Pub Date : 2025-11-21DOI: 10.1016/j.polymertesting.2025.109054
Guowen Gao , Enling Tang , Zhe Zhai , Guolai Yang , Yafei Han
To enhance the radial velocity and damage effectiveness of fragments after PELE projectile penetration, Al/Ep/B reactive material was selected as the core filler. Ballistic gun tests were conducted to study the dynamic penetration of steel targets by PELE projectiles with different core structures. The damage mechanisms of fragments were analyzed through mass distribution statistics and three-dimensional morphological reconstruction, while high-speed imaging was used to quantitatively characterize the axial and radial velocity fields of the fragments. A numerical model corresponding to the experimental conditions was established using Autodyn, incorporating a subroutine to describe the equation of state of the reactive material. The results showed high consistency between the simulated fragment morphology and velocity distribution and the experimental data. To further optimize the reactive core structure, a deep neural network was employed to establish the relationship between material parameters, fragment mass, and radial velocity. Multi-objective optimization was performed using the Non-dominated Sorting Genetic Algorithm (NSGA-II), ultimately identifying the gradient configuration as the optimal solution. A comparison between the optimization results and numerical simulations showed less than 5 % error in key parameters, verifying the reliability of the optimization.
{"title":"Damage characteristics and structural optimization of PELE with gradient reactive filling penetrating steel targets","authors":"Guowen Gao , Enling Tang , Zhe Zhai , Guolai Yang , Yafei Han","doi":"10.1016/j.polymertesting.2025.109054","DOIUrl":"10.1016/j.polymertesting.2025.109054","url":null,"abstract":"<div><div>To enhance the radial velocity and damage effectiveness of fragments after PELE projectile penetration, Al/Ep/B reactive material was selected as the core filler. Ballistic gun tests were conducted to study the dynamic penetration of steel targets by PELE projectiles with different core structures. The damage mechanisms of fragments were analyzed through mass distribution statistics and three-dimensional morphological reconstruction, while high-speed imaging was used to quantitatively characterize the axial and radial velocity fields of the fragments. A numerical model corresponding to the experimental conditions was established using Autodyn, incorporating a subroutine to describe the equation of state of the reactive material. The results showed high consistency between the simulated fragment morphology and velocity distribution and the experimental data. To further optimize the reactive core structure, a deep neural network was employed to establish the relationship between material parameters, fragment mass, and radial velocity. Multi-objective optimization was performed using the Non-dominated Sorting Genetic Algorithm (NSGA-II), ultimately identifying the gradient configuration as the optimal solution. A comparison between the optimization results and numerical simulations showed less than 5 % error in key parameters, verifying the reliability of the optimization.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"154 ","pages":"Article 109054"},"PeriodicalIF":6.0,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.polymertesting.2025.109052
Leire Unanue , Jorge L. Olmedo-Martínez , Cuong Minh Quoc Le , Abraham Chemtob , Alejandro J. Müller
This work examines the self-nucleation of three different polymorphic alternating polythioether homopolymers, i.e., DMDS-alt-DVE, DMDS-alt-TEGDVE and DMDS-alt-BBDVE. The repeating unit of these materials consists of an identical sulfur-containing part and ether functionalities that vary in chemical structure. All of the materials show three different polymorphic crystal phases, denoted by their distinct melting temperatures as: very low-temperature melting phase (), low-temperature melting phase () and high-temperature melting phase (). A detailed self-nucleation study was performed by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). The different self-nucleation Domains were determined for each of the polymers, and the polymorphs that formed in each Domain were assigned. Self-seeding promoted the crystallization of the highest thermodynamically stable phase that was present in a given polythioether (e.g., DMDS-alt-DVE) and substantially increased its quantity reducing the formation of less stable phases. PLOM was indispensable to identify the multiple polymorphs present in the samples. This work establishes a robust testing protocol for polymorph selection in sulfur-containing polymers and offers thermal processing parameters for achieving desired crystal structures in functional polymer materials.
