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

Journal Menu

Journal Browser

Research Progress on Mechanical Behavior of Polymers, 2nd Edition

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

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

Deadline for manuscript submissions: 30 September 2026 | Viewed by 4806

Share This Special Issue

Special Issue Editor

Dr. Rui F. Martins

E-Mail Website
Guest Editor

Department of Mechanical and Industrial Engineering, NOVA School of Science & Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
Interests: fatigue; fracture; structural integrity; failure analysis; mechanical behaviour of materials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Polymers offer a wide range of mechanical behaviors that profoundly affect their performance and determine their application in transforming healthcare, consumer goods, and the automotive and aerospace industries, among others. Moreover, additive manufacturing has revolutionized polymer applications, allowing for the creation of complex components with reduced waste and customized mechanical properties that depend on the materials used, process parameters, printing strategies, and postprocessing. Therefore, prominent thermoplastics such as polylactic acid (PLA), polyethylene terephthalate glycol (PETG), or polyethylether ketone (PEEK), to name just a few, are now widely employed for prototyping and making functional parts of consumer products, e.g., for biomedical, aerospatial, oil, and gas applications.

Hence, a thorough understanding of the mechanical properties of this class of engineering materials, either at room or at low/high temperatures, is crucial for designing durable polymer components.

In this Special Issue, we invite researchers and practitioners to contribute their expertise and insights to further our understanding of topics such as the yield strength, tensile strength, hardness, ductility, fracture toughness, fatigue, creep deformation, and failure mechanisms of recently developed or newly applied polymers.

Dr. Rui F. Martins
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 250 words) can be sent to the Editorial Office for assessment.

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
additive manufacturing
mechanical behavior
structural integrity

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

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, 3981 KB

Open AccessArticle

Static and Cyclic Mechanical Behavior of 3D-Printed PEEK Under Tensile and Compressive Loads

by Francisco Pina, Carlos M. S. Vicente, Joaquim Justino Netto and Luís Reis

Polymers 2026, 18(6), 748; https://doi.org/10.3390/polym18060748 - 19 Mar 2026

Viewed by 651

Abstract

Polyether ether ketone (PEEK) is a high-performance polymer with exceptional mechanical properties, durability and lightweight. 3D printing of PEEK can be very beneficial in the medical industry to manufacture patient-specific implants; however, there is a lack of studies regarding the fatigue behavior of 3D-printed PEEK, especially under compression, which is closely related to its potential applications. This paper investigates the static and dynamic mechanical performance of 3D-printed PEEK. Tensile and compression tests were conducted on specimens with ±45° raster orientation. Annealing at 270 °C for 5 h increased crystallinity from 34.4% to 41.4% yet unexpectedly reduced tensile strength from 60.8 MPa to 47.3 MPa, while increasing Young’s modulus from 2.51 GPa to 3.51 GPa. Micro-CT analysis revealed increased pore size after annealing. Static compression strength showed improvement post-annealing, increasing from 80.1 MPa to 126.7 MPa, with modulus rising from 1.64 GPa to 2.28 GPa. Compression–compression fatigue tests, performed at 5 Hz and 2.5 Hz with stress amplitudes of 70–95% of maximum strength (R = 0.1), enabled the construction of the first S-N curve for 3D-printed PEEK under compressive loading. Annealed specimens exhibited superior fatigue life, with infinite life achieved at 83.3 MPa (70% of static strength). Thermal imaging highlighted the role of temperature in fatigue failure, showing that annealed specimens endured higher thermal loads. These findings support the suitability of 3D-printed PEEK for load-bearing biomedical applications under cyclic compressive loads. Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Figure 1

20 pages, 4795 KB

Open AccessArticle

Photocrosslinkable Dexamethasone-Loaded GelMA Hydrogel for Peripheral Nerve Injury: Mechanical Behaviour and Anti-Adhesion Effect

