1、BRITISH STANDARD BS EN ISO 1158:1998 Plastics Vinyl chloride homopolymers and copolymers Determination of chlorine content The European Standard EN ISO 1158:1998 has the status of a British Standard ICS 83.080.20BSEN ISO 1158:1998 This British Standard, having been prepared under the direction of th
2、e Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 June 1998 BSI 04-1999 ISBN 0 580 29857 4 National foreword This British Standard is the English language version of ENISO1158:1998. Itis identical with ISO1158:1998. The U
3、K participation in its preparation was entrusted to Technical Committee PRI/34, Vinyl materials, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep t
4、he 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 Attention is drawn to the fact that CEN and CENELEC Standards normally
5、include an annex which lists nonnative references to international publications with their corresponding European publications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section enti
6、tled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. 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. Complia
7、nce with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, page ii, pages 1 to 5 andaback cover. This standard has been updated
8、 (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. Date CommentsBSEN ISO 1158:1998 BSI 04-1999 i Contents Page National foreword Inside front cover Foreword 2 Foreword i
9、i Text of ISO 1158 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM ENISO1158 April1998 ICS83.080 Descriptors: See ISO document English version Plastics Vinyl chloride homopolymers and copolymers Determination of chlorine content (ISO1158:1998) Plastiques Homopolymres et copolymres de chlo
10、rure de vinyle Dosage du chlore (ISO1158:1998) This European Standard was approved by CEN on23 March1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteratio
11、n. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translatio
12、n under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
13、 Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form
14、 and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 1158:1998 EENISO 1158:1998 BSI 04-1999 2 Foreword The text of the International Standard ISO1158:1998 has been prepared by Technical Committee ISO/TC61 “Plastics” in collaboration with Technical Committee CEN/TC249 “Plast
15、ics”, the secretariat of which is held by IBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October1998, and conflicting national standards shall be withdrawn at the latest by October1998. Acco
16、rding to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal
17、, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO1158:1998 was approved by CEN as a European Standard without any modification. Contents Page Foreword 2 1 Scope 1 2 Principle 1 3 Reagents 1 4 Apparatus 1 5 Test sample 1 6 Procedure 3 7
18、 Expression of results 5 8 Precision 5 9 Test report 5 Figure 1 Example of a combustion bomb, gas-fired type 2 Figure 2 Example of a flask for oxygen combustion with platinum wire attached to stopper 3 Figure 3 Folding of filter paper containing test portion 4EN ISO 1158:1998 ii BSI 04-1999 Foreword
19、 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 committees. Each member body interested in a subject for which a technical
20、 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 the International Electrotechnical Commission (IEC) on all matters of elec
21、trotechnical 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 member bodies casting a vote. International Standard ISO1158 was prepared b
22、y Technical Committee ISO/TC61, Plastics, Subcommittee SC9, Thermoplastic materials. This third edition cancels and replaces the second edition (ISO1158:1984), which has been technically revised. Descriptors: Plastics, thermoplastic resins, homopolymers, copolymers, vinyl chloride, chemicalanalysis,
23、 determination of content, chlorine, combustion analysis.EN ISO 1158:1998 BSI 04-1999 1 WARNING All precautions shall be taken, particularly those mentioned in the text of the present International Standard, to protect operators from risks presented by both methods. 1 Scope This International Standa
24、rd specifies two methods for the determination of the chlorine content of homopolymers and copolymers of vinyl chloride, free from plasticizers or additives, namely: method A (combustion in a bomb); method B (combustion in a flask). 2 Principle A test portion is oxidised with sodium peroxide (method
25、 A) or gaseous oxygen (method B) followed by potentiometric or volumetric titration of the resulting chlorides. 3 Reagents During the analysis, use only reagents of recognized grade, and only distilled water or water of equivalent purity. 3.1 Silver nitrate, standard volumetric solution, c(AgNO 3 )=
26、0,1mol/l or0,05mol/l. 3.2 Nitric acid solution, c(HNO 3 )=2mol/l. For method A only: 3.3 Nitric acid, concentrated. 3.4 Sodium peroxide, granulated. 3.5 Starch, sucrose or ethylene glycol, as combustion aids. For method B only: 3.6 Oxygen, gaseous. 3.7 Sodium nitrate 3.8 Potassium hydroxide solution
27、, 100g/l. 3.9 Hydrogen peroxide solution, 300g/l. 4 Apparatus 4.1 Drying oven, capable of being maintained at50C 2C or75C 2C. 4.2 Balance, to weigh to an accuracy of0,1mg (method A) or0,01g (method B). 4.3 Equipment for Volhard titration or for potentiometric titration, with a burette having a capac
28、ity and accuracy appropriate to the chosen method (A or B). For method A only: 4.4 Combustion bomb, (for example Parr bomb or another bomb which gives the same results), gas or electrically fired. An example of a suitable gas-fired bomb is shown inFigure 1. 4.5 Nickel crucible with lid, to fit into
29、the bomb (gas-fired). Suitable dimensions are: diameter25mm, height40mm. A smaller crucible could be used if the amount of test sample is reduced. 4.6 Safety oven 4.7 Beaker, capacity600ml. For method B only: 4.8 Round- or flat-bottomed flask, capacity500ml to1000ml, with head designed for oxygen co
