Incompatibility of chemicals

Two high polymers are mutually compatible with one another only if their free energy of interaction is favorable, i.e., negative. Since the mixing of a pair of polymers, like the mixing of simple liquids, in the great majority of cases, is endothermic, incompatibility of chemically dissimilar polymers is observed to be the rule and compatibility is the exception. 

A commonly used answer to the incompatibility of chemical properties and method of preferred structure determination has been to protect the crystal by sealing it in a glass capillary. Many otherwise inaccessible, but important structures have been determined by use of this method. However, the procedure is far from simple, and requires relatively elaborate equipment for maintaining an inert atmosphere during manipulation of the specimen. 

Storage Requirements for maximum allowable flammable storage by class, incompatibility of chemicals in stock, chemical inventory maintenance. Material Safety Data Sheet (MSDS) location and management, and use of refrigerators, flammable cabinets and bench top. 

Use chemical interaction matrices to identify potential incompatibilities between chemicals including utilities, solvents and materials of construction... 

ASTM 1986. American Society of Testing and Materials Committee D-34, Proposal-168, Vroposed Guide for Estimating the Incompatibility of Selected Hazardous "Wastes Based on Binary Chemical Reactions, and included Minority Report. 

Unlike incompatible heterogeneous blends of elastomer-elastomer, elastomer-plastic, and plastic-plastic, the reactively processed heterogeneous blends are expected to develop a variable extent of chemical interaction. For this reason the material properties, interfacial properties, and phase morphology of reactively processed blends would differ significantly from heterogeneous mixtures. 

Star molecules containing branches made of two blocks have also been prepared by these methods102 103. Recently it was shown that such star-block copolymers exhibit very interesting so-called double-diamond structures in the bulk owing to segregation due to incompatibility between chemically unlike blocks 104. ... 

Controls for the safe transfer of chemicals between ship and shore will vary in detail. The escape of dust and vapour should be minimized when loading and unloading of bulk liquids or solids and persons should not be at risk. Precautions to avoid contact with water are needed when transferring water-incompatible materials (page 229). Precautions for handling explosives include ... 

When it is mixed with potassium nitrite in the melted state (440°C), ammonium nitrate detonates. The presence of rust decreases the temperature of the explosion to 80-120°C. This behaviour is linked to the chemical incompatibility of the nitrite ion and ammonium ion. 

Coatings, cathodic protection, and chemical additives are used extensively to prevent internal and external pipeline corrosion. The excessive use of incompatible chemical additives has caused severe problems in gas-transporting systems. Costs arising from these problems often exceed the costs of the chemicals themselves. The careful evaluation and selection of chemical additives can minimize these problems and reduce operating costs [I860]. 

A major challenge in providing electrical power for implantable devices is the isolation of toxic or bio-incompatible materials. As the size of the device decreases to a centimeter or millimeter scale, the parts responsible for isolation, such as canisters and seals, begin to determine the size of the device. An alternative is to design an electrochemical system that is compatible with the physiological environment and can take advantage of chemical species available in that environment, specifically the... 

Two substances which have no hazardous reactivity properties in themselves can become dangerous when mixed. Certain groups of chemicals are likely to react with common substances such as air, water, acids, alkalies, and metals. Information about the possibility of such reactions is available in manuals on hazardous chemical reactions [35, 61, 62]. Examples of substances having incompatibility hazards when mixed are shown on Table 2.14. Applications of CHETAH to mixture instability determination [63,64] and to binary incompatibility [65] have been published. 

No general rules or easy answers exist for understanding the potential consequences of uncontrolled chemical reactions, due to the diversity of chemicals and reaction pathways. Table 4.5 shows the potential consequences of oxidizers as one specific category of reactive chemicals. Table 4.6, taken from the NOAA Chemical Reactivity Worksheet, lists some general consequences that could occur if incompatible materials are combined. 

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