Elastomers ASTM standards

Prut, E.V., Zelenetskii, A.N., Chepel, L.M., Erina, N.A., Dubnikova, I.L., and Novikov, D.D., Thermoplastic elastomer composition and the way of its manufacturing, Russian Patent 206927/B.I., 32, 1996. ASTM. Standard Test Method for Vickers Hardness of Metallic Materials, 1987. 

Standard Test Method for Vulcanized Rubber and Thermoplastic Elastomers-Tension, ASTM standard D412-98a... 

ASTM D6048, Standard practice for stress relaxation testing of raw rubber, unvulcanized rubber compounds and thermoplastic elastomers. New ASTM standard prepared in Stress Relaxation Task Group to D11.12, Subcommittee on Processability. 

The rest of this hook consists of property data on many plastics and elastomers. Chapters 2—10 contain multipoint data in the form of plots. The plastics are grouped hy the basic chemical structures of the plastics. Each of these chapters contains a short introduction that descrihes the basic chemical structures of the plastics in that chapter. The figures that follow contain the multipoint data. They are grouped by the t5rpe of data. Generally stress vs. strain curves start the chapter, followed by various modulus measurements, strength measures, other physical properties, and electrical properties. These properties are measured by the appropriate ISO or ASTM standards. 

There are roughly 20 major classes of elastomers. Two basic specifications provide a standard nomenclature and classification system. The ASTM standard D1418 categorizes elastomers into compositional classes. A joint ASTM-Sodety of Automotive Engineer (SAE) specification, ASTM 2000/SAE J200, provides a classification system based on material properties. 

Physical properties of common polymers and elastomers are reported in Tables 11.4 and 11.5, while physical quantities commonly used in the previous table to describe polymers characteristics are listed in Table 11.6 with the corresponding ASTM standards. On the other hand, particular mechanical properties are briefly described below. 

Hakvoort (16) and also Della Gatta and Barczynska (17) advocate certain solid-state first-order transitions for use as subambient temperature standards. For relatively low temperature ranges, such as the glass transitions (Tg) for elastomers, Tan and Sabbah (18) have proposed the melting transitions of various organic compounds. Certified reference materials for heat capacity calibration, which are recommended by International Union of Pure and Applied Chemistry (lUPAC), are also available (Ref 5, pp. 46 and 353-356). Two ASTM standards document procedures for temperature (ASTM E967) and heat-fiow (ASTM E968) calibration in DSC. 

International Rubber Hardness. The International mbber hardness test (ASTM D1415) (2) for elastomers is similar to the Rockwell test ia that the measured property is the difference ia penetration of a standard steel ball between minor and major loads. The viscoelastic properties of elastomers require that a load appHcation time, usually 30 seconds, be a part of the test procedure. The hardness number is read directly on a scale of 0 to 100 upon return to the minor load. International mbber hardness numbers are often considered equivalent to Durometer hardness numbers but differences ia iadenters, loads, and test time preclude such a relationship. 

Specialty Elastomers. Polychloroprene and polysulfide mbber were the first synthetic specialty elastomers discovered. Since theh invention in the 1930s the total number of classes of synthetic mbbers has grown to almost 30. The foUowing lists standard acronyms by the International Synthetic Rubber Producers (IISRP) and the American Society for Testing and Materials (ASTM) for several specialty elastomers. 

To relate the physical properties of carbon black to rubber properties, we tested these tread blacks in the ASTM natural rubber recipe and in an SBR 1500 test recipe. In both elastomers, we checked standard stress/strain properties of modulus, tensile strength, and hardness. In the natural rubber recipe we also tested Firestone running temperature and rebound, and Goodyear rebound. In the SBR we checked percent swell, extrusion rate, viscosity, and laboratory abrasion. 

Currently, seven major manufacturers produce fluorocarbon elastomers, and these are listed in Table 5.1. The main commercially available fluorocarbon elastomers are listed in Table 5.2. In the ASTM D1418, fluorocarbon elastomers have a designation FKM, and in the International Organization of Standardization (ISO) R1629 their designation is FPM. Current worldwide fluoroelastomer demand is 21,000 metric tons, with average annual growth of approximately 7% [5]. 

ASTM D 746-79 (1987) Standard Test Method ioxBrittleness Temperature of Plastics and Elastomers by Impact, 7 pp (DOD Adopted) (FSC 9330) (Comm D-20)... 

The determination of peroxide number of aviation turbine fuel is important because of the adverse effects of peroxides on certain elastomers in the fuel system. In the test, the sample is dissolved (unlike ASTM D-6447) in l,l,2-trichloro-l,2,2-trifluoroethane and is contacted within an aqueous potassium iodide solution. The peroxides present are reduced by the potassium iodide, whereupon an equivalent amount of iodine is released that is titrated with standard sodium thiosulfate solution and a starch indicator. 

The above criteria were employed to select several commercially supplied Class PS elastomers for laboratory screening by employing selected tests taken from National Bureau of Standards NBSIR 77-1437(j4) and ANSI/ASTM D-3667-78 specifications for "Rubber Seals Used in Flat-Plate Solar Collectors". Four silicone, three EPDM, two fluorocarbon, three epichlorohydrin, one ethylene-acrylic, one polyacrylic, one chlorosulfonated polyethylene, one bromobutyl and two butyl rubbers were studied in these screening tests. These materials are identified in Table I and those compositions which were revealed by their manufacturers are shown in Table II. Undoubtedly some materials which should have been included were omitted however, we hope that this sampling will provide an indication of the applicability of a wide range of materials for use as sealants in thermal solar collectors. 

Lubrication of the test pieces is now standard practice in order to eliminate one obvious source of variation. The more uniform flattening of the test piece also eases measurement of thickness after release from compression. However, there remain specifications in which set is determined in the absence of lubricants. It has also become common practice with general-purpose rubbers to measure compression. set after just one day at 70°C, which for sulfur-vulcanized elastomers can be a. sensitive measure of the state of cure. Higher test temperatures are specified for special-purpose and speciality synthetic rubbers, but the one-day test has remained popular, not least as a cla.ssification criterion and grade requirement in such specifications as ASTM D2000 and the British Standard series of material specifications for individual rubber types. Tests seldom last more than seven days, and recovery is usually confined to the standard. 30 minutes after release, during which time the test piece cools to standard laboratory temperature if taken from an oven. The short-term nature of the test and the absence of isothermal conditions during recovery has been questioned by Birley and other workers [43]. 

ASTM D412-98a Standard Test Methods for Vulcanized Ruhher and Thermoplastic Rubbers and Thermoplastic Elastomers-Tension... 

ASTM D746-98e Standard Test Method for Brittleness Temperature of Plastics and Elastomers by Impact... 

ASTM D4474-00 Standard Classification System for Styrenic Thermoplastic Elastomer Injection Molding and Extrusion Materials (TES)... 

ASTM Cl 166, Standard Test Method for Flame Propagation of Dense and Cellular Elastomers Gaskets and Accessories, 2011. 

Flame propagation is the extent to which flame spreads along a material when exposed in heat and flame. Under ASTM Cl 166 [ 11 ] guidelines for both cellular and dense elastomers require testing samples that are 1.25 x 2.5 x 45 cm. The standard requires that the cellular and dense elastomers are exposed to a Bunsen burner with a specific flame for 5 and 15 minutes, respectively. In either case, the flame must not spread more than 10 cm. 

Standard methods of testing elastomers used for medical applications are given by specific ASTM test methods. Physical and biological tests are provided here to serve as references for the data cited in the tables and listed in Table 4.17. They are also designated in the FDA Guidance Document. 

ASTM D412-98a(2002)el Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension... 

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