1.1 本规程涵盖聚合物稀溶液粘度的测定。有几种ASTM标准（试验方法 D789 , D1243 , D1601 和 D4603 ，并练习 D3591 )描述了特定聚合物（如尼龙、聚氯乙烯、聚乙烯和聚对苯二甲酸乙二醇酯）的稀溶液粘度程序。编写本规程是为了在出现与具体程序无关的问题时，或在没有适用于所研究聚合物的标准时，补充这些标准。 1.2 本规程适用于在环境温度和150°C之间的温度下完全溶解而不发生化学反应或降解以形成随时间稳定的溶液的所有聚合物。结果通常表示为相对粘度（粘度比）、固有粘度（对数粘度数）或特性粘度（极限粘度数）（见 3.1 ). 1.3 对于聚酰胺，通过本程序测定的相对粘度值与通过试验方法测定的值不相等 D789 . 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 本标准和ISO 1628“塑料粘度值和极限粘度值的测定”在技术上是等效的。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 稀溶液粘度的测定为聚合物的分子表征提供了一项信息。当粘度数据与其他分子参数结合使用时，可以根据聚合物的分子结构预测聚合物的性能。 5.2 粘度取决于分子量分布，因此在一定的限制条件下，稀溶液粘度与分子量或链长等分子参数之间可以获得满意的相关性。必须遵守的最大限制条件如下: 5.2.1 必须知道，用于建立相关性的聚合物及其应用的聚合物不包含或不包含支链物种。基本上是分子大小而不是分子量的量度，只有当溶解聚合物分子的质量和大小之间存在唯一关系时，稀溶液粘度才能与分子量或链长适当相关。 这适用于线性聚合物，但不适用于大多数支链聚合物。 5.2.2 原因与 5.2.1 ，必须要求应用相关性的聚合物具有与建立关系所用聚合物相同的化学成分。 5.3 对于满足以下限制的聚合物: 5.2 ，可以在聚合物的稀溶液粘度与其流体动力体积或平均链尺寸（回转半径或端到端距离）之间建立经验关系。这种关系取决于影响溶解聚合物分子大小的任何变量。这些变量中最重要的是溶剂类型和温度。因此，给定聚合物样品的溶液粘度取决于这些变量的选择，必须始终用粘度来指定这些变量，以便完全识别。 5.4 分子量足够大的聚合物的溶液粘度可能取决于粘度计中的剪切速率，而聚电解质（含有可电离化学基团的聚合物）的粘度将取决于溶剂的组成和离子强度。测量此类聚合物时，需要采取超出本规程范围的特殊预防措施。 5.5 最后，聚合物溶液的粘度可能会受到样品中已识别或未识别添加剂的显著影响，包括但不限于着色剂、填料或低分子量物种。

1.1 This practice covers the determination of the dilute solution viscosity of polymers. There are several ASTM standards (Test Methods D789 , D1243 , D1601 , and D4603 , and Practice D3591 ) that describe dilute solution viscosity procedures for specific polymers, such as nylon, poly(vinyl chloride), polyethylene, and poly(ethylene terephthalate). This practice is written to augment these standards when problems arise with which the specific procedure is not concerned, or when no standard is available for the polymer under investigation. 1.2 This practice is applicable to all polymers that dissolve completely without chemical reaction or degradation to form solutions that are stable with time at a temperature between ambient and 150°C. Results are usually expressed as relative viscosity (viscosity ratio), inherent viscosity (logarithmic viscosity number), or intrinsic viscosity (limiting viscosity number) (see 3.1 ). 1.3 For polyamides, relative viscosity values by this procedure are not equivalent to those determined by Test Methods D789 . 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: This standard and ISO 1628, “Plastics—Determination of Viscosity Number and Limiting Viscosity Number,” are technically equivalent. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 The determination of dilute solution viscosity provides one item of information towards the molecular characterization of polymers. When viscosity data are used in conjunction with other molecular parameters, the properties of polymers depending on their molecular structure may be predicted. 5.2 Viscosity is dependent on molecular weight distribution, so with certain restrictions, satisfactory correlations can be obtained between dilute-solution viscosity and molecular parameters such as molecular weight or chain length. The most limiting restrictions that must be observed are as follows: 5.2.1 It must be known that the polymers used to establish the correlations and those to which they are applied do not consist of or contain branched species. Basically a measure of molecular size and not molecular weight, the dilute solution viscosity can be correlated appropriately with molecular weight or chain length only if there is a unique relationship between the mass and the size of the dissolved polymer molecules. This is the case for linear, but not for most branched, polymers. 5.2.2 For reasons similar to those outlined in 5.2.1 , it must be required that the polymers to which the correlations are applied have the same chemical composition as those used in establishing the relationships. 5.3 For polymers meeting the restrictions of 5.2 , empirical relationships can be developed between the dilute solution viscosity of a polymer and its hydrodynamic volume or average chain dimension (radius of gyration or end-to-end distance). Such relationships depend upon any variables influencing this molecular size of the dissolved polymer. The most important of these variables are solvent type and temperature. Thus, the solution viscosity of a given polymer specimen depends on the choice of these variables, and they must always be specified with the viscosity for complete identification. 5.4 The solution viscosity of a polymer of sufficiently high molecular weight may depend on rate of shear in the viscometer, and the viscosity of a polyelectrolyte (polymer containing ionizable chemical groupings) will depend on the composition and ionic strength of the solvent. Special precautions beyond the scope of this practice are required when measuring such polymers. 5.5 Finally, the viscosity of polymer solutions may be affected drastically by the presence of recognized or unrecognized additives in the sample, including but not limited to colorants, fillers, or low-molecular-weight species.