1.1 This practice describes infrared procedures for determining the molecular structural entities in the polyolefin chains (their quantitative levels with internal (Procedure A) and external (Procedure B) evaluation for sample thickness are suggested in the Appendix). The structural entities of primary concern are the types and distribution of branches. Although this practice centers its attention on polyolefins, the techniques, with proper modification, can be used for some other polymers as well.

1.2 Often these structural entities are at a level of less than 2%. Higher concentration of branching systems may be treated in other methods that address a specific problem associated with entities between 2 and 49%.

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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazards statements are given in Section 8.