Submit to Special Issue Submit Abstract to Special Issue Review for Polymers Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Special Issue "Molecular Simulation of Polymers"

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Physics and Theory".

Deadline for manuscript submissions: 5 December 2023 | Viewed by 6999

Share This Special Issue

Special Issue Editor

Dr. Xinmin Shen

E-Mail Website
Guest Editor

College of Field Engineering, Army Engineering University of PLA, Nanjing, China
Interests: polymers; rubber; process parameter optimization; molecular simulation; finite element simulation

Special Issue Information

Dear Colleagues,

Simulation has been treated as a significant method to improve research efficiency, decrease experiment cost, and promote the development of novel products. It is well known that there are many influencing factors in the fabrication of polymers, which indicates that the direct experimental study to investigate and optimize the process parameters inevitably requires a great quantity of time and economic costs. Meanwhile, for the various applications of polymers, many kinds of properties are demanded to test and analyze, such as mechanical property, thermal property, electrical property, magnetic property, and chemical property, which mean a complex and costly detection process. The booming technology of simulation can make up for these existing problems by combining with theoretical modelling and experimental validation. Thus, simulation is not only feasible, but also necessary.

Many kinds of simulation methods have been developed at present, such as molecular simulation, finite element simulation, and virtual reality technology, which provide a variety of tools to develop and detect novel polymers. Molecular simulation is a method to simulate molecular structures and behaviors using computers to simulate at the atomic level, and then to simulate the various physical and chemical properties of the molecular system for polymers. Meanwhile, the finite element simulation method is treated as another promising technique to study the property of polymers or interfacial performance among polymers and other materials. This Special Issue is dedicated to recent research advances in the fabrication, characterization, and optimization of polymers via the assistance of computational simulation, more specifically, in (1) molecular simulation, (2) finite element simulation, and (3) multi-physical computational simulation in the polymer and relevant fields.

It is our pleasure to invite you to submit a manuscript to this Special Issue, including full papers, reviews, and short communications.

Dr. Xinmin Shen
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

polymers
molecular simulation
first principle calculation
finite element simulation
mechanical property
physical performance
rubber
preparation parameters
performance characterization

Published Papers (6 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

18 pages, 4841 KiB

Open AccessArticle

Promotion of B(C₆F₅)₃ as Ligand for Titanium (or Vanadium) Catalysts in the Copolymerization of Ethylene and 1-Hexene: A Computational Study

and

Polymers 2023, 15(11), 2435; https://doi.org/10.3390/polym15112435 - 24 May 2023

Viewed by 729

Abstract

Density functional theory (DFT) is employed to investigate the promotion of B(C₆F₅)₃ as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions. The results reveal that (I) Ethylene insertion into Ti_B (with B(C₆F₅)₃ as a ligand ) is preferred over Ti_H_, both thermodynamically and kinetically. (II) In Ti_H and Ti_B catalysts, the 2,1 insertion reaction (Ti_H21 and Ti_B21) is the primary pathway for 1-hexene insertion. Furthermore, the 1-hexene insertion reaction for Ti_B21 is favored over Ti_H21 and is easier to perform. Consequently, the entire ethylene and 1-hexene insertion reaction proceeds smoothly using the Ti_B catalyst to yield the final product. (III) Analogous to the Ti catalyst case, V_B (with B(C₆F₅)₃ as a ligand) is preferred over V_H for the entire ethylene/1-hexene copolymerization reaction. Moreover, V_B exhibits higher reaction activity than Ti_B, thus agreeing with experimental results. Additionally, the electron localization function and global reactivity index analysis indicate that titanium (or vanadium) catalysts with B(C₆F₅)₃ as a ligand exhibit higher reactivity. Investigating the promotion of B(C₆F₅)₃ as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions will aid in designing novel catalysts and lead to more cost-effective polymerization production methods. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Figure 1