30、mbustion (seeFigure 2). A platinum wire1,0mm in diameter and120mm long in the shape of a tapered spiral is attached to the stopper, a suitable spiral being15mm in diameter and15mm long. It is recommended that metal gauze be wrapped around the flask for safety. 4.9 Filter paper, about3cm 3,5cm, free
31、from halogens and ash. 4.10 Beaker, capacity250ml. 5 Test sample The sample shall be in powdered or granular form, and if necessary shall be cut into pieces1mm to3mm in size. The sample shall be oven-dried for2h at75C or16h at50C.EN ISO 1158:1998 2 BSI 04-1999 Figure 1 Example of a combustion bomb,
32、gas-fired type (for method A)EN ISO 1158:1998 BSI 04-1999 3 6 Procedure 6.1 Method A (combustion bomb) 6.1.1 First place 7g to 7,5g of sodium peroxide (3.4) in the nickel crucible (4.5) (for the gas-fired bomb) or in the fusion cup of the bomb (for the electrically fired bomb), then add a test porti
33、on of about0,25g (weighed to0,1mg) mixed with0,16g to0,17g of combustion aid (3.5), then a further7g to7,5g of sodium peroxide. The placing of the sodium peroxide in the crucible or fusion cup shall be done behind a shield protecting the operator. Mix by stirring, then place the crucible, with the l
34、id in position, inside the bomb and close the bomb tightly. If an electrically fired bomb is used, assemble the bomb and tap it to settle the charge. A smaller crucible and test portion could be used. 6.1.2 Fire the bomb. If a gas-fired bomb is used, place it in the safety oven(4.6). Adjust the flam
35、e beforehand, using an empty bomb in the safety oven, so that the top of the flame is a few millimetres from the base of the bomb. Then remove the empty bomb. Heat the test bomb to300C to400C for about10min. Ignition usually starts at50C to60C, and is detected by a cracking sound, and the fact that
36、the bottom of the bomb starts to glow. 6.1.3 Cool the bomb. Open it and, if a gas-fired bomb is used, remove the crucible and carefully place it in100ml of distilled water in a600ml beaker (4.7) and immediately cover the beaker with a watch-glass. When the reaction has subsided, wash down the inside
37、 of the bomb and the plug, collecting the washings in the beaker. If an electrically fired bomb is used, dismantle it after cooling, remove the head and tip the contents into100ml of distilled water in the beaker (4.7). Lay the fusion cup in the same beaker and immediately cover with a watch-glass.
38、WARNING If the bomb is cooled in water, take care that the water does not reach the joint between the plug and the bomb. 6.1.4 Heat the beaker and its contents to boiling, then cool. Remove the crucible and lid, or the fusion cup and head, rinsing them with water and collecting the washings in the b
39、eaker. 6.1.5 Slowly add20ml of concentrated nitric acid(3.3), stirring constantly, followed by nitric acid solution (3.2) until the mixture is neutral. Then add a further2ml of nitric acid solution (3.2). NOTEMethyl orange is a suitable indicator for the neutralization. 6.1.6 Dilute the contents of
40、the beaker to about200ml with water, and titrate potentiometrically or by the Volhard method with silver nitrate solution (3.1). 6.1.7 Carry out a blank test by firing the same amount of sodium peroxide (3.4) and combustion aid(3.5) as was used with the test portion, and repeating the procedure (but
41、 without the test portion) described in6.1.4 to6.1.6. 6.1.8 When doubt exists as to whether the reaction has taken place, do not dissolve the contents of the bomb in water by the normal procedure because this might cause a violent explosion. The contents of the bomb should be spread out on dry sand,
42、 after which they should be sprayed with water from a safe distance and then washed with more water. 6.2 Method B (oxygen flask) 6.2.1 Place a test portion of about25mg to35mg, weighed to0,01mg, on a filter paper (4.9) cut as shown inFigure 3a) and having previously marked folds. Then fold the paper
43、 as shown inFigure 3b), Figure 3c) and Figure 3d) and clamp it in the platinum spiral (seeFigure 2), with the paper tail protruding. Figure 2 Example of a flask for oxygen combustion with platinum wire attached to stopper (for method B)EN ISO 1158:1998 4 BSI 04-1999 6.2.2 Introduce about20ml of wate
44、r,1ml of potassium hydroxide solution (3.8) and0,15ml of hydrogen peroxide solution (3.9) into the flask (4.8). Pass oxygen (3.6) through a glass tube at250ml/min to350ml/min for5min to displace the air. 6.2.3 Ignite the filter paper tail with a gas flame and quickly insert the stopper carrying the
45、platinum wire and burning filter paper into the flask. 6.2.4 During combustion, keep the flask inverted so that the liquid covers the bottom of the stopper and leakage through the stopper and escape of gas are avoided. When combustion is finished, turn the flask upright and gently shake under a stre
46、am of cold water to cause rapid complete absorption of the hydrochloric acid produced. 6.2.5 After30min, open the flask and transfer the contents quantitatively to a250ml beaker (4.10), rinsing so that the final volume is about60ml. Add about1g of sodium nitrate (3.7) and2,5ml of nitric acid solutio
47、n (3.2), and boil the solution for5min. After cooling, determine the chlorine content by potentiometric titration or by the Volhard method with silver nitrate solution (3.1). 6.2.6 Carry out a blank test, following the procedure described in6.2.1 to6.2.4 and using the same quantities of all the reag
48、ents used in the determination, but without the test portion. Figure 3 Folding of filter paper containing test portionEN ISO 1158:1998 BSI 04-1999 5 7 Expression of results 7.1 The chlorine content of the dry material, expressed as a percentage by mass, is given by the formula or depending on the co
49、ncentration of the silver nitrate solution used where 7.2 Express the result as the arithmetic mean of two determinations that do not differ by more than0,2% (absolute). 8 Precision The precision of this test method is not known because interlaboratory data are not available. Interlaboratory data are being obtained and a precision statement will be added at a subsequent revision. 9 Test report The test report shall include the following information: a) a reference to this International Standard; b) all details nec
