塑料 环氧树脂用固化剂和促进剂 酸酐中游离酸测定

[中文适用范围]： 该方法的原理是使酸酐硬化剂或加速剂供试品中存在的少量游离酸与罗丹明6G反应，使供试品溶液呈粉红色，在波长约510 nm处测定显色溶液的吸光度。 光谱仪，根据校准曲线测定游离酸含量。 该方法适用于大多数酸酐，但聚酯和低聚酸酐除外，因为聚酯和低聚酸酐可能会导致结果过于分散。 [外文原描述]： The principle of the method specified is reacting a small amount of free acid present in a test portion of acid anhydride hardener or accelerator with rhodamine 6G to colour the test solution pink, measuring the absorbance of the coloured solution at a wavelength of about 510 nm using a spectrometer, determining the free-acid content from a calibration curve. The method is suitable for most anhydrides except for polyester and oligomeric anhydrides which may give too wide a scatter of results.