VTechWorks staff will be away for the Thanksgiving holiday starting Wednesday afternoon, Nov. 25, through Sunday Nov. 29, and will not be replying to requests during this time. Thank you for your patience.
The purpose of this work was to determine the enthalpies and specific heats of polymethyl methacrylate, polydimethylaminoethyl methacrylate, polycyclohexyl methacrylate, polyallyl methacrylate, and polyethyl acrylate from 120 to 300°C, and to determine a method for estimating their specific heats.
Enthalpies of the selected polymers were determined by using a drop calorimeter constructed by the Chemical Engineering Department of Virginia Polytechnic Institute. Specific heats were obtained by measuring the slopes of the enthalpy-temperature curves.
Good agreement with existing data for polymethyl methacrylate was obtained. An existing semi-theoretical quantum mechanical method was modified to provide specific heat estimations for linear methacrylic polymers accurate within six percent. An empirical correlation yielding estimations within twenty percent was proposed.