by Ji-Woo Park, Jun-Kyu Kang, Chang Joo Lee, Kyoung Duck Seo and So-Jung Gwak

Polymers 2026, 18(5), 628; https://doi.org/10.3390/polym18050628 - 3 Mar 2026

Viewed by 681

Abstract

Peripheral nerve adhesion after surgical injury severely hinders functional nerve regeneration, leading to pain and neurological dysfunction. In this study, we developed a photocrosslinkable methacrylated gelatin (GelMA)-based hydrogel membrane that locally releases dexamethasone to simultaneously prevent adhesion and suppress inflammation. GelMA, synthesized by reacting gelatin with methacrylic anhydride, formed a stable crosslinked network, as confirmed by FT-IR spectroscopy and rheological analysis. Cytocompatibility assays showed that both GelMA and Dexa-GelMA hydrogels were non-cytotoxic to neuronal and fibroblast cell lines. In a Sprague-Dawley (SD) rat sciatic nerve injury model, implantation of the Dexa-GelMA hydrogel significantly reduced perineural adhesion and inflammation compared with the untreated control. Western blot analysis showed an approximately 80% reduction in ED-1 expression, indicating suppression of macrophage activation. Overall, the Dexa-GelMA hydrogel provides a biocompatible, multifunctional platform that integrates physical barrier function with anti-inflammatory drug delivery, showing strong potential for preventing postoperative nerve adhesion and modulating early inflammatory responses in a peripheral nerve injury model. Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Figure 1

19 pages, 4938 KB

Open AccessArticle

Thermo-Mechanical and Fatigue Behavior of 3D-Printed PA12 CF15 for Engineering Application

by Justas Ciganas, Tomas Kalinauskis and Urte Cigane

Polymers 2026, 18(5), 563; https://doi.org/10.3390/polym18050563 - 26 Feb 2026

Viewed by 768

Abstract

This study presents a detailed experimental investigation of the mechanical, fatigue, and dynamic properties of a 3D-printed PA12 CF15 composite at different temperatures. The mechanical properties determined in the temperature range from 23 °C to 120 °C were later implemented in numerical simulations to evaluate the suitability of the material for thermo-mechanical loading conditions. Quasi-static tensile test results revealed a decrease in elastic modulus, yield strength, and ultimate tensile strength with increasing temperature. Fatigue testing demonstrated that increasing load levels lead to reduced durability and a lower maximum number of cycles to failure. Furthermore, elevated testing temperatures caused the composite to exhibit more pronounced plastic behavior, resulting in temperature-dependent fatigue performance. SEM analysis indicated that higher temperatures increase the plasticity of the composite, thereby reducing the reinforcing effect of carbon fibers. The mechanical characteristics obtained experimentally were incorporated into a finite element model, allowing a preliminary assessment of the feasibility of manufacturing an intake manifold from PA12 CF15 using additive manufacturing technology. The results of this study provide valuable data for the design and analysis of dynamically and thermally loaded engineering components produced from PA12 CF15 composites. Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Figure 1

24 pages, 5920 KB

Open AccessArticle

Mechanical, Fatigue, and Thermal Characterization of ASA, Nylon 12, PC, and PC-ABS Manufactured by Fused Filament Fabrication (FFF)

by Ângela Rodrigues, Ricardo Branco, Margarida Franco, Rui Silva, Cândida Malça and Rui F. Martins

Polymers 2026, 18(2), 302; https://doi.org/10.3390/polym18020302 - 22 Jan 2026

Cited by 1 | Viewed by 722

Abstract

Additive manufacturing has been widely adopted in industry as an alternative to traditional manufacturing processes for complex component production. In fact, a diverse range of materials, particularly polymers, can be processed using 3D printing for biomechanical applications (e.g., prosthetics). However, in-depth evaluation of these materials is necessary to determine their suitability for demanding applications, such as those involving cyclic loading. Following previous work that studied Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol-modified (PETG) under experimental fatigue testing, this study examines the fatigue behaviour of other current 3D-printed polymeric materials, namely Acrylonitrile Styrene Acrylate (ASA), Polycarbonate (PC), Polyamide 12 (Nylon 12), and Polycarbonate–Acrylonitrile Butadiene Styrene (blend) (PC-ABS), for which fatigue data remain limited or even non-existent. The findings revealed performance differences on Tensile Strength (σ_R), Young’s Modulus and Ultimate Strain among tensile specimens made from these materials and characterised S-N curves for both high-cycle (HCF) and low-cycle (LCF) fatigue regimes at room temperature, with a tensile load ratio (R = 0.05). These results establish relationships among fatigue limit and quasi-static mechanical properties, namely 25% × σ_r for ASA (8 MPa), 7% × σ_r for PC (3.6 MPa), 17% × σ_r for Nylon 12 (7.4 MPa), and 15% × σ_r for PC-ABS (4.7 MPa), as well as between mechanical properties and preliminary potential biomechanical applications. Main conclusions were further supported by micro-computed tomography (micro-CT), which revealed levels of porosity in between 4% and 11%, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Figure 1

