All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene

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All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene. / Olsson, Pär; in 't Veld, Pieter; Andreasson, Eskil; Bergvall, Erik; Persson Jutemar, Elin; Petersson, Viktor; Rutledge, Gregory ; Kroon, Martin.

In: Polymer, Vol. 153, 26.09.2018, p. 305-316.

Research output: Contribution to journalArticle

Harvard

Olsson, P, in 't Veld, P, Andreasson, E, Bergvall, E, Persson Jutemar, E, Petersson, V, Rutledge, G & Kroon, M 2018, 'All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene', Polymer, vol. 153, pp. 305-316. https://doi.org/10.1016/j.polymer.2018.07.075

APA

Olsson, P., in 't Veld, P., Andreasson, E., Bergvall, E., Persson Jutemar, E., Petersson, V., ... Kroon, M. (2018). All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene. Polymer, 153, 305-316. https://doi.org/10.1016/j.polymer.2018.07.075

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Author

Olsson, Pär ; in 't Veld, Pieter ; Andreasson, Eskil ; Bergvall, Erik ; Persson Jutemar, Elin ; Petersson, Viktor ; Rutledge, Gregory ; Kroon, Martin. / All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene. In: Polymer. 2018 ; Vol. 153. pp. 305-316.

RIS

TY - JOUR

T1 - All-atomic and coarse-grained molecular dynamics investigation of deformation in semi-crystalline lamellar polyethylene

AU - Olsson, Pär

AU - in 't Veld, Pieter

AU - Andreasson, Eskil

AU - Bergvall, Erik

AU - Persson Jutemar, Elin

AU - Petersson, Viktor

AU - Rutledge, Gregory

AU - Kroon, Martin

PY - 2018/9/26

Y1 - 2018/9/26

N2 - In the present work we have performed classical molecular dynamics modelling to investigate the effects of different types of force-fields on the stress-strain and yielding behaviours in semi-crystalline lamellar stacked linear polyethylene. To this end, specifically the all-atomic optimized potential for liquid simulations (OPLS-AA) and the coarse-grained united-atom (UA) force-fields are used to simulate the yielding and tensile behaviour for the lamellar separation mode. Despite that the considered samples and their topologies are identical for both approaches, the results show that they predict widely different stress-strain and yielding behaviours. For all UA simulations we obtain oscillating stress-strain curves accompanied by repetitive chain transport to the amorphous region, along with substantial chain slip and crystal reorientation. For the OPLS-AA modelling primarily cavitation formation is observed, with small amounts of chain slip to reorient the crystal such that the chains align in the tensile direction. This force-field dependence is rooted in the lack of explicit H-H and C-H repulsion in the UA approach, which gives rise to underestimated ideal critical resolved shear stress. The computed critical resolved shear stress for the OPLS-AA approach is in good agreement with density functional theory calculations and the yielding mechanisms resemble those of the lamellar separation mode. The disparate energy and shear stress barriers for chain slip of the different models can be interpreted as differently predicted intrinsic activation rates for the mechanism, which ultimately are responsible for the observed diverse responses of the two modelling approaches.

AB - In the present work we have performed classical molecular dynamics modelling to investigate the effects of different types of force-fields on the stress-strain and yielding behaviours in semi-crystalline lamellar stacked linear polyethylene. To this end, specifically the all-atomic optimized potential for liquid simulations (OPLS-AA) and the coarse-grained united-atom (UA) force-fields are used to simulate the yielding and tensile behaviour for the lamellar separation mode. Despite that the considered samples and their topologies are identical for both approaches, the results show that they predict widely different stress-strain and yielding behaviours. For all UA simulations we obtain oscillating stress-strain curves accompanied by repetitive chain transport to the amorphous region, along with substantial chain slip and crystal reorientation. For the OPLS-AA modelling primarily cavitation formation is observed, with small amounts of chain slip to reorient the crystal such that the chains align in the tensile direction. This force-field dependence is rooted in the lack of explicit H-H and C-H repulsion in the UA approach, which gives rise to underestimated ideal critical resolved shear stress. The computed critical resolved shear stress for the OPLS-AA approach is in good agreement with density functional theory calculations and the yielding mechanisms resemble those of the lamellar separation mode. The disparate energy and shear stress barriers for chain slip of the different models can be interpreted as differently predicted intrinsic activation rates for the mechanism, which ultimately are responsible for the observed diverse responses of the two modelling approaches.

U2 - 10.1016/j.polymer.2018.07.075

DO - 10.1016/j.polymer.2018.07.075

M3 - Article

VL - 153

SP - 305

EP - 316

JO - Polymer Communications (Guildford, England)

JF - Polymer Communications (Guildford, England)

SN - 0032-3861

ER -