Using Combined Computational Techniques to Predict the Glass Transition Temperatures of Aromatic Polybenzoxazines

Abstract

The Molecular Operating Environment software (MOE) is used to construct a series of benzoxazine monomers for which a variety of parameters relating to the structures (e.g. water accessible surface area, negative van der Waals surface area, hydrophobic volume and the sum of atomic polarizabilities, etc.) are obtained and quantitative structure property relationships (QSPR) models are formulated. Three QSPR models (formulated using up to 5 descriptors) are first used to make predictions for the initiator data set (n = 9) and compared to published thermal data; in all of the QSPR models there is a high level of agreement between the actual data and the predicted data (within 0.63–1.86 K of the entire dataset). The water accessible surface area is found to be the most important descriptor in the prediction of Tg. Molecular modelling simulations of the benzoxazine polymer (minus initiator) carried out at the same time using the Materials Studio software suite provide an independent prediction of Tg. Predicted Tg values from molecular modelling fall in the middle of the range of the experimentally determined Tg values, indicating that the structure of the network is influenced by the nature of the initiator used. Hence both techniques can provide predictions of glass transition temperatures and provide complementary data for polymer design.

Prediction of elongation at break for linear polymers

“…For these reasons, it becomes a challenge to generate a reliable associated dataset too. One of the earliest and most widely studied of polymer properties has been the T g , and good prediction results were obtained from synthetic models [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]; in contrast, the mechanical properties of polymers have scarcely been explored. Seitz [25] developed semi-empirical and empirical relationships so as to estimate the mechanical properties of polymeric materials from the molecular weight, van der Waals volume, the length and number of rotational bonds in the repeat unit, besides the T g of the polymer.…”

Quantitative Structure-Property Relationship (QSPR) Modeling of Drug-Loaded Polymeric Micelles via Genetic Function Approximation

“…Total fifty-two kinds of molecular descriptors (including physical and chemical descriptors, fragment counts, topological, spatial and energy descriptors, atomic volumes and surfaces, and atomistic descriptors which are suitable for describing the relationship between polymer molecular structure and micellar property) could been computed using the QSAR module of Materials Studio 5.0 (Accelrys Inc.) [ 41 ] and used as candidates, as shown in S2 Table . To obtain the lowest energy conformation of the polymer molecules, the geometric structures of all polymer molecules were constructed and optimized using the following three steps.…”

Latonduine Analogs Restore F508del–Cystic Fibrosis Transmembrane Conductance Regulator Trafficking through the Modulation of Poly-ADP Ribose Polymerase 3 and Poly-ADP Ribose Polymerase 16 Activity

“…The molecules built using MOE-2012 (latonduine, MCG171, MCG172, MCG240, MCG315, and MCG559) were docked into each of the three enzymes studied by defining elastic restraints based on the distances observed between the amide of DR2313 and PARP-3 in the 3C4H crystal structure (Mhlanga et al, 2013). Plausible binding modes were obtained in all cases, although there were differences in orientation and likely PARP interactions.…”