@article{sattor_pervaje_pasquinelli_khan_santiso_2022, title={Multiscale Constitutive Modeling of the Mechanical Properties of Polypropylene Fibers from Molecular Simulation Data}, volume={55}, ISSN={["1520-5835"]}, url={https://doi.org/10.1021/acs.macromol.1c00630}, DOI={10.1021/acs.macromol.1c00630}, abstractNote={We present a multiscale approach to create a constitutive model that predicts the mechanical properties of polypropylene fibers based on chemical and physical characteristics. The development of this method relies on validation with experimental stress–strain curves from nine different isotactic polypropylene (iPP) fibers with their varying molecular weight characteristics, Hermans orientation factors, and crystallinity. Complementary molecular models were built by using molecular dynamics (MD) simulations with united atom models. Tensile deformation simulations adapting a quasi-static procedure resulted in stress–strain curves that aligned well with the experimentally measured ones. A neural network model was trained on the MD simulation data to create correlations that predict parameters for a chosen constitutive model that describes the mechanical properties of the polypropylene fibers. This computational approach is amenable to be applied to polymer fiber systems and aims to aid in the design of polymeric materials to achieve targeted mechanical properties.}, number={3}, journal={MACROMOLECULES}, publisher={American Chemical Society (ACS)}, author={Sattor, Amulya K. and Pervaje, Amulya K. and Pasquinelli, Melissa A. and Khan, Saad A. and Santiso, Erik E.}, year={2022}, month={Jan} }
 @article{pervaje_walker_santiso_2019, title={Molecular simulation of polymers with a SAFT-gamma Mie approach}, volume={45}, ISSN={["1029-0435"]}, DOI={10.1080/08927022.2019.1645331}, abstractNote={ABSTRACT We review the group contribution Statistical Associating Fluid Theory with Mie interaction potentials (SAFT-γ Mie) approach for building coarse-grained models for molecular simulation of polymeric systems. In this top-down method, force field parameters for coarse-grained polymer models can be derived from thermodynamic information on constituent monomer units using the SAFT-γ Mie equation of state (EoS). This strategy can facilitate high-throughput computational screening of polymeric materials, with a corresponding states correlation expediting the force field fitting. Accurate and transferable non-bonded parameters linked to macroscopic thermodynamic data allow for calculation of properties beyond those obtainable from the EoS alone. To overcome limitations of SAFT-γ Mie regarding polymer chain stiffness and branching, hybrid top-down/bottom-up approaches have combined non-bonded parameters from SAFT-γ Mie with bond-stretching and angle-bending potentials from higher-resolution force fields. Our review critically evaluates the performance of recent SAFT-γ Mie polymer models, highlighting the strengths and weaknesses in the context of other equation of state and coarse-graining methods.}, number={14-15}, journal={MOLECULAR SIMULATION}, author={Pervaje, Amulya K. and Walker, Christopher C. and Santiso, Erik E.}, year={2019}, month={Oct}, pages={1223–1241} }
 @article{tilly_pervaje_inglefield_santiso_spontak_khan_2019, title={Spectroscopic and Rheological Cross-Analysis of Polyester Polyol Cure Behavior: Role of Polyester Secondary Hydroxyl Content}, volume={4}, ISSN={["2470-1343"]}, url={https://doi.org/10.1021/acsomega.8b02766}, DOI={10.1021/acsomega.8b02766}, abstractNote={The sol–gel transition of a series of polyester polyol resins possessing varied secondary hydroxyl content and reacted with a polymerized aliphatic isocyanate cross-linking agent is studied to elucidate the effect of molecular architecture on cure behavior. Dynamic rheology is utilized in conjunction with time-resolved variable-temperature Fourier-transform infrared spectroscopy to examine the relationship between chemical conversion and microstructural evolution as functions of both time and temperature. The onset of a percolated microstructure is identified for all resins, and apparent activation energies extracted from Arrhenius analyses of gelation and average reaction kinetics are found to depend on the secondary hydroxyl content in the polyester polyols. The similarity between these two activation energies is explored. Gel point suppression is observed in all the resin systems examined, resulting in significant deviations from the classical gelation theory of Flory and Stockmayer. The magnitude of these deviations depends on secondary hydroxyl content, and a qualitative model is proposed to explain the observed phenomena, which are consistent with results previously reported in the literature.}, number={1}, journal={ACS OMEGA}, publisher={American Chemical Society (ACS)}, author={Tilly, Joseph C. and Pervaje, Amulya K. and Inglefield, David L. and Santiso, Erik E. and Spontak, Richard J. and Khan, Saad A.}, year={2019}, month={Jan}, pages={932–939} }
 @article{pervaje_tilly_inglefield_spontak_khan_santiso_2018, title={Modeling Polymer Glass Transition Properties from Empirical Monomer Data with the SAFT-gamma Mie Force Field}, volume={51}, DOI={10.1021/acs.macromol.8b01734}, abstractNote={We apply a recently developed coarse-graining method to build models for polyester polyols, versatile polymers with applications in coatings, by combining models for the component monomers. This strategy employs the corresponding states correlation to the group-contribution SAFT-γ Mie equation of state [Mejia, A.; et al. Ind. Eng. Chem. Res. 2014, 53, 4131–4141] to obtain force-field parameters for the constituent monomer species. Results from simulations agree favorably with experimental values of mass density, glass transition temperature (Tg), and specific heat capacity change at Tg. Further simulations over a range of Mie parameters and polymer chemical compositions yield a correlation that relates the parameters directly to Tg. This correlation is validated by experimental data and can be used as a predictive tool within the tested parameter space to expedite the design of these coating materials.}, number={23}, journal={MACROMOLECULES}, author={Pervaje, Amulya K. and Tilly, Joseph C. and Inglefield, David L. and Spontak, Richard and Khan, Saad and Santiso, Erik E.}, year={2018}, pages={9526–9537} }