Significance and Use

This test method can be used for research or for quality control to characterize aromatic isocyanates and low-acidity prepolymers. Acidity correlates with performance in some polyurethane systems.

1. Scope

1.1 This test method measures the acidity, expressed as ppm of hydrochloric acid (HCl), in aromatic isocyanate or polyurethane prepolymer samples of below 100 ppm acidity. The test method is applicable to products derived from toluene diisocyanate and methylene di(phenylisocyanate) (see Note 1). Refer to Test Method D6099 for determination of acidity in moderate- to high-acidity aromatic isocyanates.

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 1This standard is equivalent to ISO 14898, Method B.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D883 Terminology Relating to Plastics

D6099 Test Method for Polyurethane Raw Materials: Determination of Acidity in Moderate to High Acidity Aromatic Isocyanates

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

ISO Standards

Keywords

acidity; aromatic isocyanates; isocyanates; methylene-bis-(4-phenylisocyanate); methylene di(phenylisocyanate); methylene diphenyldiisocyanate; MDI; prepolymer; polyurethane; raw materials; test method; TDI; titration; toluene diisocyanate; Toluene diisocyanate (TDI); Aromatic isocyanates; Isocyanates; MDI (methylenediphenyldiisocyanate); Acidity, alkalinity, pH--plastics; Polyurethane raw materials--isocyanates; Prepolymers; Titration;

ICS Code

ICS Number Code 83.080.10 (Thermosetting materials)

DOI: 10.1520/D5629-11

ASTM International is a member of CrossRef.

ASTM D5629