By Sara Peters, Fauske & Associates, LLC (FAI)
Often, material safety data sheets refer to the thermal stability of a chemical or its stability at higher temperatures, as an intrinsic property of the chemical or mixture. In fact, this is an oversimplification of a concept that must be defined in a more comprehensive way.
Understanding the thermal stability of a chemical or mixture is critical to ensuring its safe handling in any setting. The more stable a material is at higher temperatures, the more resistant it is to breaking down or decomposing . This understanding is accomplished through thermal stability testing aimed at collecting reaction rate data and applying that data to assess whether a specified quantity of material can be used in a way such that runaway reactions are avoided. This is important when considering processing, long-term storage, or shipping of a material.
Unique testing and consulting requests make it advantageous for a reliable testing organization to have a variety of instruments and tools available to characterize the thermal stability of a material. For example, if the purpose is to characterize reactive chemical systems and consequences that could occur due to process upset conditions, then use of a low thermal inertia adiabatic calorimeters: the Vent Sizing Package 2 (VSP2TM) and the Advanced Reactive Systems Screening Tool (ARSSTTM) might be most appropriate. However, if the goal is to help quantify the heat released during intended chemical reactions– preparing for the expected, then you may look to reaction calorimetry instruments such as the Mettler-Toledo RC1, ChemiSens CPA 202, or THT μRC. Or, if the desired outcome is to formulate an accurate determination of safety parameters and plan for mitigating a potential reaction, then you may look to an instrument such as the VSP2TM, ARSSTTM, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), Thermal Activity Monitor (TAM) or Accelerating Rate Calorimetry (ARC).
All of these instruments are or should be part of a well equipped thermal hazards laboratory, to ensure that each customer’s unique system and problem is properly addressed with the correct tools. At Fauske & Associates, LLC (FAI), we have all of these instruments in our thermal hazards lab but recently saw a need to enhance our toolkit even further with the addition of the C80 Calorimeter manufactured by Setaram.
Some of the key benefits the C80 offers include:
- The C80 is a reaction, thermal and scanning calorimeter that operates like a larger version of a DSC which accommodates a larger sample size and bigger test cells - 10 ml test cells, as opposed to 20-50 µl test cells. This is especially advantageous when dealing with heterogeneous or multi-component samples that come in and are not uniformly mixed and cannot be uniformly mixed (think different colored M&Ms) as the larger size allows a more representative sample to be tested.
- It has a wide range of vessels that can be used with it which makes it flexible
- A lot of the other instruments primarily use metal cells, but the C80 can use glass-lined cells which is beneficial when dealing with peroxides or other chemicals that are highly sensitive/reactive to metals
- The C80 offers a unique level of sensitivity to thermal events and also the ability to design cells and vessels to simulate almost any potential condition
- Temperature ramp measures heat flow as a function of time and temperature
- Temperature range is from ambient to 300mC
As you can see, the C80 is a fantastic addition to our toolkit here at FAI as it nicely complements other instruments in our lab and enhances the ability of our engineers to offer practical and customized solutions to unique process safety issues dealing with thermal hazards and thermal stability. When you are considering a provider for your own process safety needs in this area make sure that they too have a robust toolkit with which to effectively address your concerns.