{"title":"Self-nucleation enhances the stability of the polymorphs present in triple polymorphic polythioethers","authors":"Leire Unanue , Jorge L. Olmedo-Martínez , Cuong Minh Quoc Le , Abraham Chemtob , Alejandro J. Müller","doi":"10.1016/j.polymertesting.2025.109052","DOIUrl":"10.1016/j.polymertesting.2025.109052","url":null,"abstract":"<div><div>This work examines the self-nucleation of three different polymorphic alternating polythioether homopolymers, i.e., DMDS-<em>alt</em>-DVE, DMDS-<em>alt</em>-TEGDVE and DMDS-<em>alt</em>-BBDVE. The repeating unit of these materials consists of an identical sulfur-containing part and ether functionalities that vary in chemical structure. All of the materials show three different polymorphic crystal phases, denoted by their distinct melting temperatures as: very low-temperature melting phase (<span><math><mrow><msub><mrow><mi>V</mi><mi>L</mi><mo>−</mo><mi>T</mi></mrow><mi>m</mi></msub></mrow></math></span>), low-temperature melting phase (<span><math><mrow><msub><mrow><mi>L</mi><mo>−</mo><mi>T</mi></mrow><mi>m</mi></msub></mrow></math></span>) and high-temperature melting phase (<span><math><mrow><msub><mrow><mi>H</mi><mo>−</mo><mi>T</mi></mrow><mi>m</mi></msub></mrow></math></span>). A detailed self-nucleation study was performed by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). The different self-nucleation <em>Domains</em> were determined for each of the polymers, and the polymorphs that formed in each <em>Domain</em> were assigned. Self-seeding promoted the crystallization of the highest thermodynamically stable phase that was present in a given polythioether (e.g., DMDS-<em>alt</em>-DVE) and substantially increased its quantity reducing the formation of less stable phases. PLOM was indispensable to identify the multiple polymorphs present in the samples. This work establishes a robust testing protocol for polymorph selection in sulfur-containing polymers and offers thermal processing parameters for achieving desired crystal structures in functional polymer materials.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"154 ","pages":"Article 109052"},"PeriodicalIF":6.0,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.polymertesting.2025.109055
K.J. Wong , H.A. Israr , T. Dickhut , S.S.R. Koloor , M.N. Tamin
Understanding mode II delamination in thermoset composites remains incomplete, particularly when fabrication-induced variability affects interfacial characteristics and fracture performance. This research fabricates unidirectional carbon/epoxy prepregs via hot-press (HP) and vacuum-bagging (VB) techniques and evaluates their interlaminar fracture behaviour through End-Notched Flexure (ENF) testing. Results indicate that the mode II fracture toughness (GIIC) of VB specimens (1387 N/m) is approximately 33 % lower than that of HP specimens (2058 N/m). Scanning electron microscopy (SEM) reveals reduced shear cusp density and matrix cracking in VB specimens. Delamination behaviour is simulated using a symmetric Trapezoidal Traction-Separation Law (TTSL) with pseudo-plasticity parameter Γ = 0.99, which, aside from differing GIIC values, employs a consistent set of cohesive parameters (interface stiffness kIIC = 4.5 × 105 MPa/mm and interface strength tu,II = 100 MPa) to accurately reproduce the force-displacement response in both fabrication methods. A higher GIIC value corresponds to greater crack extension (da) in simulated damage profiles, with da = 2.9 mm and 2.5 mm in HP and VB specimens, respectively. The numerical model is further validated using VB specimens with varied initial crack lengths, consistently producing reliable results. These outcomes validate the proposed unified framework, with all cohesive parameters, except for the experimentally determined GIIC, which are kept constant (Γ, kIIC and tu,II). This approach significantly reduces the need for extensive parametric studies in numerical simulations, thereby improving efficiency and consistency.
