Validating software and force fields for predicting the mechanical and physical properties of poly(bisbenzoxazine)s

Molecular models for two polymers, (1) based on the monomer 6,6'-bis(3,4-dihydro-3-methyl-2H-1,3-benzoxazinyl)isopropane and (2) based on the monomer 6,6'-bis(3,4-dihydro-3-methyl-2H-1,3-benzoxazinyl)sulphone, are imported from Cerius2® into Materials Studio®. Molecular dynamics (MD) and molecular mechanical analysis are performed on both models with the aim of validating the results produced by Materials Studio against previously recorded results from Cerius2 and empirical data. MD results are obtained, which are in reasonable agreement with empirical data. For instance, Materials Studio predicts a Tg range of 188-196°C for polymer (1), which is within 11 K of the empirical value of 177°C, whereas for polymer (2), a Tg of 133°C is predicted, which is within 16 K of the empirical value of 117°C. Similarly, molecular mechanics simulations produce some encouraging results, predicting a Young's modulus of 5.9 GPa for (1), compared with the empirically measured value of 4.3GPa.