ContextThe experimental values of variation of glass transition temperature (Tg) with the pressure are relatively dispersed due to the diversity of microstructure encountered in Cis-1,4-Polybutadiene (PB) and the diversity of technics used for its measurement. Fortunately, atomistic simulations allow to get valuable information for very well controlled chemistry and structures using very well-de ned protocol of acquisition. That's why, atomistic modelling will be used to evaluate the variation of Tg with the pressure for a well-de ned amorphous oligomer of cis-1,4 PB. MethodAtomistic dilatometry was performed on model of amorphous cis-1,4 PB with a molecular weight of 5402 g.mol − 1 . The analysis was carried out by reporting with respect to the temperature, the speci c volume, the coe cient of thermal expansion, the total energy, and the constant volume heat capacity averaged over 7 independent con gurations. Tait equation was used to t the evolution of the speci c volume for temperatures between 10 K and 700 K and pressure of 0, 60 and 100 MPa. ResultsThe speci c volume evolution with temperature and pressure of the melt is predicted to be within 2% of error with the experimental values extrapolated for a similar molecular weight with a very well reproduced coe cient of thermal expansion. The best predictions of Tgs are obtained using the Tait equation t with a Tg predicted at 162 K at zero pressure and a linear dependence with pressure given a slope of 0.22 K/MPa. As recently observed for PEO and PS, the different calculated properties show hysteresis between the heating and cooling curves.

Context The experimental values of variation of glass transition temperature (Tg) with the pressure are relatively dispersed due to the diversity of microstructure encountered in Cis-1,4-Polybutadiene (PB) and the diversity of technics used for its measurement. Fortunately, atomistic simulations allow to get valuable information for very well controlled chemistry and structures using very well-defined protocol of acquisition. That’s why, atomistic modelling will be used to evaluate the variation of Tg with the pressure for a well-defined amorphous oligomer of cis-1,4 PB.Method Atomistic dilatometry was performed on model of amorphous cis-1,4 PB with a molecular weight of 5402 g.mol− 1. The analysis was carried out by reporting with respect to the temperature, the specific volume, the coefficient of thermal expansion, the total energy, and the constant volume heat capacity averaged over 7 independent configurations. Tait equation was used to fit the evolution of the specific volume for temperatures between 10 K and 700 K and pressure of 0, 60 and 100 MPa.Results The specific volume evolution with temperature and pressure of the melt is predicted to be within 2% of error with the experimental values extrapolated for a similar molecular weight with a very well reproduced coefficient of thermal expansion. The best predictions of Tgs are obtained using the Tait equation fit with a Tg predicted at 162 K at zero pressure and a linear dependence with pressure given a slope of 0.22 K/MPa. As recently observed for PEO and PS, the different calculated properties show hysteresis between the heating and cooling curves.

The use of carbon nanotubes to improve the mechanical properties of polymers is one of the promising directions in materials science. The addition of single-walled carbon nanotubes (SWCNT) to a polymer results in significant improvement of mechanical, electrical, optical, and structural properties. However, the addition of SWCNTs does not always improve the polymer properties. Also, when a certain content of SWCNTs is exceeded, the mechanical properties of the nanocomposite are getting worse. This article reports the results of computer simulations for predicting the mechanical properties of polymer/single-walled carbon nanotube nanocomposites. The efficiency of reinforcing polymer composites is considered depending on the concentration of carbon nanotubes in the polymer matrix, their size and structure. The elastic moduli of the nanocomposites were predicted using computer simulations for unit cell tension (0.1%). General trends in the mechanical properties of composites with polypropylene, poly (ethyl methacrylate), polystyrene matrices and SWCNTs are shown.

The use of carbon nanotubes to improve the mechanical properties of polymers is one of the promising directions in materials science. The addition of single-walled carbon nanotubes (SWCNTs) to a polymer results in significant improvements in its mechanical, electrical, optical, and structural properties. However, the addition of SWCNTs does not always improve the polymer properties. Also, when a certain content of SWCNTs is exceeded, the mechanical properties of the nanocomposite become worse. This article reports the results of computer simulations for predicting the mechanical properties of polymer/single-walled carbon nanotube nanocomposites. The efficiency of reinforcing polymer composites is considered depending on the concentration of carbon nanotubes in the polymer matrix, their size, and structure. The elastic moduli of the nanocomposites are predicted using computer simulations for unit cell tension (0.1%). General trends in the mechanical properties of composites with polypropylene (PP), poly(ethyl methacrylate) (PEMA), polystyrene (PS) matrices, and SWCNTs are shown.