ASTM D4273-11

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

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 %.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory limitations prior to use.

Note 1—There is no known ISO equivalent to this standard.

X1.1.1 Fluorine-19 Nuclear Magnetic Resonance Spectroscopy (fluorine-19 NMR), measures the primary hydroxyl content in ethylene oxide-propylene oxide polyethers used in flexible urethane foams. It is suitable for polyethers with hydroxyl numbers of 24 to 300 and primary hydroxyl percentages of 2 to 98.