1、 Standard Method of Test for Non-Instrumental Determination of Metallic Zinc in Zinc-Rich Primers AASHTO Designation: T 337-09 (2014)1American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4c T 337-1 AASHTO Standard Metho
2、d of Test for Non-Instrumental Determination of Metallic Zinc in Zinc-Rich Primers AASHTO Designation: T 337-09 (2014)11. SCOPE 1.1. This test method determines the amount of metallic zinc in the dried paint film (nonvolatile matter) of inorganic zinc-rich and organic zinc-rich primers. 1.2. The val
3、ues 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 appli
4、cability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. ASTM Standards: D521, Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder) D2369, Standard Test Method for Volatile Content of Coatings D2371, Standard Test Method for Pigment Content of Solvent-
5、Reducible Paints 3. PROCEDURES 3.1. Procedure AIndividual Components: Note 1Procedure A does not purport to determine the percentage of metallic zinc in the total pigment. Procedure A does not take into account any additional pigmentation that may be present in the mixed primer. 3.1.1. Prepare a sam
6、ple of the liquid primer by mixing weighed amounts of the zinc-dust pigment component with weighed amounts of the liquid component(s), using mix ratios (by mass) supplied by the manufacturer. The quantity of mixed primer shall be a minimum of 100 g, with the mass of each component determined to the
7、nearest 0.1 g. 3.1.2. Determine the nonvolatile matter percentage by mass of the mixed primer in accordance with ASTM D2369. Note 2It is extremely important to keep the mixed primer sample well agitated immediately prior to performing the ASTM D2369 or D2371 test method so as not to allow the zinc d
8、ust to appreciably settle out of the sample. 3.1.3. Determine the percentage of metallic zinc in the initial, dry zinc-dust pigment component in accordance with ASTM D521. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation o
9、f applicable law.TS-4c T 337-2 AASHTO 3.2. Procedure BPremixed Components: 3.2.1. Prepare a sample of the liquid primer by mixing weighed amounts of the liquid components (the zinc-dust pigment will be supplied incorporated in one of the liquid components) using the mix ratios by mass supplied by th
10、e manufacturer. The quantity of mixed primer shall be a minimum of 100 g, with the mass of each component determined to the nearest 0.1 g. 3.2.2. Determine the nonvolatile matter percentage by mass of the mixed primer in accordance with ASTM D2369. See Note 2. 3.2.3. Determine the pigment content pe
11、rcentage by mass of the mixed primer in accordance with ASTM D2371 (high-speed centrifugation). See Note 2. 3.2.4. Determine the metallic zinc percentage by mass of the pigment in accordance with ASTM D521 using the extracted dried pigment obtained from the ASTM D2371 test method. 4. CALCULATIONS 4.
12、1. Procedure A Calculations: 4.1.1. Calculate the percentage of volatile matter, V, in the mixed primer as follows (ASTM D2369): VA= 100 (W2 W1)/SA) 100 (1) where: VA= percentage of volatiles (first determination); W1= weight of dish; W2= weight of dish plus specimen after heating; SA= specimen weig
13、ht; and VB= percentage of volatiles (duplicate determination, calculated in the same manner as VA). V = (VA+ VB)/2 4.1.2. Calculate the percentage of nonvolatile matter, N, in the mixed primer as follows (ASTM D2369): N = (NA+ NB)/2 (2) where: NA= 100 VA; and NB= 100 VB. 4.1.3. Calculate the percent
14、age of zinc dust by mass of the mixed primer, ZnPT, as follows: ZnPT= (Z/(Z + L) 100 (3) where: Z = mass of zinc-dust component; and L = mass of liquid component(s). 4.1.4. Calculate the percentage of metallic zinc, ZnPG, by mass of the zinc-dust component as follows (ASTM D521): 2015 by the America
15、n Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4c T 337-3 AASHTO ZnPG= (V3 B3)(N 0.0327)/S2 100 (4) where: V3= titrant solution required for titration of the specimen, mL; B3= titrant solution required for titration of
16、 the blank, mL; N = normality of the titrant solution; S2= sample used, grams; and 0.0327 = milliequivalent weight of zinc. 4.1.5. Determine the amount of metallic zinc in the dried paint film (nonvolatile matter), by calculating the percentage of metallic zinc of the nonvolatile matter, ZnNV, as fo
17、llows: ZnNV= (ZnPG ZnPT)/N (5) where: ZnPG= percentage of metallic zinc, percentage by mass of zinc dust component, from Section 4.1.4; ZnPT= percentage of zinc-dust component by mass of mixed primer, from Section 4.1.3; and N = percentage of nonvolatile matter, from Section 4.1.2. 4.2. Procedure B
18、Calculations: 4.2.1. Calculate volatile and nonvolatile content as in Sections 4.1.1 and 4.1.2. 4.2.2. Calculate the percentage of pigment, P, as follows (ASTM D2371): P = (W1 W2)/S 100 (6) where: W1= weight of the tube (including stirring rod) plus pigment, g; W2= weight of tube (including stirring
19、 rod), g; and S = weight of paint sample used, g. 4.2.3. Calculate the percentage of metallic zinc, ZnP, in the pigment as follows (ASTM D521): ZnP= (V3 B3)(N 0.0327)/S2 100 (7) where: V3= titrant solution required for titration of the specimen, mL; B3= titrant solution required for titration of the
20、 blank, mL; N = normality of the titrant solution; S2= sample used, g; and 0.0327 = milliequivalent weight of zinc. 4.2.4. Calculate the percentage of pigment in the nonvolatile matter, PNV, as follows: PNV= (P/N) 100 (8) where: P = percentage of pigment calculated from Section 4.2.2; and N = percen
21、tage of nonvolatile matter (total solids) from Section 4.2.1. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4c T 337-4 AASHTO 4.2.5. Determine the amount of metallic zinc in the dried paint film (no
22、nvolatile matter), by calculating the percentage of metallic zinc of the nonvolatile matter, ZnNV, as follows: ZnNV= (Znp/100) PNV(9) where: Znp= percentage of metallic zinc, percent by mass of pigment, from Section 4.2.3; and PNV= percentage of pigment, by mass of the nonvolatile matter, from Section 4.2.4. 1Formerly AASHTO Provisional Standard TP 65. First published as a full standard in 2009. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
