Material compatibility tests

Standard tests are utilized early in the evaluation phase to evaluate flammability, ignition and explosive characteristics. These include differential thermal analysis, thermo gravometric analysis, drop weight tests, friction tests, card gap (shock initiation) tests, and materials compatibility tests. Information derived from the above tests serve as a basis to establish safe procedures and techniques to handle and process the chemicals into propellants. 

PP, PVDF, and PE are not jointed using solvent cements, but the weld regions contain relatively high levels of intrinsic stress caused by the thermal fusion process. Chemical stress cracking could occur at these welds if exposed to certain chemicals. When performing material compatibility tests for any... 

Materials Compatibility Einally, any lubricant is required to be compatible with non-metallic components used in the engine, such as plastics, resins and elastomers. In particular, polymeric materials used in seals and plastics need to retain their integrity when in contact with the lubricant. ACEA and most OEMs have material compatibility tests to ensure that the lubricant will not cause undue degradation in key physical parameters of the polymer. These parameters include tensile strength, hardness, volume and crack formation. Any such loss of polymer integrity could be manifest as oil seal leaks or in more extreme cases as a blown gasket. Current engine test examples for American, European and selected OEM specifications are shown in Table 9.5. 

The results of the bonded joint tests are presented in Tables 6 to 9. The results of material compatibility tests are presented in Table 10 and the results of surface treatment tests in Table 11. The following abbreviations and notation are used ... 

Table 10 Compilation of material compatibility tests (Dow Derakane 441 laminates).

In material compatibility tests no critical material combinations in respect of adhesion were detected. 

L. Rosenblum, C.M. Scheurmann, and TA. Moss. 1967. Space-power-system material compatibility tests of selected refractory metal alloys with boiling potassium. Symposium on Alkali Metal Coolants-Corrosion Studies and Systems Operating Experience, Vienna, Austria. 

Because of the number of chemicals and subsequent multiple number of potential reactions, it is impractical and (perhaps impossible) to list all potential reactions. Several systems exist for determining the reactions between classes of chemicals, however, none of them is definitive. Because all of the potential reactions for individual chemicals are not cataloged and because there are no (or very few), pure solutions of waste materials, laboratory compatibility testing is recommended for most materials. An appropriate protocol for compatibility testing would involve the following steps ... 

The usual problems encountered with any sedimentation procedure are present. It is necessary to use a dispersing liq compatible with the material being tested. Also, dispersing agents and technique must insure complete dispersion and prevent agglomeration. These factors may vary with materials, and therefore will require special attention when new materials are to be analyzed... 

Although the initially reported tissue compatibility tests for subcutaneous implants of poly(BPA-iminocarbonate) were encouraging (41,42), it is doubtful whether this polymer will pass more stringent biocompatibility tests. In correspondence with the properties of most synthetic phenols, BPA is a known irritant and most recent results indicate that BPA is cytotoxic toward chick embryo fibroblasts in vitro (43). Thus, initial results indicate that poly(BPA-iminocarbonate) is a polymer with highly promising material properties, whose ultimate applicability as a biomaterial is questionable due to the possible toxicity of its monomeric building blocks. 

To avoid compatibility problems, compatibility tests under conditions typical for the planned application are performed. From their results suitable material combinations are selected. Figure 110 shows a compatibility test for metals in contact with inorganic PCM. Test tubes containing both materials (center) are kept in a controlled environment for a fixed time (left) and later effects on the metal are analyzed (right). 

Chemical compatibility tests using U.S. EPA Method 909040 should always be performed for hazardous waste sites, but some municipal waste sites also contain hazardous, nondegradable materials. U.S. EPA conducted a 5-year study of the impact of municipal refuse on commercially available liner materials and found no evidence of deterioration within that period. However, in a current study of leachate quality in municipal landfills, the Agency has discovered some organic chemical constituents normally found in hazardous waste landfill facilities. Apparently, small quantities of household hazardous waste enter municipal sites or are disposed of as small quantity generator wastes. As a result of these findings, U.S. EPA developed a position on the need for chemical compatibility tests for thousands of municipal waste disposal sites. 

