4.1 These test methods can be used for research, quality control, or specification tests to characterize isocyanates used in polyurethane products.

4.2 Viscosity measures the resistance of a fluid to uniform continuous flow without turbulence or other forces.

4.3 Some isocyanates exhibit non-Newtonian behavior under certain conditions. Whenever possible, generate results for comparison under the same conditions, that is, the same spindle/speed combination for rotational viscosity and the same tube size for kinematic viscosity.

1.1 These test methods (A and B) determine the viscosity of crude or modified isocyanates. They are applicable to products derived from toluene diisocyanate, methylene di(phenylisocyanate), and polymeric (methylene phenylisocyanate) (see Note 1).

1.2 The values stated in SI units are to be regarded as 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. For specific hazards statement, see Warning at the end of 5.1.