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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 83.080.20 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontr
2、olled Copy, (c) BSI BS EN ISO 1158:1998 This British Standard, having been prepared under the direction of the 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 Thi
3、s British Standard is the English language version of EN ISO 1158:1998. It is identical with ISO 1158:1998. The UK 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 resp
4、onsible international/European committee any enquiries on the interpretation, 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 r
5、equest to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists nonnative references to international publications with their corresponding European publications. The British Standards which implement international or Euro
6、pean 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 purport to include all the nece
7、ssary 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 front cover, pages i and ii, the E
8、N ISO title page, page 2, the ISO title page, page ii, pages 1 to 5 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.Dat
9、eComments Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 1158:1998 BSI 04-1999i Contents Page National forewordInside front cover Foreword2 Forewordii Text of ISO 11581 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:
10、55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 1158 April 1998 ICS 83.080 Descriptors: See ISO document English version Plastics
11、 Vinyl chloride homopolymers and copolymers Determination of chlorine content (ISO 1158:1998) Plastiques Homopolymres et copolymres de chlorure de vinyle Dosage du chlore (ISO 1158:1998) This European Standard was approved by CEN on 23 March 1998. CEN members are bound to comply with the CEN/CENELEC
12、 Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN
13、member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation 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 mem
14、bers are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normal
15、isation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 1158:1998 E Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GM
16、T+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1158:1998 BSI 04-1999 2 Foreword The text of the International Standard ISO 1158:1998 has been prepared by Technical Committee ISO/TC 61 “Plastics” in collaboration with Technical Committee CEN/TC 249 “Plastics”, the secretariat of which is held by IBN
17、. 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 October 1998, and conflicting national standards shall be withdrawn at the latest by October 1998. According to the CEN/CENELEC Internal Regulatio
18、ns, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the Unite
19、d Kingdom. Endorsement notice The text of the International Standard ISO 1158:1998 was approved by CEN as a European Standard without any modification. Contents Page Foreword2 1Scope1 2Principle1 3Reagents1 4Apparatus1 5Test sample1 6Procedure3 7Expression of results5 8Precision5 9Test report5 Figur
20、e 1 Example of a combustion bomb, gas-fired type2 Figure 2 Example of a flask for oxygen combustion with platinum wire attached to stopper3 Figure 3 Folding of filter paper containing test portion4 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c)
21、 BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1158:1998 ii BSI 04-1999 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of pr
22、eparing International Standards is normally carried out through ISO technical 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, i
23、n liaison with ISO, also take part in the work. ISO collaborates closely with 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. Publ
24、ication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 1158 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materials. This third edition cancels and replaces the second edition
25、 (ISO 1158:1984), which has been technically revised. Descriptors: Plastics, thermoplastic resins, homopolymers, copolymers, vinyl chloride, chemical analysis, determination of content, chlorine, combustion analysis. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Unc
26、ontrolled Copy, (c) BSI EN ISO 1158:1998 BSI 04-19991 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 Standard specifies two methods for the d
27、etermination 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 A) or gaseous oxygen (method B) f
28、ollowed 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(AgNO3) = 0,1 mol/l or 0,05 mol/l. 3.2 Nitri
