1、Designation: D4817 88 (Reapproved 2012)Standard Classification forRubber Compounding MaterialsStearic Acid1This standard is issued under the fixed designation D4817; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 purport t
3、o 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:2D1466 St
4、andard Test Method for Sampling Liquid Oils andFatty Acids Commonly Used in Paints, Varnishes, andRelated Materials3D1951 Standard Test Method for Ash in Drying Oils andFatty Acids3D1959 Test Method for Iodine Value of Drying Oils andFatty Acids3D1962 Standard Test Method for Saponification Value of
5、Drying Oils, Fatty Acids, and Polymerized Fatty Acids3D1965 Test Method for Unsaponifiable Matter in DryingOils, Fatty Acids, and Polymerized Fatty Acids3D1980 Test Method for Acid Value of Fatty Acids andPolymerized Fatty Acids3D1982 Test Method for Titer of Fatty AcidsD1983 Standard Test Method fo
6、r Fatty Acid Compositionby Gas-Liquid Chromatography of Methyl Esters3D4075 Test Methods for Rubber Compounding MaterialsFlame Atomic Absorption AnalysisDetermination ofMetals3. Significance and Use3.1 Stearic acid is important in the rubber vulcanizationprocess. It is believed that the stearic acid
7、 reacts with zinc-oxide or other 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
8、stock but can be derived from other 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
9、 rubber compounding.4.1.1.1 Class Number 1: Stearic Acid Containing Unsatu-rated 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
10、in rubbercompounding where unsaturated 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 us
11、ed in rubber compoundingwhere a 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 c
12、hecked by TestMethod D1983. (See 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 to1This classification is under the j
13、urisdiction of ASTM Committee D11 onRubber and is the direct responsibility of Subcommittee D11.20 on CompoundingMaterials and Procedures.Current edition approved May 1, 2012. Published June 2012. Originallyapproved in 1988. Last previous edition approved in 2005 as D4817 88 (2005).DOI: 10.1520/D481
14、7-88R12.2For referenced ASTM standards, 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. The last approved version of this histori
15、cal standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.improve color and distillation, or crystallization to changechain length distribution or improve color, or both. A combi-nation of the processi
16、ng 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 D1466.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
17、in 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 standard is subject to revision at any time by the responsible technical committee and m
18、ust 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 International Headquarters. Your comments will receive careful consideration at a meeting of t
19、heresponsible 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 below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C7
20、00, 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). Permissi
21、on rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Typical Physical and Chemical Properties of StearicAcidClass Number 1APropertyTestMethodGrade 1Low-IVBGrade 2Med-IVBGradeHigh-IVBAsh, % D1951 0.2 max 0.2 max 0.2 maxIodine value, g/100 g D
22、1959 8 max 15 max 39 6 5Saponification value,mg KOH/gD1962 204.5 6 5.0 204.5 6 5.0 .Unsaponificationmatter, %D1965 3.0 max 3.0 max .Acid value, mg KOH/g D1980 203.56 4.5 203.0 6 4.5 203.5 6 4.5Titer, C D1982 56.06 4.5 53.0 6 3.0 48.5 6 4.5CTrace metals, ppm D4075 varies from industry to industryAThe
23、 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 D4075.TABLE 2 Typical Physical and Chemical Properties of StearicAcidClass Number 2AProperty Test MethodGrade 1,Palmiti
24、c/Stearic50/40BGrade 2,Palmitic/Stearic30/65Ash,% D1951 0.1 0.1Iodine, value, g/100 g D1959 1.0 max 1.0 maxSaponification value,mg KOH/gD1962 208.5 6 2.5 203.5 6 3.0Unsaponificationmatter, %D1965 0.2 max 0.5 maxAcid value, mg KOH/g D1980 208.56 2.0 203.0 6 3.0Titer, C D1982 55.56 1.0 60.0 6 2.0CTrac
25、e metals, ppm D4075 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 D4075.D4817 88 (2012)2
