1、BRITISH STANDARD BS 2782-4: Method 452B: 1993 Methods of testing Plastics Part 4: Chemical properties Method 452B: Determination of carbon black content of polyolefin compound IMPORTANT NOTE. Before reading this method it is essential to read BS2782-0, Introduction, issued separately. UDC 678.5/.7.0
2、1:543.86:678.742:678.046.2BS2782-4:Method452B:1993 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 15January1993 BSI 08-1999 First published Februa
3、ry 1978 Second edition January 1993 The following BSI references relate to the work on this standard: Committee reference PRM/21 Draft for comment 92/40573 DC ISBN 0 580 21412 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plastics an
4、d Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/21, upon which the following bodies were represented: British Plastics Federation British Textile Confederation Department of the Environment (Building Research Establishment) Department of the Trade and Industry (National Physic
5、al Laboratory) EEA (the Association of Electronics, Telecommunications and Business Equipment Industries) Electrical and Electronic Insulation Association (BEAMA Ltd.) GAMBICA (BEAMA Ltd.) Ministry of Defence Packaging and Industrial Films Association Plastics and Rubber Institute PIRA International
6、 RAPRA Technology Ltd. Yarsley Technical Centre Ltd. Amendments issued since publication Amd. No. Date CommentsBS2782-4:Method452B:1993 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Informative reference 1 3 Principle 1 4 Reagent 1 5 Apparatus 1 6 Proc
7、edure for combustion in nitrogen 1 7 Procedure for ashing 2 8 Calculation of result 2 9 Test report 2 List of references Inside back coverBS2782-4:Method452B:1993 ii BSI 08-1999 Foreword This method has been prepared under the direction of the Plastics and Rubber Standards Policy Committee. It super
8、sedes BS2782:Method 452B:1978, which is withdrawn. This edition permits variations in the temperature of combustion of the polyolefin compound and the time at temperature, provided these are given in the test report. WARNING NOTE. This method does not necessarily detail all the precautions necessary
9、 to meet the requirements of the Health and Safety at Work etc. Act19741. Attention should be paid to any necessary safety precautions, and the method should only be operated by trained personnel. A British Standard does not purport to include all the necessary provisions of a contract. Users of Bri
10、tish 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, pagesi andii, pages1 and2, an inside back cover and a back cover.
11、 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.BS2782-4:Method452B:1993 BSI 08-1999 1 1 Scope This British Standard describes a method for the determination of the percentage of ca
12、rbon black in a polyolefin compound. It is not suitable for polyolefins containing fillers which are unstable at850 C. NOTEFor such fillers, e.g. chalk, the method will need to be adapted by calibration and the use of blanks, which is outside the scope of this standard. 2 Informative reference This
13、method refers to another publication that provides information or guidance. The edition of this publication current at the time of issue of this standard is given on the inside back cover, but reference should be made to the latest edition. 3 Principle The sample of polyolefin compound is heated at
14、a selected temperature in a stream of nitrogen in a combustion tube to remove the polyolefins. The residue is then cooled, weighed and ashed by heating slowly to850 C in a muffle furnace. The ash is then cooled and weighed. The carbon black content is then calculated as the material which is not vol
15、atilized in nitrogen but is removed by the ashing procedure. 4 Reagent 4.1 High-purity nitrogen, which shall be as far as possible free from oxygen (seealso5.2). 5 Apparatus 5.1 Combustion boat, of minimum dimensions75mm length,9mm width and8mm height. 5.2 Combustion tube, made of borosilicate glass
16、 and of internal diameter approximately30mm and length400mm 50mm. The tube may optionally contain some copper wool positioned near the inlet for the nitrogen, to remove any traces of oxygen before these can reach the sample. 5.3 Flowmeter, to measure rates of gas flow of up to2l/min. 5.4 Temperature
17、 measuring device, such as a radiation pyrometer, thermometer or thermocouple. NOTEThe radiation pyrometer is preferred. 5.5 Two cold traps, containing an organic solvent. 5.6 Tube furnace, of suitable size to accommodate the combustion tube, and capable of being controlled to 25 C within the range3
18、00 C to700 C. 5.7 Muffle type furnace, capable of being controlled to within 25 C at temperatures up to900 C. 5.8 Laboratory balance, capable of weighing to an accuracy of0.0001g. 5.9 Desiccator 6 Procedure for combustion in nitrogen 6.1 Full procedure 6.1.1 Select a combustion temperature of betwee