{"title":"Mode-II interlaminar damage in carbon/epoxy composites fabricated via hot-press and vacuum-bagging techniques","authors":"K.J. Wong , H.A. Israr , T. Dickhut , S.S.R. Koloor , M.N. Tamin","doi":"10.1016/j.polymertesting.2025.109055","DOIUrl":"10.1016/j.polymertesting.2025.109055","url":null,"abstract":"<div><div>Understanding mode II delamination in thermoset composites remains incomplete, particularly when fabrication-induced variability affects interfacial characteristics and fracture performance. This research fabricates unidirectional carbon/epoxy prepregs via hot-press (HP) and vacuum-bagging (VB) techniques and evaluates their interlaminar fracture behaviour through End-Notched Flexure (ENF) testing. Results indicate that the mode II fracture toughness (<em>G</em><sub><em>IIC</em></sub>) of VB specimens (1387 N/m) is approximately 33 % lower than that of HP specimens (2058 N/m). Scanning electron microscopy (SEM) reveals reduced shear cusp density and matrix cracking in VB specimens. Delamination behaviour is simulated using a symmetric Trapezoidal Traction-Separation Law (TTSL) with pseudo-plasticity parameter <em>Γ</em> = 0.99, which, aside from differing <em>G</em><sub><em>IIC</em></sub> values, employs a consistent set of cohesive parameters (interface stiffness <em>k</em><sub><em>IIC</em></sub> = 4.5 × 10<sup>5</sup> MPa/mm and interface strength <em>t</em><sub><em>u,II</em></sub> = 100 MPa) to accurately reproduce the force-displacement response in both fabrication methods. A higher <em>G</em><sub><em>IIC</em></sub> value corresponds to greater crack extension (<em>da</em>) in simulated damage profiles, with <em>da</em> = 2.9 mm and 2.5 mm in HP and VB specimens, respectively. The numerical model is further validated using VB specimens with varied initial crack lengths, consistently producing reliable results. These outcomes validate the proposed unified framework, with all cohesive parameters, except for the experimentally determined <em>G</em><sub><em>IIC</em></sub>, which are kept constant (<em>Γ, k</em><sub><em>IIC</em></sub> and <em>t</em><sub><em>u,II</em></sub>). This approach significantly reduces the need for extensive parametric studies in numerical simulations, thereby improving efficiency and consistency.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"154 ","pages":"Article 109055"},"PeriodicalIF":6.0,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.polymertesting.2025.109050
Pilar Bernal-Ortega , Frances van Elburg , Javier Araujo-Morera , Elif Uzun , Brechtje van Biesbergen , Hubert Gojzewski , Anke Blume
Recent EU regulations have increased the demand for tire materials with improved performance and sustainability. In response, new hydrocarbon resins have been developed to optimize the balance between wet grip, rolling resistance, and wear resistance in tire tread compounds. One of the most important characteristics of resins is their softening point (SP). The softening point of resins plays a critical role in rubber performance due to their influence on the processability and compatibility with other materials. This study investigates the influence of five hydrocarbon resins with the same chemical base but different softening point (ranging from 10 to 160 °C), on the properties of a carbon black-filled styrene butadiene rubber (SBR) compound. The increase in the SP of the resins resulted in higher Mooney viscosity, hardness, tensile strength and Payne effect, indicating a transition from plasticizing to reinforcing behavior. The results also revealed a strong temperature dependence: when the testing temperature exceeded the SP, the resins transitioned to a softened or liquid state, improving dispersion and mechanical performance. Overall, the SP and operating temperature are shown to be key design parameters for tailoring rubber compound properties to specific tire applications.
