1.1 本试验方法适用于所有类型的聚乙烯、由比丙烯更长的乙烯和α-烯烃共聚物组成的乙烯塑料以及上述混合物的任何比例。 1.2 以国际单位制表示的数值应视为标准。 1.3 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。 具体危害说明见第节 8. . 注1: 没有已知的ISO等效于本标准。 1.4 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 有三种类型的烯烃基团以足够的浓度存在，以保证考虑，其中一种或多种通常可以在任何聚乙烯中找到 ( 4. ) . 这三种类型是:反式乙烯、R - 中国 = 中国 - R ′ ，有时称为跨肠不饱和；亚乙烯或悬垂亚甲基，RR ′ C = 中国 2. ; 和乙烯基不饱和，R - 中国 = 中国 2. ，也称为末端不饱和。 5.2 这些基团的类型和数量会影响树脂的化学和物理性能。有关其存在的信息也可用于表征或识别未知树脂或树脂混合物。 5.3 偏乙烯不饱和度代表了大多数低密度聚乙烯中存在的主要不饱和度。 5.4 红外光谱法可用于测定聚乙烯中的不饱和度 ( 1. , 3. , 5. ) . 红外测定值与IC1摄取测定值一致 ( 5 ) .

1.1 This test method is applicable to all types of polyethylenes, those ethylene plastics consisting of ethylene and α-olefin copolymers longer than propylene, and blends of the above in any ratio. 1.2 The values stated in SI units are to be regarded as the standard. 1.3 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. Specific hazards statements are given in Section 8 . Note 1: There is no known ISO equivalent to this standard. 1.4 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 There are three types of olefinic groups present in sufficient concentrations to warrant consideration, one or more of which can normally be found in any polyethylene ( 4 ) . The three types are: trans-vinylene, R - CH = CH - R ′ , sometimes referred to as transinternal unsaturation; vinylidene or pendent methylene, RR ′ C = CH 2 ; and vinyl unsaturation, R - CH = CH 2 , also referred to as terminal unsaturation. 5.2 The type and quantity of these groups can influence the chemical and physical properties of the resin. Information concerning their presence may also be used to characterize or identify unknown resins or blends of resins. 5.3 Vinylidene unsaturation represents the major portion of the unsaturation present in most low-density polyethylenes. 5.4 Infrared spectroscopy can be used for the determination of unsaturation in polyethylene ( 1 , 3 , 5 ) . The values determined by infrared agree with those determined by IC1 uptake ( 5 ) .