P-V-T data and their uses

Pressure-volume-temperature (P-V-T) investigations represent an underappreciated area of polymer science and engineering. Such data can be obtained for both polymer solids and melts, sometimes in a single experiment (see the next section). Needless to say, such experiments can be conducted also for materials other than polymeric. The main applications of P-V-T results in the field of polymers are  

prediction of service performance and service life of polymeric materials and components on the basis of free volume concepts  

evaluation of start and progress of chemical reactions in polymer melts in cases when volume effects accompany the reaction  

optimization of processing parameters, instead of establishing such parameters by trial and error  

We shall briefly characterize below the experimental procedure for P-V-T determination, then parameters derivable directly from the experiments including the equations of state, the areas listed above, and finally the information on polypropylene (PP). 

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