27 pages, 20500 KiB

Open AccessArticle

Modeling and Verification of Rolling Resistance Torque of High-Speed Rubber Track Assembly Considering Hysteresis Loss

and

Polymers 2023, 15(7), 1642; https://doi.org/10.3390/polym15071642 - 25 Mar 2023

Cited by 1 | Viewed by 1299

Abstract

Due to the viscoelasticity of rubber materials, hysteresis loss due to deformation is the main reason for the rolling resistance of high-speed rubber tracks. Since the structure and material of high-speed rubber track assemblies are different from traditional tires and metal tracks, the rolling resistance theory of traditional wheeled and tracked vehicles is not applicable. Therefore, in order to determine the rolling resistance scientifically and accurately, the mechanism research of the rolling resistance of high-speed rubber track assembly is the key to the design of high-speed rubber crawler vehicles. In this paper, the stress–strain characteristics of rubber track under the action of compression, tension, bending, and driving were studied. The strain load spectrum of rubber tracks was established, and the strain cyclic load was extracted by the rainflow method. The temperature model of the rubber track was developed based on its dynamic characteristics. On the basis of energy conservation, the hysteresis loss of rubber is equivalent to the energy consumption of rolling resistance, and the theoretical model of rolling resistance of high-speed rubber track assembly is established. In accordance with the model above, the key influencing factors and changing trends of rolling resistance are analyzed, which provides a theoretical basis for the performance optimization of high-speed rubber track assembly. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Figure 1

26 pages, 6762 KiB

Open AccessArticle

Research on the Sound Insulation Performance of Composite Rubber Reinforced with Hollow Glass Microsphere Based on Acoustic Finite Element Simulation

and

Polymers 2023, 15(3), 611; https://doi.org/10.3390/polym15030611 - 25 Jan 2023

Cited by 3 | Viewed by 1266

Abstract

The composite rubber reinforced with hollow glass microsphere (HGM) was a promising composite material for noise reduction, and its sound insulation mechanism was studied based on an acoustic finite element simulation to gain the appropriate parameter with certain constraint conditions. The built simulation model included the air domain, polymer domain and inorganic particles domain. The sound insulation mechanism of the composite material was investigated through distributions of the sound pressure and sound pressure level. The influences of the parameters on the sound transmission loss (STL) were researched one by one, such as the densities of the composite rubber and HGM, the acoustic velocities in the polymer and inorganic particle, the frequency of the incident wave, the thickness of the sound insulator, and the diameter, volume ratio and hollow ratio of the HGM. The weighted STL with the 1/3 octave band was treated as the evaluation criterion to compare the sound insulation property with the various parameters. For the limited thicknesses of 1 mm, 2 mm, 3 mm and 4 mm, the corresponding optimal weighted STL of the composite material reached 14.02 dB, 19.88 dB, 22.838 dB and 25.27 dB with the selected parameters, which exhibited an excellent sound insulation performance and could promote the practical applications of the proposed composite rubber reinforced with HGM. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Figure 1

15 pages, 6194 KiB

Open AccessArticle

Adjustable Sound Absorber of Multiple Parallel-Connection Helmholtz Resonators with Tunable Apertures Prepared by Low-Force Stereolithography of Photopolymer Resin

and

Polymers 2022, 14(24), 5434; https://doi.org/10.3390/polym14245434 - 12 Dec 2022

Cited by 4 | Viewed by 1137

Abstract

The variable noise spectrum for many actual application scenarios requires a sound absorber to adapt to this variation. An adjustable sound absorber of multiple parallel-connection Helmholtz resonators with tunable apertures (TA–MPCHRs) is prepared by the low-force stereolithography of photopolymer resin, which aims to improve the applicability of the proposed sound absorber for noise with various frequency ranges. The proposed TA–MPCHR metamaterial contains five metamaterial cells. Each metamaterial cell contains nine single Helmholtz resonators. It is treated as a basic structural unit for an array arrangement. The tunable aperture is realized by utilizing four segments of extendable cylindrical chambers with length l₀, which indicates that the length of the aperture l is in the range of [l₀, 4l₀], and that it is tunable. With a certain group of specific parameters for the proposed TA–MPCHR, the influence of the tunable aperture with a variable length is investigated by acoustic finite element simulation with a two-dimensional rotational symmetric model. For the given noise spectrum of certain actual equipment with four operating modes, the TA–MPCHR sample with a limited total thickness of 40 mm is optimized, which is made of photopolymer resin by the low-force stereolithography, and its actual average sound absorption coefficients for the frequency ranges of 500–800 Hz, 550–900 Hz, 600–1000 Hz and 700–1150 Hz reach 0.9203, 0.9202, 0.9436 and 0.9561, respectively. Relative to common non-adjustable metamaterials, the TA–MPCHR made of photopolymer resin can reduce occupied space and improve absorption efficiency, which is favorable in promoting its practical applications in the noise pollution prevention. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Graphical abstract

