ASTM D4273-05

1.1 Carbon-13 Nuclear Magnetic Resonance Spectroscopy(carbon-13 NMR), measures the primary hydroxyl content of ethylene oxide-propylene oxide polyethers used in preparing flexible foams. It is best suited for polyethers with primary hydroxyl contents of 10 to 90 %.

Note 1—There is no equivalent ISO standard.

1.2 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.

Measurements of primary hydroxyl content are useful for providing information regarding the relative reactivities of polyols.