Development of dissociative force field for all-atomistic molecular dynamics calculation of fracture of polymers

Kazushi Fujimoto, Rajadeep Singh Payal, Tomonori Hattori, Wataru Shinoda, Masayuki Nakagaki, Shigeyoshi Sakaki, Susumu Okazaki

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

A dissociative force field for all-atomistic molecular dynamics calculations has been developed to investigate impact fracture of polymers accompanying dissociation of chemical bonds of polymer main chain. Energy of dimer molecules was evaluated as a function of both bond-length b and bond-angle θ by CASPT2 calculations, whose quality is enough to describe dissociation of chemical bonds. Because we found that the bond dissociation energy D decreases with increasing bond-angle, we employed the Morse-type function VBond(b, θ) = {D − VAngle(θ)}[1 − exp{−α(b − b0) − β(b − b0)2}] where a quartic function VAngle(θ) = k1(θ − θ0) + k2(θ − θ0)2 + k3(θ − θ0)3 + k4(θ − θ0)4. This function reproduced well the CASPT2 potential energy surface in a wide range of b and θ. The parameters have been obtained for four popular glassy polymers, polyethylene, poly(methyl methacrylate), poly(styrene), and polycarbonate.

Original languageEnglish
Pages (from-to)2571-2576
Number of pages6
JournalJournal of Computational Chemistry
Volume40
Issue number29
DOIs
Publication statusPublished - Nov 5 2019
Externally publishedYes

Keywords

  • angle dependence Morse-type function
  • bond dissociation potential function for classical AA-MD
  • polymer fracture
  • quartic function

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics

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