{"title":"New insights into resins behavior: Influence of resin softening point on in-rubber properties of carbon black-filled SBR compounds","authors":"Pilar Bernal-Ortega , Frances van Elburg , Javier Araujo-Morera , Elif Uzun , Brechtje van Biesbergen , Hubert Gojzewski , Anke Blume","doi":"10.1016/j.polymertesting.2025.109050","DOIUrl":"10.1016/j.polymertesting.2025.109050","url":null,"abstract":"<div><div>Recent EU regulations have increased the demand for tire materials with improved performance and sustainability. In response, new hydrocarbon resins have been developed to optimize the balance between wet grip, rolling resistance, and wear resistance in tire tread compounds. One of the most important characteristics of resins is their softening point (SP). The softening point of resins plays a critical role in rubber performance due to their influence on the processability and compatibility with other materials. This study investigates the influence of five hydrocarbon resins with the same chemical base but different softening point (ranging from 10 to 160 °C), on the properties of a carbon black-filled styrene butadiene rubber (SBR) compound. The increase in the SP of the resins resulted in higher Mooney viscosity, hardness, tensile strength and Payne effect, indicating a transition from plasticizing to reinforcing behavior. The results also revealed a strong temperature dependence: when the testing temperature exceeded the SP, the resins transitioned to a softened or liquid state, improving dispersion and mechanical performance. Overall, the SP and operating temperature are shown to be key design parameters for tailoring rubber compound properties to specific tire applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"154 ","pages":"Article 109050"},"PeriodicalIF":6.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.polymertesting.2025.109051
Dohee Kwon , Doyeon Lee , Jechan Lee , Jee Young Kim , Eilhann E. Kwon
The global production and consumption of polyethylene terephthalate (PET) have continued to rise, accounting for approximately one-quarter of total plastic output. Currently, PET is derived from fossil-based resources, and the majority of used PET follows a linear, single-use trajectory, ultimately contributing to environmental burdens. While PET has contributed to modern convenience, the alarming statistic that nearly one million PET bottles are discarded every minute emphasises the urgent need to reassess the sustainability of its current production and disposal practices. In this study, a catalyst-free depolymerisation technology, termed pseudo-catalytic transesterification, was developed as a sustainable valorisation approach for the recovery of resources from PET. This approach enabled rapid depolymerisation, achieving high yields of dimethyl terephthalate (DMT, 75.0 %) and ethylene glycol (EG, 17.0 %) within 1 min at 400 °C. Dimethyl carbonate (DMC) was introduced as a (co) solvent to enhance monomer recovery. A 1:1 M ratio of methanol:DMC yielded the highest DMT and EG recoveries outperforming methanol alone. However, excessive DMC promoted ethylene carbonate (EC) formation, thereby reducing the EG yield. Under optimised conditions, the process achieved a recycled PET (rPET) conversion of 68 % with an estimated economic value of $4392 per tonne of rPET. Although the production cost remains higher than that of fossil-based PET, this approach offers substantial environmental benefits by reducing 2 tonnes of CO2 emissions per tonne of recycled PET waste.
{"title":"Thermochemical methanolysis-based recyclability of polyethylene terephthalate (PET) via pseudo-catalytic depolymerisation","authors":"Dohee Kwon , Doyeon Lee , Jechan Lee , Jee Young Kim , Eilhann E. Kwon","doi":"10.1016/j.polymertesting.2025.109051","DOIUrl":"10.1016/j.polymertesting.2025.109051","url":null,"abstract":"<div><div>The global production and consumption of polyethylene terephthalate (PET) have continued to rise, accounting for approximately one-quarter of total plastic output. Currently, PET is derived from fossil-based resources, and the majority of used PET follows a linear, single-use trajectory, ultimately contributing to environmental burdens. While PET has contributed to modern convenience, the alarming statistic that nearly one million PET bottles are discarded every minute emphasises the urgent need to reassess the sustainability of its current production and disposal practices. In this study, a catalyst-free depolymerisation technology, termed pseudo-catalytic transesterification, was developed as a sustainable valorisation approach for the recovery of resources from PET. This approach enabled rapid depolymerisation, achieving high yields of dimethyl terephthalate (DMT, 75.0 %) and ethylene glycol (EG, 17.0 %) within 1 min at 400 °C. Dimethyl carbonate (DMC) was introduced as a (co) solvent to enhance monomer recovery. A 1:1 M ratio of methanol:DMC yielded the highest DMT and EG recoveries outperforming methanol alone. However, excessive DMC promoted ethylene carbonate (EC) formation, thereby reducing the EG yield. Under optimised conditions, the process achieved a recycled PET (rPET) conversion of 68 % with an estimated economic value of $4392 per tonne of rPET. Although the production cost remains higher than that of fossil-based PET, this approach offers substantial environmental benefits by reducing 2 tonnes of CO<sub>2</sub> emissions per tonne of recycled PET waste.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109051"},"PeriodicalIF":6.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-15DOI: 10.1016/j.polymertesting.2025.109049
Wondu Lee , Min Park , Pei-Chen Su , Jooheon Kim
The increasing demand for efficient thermal regulation in high-power electronic devices necessitates the development of advanced thermal interface materials. In this work, a novel composite was fabricated to address this challenge. The foundational material, an epoxy–erythritol (EPET) matrix, was synthesized by chemically grafting a phase-change material (PCM) onto an epoxy base, resulting in a single endothermic transition within the range of 110–124 °C. To broaden the thermal response, docosane was introduced, producing an EPET/docosane hybrid system that exhibited multiple endothermic transitions in the ranges of 40–60 °C and 110–124 °C. To enhance heat transfer performance, spherical aluminum nitride (AlN) was incorporated as a thermally conductive filler. The AlN particles were surface-modified with cellulose nanofiber (CNF) to improve interfacial adhesion with the polymer matrix and promote efficient thermal transport. The optimized composite, EPET/Docosane/AlN-CNF, achieved a thermal conductivity of 6.31 W/m·K and a total latent heat of 130.7 J/g. When applied to a CPU, the composite demonstrated superior heat-buffering capability, attributed to its dual endothermic transitions and high latent heat. These findings validate the potential of the developed composite as a high-performance thermal interface material for next-generation electronic devices.
