ASTM D6437-05(2016)e1

5.1 This test method is suitable for quality control, as a specification test and for research. The urethane reaction between polyols and isocyanates to form polyurethane polymers is known to be sensitive to the presence of basic substances. This is particularly important in the preparation of polyurethane prepolymers which contain isocyanate groups that are known to react in the presence of trace amounts of basic substances. Since many polyether polyols are often made with strongly basic catalysts, it is important to have an analytical method capable of detecting small quantities of residual basic substances. This test method is capable of detecting ppm levels of base (as KOH).1.1 This test method covers measuring alkalinity in low-alkalinity (<0.002 meq/g basicity) polyols. This alkalinity is often expressed as CPR (controlled polymerization rate) of polyether polyols. This test method is not applicable to amine-based polyols.

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 and health practices and determine the applicability of regulatory limitations prior to use.