29、c acid solution, c(HNO3) = 2 mol/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, 100 g/l. 3.9 Hydrogen peroxi
30、de solution, 300 g/l. 4 Apparatus 4.1 Drying oven, capable of being maintained at 50 C 2 C or 75 C 2 C. 4.2 Balance, to weigh to an accuracy of 0,1 mg (method A) or 0,01 g (method B). 4.3 Equipment for Volhard titration or for potentiometric titration, with a burette having a capacity and accuracy a
31、ppropriate 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 in Figure 1. 4.5 Nickel crucible with lid, to fit into the bomb (gas-fir
32、ed). Suitable dimensions are: diameter 25 mm, height 40 mm. A smaller crucible could be used if the amount of test sample is reduced. 4.6 Safety oven 4.7 Beaker, capacity 600 ml. For method B only: 4.8 Round- or flat-bottomed flask, capacity 500 ml to 1 000 ml, with head designed for oxygen combusti
33、on (see Figure 2). A platinum wire 1,0 mm in diameter and 120 mm long in the shape of a tapered spiral is attached to the stopper, a suitable spiral being 15 mm in diameter and 15 mm long. It is recommended that metal gauze be wrapped around the flask for safety. 4.9 Filter paper, about 3 cm 3,5 cm,
34、 free from halogens and ash. 4.10 Beaker, capacity 250 ml. 5 Test sample The sample shall be in powdered or granular form, and if necessary shall be cut into pieces 1 mm to 3 mm in size. The sample shall be oven-dried for 2 h at 75 C or 16 h at 50 C. Licensed Copy: sheffieldun sheffieldun, na, Mon N
35、ov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1158:1998 2 BSI 04-1999 Figure 1 Example of a combustion bomb, gas-fired type (for method A) Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1158:1998 BSI 04-19993 6 Pro
36、cedure 6.1 Method A (combustion bomb) 6.1.1 First place 7 g to 7,5 g 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 portion of about 0,25 g (weighed to 0,1 mg) mixed with 0,16 g to 0,1
37、7 g of combustion aid (3.5), then a further 7 g to 7,5 g 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 lid in position, inside the bomb and close the bomb
38、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 flame beforehand, using an empty bomb in the safety ov
39、en, 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 to 300 C to 400 C for about 10 min. Ignition usually starts at 50 C to 60 C, and is detected by a cracking sound, and the fact that the bottom of the bomb starts to glow. 6
40、.1.3 Cool the bomb. Open it and, if a gas-fired bomb is used, remove the crucible and carefully place it in 100 ml of distilled water in a 600 ml beaker (4.7) and immediately cover the beaker with a watch-glass. When the reaction has subsided, wash down the inside of the bomb and the plug, collectin
41、g the washings in the beaker. If an electrically fired bomb is used, dismantle it after cooling, remove the head and tip the contents into 100 ml of distilled water in the beaker (4.7). Lay the fusion cup in the same beaker and immediately cover with a watch-glass. WARNING If the bomb is cooled in w
42、ater, 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 beaker. 6.1.5 Slowly add 20 ml of c
43、oncentrated nitric acid (3.3), stirring constantly, followed by nitric acid solution (3.2) until the mixture is neutral. Then add a further 2 ml of nitric acid solution (3.2). NOTEMethyl orange is a suitable indicator for the neutralization. 6.1.6 Dilute the contents of the beaker to about 200 ml wi
44、th 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 without the test portion)
45、 described in 6.1.4 to 6.1.6. 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, after which they should
46、 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 about 25 mg to 35 mg, weighed to 0,01 mg, on a filter paper (4.9) cut as shown in Figure 3 a) and having previously marked folds. Then fold the paper as shown in Fig
47、ure 3 b), Figure 3 c) and Figure 3 d) and clamp it in the platinum spiral (see Figure 2), with the paper tail protruding. Figure 2 Example of a flask for oxygen combustion with platinum wire attached to stopper (for method B) Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 20 02:18:55 GMT+00:00
48、2006, Uncontrolled Copy, (c) BSI EN ISO 1158:1998 4 BSI 04-1999 6.2.2 Introduce about 20 ml of water, 1 ml of potassium hydroxide solution (3.8) and 0,15 ml of hydrogen peroxide solution (3.9) into the flask (4.8). Pass oxygen (3.6) through a glass tube at 250 ml/min to 350 ml/min for 5 min to displ
49、ace the air. 6.2.3 Ignite the filter paper tail with a gas flame and quickly insert the stopper carrying the 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 stream of cold water to cause rapid complete absorption of the hydrochloric acid produced. 6.2.5 After 30 min, open t