DIN ISO 976-2008 橡胶和塑料.聚合物分散体和橡胶胶乳.pH值的测定

标准号：DIN ISO 976-2008
中文标准名称：橡胶和塑料.聚合物分散体和橡胶胶乳.pH值的测定
英文标准名称：Rubber and plastics - Polymer dispersions and rubber latices - Determination of pH (ISO 976:1996 + Amd. 1:2006);English version of DIN ISO 976:2008-07
标准类型：G31
发布日期：1999/12/31 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：G31
国际标准分类号：83.040.10
引用标准：ISO 123-2001;ISO 3696-1987;ISO 15528-2000;ISO/TR 9272
适用范围：This International Standard specifies a method for thedetermination of the pH of polymer dispersions andrubber latices (natural and synthetic) by means of apH-meter equipped with a combined glass and silverreference electrode.The method is also suitable for prevulcanized latexand compounds containing polymer dispersions orrubber latices, including adhesives.NOTE 1 The accuracy of the method decreases at pHvalues above 11.Users should note that this edition of ISO 976 not onlyrepresents a revision of the previous edition, but alsosupersedes ISO 1148:1980, Plastics -- Aqueousdispersions of polymers and copolymers -- Determi-nation of pH. This edition represents a harmonizedversion of the two standards.One of the major changes in this new edition ofISO 976 is the use of a combined electrode ratherthan the separate electrodes used in the previousedition, the combined electrode being consideredsuperior to the separate electrodes since the latterare prone to latex deposits blocking the electro-lyte iunction, thus adversely affecting repeatability.Although older-type twin electrodes are capable ofgiving accurate results, they should be progressivelyreplaced because of this problem of cleaning andrepeatability.