A NOVEL-APPROACH TOWARD THE PREDICTION OF THE GLASS-TRANSITION TEMPERATURE - APPLICATION OF THE EVM MODEL, A DESIGNER QSPR EQUATION FOR THEPREDICTION OF ACRYLATE AND METHACRYLATE POLYMERS

We describe an original QSPR model called the EVM model (Energy, Volum e, Mass) to calculate the glass transition temperature (T-g) of alipha tic acrylate and methacrylate homopolymers using classical molecular m echanics and dynamics. The latter was used to calculate an energy dens ity function related to the cylindrical volume of a 20 monomer unit po lymer segment (TSSV, Total Space around a Standard deviation Volume). We then calculated the T-g as a function of this density function and the repeat unit molecular weight, although no interchain interactions were taken into account. For linear and branched aliphatic acrylate an d methacrylate polymers, the standard deviation from linear regression was 12 K, and the r(2) was 0.96. The model allows calculation of the T-g with an average absolute error of error of 10% for linear and bran ched derivatives not included in the original linear regression analys is. The results obtained with the EVM model are compared with those ob tained with Bicerano's model. (C) 1997 John Wiley & Sons, Inc.