19 pages, 12237 KB

Open AccessArticle

Mechanical, Electrical, and Thermal Performance of Hemp Fiber-Reinforced Elium Biocomposites Modified with Activated Carbon Nanoparticles: Experiment and Simulation

by Zeenat Akhter, Arvydas Palevicius, Raul Fangueiro, Sultan Ullah and Giedrius Janusas

Polymers 2026, 18(1), 66; https://doi.org/10.3390/polym18010066 - 25 Dec 2025

Cited by 1 | Viewed by 790

Abstract

This research examines the influence of various concentrations (0%, 1%, 1.4% and 1.8% by weight) of activated carbon nanoparticles (AC NPs) on the performance of Elium biocomposites reinforced with hemp fibers. Unidirectional [0°/0°] laminates with 20% fiber volume fraction were fabricated via hand layup using two layers of 150 GSM hemp fabric and compression molded to achieve 0.9 mm cured thickness. Quasi-static tensile testing (ASTM D3039, 2 mm/min, 100 mm gauge length) revealed a pronounced non-monotonic relationship between AC NPs loading and mechanical properties, with optimal performance at 1.0 wt.% fillers and catastrophic degradation at 1.8 wt.%. AC NPs filled composites, which were then characterized by their electrical and thermal behavior. Electrically, it also achieved minimum resistivity (1.62 Ω·m) and maximum conductivity (0.62 S·m⁻¹), in contrast to the elevated resistance (42.5 kΩ) found in samples with a higher filler content. Thermal analysis showed a slight effect on the degradation of the onset temperature (300 °C) and a higher charring after addition of AC NP. Finite element analysis (FEA) provided a corroboration for these experimental findings, with simulations verification. Microscopy revealed cohesive fractures in the 1.0 wt.% composite whereas voids and brittle failure were evident in samples with higher loading. Hence, the concentration of 1.0 wt.% AC NP offers the best trade off of mechanical, electrical, and thermal properties. Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Figure 1

23 pages, 8590 KB

Open AccessArticle

The Effect of Pattern Addition on the Mechanical Properties of 3D-Printed Parts

by Nergizhan Anaç and Oğuz Koçar

Polymers 2025, 17(24), 3327; https://doi.org/10.3390/polym17243327 - 17 Dec 2025

Cited by 1 | Viewed by 794

Abstract

Additive manufacturing is a suitable method for multi-material production, as it offers flexibility in structural design and enables layer-by-layer fabrication of materials. However, the different chemical structures and formulations of the materials used may affect the mechanical integrity of the part. In nature, there are many patterned structures that inspire the design of multi-material additive manufacturing components. Integrating the harmony and advantages of these natural structures into the manufacturing process will significantly contribute to human development. This study presents a novel manufacturing approach for using existing natural or artificially produced pattern forms in the development of composite materials. In this aim, patterned parts composed of multiple materials were produced using a 3D printer with combinations of PLA Plus, PLA CF, and PLA GF. Mechanical tests were conducted on the produced parts, and their fracture surfaces were examined. In patterned specimens, tensile strength decreased compared to reference (non-patterned) specimens. In the PLA Plus–PLA Plus and PLA Plus–PLA CF combinations, tensile strength generally decreased in samples with three patterns, while the greatest reduction in tensile strength occurred in the PLA Plus–PLA GF patterned specimens. The highest bending forces were obtained in single- and five-pattern samples with PLA Plus–PLA Plus and PLA Plus–PLA CF combinations, as well as in five-pattern samples with the PLA Plus–PLA GF combination. The results indicate that the presence and number of patterns are important factors influencing the mechanical properties of the specimens. Full article

(This article belongs to the Special Issue Research Progress on Mechanical Behavior of Polymers, 2nd Edition)

► Show Figures

Journal Menu

Journal Browser

Research Progress on Mechanical Behavior of Polymers, 2nd Edition

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI