GLASS-TRANSITION TEMPERATURE CALCULATIONS FOR STYRENE DERIVATIVES USING THE ENERGY, VOLUME, AND MASS MODEL

We have previously described an original model called the EVM (energy, volume, and mass) model, which uses only three descriptors, the energ y of a polymer segment conformation using molecular mechanics and mole cular dynamics, its volume (the occupied space by the atoms as well th e unoccupied space between them), and the repeat unit molar mass, to c alculate successfully the glass transition temperatures (T-g) of aliph atic acrylate and methacrylate polymers. We report here the applicatio n of this model to a series of various polystyrenes. The EVM mode]. al lows correct description of the substituent position effect on the rin g as well as on the backbone, for various alkyl group and halides. The estimated T-g values with the EVM model are in excellent agreement wi th Literature values. We compare this model with two other methods (Bi cerano's model and Porter's approach) and find better or comparable co rrelations.