Amorphous cis-1,4-polybutadiene P–V-T properties from atomistic simulations

• Published in: Journal of molecular modeling 2023-08, Vol.29 (8), p.249-249, Article 249
• Main Authors: Shamsieva, Aigul, Piyanzina, Irina, Minisini, Benoit
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Dilatometry; Elastomers; equations; Glass transition temperature; Measurement methods; Molecular Medicine; molecular weight; Original Paper; Phase Transition; Polybutadiene; Specific volume; Temperature; Theoretical and Computational Chemistry; Transition Temperature
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-023-05658-6

Context As a result of the diversity of microstructures encountered in cis-1,4-polybutadiene and the variety of measurement methods used, experimental values of variation of glass transition temperature (Tg) with pressure are relatively dispersed. However, atomistic simulations enable access to valuable information for very well-controlled chemistry and structures with a well-defined and systematic acquisition protocol. By varying the temperature and pressure, the specific volume of the melt was computed, yielding results that deviated by only 2% from experimental data. A linear relationship between Tg and pressure was observed, with Tg predicted to be 162 K at zero pressure and a rate of change of Tg with respect to pressure (dTg/dP) of 0.24 K/MPa. Method The atomistic dilatometry experiments were conducted on a model of amorphous cis-1,4 polybutadiene with an approximate molecular weight of 5400 g/mol using the LAMMPS code and the all-atom forcefield pcff + . The dilatometry process involved cooling and heating at a rate of 9 × 10 12  K/min. The specific volume was calculated by averaging over seven independent configurations for each temperature. The Tait equation was employed to fit the specific volume evolution within the temperature range of 10 to 700 K under different pressures of 0, 60, and 100 MPa.