Active Standard ASTM D6437 | Developed by Subcommittee: D20.22
Book of Standards Volume: 08.03
Historical (view previous versions of standard)
Significance and Use
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.
Note 1—There is no known ISO equivalent to this standard.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D883 Terminology Relating to Plastics
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
ICS Number Code 83.040.01 (Raw materials for rubber and plastics in general)
UNSPSC Code 12352100(Organic derivatives and substituted compounds)