标准编号：ISO 15512:2014
中文名称：塑料 含水量的测定
英文名称：Plastics — Determination of water content
发布日期：2014-09
标准范围
1.1 This International Standard specifies methods for the determination of the water content of plasticsin the form of powder, granules, and finished articles. These methods do not test for water absorption(kinetics and equilibrium) of plastics as measured by ISO 62.Method A is suitable for the determination of water content as low as 0,1 % with an accuracy of 0,1 %.Method B and Method C are suitable for the determination of water content as low as 0,01 % with anaccuracy of 0,01 %.Water content is an important parameter for processing materials and has to remain below the levelspecified in the appropriate material standard.1.2 Four alternative methods are specified in this International Standard.— Method A is an extraction method using anhydrous methanol followed by a Karl Fischer titrationof the extracted water. It can be used for all plastics and is applicable to granules smaller than4 mm × 4 mm × 3 mm. The method can also be used for, e.g. prepolymer materials in the form of apowder that are insoluble in methanol.— Method B1 is a vaporization method using a tube oven. The water contained in the test portion isvaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followed by a KarlFischer titration of the collected water. It can be used for all plastics and is applicable to granulessmaller than 4 mm × 4 mm × 3 mm.— Method B2 is a vaporization method using a heated sample vial. The water contained in the testportion is vaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followedby a Karl Fischer titration of the collected water. It can be used for all plastics and is applicable togranules smaller than 4 mm × 4 mm × 3 mm.— Method C is a manometric method. The water content is determined from the increase in pressure,which results when the water is evaporated under a vacuum. This method is not applicable to plasticsamples containing volatile compounds, other than water, in amounts contributing significantlyto the vapour pressure at room temperature. Checks for the presence of large amounts of volatilecompounds are to be carried out periodically, for example by gas chromatography. Such checks areparticularly required for new types or grades of material.
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