1、Designation: D 6738 01 (Reapproved 2006)Standard Test Method forPrecipitated SilicaVolatile Content1This standard is issued under the fixed designation D 6738; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure to determine thevolatile content of precipitated hydrated silicas. These volatilesare genera
3、lly excess water adsorbed onto the surface of thesilica. This test method does not determine water of hydrationof the silica.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This standard does not purport to address all of th
4、esafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 The volatiles content of a precipitated sil
5、ica may affectthe processing properties of a rubber mixture containing silicaand the properties of the final product.3. Apparatus3.1 Oven, gravity-convection type, capable of maintaining105 6 5C.3.2 Aluminum Pans, oil free.3.3 Analytical Balance, sensitive to 0.1 mg.3.4 Desiccator.NOTE 1It is import
6、ant that the desiccant is very dry, or moisture maybe drawn from the desiccant into the sample during cooling.4. Procedure4.1 Weigh an aluminum pan to the nearest 0.1 mg andrecord its weight (W1).4.2 Add approximately2gofthesilica sample to the panand reweigh to the nearest 0.1 mg (W2).4.3 Place the
7、 pan with the silica sample into the 105C ovenfor2h6 5 min.4.4 Transfer the pan containing the silica sample from theoven into a desiccator and cool for1horuntil roomtemperature.4.5 Remove the pan containing the silica sample from thedesiccator and reweigh to the nearest 0.1 mg (W3).NOTE 2A ground-g
8、lass stoppered low-form weighing bottle (approxi-mately 30 mm in height by 60 mm in diameter) may be substituted for thealuminum weighing dish in this test method. The sample then is dried inthe oven and cooled in the dessicator with the stopper removed, but finalweighing would be done with the stop
9、per in the bottle to minimizemoisture pick-up from the atmosphere. The thermal transfer of glassdiffers from that of aluminum, so cooling time may be lengthened usinga glass container.5. Calculation5.1 The volatile material is given by the following equation:% Volatiles 5 W2 W3!/W2 W1!# 3 100 (1)whe
10、re:W1= mass of aluminum pan, g,W2= mass of aluminum pan and silica sample beforeheating, g, andW3= mass of aluminum pan and silica sample after heat-ing, g.6. Report6.1 Report the following information:6.1.1 Identification of the sample, and6.1.2 Result reported to the nearest 0.1 %.7. Precision and
11、 Bias7.1 Precision and bias studies have not been conducted.8. Keywords8.1 precipitated hydrated silica; silica; volatile content1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.20 on Compounding Materialsand Procedures.C
12、urrent edition approved Oct. 1, 2006. Published November 2006. Originallyapproved in 2001. Last previous edition approved in 2001 as D 6738 01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ASTM International takes no position respe
13、cting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This st
14、andard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Internat
15、ional Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown belo
16、w.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 6738 01 (2006)2