{"title":"Design of high-performance phase change composites using erythritol-modified epoxy/docosane and cellulose-grafted spherical aluminum nitride","authors":"Wondu Lee , Min Park , Pei-Chen Su , Jooheon Kim","doi":"10.1016/j.polymertesting.2025.109049","DOIUrl":"10.1016/j.polymertesting.2025.109049","url":null,"abstract":"<div><div>The increasing demand for efficient thermal regulation in high-power electronic devices necessitates the development of advanced thermal interface materials. In this work, a novel composite was fabricated to address this challenge. The foundational material, an epoxy–erythritol (EPET) matrix, was synthesized by chemically grafting a phase-change material (PCM) onto an epoxy base, resulting in a single endothermic transition within the range of 110–124 °C. To broaden the thermal response, docosane was introduced, producing an EPET/docosane hybrid system that exhibited multiple endothermic transitions in the ranges of 40–60 °C and 110–124 °C. To enhance heat transfer performance, spherical aluminum nitride (AlN) was incorporated as a thermally conductive filler. The AlN particles were surface-modified with cellulose nanofiber (CNF) to improve interfacial adhesion with the polymer matrix and promote efficient thermal transport. The optimized composite, EPET/Docosane/AlN-CNF, achieved a thermal conductivity of 6.31 W/m·K and a total latent heat of 130.7 J/g. When applied to a CPU, the composite demonstrated superior heat-buffering capability, attributed to its dual endothermic transitions and high latent heat. These findings validate the potential of the developed composite as a high-performance thermal interface material for next-generation electronic devices.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109049"},"PeriodicalIF":6.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.polymertesting.2025.109024
Sara Sarbaz , Zhi Xin Liu , Heidi Feigenbaum , Samaneh Bayati , Winston Wang , Jennifer Wade , Husain Mithaiwala , Matthew D. Green
A new direct air capture (DAC) technology uses a moisture swing (MS) process with anion exchange membranes, potentially offering a more energy-efficient way to remove CO from the air. In this MS process, the membrane absorbs CO as it dries and releases it when water is added. Understanding the mechanical behavior of these membranes is essential for improving the design and efficiency of DAC systems and prolonging sorbent lifetime.
This study tested one anion exchange membrane, Fumasep’s FAA-3, under mechanical loading and various temperature and humidity conditions to measure its swelling, stiffness, strength, plastic deformation, and stress relaxation. Experimental results were used to identify a mechanical model for FAA-3 that can be used to predict the material’s nonlinear viscous behavior under various loads and environments. Unlike prior studies that assumed linear elastic behavior, this work incorporates humidity-dependent swelling, thermal expansion, and nonlinear viscoelasticity of FAA-3 in both the experiments and the model.
