Modeling of polyethylene, poly(l-lactide), and CNT composites: a dissipative particle dynamics study

Abstract

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, is used to investigate the effect of volume fraction of polyethylene (PE) and poly(l-lactide) (PLLA) on the structural property of the immiscible PE/PLLA/carbon nanotube in a system. In this work, the interaction parameter in DPD simulation, related to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in molecular dynamics simulation. Volume fraction and mixing methods clearly affect the equilibrated structure. Even if the volume fraction is different, micro-structures are similar when the equilibrated structures are different. Unlike the blend system, where no relationship exists between the micro-structure and the equilibrated structure, in the di-block copolymer system, the micro-structure and equilibrated structure have specific relationships.

Water Uptake, Distribution, and Mobility in Amorphous Poly( d , l ‐Lactide) by Molecular Dynamics Simulation

“…On the basis of swelling experiments, Tsuji and Sumida 74 estimated a solubility parameter for L-PLA in a range of 19-20.5 MPa 1/2 . In a dissipative particle dynamics study of L-PLA, Wang et al 21 obtained δ PLA of 20.5 MPa 1/2 . In this explicit allatom MD simulation, we obtained a δ PLA of 20.6 MPa 1/2 for PLA (L-D = 50:50).…”

“…based on a group‐contribution method, though both components are markedly smaller than our results. In contrast, Wang et al . reported a much smaller contribution from electrostatic interactions (6.4 vs. 19.5 MPa 1/2 for δ vdW ).…”

“…A similar result (9.7 vs. 11.8 MPa 1/2 ) was found by Liu et al 66 based on a group-contribution method, though both components are markedly smaller than our results. In contrast, Wang et al 21 reported a much smaller contribution from electrostatic interactions (6.4 vs. 19.5 MPa 1/2 for δ vdW ). It is unclear whether this has something to do with their use of a cruder coarse-grain molecular model in their computation.…”

“…16,17 Recent years have witnessed a growing interest in the field of biodegradable polymers and, consequently, in computational activities to explore various molecular properties of biodegradable polymers. [18][19][20][21] Poly(lactide) (PLA) and its copolymers are among the most widely used synthetic biodegradable polymers for drug encapsulation and delivery with several products for controlled release of proteins or peptides on the market. [22][23][24] Biodegradable polymers such as PLA and its copolymers are also useful for applications in biotechnology (e.g., medical devices, implants, and tissue engineering), packaging, and other areas.…”

A coarse-grained model for polylactide: glass transition temperature and conformational properties

“…To the best of our knowledge, no CG model has been developed for the neat PLA system. Works relating to this study are dissipative particle dynamics (DPD) simulations of polymer blends of polyethylene (PE)/poly(L-lactide) (PLLA) [20] and PE/PLLA/carbon nanotube [21]. For these DPD models, interactions between polymer beads, relating to the Flory-Huggins interaction parameter χ, is estimated by the calculation of mixing energy for each pair of components in atomistic molecular dynamics simulation.…”