Measurements of EO content correlate with polyol reactivity (as related to primary hydroxyl content), linearity of foam rise, and the hydrophilicity of the polyol and final product.

Statistical data suggest that the ¹³C NMR test method is the preferred method for measuring low levels (less than 10 %) of polymerized EO in polyols.

The ¹H and ¹³C NMR test methods give different results which are highly correlated. The equation of the linear regression is:

The standard deviation of the regression is 0.49 and the multiple R-square is 0.9990.

1.1 Test Method A—Proton Nuclear Magnetic Resonance Spectroscopy (¹H NMR) measures polymerized ethylene oxide (EO) in ethylene oxide-propylene oxide polyethers used in flexible urethane foams and nonfoams. It is suitable for diols made from the commonly used initators and containing EO percentages above five. For triols initiated with glycerin and trimethylol propane, an uncorrected EO value is obtained since both initiators have protons that contribute to the EO measurement.

1.2 Test Method B—Carbon-13 Nuclear Magnetic Resonance Spectroscopy (¹³C NMR) measures the polymerized EO content of ethylene oxide-propylene oxide polyethers used in flexible urethane foams and nonfoams. It is suitable for diols and triols made from the commonly used initiators and containing EO percentages above five.

Note 1—There are no equivalent ISO standards.

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.