Reaction calorimetry, chemical reactivity

Chemical reactivity risk. See Risk assessment Chemical reactivity tests, 84-90 decision point, 90 deflagration screening tests, 85,87 reaction calorimetry, 88-90 screening data interpretation, 85, 86 small-scale screening tests, 87-88 Chemical structure and bonds, hazards identification, 80, 82 CHETAH program (ASTM), 79,82 Clean Air Act Amendments (CAAA) of 1990, 174... 

Isoperibol titration calorimetry was also extensively used by Drago s group [215] to determine enthalpies and equilibrium constants of a variety of reactions where acid-base adducts are formed. These results are the source of Drago s ECW model, which has been widely used to rationalize chemical reactivity [216-218]. 

Inevitably, the quality of the raw materials (epoxy equivalent weight, reactivity of TMBDA, etc.) vary from batch to batch and adjustments in the formulation and/or treater speed are necessary. Most techniques designed for characterizing chemical reactivity depend on the system remaining soluble. Thus, by their very nature, thermosets become intractable once the gel point has been passed. Calorimetry monitors the inherent energetics associated with any chemical reaction or physical transition and thus is ideally suited for this system. 

The results of the hazardous chemical evaluation are used to determine to what extent detailed thermal stability, runaway reaction, and gas evolution testing is needed. The evaluation may include reaction calorimetry, adiabatic calorimetry, and temperature ramp screening using accelerating rate calorimetry, a reactive system screening tool, isoperibolic calorimetry, isothermal storage tests, and adiabatic storage tests. 

The first major objective for the inherent safety review is the development of a good understanding of the hazards involved in the process. Early understanding of these hazards provides time for the development team to implement recommendations of the inherent safety effort. Hazards associated with flammability, pressure, and temperature are relatively easy to identify. Reactive chemistry hazards are not. They are frequently difficult to identify and understand in the lab and pilot plant. Special calorimetry equipment and expertise are often necessary to fully characterize the hazards of runaway reactions and decompositions. Similarly, industrial hygiene and toxicology expertise is desirable to help define and understand health hazards associated with the chemicals employed. 

ASSESSMENT OF REACTIVE CHEMICAL HAZARDS COMPUTATION OF REACTIVE CHEMICAL HAZARDS DIFFERENTIAL SCANNING CALORIMETRY DIFFERENTIAL THERMAL ANALYSIS MAXIMUM REACTION HEAT REACTION SAFETY CALORIMETRY... 

In combustion calorimetry [47,48] the enthalpies of chemical reactions of elements and compounds with reactive gases like oxygen or fluorine are determined. 

CHEMICAL STABILITY/REACTIVITY ASSESSMENT COMPUTATION OF REACTIVE CHEMICAL HAZARDS EXOTHERMIC DECOMPOSITION REACTIONS HEAT FLOW CALORIMETRY HIGH RATE DECOMPOSITION MAXIMUM REACTION HEAT... 

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