12 pages, 4322 KiB

Open AccessArticle

Molecular Dynamics Studies of the Mechanical Behaviors and Thermal Conductivity of Polyisoprene with Different Degrees of Polymerization

and

Polymers 2022, 14(22), 4950; https://doi.org/10.3390/polym14224950 - 16 Nov 2022

Viewed by 1186

Abstract

Polyisoprene, with a high degree of polymerization, is the main component of natural rubber. In the industrial production process, it is necessary to adjust the length of the macromolecule of polyisoprene to improve its plasticity. It is thus of vital importance to explore the effect of the degree of polymerization of polyisoprene on its properties, e.g., mechanical property and thermal property. Molecular dynamics simulations link microstructure to macroscopic properties. In this paper, Moltemplate was used to establish polyisoprene models with different degrees of polymerization, and the mechanical properties of polyisoprene under uniaxial tension were analyzed under an OPLS all-atom force field. The results showed that the strength and elastic modulus of the material increased with the increase in the degree of polymerization of the molecular chain. In the process of tensile loading, the non-bonded potential energy played a dominant role in the change of the total system potential energy. Then, the thermal conductivity of polyisoprene with different degrees of polymerization was calculated by the non-equilibrium molecular dynamics method (NEMD). The thermal conductivity of PI was predicted to converge to 0.179 W/(m·K). The mechanism of thermal conductivity of the polymer containing branched chains was also discussed and analyzed. The research content of this paper aims to provide theoretical support for improving the mechanical and thermal properties of natural rubber base materials. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Figure 1

26 pages, 4645 KiB

Open AccessArticle

Effects of Air Plasma Modification on Aramid Fiber Surface and Its Composite Interface and Mechanical Properties

and

Polymers 2022, 14(22), 4892; https://doi.org/10.3390/polym14224892 - 13 Nov 2022

Cited by 2 | Viewed by 956

Abstract

In order to improve the interface and mechanical properties of aramid fiber (AF)-reinforced epoxy resin (EP) composites (AF/EPs), the surface modification of AF was carried out with atmospheric pressure air plasma, and the effects of plasma treatment time and discharge power on the AF surface and the interface and mechanical properties of AF/EPs were investigated. The results show that, when plasma treatment time was 10 min and discharge power was 400 W, AF showed the best modification effect. Compared to the unmodified material, the total content of active groups on the surface of AF increased by 82.4%; the contact angle between AF and EP decreased by 20%; the interfacial energy and work of adhesion increased by 77.1% and 19.1%, respectively; the loss of AF monofilament tensile strength was controlled at only 8.6%; and the interlaminar shear strength and tensile strength of AF/EPs increased by 45.5% and 10.4%, respectively. The improvement in AF/EP interfacial and mechanical properties is due to the introduction of more active groups on the AF surface with suitable plasma processing parameters, which strengthens the chemical bonding between the AF and EP matrix. At the same time, plasma treatment effectively increases the surface roughness of AF, and the mechanical meshing effect between the AF and EP matrix is improved. The synergistic effect of chemical bonding and mechanical meshing improves the wettability and interfacial bonding strength between the AF and EP matrix, which enables the load to be transferred from the resin to the fiber more efficiently, thereby improving the mechanical properties of the AF/EP. Full article

(This article belongs to the Special Issue Molecular Simulation of Polymers)

► Show Figures

Journal Menu

Journal Browser

Special Issue "Molecular Simulation of Polymers"

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI