ISO INTERNATIONAL 585 STANDARD Second edition 1990-12-15 Plastics - Unplasticized cellulose acetate - Determination of moisture content Plastiques - Acetate de cellulose non plastifie -- Determination de I'humidite Reference number ISO 585 : 1990 (E) ymatganzaSandardza unSHIAqpe Not for Resale rmitted without license from IHS ISO 585 : 1990 (E) 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 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, govern- mental and non-governmental, in liaison with IsO, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on al! 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 least 75 % of the member bodies casting a vote. International Standard ISO 585 was prepared by Technical Committee ISO/TC 61, Plastics. This second edition cancels and replaces the first edition (1S0 585 : 1982), of which it constitutes a minor revision. ? ISO 1990 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 . CH-1211 Geneve 20 . Switzerland Printed in Switzerland yrgheationarganizatioStandardizatio Not for Resale itted without license from IHS INTERNATIONAL STANDARD ISO 585 : 1990 (E) Plastics - Unplasticized cellulose acetate Determination of moisture content WARNiNG - The use of this International Standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prlor to use. Scope Remove the weighing bottle from the oven, cover with its lid, cool in the desiccator and then re-weigh to the nearest 1 mg. This International Standard specifies a method for the deter- mination of the moisture content of non-plasticized cellulose 4.2 Carry out tiwo determinations. If the difference in per- acetate. centage moisture content between the two is more than o,1, This determination may be required for the calculation of the repeat the test. dry mass of the cellulose acetate used in analytical methods. This method applies only to cellulose acetate with a moisture 5Expression of results content of not more than 10 %. The moisture content, expressed as a percentage by mass, is given by the formula 2 Principle m1 - m2 × 100 A test portion is dried at 105 oc in a thermostatic oven, then m1 weighed. The moisture content is caiculated from the loss of mass of the test portion. where is the mass, in grams, of the test portion before 3 Apparatus drying; m2 is the mass, in grams, of the test portion after drying. 3.1 Glass weighing bottle, low wide form, with a ground- glass lid. Take as the result the mean of two acceptable determinations (see 4.2). 3.2 Desiccator, containing anhydrous calcium chloride. 6 Precision 3.3 Oven, capable of being maintained at 105 oc ± 2 °c. The precision of this test method is not known because inter- 3.4 Balance, accurate to 1 mg. laboratory data are not available. This method may not be suitable for use in specifications or in case of disputed results as long as these data are not available. Procedure 4 4.1 Dry the weighing bottle and its ground-glass lid (3.1) in 7 Test rep