19、n500 C and700 C, and report see item f) of clause9. 6.1.2 Thoroughly dry the combustion boat(5.1) by first heating it to red heat and then allowing it to cool in a desiccator for30min. Weigh the combustion boat to the nearest0.0001g. 6.1.3 Weigh out a sample of1.0g 0.1g of the polyolefin compound to
20、 be tested, place it in the combustion boat and weigh the whole to the nearest0.0001g. The sample shall be in the form of granules or similar sized pieces not exceeding5mm, and shall be evenly spread throughout the boat to guard against any boiling over during volatilization. Place the combustion bo
21、at and contents in the centre of the combustion tube(5.2). Close one end of the combustion tube with a stopper containing an inlet tube for the nitrogen gas (see4.1) and an inlet for a thermometer or thermocouple (5.4) if required, the end of which shall be in contact with the combustion boat. 6.1.4
22、 Place the combustion tube in the tube furnace(5.6) and either arrange the outlet from the combustion tube to lead to the outside atmosphere or connect the outlet to two cold traps(5.5) placed in series. NOTEThe first trap should be cooled with solid carbon dioxide and the outlet of the second shoul
23、d lead either to a fume hood or to the outside atmosphere 6.1.5 Pass nitrogen through the combustion tube at a rate of1.7l/min 0.3l/min and maintain this flow rate during the test until the combustion boat is removed from the combustion tube. Heat the furnace so as to attain a temperature of325 C 25
24、 C after10min, of about450 C after a further10min, and of the temperature selected for combustion within a further20min. Maintain the temperature selected for combustion for between10min and30min, reporting the time used.BS2782-4:Method452B:1993 2 BSI 08-1999 6.1.6 Disconnect the outlet from the col
25、d traps if these were used. Withdraw the combustion tube from the furnace and allow it to cool for5min, maintaining the flow of nitrogen. Remove the combustion boat from the combustion tube through the nitrogen inlet end and allow it to cool in the desiccator for between20min and30min. Reweigh the c
26、ombustion boat and contents to the nearest0.0001g. NOTEBefore carrying out a further determination, allow the temperature of the tube furnace to fall to300 C or below. 6.2 Simplified procedure As an alternative to the procedure given in6.1, a simplified procedure may be used for repetitive testing.
27、In this alternative procedure, the combustion tube is slowly introduced into the tube furnace, which is set at the selected combustion temperature (see6.1.1). Use of this procedure shall be reported (seeclause9). 7 Procedure for ashing 7.1 Heat the muffle type furnace(5.7) to850 C 50 C at its centre
28、. Place the combustion boat and contents in the door of the furnace and move it into the centre gently by stages. NOTEThis ashing process is carried out slowly so that particles of ash are not carried off with the volatile matter. 7.2 Maintain the furnace at850 C 50 C for10min, then remove the combu
29、stion boat, allow it to cool in the desiccator and weigh it to the nearest0.0001g. 8 Calculation of result Calculate the percentage of carbon black, C, in the polyolefin compound from the following expression: where 9 Test report The test report shall include the following information: a) the name o
30、f the testing establishment; b) the date of the test; c) complete identification of the material tested, its type, source, manufacturers code number and previous history; d) a reference to this British Standard i.e,BS2782:Method 452B:1993; e) the temperature selected for combustion (see6.1.1); f) th
31、e time at the combustion temperature (see6.1.5); g) any use of a simplified procedure (see6.2); h) the percentage carbon black content of the material. M 1 is the mass of the residue after heating in the combustion tube (in grams); M 2 is the mass of the ash after ashing (in grams); M 3 is the initi
32、al mass of the sample (in grams). C M 1 M 2 M 3 -100 =BS2782-4:Method452B:1993 BSI 08-1999 List of references (see clause2) Informative reference Other reference 1 GREAT BRITAIN. Health and Safety at Work etc. Act 1974. London:HMSO.BS 2782-4: Method 452B: 1993 BSI 389 Chiswick High Road London W4 4A
33、L 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 BritishStandards are updated by amendment or revision. Users
34、 of BritishStandards 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 inaccuracy or ambiguity while using this BritishStandard would inform the Secretary
35、of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standard
36、s Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandard
37、s, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all
38、 its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Ad
39、ministration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the internationalstandardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be repro
40、duced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size,
41、type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