A primary objective of chemical compatibility testing is to ensure that liner materials will remain intact not just during a landfill s operation but also through the postclosure period, and preferably longer. It is difficult, however, to predict future chemical impacts. There is no guarantee that liner materials selected for a site today will be the same as materials manufactured 20 years from now. For example, the quality of basic resins has improved considerably over the last few years. 

Compatibility Charts Permeation and penetration data supplied by the manufacturers of protective clothing to indicate chemical resistance and breakthrough time of various garment materials as tested against a battery of chemicals. 

Forbes MJ (1980) Cross-flow filtration, Transmission electron micrographic analysis and blood compatibility testing of collagen composite materials for use as vascular prostheses. M.S. Thesis, Massachusetts Institute of Technology, Cambridge, MA... 

In the compatibility test, 5.0 0.05 g of an explosive is thoroughly mixed with 0.5 0.05 g of finely ground polymer or contact material and the mixture is subjected to vacuum stability test. This experiment is also repeated with explosive and polymer or contact material separately. Most of the time, a temperature of 120 °C is used for high explosives and period of heating is limited to 40 h. The volume of gas (V, cm3) evolved by the mixture in excess of the volume of gas evolved by individual materials is calculated by Equation 3.2 ... 

Compatibility of TATB PBX with Weapons Materials , PlastOtherMaterExplosProplntsSymp, IIIA (1976) CA 87,87227 (1977) [Reported is the use of Viton-A, Kel-F 800 and Estane 5702-F1 as a binder for TATB contg expl compns. Compatibility tests (the object of the study with stainless steel, V, polyamide film and several sealant/adhesives at 120° for 1 to 4 months revealed no definite reaction. However, it was concluded that the major cause of gas evoln and chemical interaction between expl and test materials is the presence of w]... 

The fuel lines onboard flexible fuel vehicles using ethanol will typically be designed to accommodate methanol fuels and should be more than adequate for ethanol. Most fuel system components designed for gasoline are likely also to be compatible with ethanol. In a test of a 1994 model fuel injected vehicle, only slight stiffening of the fuel line was observed [3.11]. No other materials compatibility problems were observed in the fuel system. 

Experiments showed that coagulation increases for applied potential differences greater than +0.2 V vs. NHE below this value, clot formation is very small. The rest potential of various materials used for vascular prostheses and cardiac valves was determined. In Table 17.2 some of the materials tested are mentioned. It was concluded that metallic electrodes with a negative potential vs. NHE in the blood are anticoagulant while those with positive potential are coagulant. Unfortunately, the metals most useful for prostheses are the most easily corroded those of platinum and gold, not corroded, are unsuitable because of their positive rest potentials. Attempts to resolve the problem have utilized prostheses of plastic materials compatible in terms of their qualities of physical resistance, durability, etc. with their end use. 

The American Society for Testing and Materials (ASTM) provides standards, compatibility testing, and tests for mechanical properties, recommended practices and procedures as well as codes for polymeric materials. The various industry codes and standards are summarized in Table 4.95. 

The vacuum test is used for compatibility testing and applied as a so-called reactivity test. The compatibility between the explosive and the contact material (adhesive, varnish, etc.) is tested by determining the gases liberated by the explosive alone, by the contact material alone, and by the two together. The measure of compatibility (reactivity) is the difference between the sum of the gas volume liberated by each component separately and the gas volume obtained after storing the explosive and the contact material together. If this difference is between 3 and 5 ml, the compatibility is considered un-certain" above 5 ml, the two materials are incompatible. 

In the compatibility test between formulation and the conditioning material, several options of conditioning materials are evaluated to determine the most adequate for the product. 

As a first step, we need a compatibility screening test for the development of insulator coatings Results of compatibility tests on electrically insulating ceramic candidates in liquid Li are shown in Table In general, compatibility of ceramic insulators with liquid Li follows the criterion for thermodynamic stability. Although some ceramic materials are considered to be thermodynamically stable materials, e.g., sintered AIN and SiC (applied... 

Material Composition (Form) Compatibility/ Test Method Observation... 

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