ISO 15512:2008 塑料 含水量的测定

标准编号：ISO 15512:2008

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：2008-05

标准范围

ISO 15512:2008规定了颗粒和成品形式的塑料含水量的测定方法。这些方法不测试通过ISO 62测量的塑料的吸水率（动力学和平衡）。这些方法适用于测定低至以下水平的水含量:方法A 0.1%或更好；方法B 0.01%或更好；方法C 0.01%或更好。指定了三种替代方法:方法A是使用无水甲醇的提取方法，然后对提取的水进行卡尔费休滴定。它可用于所有塑料，适用于最大尺寸为4mm × 4mm × 3mm的颗粒。方法B是使用加热的干燥空气或氮气蒸发水的蒸发方法，然后对收集的水进行卡尔费休滴定。它可用于所有塑料，适用于小于4毫米x 4毫米x 3毫米的颗粒。方法C是测压法。水含量由当水在真空下蒸发时产生的压力增加来确定。该方法不适用于含有除水以外的挥发性化合物的塑料样品，其量对室温下的蒸气压有显著贡献。应定期检查是否存在大量挥发性化合物，例如通过气相色谱法。对于新类型或新等级的材料尤其需要此类检查。

ISO 15512:2008 specifies methods for the determination of the water content of plastics in the form of granules and finished articles. These methods do not test for water absorption (kinetics and equilibrium) of plastics as measured by ISO 62. The methods are suitable for the determination of water content as low as the following levels:

• Method A 0,1 % or better;
• Method B 0,01 % or better;
• Method C 0,01 % or better.

1. Method A is an extraction method using anhydrous methanol followed by a Karl Fischer titration of the extracted water. It can be used for all plastics and is applicable to granules having a maximum size of 4 mm x 4 mm x 3 mm.
2. Method B is a vaporization method using heated, dry air or nitrogen gas to evaporate the water, followed by a Karl Fischer titration of the collected water. It can be used for all plastics and is applicable to granules smaller than 4 mm x 4 mm x 3 mm.
3. 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 plastic samples containing volatile compounds, other than water, in amounts contributing significantly to the vapour pressure at room temperature. Checks for the presence of large amounts of volatile compounds should be carried out periodically, for example by gas chromatography. Such checks are particularly required for new types or grades of material.

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