ISO INTERNATIONAL STANDARD 1599 Second edition 1990-12-01 Plastics - Cellulose acetate -Determination of viscosity loss on moulding Plastiques -- Acetate de cellulose -- Determination de la perte de viscositeaumoulage Referencenumber ISO 1599:1990(E) ISO1599:1990(E) Foreword iso(theInternationalOrganizationforStandardization)isaworldwide federation of national standards bodies (IsO member bodies).The work ofpreparingInternational Standards isnormally carriedoutthroughiso technical committees.Each'member body interested in a subjectfor 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 closelywith the International Electrotechnical Commission (IEC)on alfmatters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at least 75% of the member bodies casting a vote. InternationalStandardIso1599waspreparedbyTechnicalCommittee IsO/TC61,Plastics. This ssecond edition cancels and replaces the first edition (Iso 1599:1975), of which it constitutes a minor revision. ISO 1990 All rights reserved.No part of this publicatlonmaybe reproduced or utillzed in any form permission in writing from the publisher. InternationalOrganizationforStandardization Case Postale 56.CH-1211Geneve 20Switzerland Prlnted In Switzerland 1 ISO1599:1990(E) INTERNATIONAL STANDARD Plastics -- Cellulose acetate -- Determination of viscosity loss on moulding 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 prior to use. 1 Scope Is0 1157:1990, Plastics -Cellulose.acetate in dilute solution -Determination of viscosity number and This International Standard specifies a method for viscosity ratio. the determination of the reduction in viscosity which occurs when cellulose acetate is moulded. The vis- mouldingisrelated tothe Principle cosity losson depolymerization of cellulose acetate, which gener- ally increases brittleness in the moulded product. Cellulose acetate plasticized with dimethyl phthalate is moulded under specified conditions of tempera- This method is suitable for cellulose acetate which ture, pressure and time. After cooling, the moulding does not contain additives, fillers, etc., which may is ground up. The viscosity ratio of the ground ma- interfere with the determination of viscosity. terial from the moulding and also that of the original cellulose acetate are determined in accordance with It is suitable for cellulose acetate having an acetic Iso 1157.The percentage viscosity loss is calcu- acid yield above 50 %. lated from the values of viscosity before and after mouiding. NOTE1 Since the moulded cellulose acetate contains 2 Normative references dimethyl phthalate, this is also present in the solution for viscosity measurement; the solution of original cellulose The following standards contain provisions which, acetate does not contain dimethyl phthalate, However, the through reference in this text, constitute provisions concentrationofdimethylphthalateinthesolutionfor of this International Standard. At the time of publi- viscosity measurement is too small to have any significant effect on viscosity. cation, the editions indicated were valid. All stan- dards are subject to revision, and parties to agreements based on this International Standard 4 Reagents are encouraged to investigate the possibility of ap- plying the most recent editions of the standards in- dicated below. Members of IEc and ISo maintain D