Improving rotational isomeric state theory for application to mechanical properties prediction

2007 ◽  
Author(s):  
Fei Gao ◽  
Lisa Mauck Weiland
2005 ◽  
Vol 20 (9) ◽  
pp. 2443-2455 ◽  
Author(s):  
Lisa Mauck Weiland ◽  
Emily K. Lada ◽  
Ralph C. Smith ◽  
Donald J. Leo

Presently, rotational isomeric state (RIS) theory directly addresses polymer chain conformation as it relates to mechanical response trends. The primary goal of this work is to explore the adaptation of this methodology to the prediction of material stiffness. This multiscale modeling approach relies on ionomer chain conformation and polymer morphology and thus has potential as both a predictive modeling tool and a synthesis guide. The Mark–Curro Monte Carlo methodology is applied to generate a statistically valid number of end-to-end chain lengths via RIS theory for four solvated Nafion® cases. For each case, a probability density function for chain length is estimated using various statistical techniques, including the classically applied cubic spline approach. It is found that the stiffness prediction is sensitive to the fitting strategy. The significance of various fitting strategies, as they relate to the physical structure of the polymer, are explored so that a method suitable for stiffness prediction may be identified.


1973 ◽  
Vol 46 (3) ◽  
pp. 593-618 ◽  
Author(s):  
J. E. Mark

Abstract Thermoelastic measurements and their interpretation by means of rotational isomeric state theory provide a great deal of insight into both thermodynamic and molecular aspects of rubberlike elasticity. Furthermore, conformational energies obtained in part from thermoelastic studies can in turn be used in the interpretation and even prediction of a variety of configurationally dependent properties of chain molecules, as is shown in many of the theoretical investigations cited in Sections IV and VII of this review.


2021 ◽  
Author(s):  
IVAN GALLEGOS ◽  
JOSHUA KEMPPAINEN ◽  
SAGAR U. PATIL ◽  
PRATHAMESH DESHPANDE ◽  
JACOB GISSINER ◽  
...  

Carbon-carbon composites (CCCs) widely used in the aerospace and automotive industries due to their excellent mechanical and thermal properties. Phenolic resins have a relatively high carbon yield, which makes them a suitable candidate for CCCs manufacturing. Molecular Dynamics (MD) can further reduce costs by predicting properties of a material before manufacturing and testing. In the present work, a Molecular Dynamics (MD) model of a crosslinked phenolic resin was developed to predict mechanical properties by implementing the fix bond/react algorithm in LAMMPS. The predicted mass density (ρ) and Young’s Modulus (E) agree well with experimental values and highlights the validity of the topologybased approach to building stable molecular models of phenolic resins.


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