1264 International Standard (Iso INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAH OPrAHW3ALMR IO CTAHAAPTW3ALWWGORGANISATION INTE RNATIONALE DE NORMALISATION Plastics -- Homopolymer and 'copolymer resins of vinyl chloride - Determination of pH of aqueous extract Plastiques - Resines d'homopolymeres et de copolymeres de chlorure de vinyle -- Détermination du pH de I'extrait aqueux Second edition -- 1980-11-01 UDC 678.743.22-13 : 543.257.1 Ref. No. 1SO 1264-1980 (E) Descriptors : plastics, homopolymers, copolymers, vinyl chloride, resins, tests, determination, pH. Copyright International Organization for Standardization Price based on 2 pages Not for Resale Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing Inter- body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as Internationai Standards by the ISO Council. International Standard ISO 1264 was developed by Technical Committee ISO/TC 61, Plastics. This second edition was submitted directly to the Iso Council, in accordance with clause 5.10.1 of part 1 of the Directives for the technical work of IS0. It cancels and repiaces the first edition (i.e. iso 1264-1975), which had been approved by the member bodies of the following countries : Australia Hungary Poland Austria India Romania Belgium Iran South Africa, Rep. of Bulgaria Israel Spain Canada Italy Sweden Czechoslovakia Japan Switzerland Egypt, Arab Rep. of Korea, Dem. P. Rep. of Turkey USA France Korea, Rep. of Germany, F. R. Netheriands Yugoslavia Greece New Zealand The member body of the following country had expressed disapproval of the docu- ment on technical grounds : United Kingdom * Later on the member body of the United Kingdom expressed approval of the second edition. @ International Organization for Standardization, 1980 Printed in Switzerland Copyright International Organization for Standardization ithout license from IHS Not for Resale INTERNATIONAL STANDARD ISO 1264-1980 (E) Plastics --- Homopolymer and copolymer resins of vinyl chloride -- Determination of pH of aqueous extract Scope and field of application 4.2 Pipette. This International Standard specifies a method for the deter- 4.3 Beaker, of capacity 100 ml. mination of the pH of the aqueous extract from homopolymer and copolymer resins of vinyl chloride, by means of a pH meter 4.4 Flask, of capacity 100 ml, fitted with a ground glass equipped witha glass electrode. stopper. This determination is not suitable for estimating the electricai qualities of the resin, but may be of interest in selecting 4.5 Mechanical shaker/stirrer. additives and, especially, stabilizers which are to be used for the preparation of compounds. 5 Procedure 2 Principle Before all measurements of pH of the aqueous extract, carry out a blank test on the sodium chioride solution (ciause 3). This Treatment of a test portion of resin with a given volume of an solution can be regarded as correct if the value of the pH, so aqueous solution of sodium chloride previously neutralized to determined, is between 6,8 and 7,2. pH 7,0 ± 0,2. After stirring and decanting, measurement of the potential difference existing between a glass electrode and If such is not the case, neutralize the soiution again as des- a reference calomel electrode immersed in the liquid phase of cribed in clause 3 and carry out a fresh confirmation. the mixture maintained at 23 ± 2 °C, and reading of this dif- ference, expressed in pH units, directly on the pH meter scale. If the value of pH is between 6,8 and 7,2, continue the deter- mination as described below : 3 Reag