic matter and treating the residue at a high temperature until constant mass i
24、s reached (ISO3451-1:1997,methodA) (seenote1 in3.3). 3.3 Flame-retardant materials reinforced with glass fibre Calcination by burning the organic matter in the presence of decabromobiphenyl (DBB) and finally treating the residue at a high temperature until constant mass is reached (ISO3451-1:1997,me
25、thodA). NOTE 1Some additives, for instance zinc sulfide, are also completely volatilized as bromides by burning the organic matter in contact with decabromobiphenyl (DBB). Information with respect to the additive(s) present in the material and the potential to evaporate during burning in contact wit
26、h DBB should be requested from the supplier or obtained by testing on the pure chemical. NOTE 2Flame retardants with a high bromine content, for instance ethylene bis(tetrabromophthalimide) or brominated polystyrene, may also be used. The applicability and amount of chemical to be used can be determ
27、ined by carrying out ash determinations in accordance with6.4 with increasing amounts of flame retardant until a constant result is obtained. The chemical should be applied as a powder. 4 Reagents (methodC or methodA in the presence of DBB) During the analysis, use only reagents of analytical grade
28、or specified grade and only distilled water or water of equivalent purity. 4.1 Ammonium carbonate, anhydrous. 4.2 Ammonium nitrate, approximately10%(m/m) solution. 4.3 Sulfuric acid, 1,84g/ml. 4.4 Decabromobiphenyl (DBB), powder, technical grade or higher purity. WARNINGThe use of decabromobiphenyl
29、may result in the formation of dioxins. Temperatures in the order of600 C to850 C are generally known as ideal temperatures for the formation of dioxins.BS 2782-4-470B:1999 2 BSI 03-2000 5 Apparatus Apparatus specified in clause4 of ISO3451-1:1997, and in particular: 5.1 Crucibles of silica, porcela
30、in or platinum, inert to the material tested, and typically of diameter (upper part)50mm to60mm and height equal to the diameter (seenote2 in3.3). 5.2 Muffle furnace, capable of being maintained at(600 25) C,(850 50) C or at a minimum temperature of850 C. 5.3 Fume cupboard 6 Procedure The material s
31、hall be in the form of small pieces of1cm 0,5cm 0,2cm or smaller, granules or powder. Filled or reinforced materials shall be dried before calcination, i.e.by heating at100 C until constant mass is reached. 6.1 Test portion Take a quantity of the test sample sufficient to yield5mg to200mg of ash (se
32、eTable 1). In the case of reinforced materials, take a test portion of2g or more (seeTable 1). If the likely quantity of ash is unknown, carry out a preliminary ash determination. According to the approximate ash content, choose the size of the test portion to be used from Table 1. 6.2 Unfilled mate
33、rials Follow the procedure described in ISO3451-1:1997,methodA, applying a calcination temperature of(850 50) C. If the material contains metal halides or metals in the presence of halogenated material, liable to evaporate during the calcination procedure, or in those cases where “sulfated ash” is r
34、equired, methodC shall be applied (ISO3451-1:1997,methodC). 6.3 Filled and glass-fibre reinforced materials Follow the procedure described in ISO3451-1:1997,methodA, applying a calcination temperature of(850 50) C. If at that temperature glass fibres present become molten and thus prevent further ca
35、lcination of the polymer, lower the temperature of calcination to(600 25) C and repeat the procedure with a fresh test portion. 6.4 Materials reinforced with glass fibre containing flame-retardant antimony trioxide and/or other volatilizable additives The sample shall be ground or cut to pieces of1c
36、m 0,5cm 0,2cm or smaller. Proceed as in5.3.1 and5.3.2 of ISO3451-1:1997,methodA. Add to the sample a quantity of DBB(4.4) equal to half the mass of the sample in grams and mix well in the crucible. Place the crucible in the muffle furnace, applying a calcination temperature of at least850 C. The muf
37、fle furnace shall be placed in a fume cupboard. Continue as directed in ISO3451-1:1997, from5.3.4 ofmethodA. Directly placing the crucible into the muffle furnace is preferred. If direct calcination leads to large differences between repeated tests, for instance due to loss of ash-containing materia
38、l, gently heat the crucible over a quiet flame until formation of fumes ceases. Make sure that the volatile components are properly drawn off by a fume cupboard. Place the crucible in the muffle furnace and apply a calcination temperature of at least850 C. Continue as directed in ISO3451-1:1997, fro
39、m5.3.4 ofmethodA. Glass-fibre crucibles provided with two glass-fibre discs may also be used. The crucible shall be prepared by heating it in the muffle furnace at the test temperature and cooling it in a desiccator until constant mass is reached. Introduce the sample between the glass-fibre discs i
40、nto the crucible. Place the crucible in the muffle furnace for30min. Allow the crucible to cool in a desiccator for20min. Table 1 Mass of test portion Approximate ash % Test portion g Mass of ash obtained mg u 0,01 W 200 5to10 0,01to0,05 100 10to50 0,05to0,1 50 25to50 0,1to0,2 25 25to50 0,2to1 10 20
41、to100 1to10 5 50to500 10 2 200BS 2782-4-470B:1999 BSI 03-2000 3 For unground material, the residue in the crucible shall be calcinated a second time according to the procedure described in6.4. The amount of DBB added to the residue shall be1g. 7 Expression of results The ash or sulfated ash, express
42、ed as a percentage by mass, is given by the formula Calculate the average of two results and round off to the nearest0,1%. 8 Precision Precision data of the ash determination are described in clause8 of3451-1:1997, with the exception of the DBB method described in6.4. The precision data were determi
43、ned with eight laboratories and eight materials. For SiO 2and TiO 2containing poly(ethylene terephthalate) (PET), the precision data given in Table 2 were obtained. The precision of the direct calcination of glass-fibre-containing materials and the DBB method is not known because inter-laboratory da
44、ta are not available. However, the precision of these methods is expected not to deviate significantly from the known data. Inter-laboratory data are being, gathered and will be added at the next revision. 9 Test report The test report shall include the following information: a) a reference to this
45、part of ISO3451; b) all details necessary for identification of the material tested; including type, manufacturers code number, source, trade name,etc.; c) the method of calcination used; d) the temperature used for calcination; e) the treatment of the sample prior to the test, if any; f) the indivi
46、dual results of the two determinations and the average for the ash or sulfated ash obtained; g) the mass of test portion used. Table 2 Precision data for filled PET where m 0 is the mass, in grams, of test portion; m 1 is the mass, in grams, of ash obtained. m 1 m 0 -100 Material/Filler Mean ash % s
47、 r s R r R PET/SiO 2 3,18 0,045 0,045 0,125 0,125 PET/TiO 2 12,46 0,046 0,052 0,129 0,144 PET/TiO 2 44,81 0,371 0,400 1,038 1,120 where s r is the repeatability standard deviation; s R is the reproducibility standard deviation; r is the repeatability value, comprising the value below which the absol
48、ute difference between two single test results obtained under repeatability conditions (same operator, same apparatus, same laboratory and within a short interval of time) may be expected to lie with a probability of95%; R is the reproducibility value, comprising the value below which the absolute d
49、ifference between two single test results obtained under reproducibility conditions (different operator, different apparatus, different laboratories) may be expected to lie with a probability of95%.BS2782-4: Method470B: 1999 ISO3451-2: 1998 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 level. It is incorporated by Royal Charter. Revisions Brit
