APTAC

What is the potential temperature rise by undesired reactions or thermal decomposi- tion, such as from contaminants, impurities, etc. What are the consequences What is the maximum pressure Enthalpy of undesired reaction Specific heat Rate of undesired reaction as a function of temperature DTA/DSC Dewar flask experiments APTAC /ARC /RSST/VSP... 

AUTOMATED PRESSURE TRACKING ADIABATIC CALORIMETER (APTAC)... 

Data analysis Analyzing the basie temperature and pressure data from the APTAC is less eomplex. The APTAC design gives data that are easier to use than the ARC. 

Figure 12-12. Automated pressure tracking adiabatic calorimeter (APTAC). (Source Arthur D. Little.)...

Reagent delivery It is possible to add reagents to the sample while the experiment is running using the APTAC instrument. Sample venting The pressure in APTAC s sample eontainer ean be automatieally released and the material eolleeted into an external vessel. 

Several commercial calorimeters are available to characterize runaway reactions. These include the accelerating rate calorimeter (ARC), the reactive system screening tool (RSST), the automatic pressure-tracking adiabatic calorimeter (APTAC), and the vent sizing package (VSP). Each calorimeter has a different sample size, container design, data acquisition hardware, and data sensitivity. 

APTAC Automatic Pressure Tracking Adiabatic Calorimeter... 

Figure 12-12. Automated pressure tracking adiabatic calorimeter (APTAC).

Reagent delivery It is possible to add reagents to the sample while the experiment is running using the APTAC instrument. 

Sample venting The pressure in APTAC s sample container can be automatically released and the material collected into an external vessel. 

Figure 35 combines the temperature-dependent and acetone-content-de-pendent behaviour of amphoteric gel APTAC-SA [155]. Equimolar polyampholyte gel undergoes a gradual volume change w ith an increase in acetone composition in an acetone/water mixture. When the content of the cationic groups increases, collapse of gel is observed. On the other hand, the same sample immersed in acetone/water mixtures of 60 and 65% acetone swells in a low... 

Hydrolytic stability and pH have to be considered when selecting a cationic monomer. Cationic acrylate esters are susceptible to base hydrolysis above pH 6, resulting in the loss of cationic charge on the polymer. The rate of hydrolysis is concentration and temperature dependent. In contrasL cationic acrylamide copolymers containing amide monomers such as APTAC and MAPTAC are reasonably stable up to a pH of 9-10. Acrylamide/MAPTAC copolymers and... 

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