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1、BRITISH STANDARD BS 2782-4: Method 470C:1991 ISO 3451-3: 1984 Methods of testing Plastics Part 4: Chemical properties Method 470C: Determination of ash of unplasticized cellulose acetate IMPORTANT NOTE. Before reading this method it is essential to read BS 2782-0, Introduction, issued separately. Li
2、censed Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 470C:1991 This British Standard, having been prepared under the direction of the Plastics and Rubber Standards Policy Committee, was published unde
3、r the authority of the Standards Board and comes into effect on 30 April 1991 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference PRM/21 Draft for comment 80/52357 DC ISBN 0 580 19567 8 Committees responsible for this British Standard The preparation of
4、this British Standard was entrusted by the Plastics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/21, upon which the following bodies were represented: British Plastics Federation British Steel Industry British Telecommunications plc Department of Trade and Industry (Natio
5、nal Physical Laboratory) EEA (the Association of Electronics, Telecommunications and Business Equipment Industries) Electrical and Electronic Insulation Association (BEAMA Ltd.) Electrical Installation Equipment Manufacturers Association (BEAMA Ltd.) GAMBICA (BEAMA Ltd.) Man-made Fibres Producers Co
6、mmittee Ministry of Defence Packaging and Industrial Films Association PIRA Plastic Industrial Containers Association Plastics and Rubber Institute RAPRA Technology Ltd. Standards Association of Australia Yarsley Technical Centre Ltd. Amendments issued since publication Amd. No.DateComments Licensed
7、 Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 470C:1991 BSI 12-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope and field of application1 2References1 3Principl
8、e1 4Apparatus1 5Procedure1 6Number of determinations1 7Expression of results1 8Test report2 Publication(s) referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 470C:1991
9、 ii BSI 12-1999 National foreword This method has been prepared under the direction of the Plastics and Rubber Standards Policy Committee and is identical with ISO 3451-3:1984 “Plastics Determination of ash Part 3: Unplasticized cellulose acetate”, published by the International Organization for Sta
10、ndardization (ISO). The Technical Committee has reviewed the provisions of ISO 585:1982, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this British Standard. A British Standard does not purport to include all the necessary provisions of
11、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. Cross-references International StandardCorresponding British Standard ISO 3451-1:1981BS 2782 Methods of testing plastics
12、 Method 470A:1991 Determination of ash (general methods) (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments in
13、corporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 470C:1991 BSI 12-19991 1 Scope and field of application 1.1
14、This part of ISO 3451 specifies a method for determining the ash, consisting of inorganic residue, yielded by unplasticized cellulose acetate. 1.2 This method applies to unplasticized cellulose acetate free of additives, fillers, dyes or other materials which may affect the result. 1.3 When plastici
15、zers, additives, fillers or dyes which may affect the result are present, they shall be separated by a method agreed between the interested parties. 1.4 The ash content at 575 25 C is a reasonable measure of the mineral salts and inorganic foreign matter in the cellulose acetate. The weight of ash o
16、btained varies with the temperature of ignition. Higher temperatures such as 850 C will convert calcium carbonate and other carbonates to the oxides and thus give lower values for the ash. The composition of ash may vary with the pulping process used in manufacture, which limits the significance of
17、the ash determination in absolute terms. 2 References ISO 585, Plastics Non-plasticized cellulose acetate Determination of moisture content. ISO 3451-1, Plastics Determination of ash Part 1: General methods. 3 Principle Ignition of a test portion and calcination in a muffle furnace maintained at 575
18、 25 C or 850 50 C (as agreed between the interested parties), in accordance with ISO 3451-1, method A (direct calcination). 4 Apparatus 4.1 Crucible, of capacity 50 to 200 ml, made of silica, platinum or porcelain. 4.2 Bunsen burner, with silica triangle and tripod, or other suitable heating device.
19、 4.3 Muffle furnace, thermostatically controlled at 575 25 C or 850 50 C. 4.4 Analytical balance, accurate to 0,1 mg. 4.5 Desiccator, containing a drying agent, for example anhydrous chloride. 4.6 Weighing bottle 5 Procedure 5.1 Prepare the crucible (4.1) by heating in the muffle furnace (4.3) at 57
20、5 25 C or 850 50 C until constant mass is reached. Allow to cool in the desiccator (4.5) to room temperature for at least 1 h and weigh to the nearest 0,1 mg. 5.2 Introduce into the tared weighing bottle (4.6) a quantity of test sample, predried as prescribed in ISO 585 or with a known moisture cont
21、ent, corresponding to 5 to 50 mg of ash (usually 10 to 25 g) and weigh it to the nearest 0,1 mg. NOTEIf the crucible will accommodate the quantity of test portion corresponding to the 5 to 50 mg of ash, this quantity may be weighed directly into the crucible. High bulk materials may be compressed in
22、to tablets which may be broken up into fragments of appropriate size. 5.3 Half fill the crucible with the test portion from the weighing bottle. Heat the crucible directly on the heating device (4.2) so that the sample burns slowly and loss of ash is avoided. Allow to cool and add another part of th
23、e test portion. Repeat this operation until the total quantity of the test portion is consumed. 5.4 Place the crucible in the muffle furnace, preheated to 575 25 C or 850 50 C, and calcine for 30 min. 5.5 Remove the crucible from the muffle furnace, place in the desiccator, allow to cool to room tem
24、perature for 1 h and weigh to the nearest 0,1 mg. 5.6 Calcine again under the same conditions until constant mass is reached, i.e. until the results of two consecutive weighings do not differ by more than 0,5 mg. 6 Number of determinations Carry out two determinations. Calculate the arithmetic mean
25、of the results. If the single test results differ by more than 10 % of their mean, repeat the procedure until two successive results do not differ from each other by more than 10 % of their mean. 7 Expression of results The ash expressed in grams per 100 g of dry cellulose acetate, is given by the f
26、ormula where mis the mass of ash, in grams; m0is the mass of dry acetate, in grams, calculated from the actual mass of the test portion and its moisture content determined in accordance with ISO 585. m m0 - -100 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 08
27、:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4:Method 470C:1991 2 BSI 12-1999 8 Test report The test report shall include the following particulars: a) reference to this International Standard; b) complete identification of the sample; including type manufacturers code number, source, t
28、rade name, etc.; c) temperature used for calcination; d) treatment of the sample before the test, if any; e) single results of the two determinations and the average for the ash. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontroll
29、ed Copy, (c) BSI BS 2782-4:Method 470C:1991 BSI 12-1999 Publication(s) referred to See national foreword. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 08:46:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-4: Method 470C:1991 ISO 3451-3: 1984 BSI 389 Chi
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