標準號：DIN ISO 976-2008
中文標準名稱：橡膠和塑料.聚合物分散體和橡膠膠乳.pH值的測定
英文標準名稱：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
標準類型：G31
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：G31
國際標準分類號：83.040.10
引用標準：ISO 123-2001;ISO 3696-1987;ISO 15528-2000;ISO/TR 9272
適用范圍：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.