橡胶.溶剂提取物的测定

[中文适用范围]： 本文件规定了四种定量测定从天然和合成生橡胶中提取的物质的方法；其中两种方法也适用于未硫化和硫化橡胶混合物。 方法 A 测量溶剂蒸发后溶剂提取物的质量相对于原始测试部分的质量。 方法 B 测量提取前后测试部分的质量差异。 方法C仅适用于生橡胶，测量使用沸腾溶剂萃取前后测试部分的质量差异。 方法 D 仅适用于生橡胶，测量提取前后测试部分的质量相对于原始测试部分的质量的差异。 注1：根据所使用的测试方法、测试部分的调节和所使用的溶剂，测试结果不一定相同。 注 2：由于建立了平衡，方法 C 给出的结果通常低于方法 A 和 B 获得的结果，特别是如果使用大的测试部分，这取决于可萃取物质的含量和性质。 然而，方法 C 比方法 A 或方法 B 更快。 注 3：如果测试部分在提取过程中崩解，则方法 C 和 D 不适用。 注 4：方法 D 通常用于生产控制。 附录 A 中给出了最适合每种橡胶的溶剂的建议。 [外文原描述]： This document specifies four methods for the quantitative determination of the material extractable from raw rubbers, both natural and synthetic; two of the methods are also applicable to the unvulcanized and vulcanized rubber compounds. Method A measures the mass of the solvent extract, after evaporation of the solvent, relative to the mass of the original test portion. Method B measures the difference in the mass of the test portion before and after extraction. Method C, which is for raw rubbers only, measures the difference in the mass of the test portion before and after extraction using boiling solvent. Method D, which is for raw rubbers only, measures the difference in the mass of the test portion before and after extraction relative to the mass of the original test portion. NOTE 1 Depending on the test method used, the conditioning of the test portion and the solvent used, the test result is not necessarily the same. NOTE 2 Method C generally gives results which are lower than those obtained with methods A and B due to an equilibrium which is set up, particularly if large test portions are used, depending on the content and the nature of the extractable matter. Method C is, however, a quicker method than method A or method B. NOTE 3 Methods C and D are not suitable if the test portion disintegrates during the extraction. NOTE 4 Method D is normally used for production controls. Recommendations as to the solvent most appropriate for each type of rubber are given in Annex A.