1、Designation: D 4817 88 (Reapproved 2005)Standard Classification forRubber Compounding MaterialsStearic Acid1This standard is issued under the fixed designation D 4817; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. 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 classification covers the compounding materialscommercially known as stearic acid.1.2 This standard does not purpor
3、t to address all of thesafety 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. Referenced Documents2.1 ASTM Standards:2D 146
4、6 Test Method for Sampling Liquid Oils and FattyAcids Commonly Used in Paints, Varnishes, and RelatedMaterials3D 1951 Test Method for Ash in Drying Oils and FattyAcids3D 1959 Test Method for Iodine Value of Drying Oils andFatty AcidsD 1962 Test Method for Saponification Value of DryingOils, Fatty Ac
5、ids, and Polymerized Fatty Acids3D 1965 Test Method for Unsaponifiable Matter in DryingOils, Fatty Acids, and Polymerized Fatty AcidsD 1980 Test Method for Acid Value of Fatty Acids andPolymerized Fatty AcidsD 1982 Test Method for Titer of Fatty AcidsD 1983 Test Method for Fatty Acid Composition by
6、Gas-Liquid Chromatography of Methyl Esters3D 4075 Test Methods for Compounding MaterialsFlameAtomic Absorption TechniqueDetermination of Metals3. Significance and Use3.1 Stearic acid is important in the rubber vulcanizationprocess. It is believed that the stearic acid reacts with zinc-oxide or other
7、 metallic oxides, during vulcanization, to form arubber soluble salt or soap, that reacts with the acceleratorenabling it to exert its full effect.3.2 Stearic acid of commerce is generally a mixture ofpalmitic, stearic, and oleic acids usually derived from tallowbase stock but can be derived from ot
8、her fats and oils of animalor vegetable origins.4. Basis of Classification4.1 Classification of Stearic Acid by Classes:4.1.1 There are several different classes of stearic acid,based on stearic acid content and iodine value. There are twoclasses predominantly used in rubber compounding.4.1.1.1 Clas
9、s Number 1: Stearic Acid Containing Unsatur-ated Fatty AcidsStearic acid containing unsaturated acids iscommonly referred to as rubber grade stearic acid. Threegrades are commonly available with low, medium, and highunsaturation. These grades of stearic acid are used in rubbercompounding where unsat
10、urated fatty acids can be tolerated.(See Table 1 for typical analysis of Class 1 stearic acid.)4.1.1.2 Class Number 2Stearic Acid with Low Levels ofUnsaturated Fatty AcidsLow IV:(1) Low iodine value stearic acid is produced in severalgrades. Two grades are commonly used in rubber compoundingwhere a
11、1.0 maximum iodine value is needed. These twogrades are distinguished by their ratios of palmitic to stearicacid content. The physical and chemical properties of thestearic acid will change as the palmitic/stearic acid ratiochanges. The palmitic/stearic ratio may be checked by TestMethod D 1983. (Se
12、e Table 2 for a typical analysis of the Class2 stearic acid.)(2) Stearic acid can be made to customer specifications byemploying various processing steps such as hydrogenation tolower iodine value, bleaching with diatomaceous earth toimprove color and distillation, or crystallization to changechain
13、length distribution or improve color, or both. A combi-nation of the processing steps may be used to produce the finalproduct.5. Sampling5.1 Sampling to conduct tests as outlined in Section 2 shallbe carried out in accordance with Test Method D 1466.1This classification is under the jurisdiction of
14、ASTM Committee D11 onRubber and is the direct responsibility of Subcommittee D11.20 on CompoundingMaterials and Procedures.Current edition approved May 1, 2005. Published May 2005. Originallyapproved in 1988. Last previous edition approved in 1999 as D 4817 - 88(1999).2For referenced ASTM standards,
15、 visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
16、ken, PA 19428-2959, United States.ASTM International takes no position respecting 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 risko
17、f infringement of such rights, are entirely their own responsibility.This standard 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
18、standard or for additional standardsand should be addressed to ASTM International 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 yo
19、ur views known to the ASTM Committee on Standards, at the address shown below.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 co
20、ntacting 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).TABLE 1 Typical Physical and Chemical Properties of StearicAcidClass Number 1APropertyTestMethodGrade 1Low-IVBGrade 2Med-IVBGradeHigh-IVBAsh, % D 1
21、951 0.2 max 0.2 max 0.2 maxIodine value, g/100 g D 1959 8 max 15 max 39 6 5Saponification value,mg KOH/gD 1962 204.5 6 5.0 204.5 6 5.0 .Unsaponificationmatter, %D 1965 3.0 max 3.0 max .Acid value, mg KOH/g D 1980 203.56 4.5 203.0 6 4.5 203.5 6 4.5Titer, C D 1982 56.06 4.5 53.0 6 3.0 48.5 6 4.5CTrace
22、 metals, ppm D 4075 varies from industry to industryAThe values listed in Table 1 are typical ranges and values.BIV = iodine value.CTrace metals such as nickel, iron, copper, and manganese can be determinedin accordance with Test Method D 4075.TABLE 2 Typical Physical and Chemical Properties of Stea
23、ricAcidClass Number 2AProperty Test MethodGrade 1,Palmitic/Stearic50/40BGrade 2,Palmitic/Stearic30/65Ash,% D 1951 0.1 0.1Iodine, value, g/100 g D 1959 1.0 max 1.0 maxSaponification value,mg KOH/gD 1962 208.5 6 2.5 203.5 6 3.0Unsaponificationmatter, %D 1965 0.2 max 0.5 maxAcid value, mg KOH/g D 1980
24、208.56 2.0 203.0 6 3.0Titer, C D 1982 55.56 1.0 60.0 6 2.0CTrace metals, ppm D 4075 varies from industry to industryAThe values listed in Table 2 are typical ranges and valuesBEven though this grade contains more palmitic acid than stearic acid, thisgrade is still referred to as “stearic acid” in the rubber industry.CTrace metals such as nickel, iron, copper, and manganese can be determinedin accordance with Test Method D 4075.D 4817 88 (2005)2
