AASHTO T 339-10（2019） Standard Method of Test for Analysis of Structural Steel Coatings for Isocyanate Content.pdf

Standard Method of Test for Analysis of Structural Steel Coatings for Isocyanate Content AASHTO Designation:T 339-10(2019)1 Technical Submittee:4c Markings and Coatings Release:Group 2(June) AASHIO American Association of State Highway and Transportation Officials 444 North Capitol Street N.W. Suite 249 Washington D.C.20001 Standard Method of Test for Analysis of Structural Steel Coatings for Isocyanate Content AASHTO Designation:T 339-10(2019)1 AASHO Technical Submittee:4c Markings and Coatings Release:Group 2(June) 1. SCOPE 1.1. This method is designed for the determination of the isocyanate (NCO)content of the resin system found in polyurethane paints. 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 associated with its use.It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. APPARATUS AND MATERIALS 2.1. Analytical balance. 2.2. High-speed centrifuge. 2.3. Centrifuge tubes minimum 50-mL heavy-wall glass with vinyl-lined screw caps or 50-mL high- speed [9400 relative centrifugal force (RCF)]polypropylene tubes with screw caps. 2.4. 10-mL syringes with Luer slip tip and caps. 2.5. Automatic titrator with stirrer (Mettler-Toledo DL 50 or equivalent). 2.6. pH electrodes. 2.7. Fleaker or other vessel with stopper or cap 200-mL minimum volume. 2.8. o-xylene reagent grade dried over 3A molecular sieve (see Section 4.1). 2.9. Standard buffer solutions pH 4.00 and pH 7.00. 2.10. Dibutylamine 99 percent assay. 2.11. Methanol ACS reagent grade dried over 3A molecular sieve (see Section 4.1). 2.12. Hydrochloric acid solution 1.0 N. TS-4c T339-1 AASHTO 2019 by the American Association of State Highway and Transportation Officials. All rights reserved.Duplication is a violation of applicable law. 3. PROCEDURE 3.1. To analyze a one-pone...