{"title":"Characterizing and modeling the mechanical behavior of an anion exchange membrane for carbon capture applications","authors":"Sara Sarbaz , Zhi Xin Liu , Heidi Feigenbaum , Samaneh Bayati , Winston Wang , Jennifer Wade , Husain Mithaiwala , Matthew D. Green","doi":"10.1016/j.polymertesting.2025.109024","DOIUrl":"10.1016/j.polymertesting.2025.109024","url":null,"abstract":"<div><div>A new direct air capture (DAC) technology uses a moisture swing (MS) process with anion exchange membranes, potentially offering a more energy-efficient way to remove CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> from the air. In this MS process, the membrane absorbs CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> as it dries and releases it when water is added. Understanding the mechanical behavior of these membranes is essential for improving the design and efficiency of DAC systems and prolonging sorbent lifetime.</div><div>This study tested one anion exchange membrane, Fumasep’s FAA-3, under mechanical loading and various temperature and humidity conditions to measure its swelling, stiffness, strength, plastic deformation, and stress relaxation. Experimental results were used to identify a mechanical model for FAA-3 that can be used to predict the material’s nonlinear viscous behavior under various loads and environments. Unlike prior studies that assumed linear elastic behavior, this work incorporates humidity-dependent swelling, thermal expansion, and nonlinear viscoelasticity of FAA-3 in both the experiments and the model.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109024"},"PeriodicalIF":6.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-13DOI: 10.1016/j.polymertesting.2025.109048
Paul Roumeliotis , Samuel Schlicht , Rainer Detsch , Qaisar Nawaz , Aldo R. Boccaccini , Dietmar Drummer
Flame retardant polymer based powders for laser based powder bed fusion (PBF-LB/P) are currently not reusable. This leads to crucial economic and environmental disadvantages of the process, when using flame retardant powder. In this study, we demonstrate the processability and emerging part characteristics of samples manufactured from 100 % reused powder, based on a flame retardant system of ammonium polyphosphate and pentaerythritol, opening the possibility to understand the aging process behind flame retardant powders for PBF-LB/P. To investigate the effect of aging during manufacturing, mixtures from virgin PA12 and flame retardant additives, aged PA12 and aged flame retardant additives and combinations of virgin and aged powder were prepared. The mixtures were processed using PBF-LB/P and investigated regarding the impact of PA12 and flame retardant additives. Our findings indicate both the formation of agglomerations and mutual chemical reactions between the flame retardant additives, particularly through esterification reactions. The agglomeration and aging of PA12 hinder the coalescence of the powder, resulting in reduced mechanical properties. In contrast to the mechanical characteristics, aged specimens demonstrate enhanced burning behavior, yielding an increase of the LOI by 1.2 pp and a V-0 rating for specimens of 3 mm thickness for aged powder compared to virgin powder. Moreover, the aging is associated with distinct influences on the burning behavior during cone calorimetry testing. While aged flame retardant additives cause a steep increase of HRR within the first seconds of ignition, followed by a decline and plateau formation, aged PA12 shows a slower increase in HRR, followed by a plateau formation on a higher HRR level.
{"title":"Powder Aging Effects on Mechanical and Fire Properties of a Flame Retardant PA12 in Laser Powder Bed Fusion","authors":"Paul Roumeliotis , Samuel Schlicht , Rainer Detsch , Qaisar Nawaz , Aldo R. Boccaccini , Dietmar Drummer","doi":"10.1016/j.polymertesting.2025.109048","DOIUrl":"10.1016/j.polymertesting.2025.109048","url":null,"abstract":"<div><div>Flame retardant polymer based powders for laser based powder bed fusion (PBF-LB/P) are currently not reusable. This leads to crucial economic and environmental disadvantages of the process, when using flame retardant powder. In this study, we demonstrate the processability and emerging part characteristics of samples manufactured from 100 % reused powder, based on a flame retardant system of ammonium polyphosphate and pentaerythritol, opening the possibility to understand the aging process behind flame retardant powders for PBF-LB/P. To investigate the effect of aging during manufacturing, mixtures from virgin PA12 and flame retardant additives, aged PA12 and aged flame retardant additives and combinations of virgin and aged powder were prepared. The mixtures were processed using PBF-LB/P and investigated regarding the impact of PA12 and flame retardant additives. Our findings indicate both the formation of agglomerations and mutual chemical reactions between the flame retardant additives, particularly through esterification reactions. The agglomeration and aging of PA12 hinder the coalescence of the powder, resulting in reduced mechanical properties. In contrast to the mechanical characteristics, aged specimens demonstrate enhanced burning behavior, yielding an increase of the LOI by 1.2 pp and a V-0 rating for specimens of 3 mm thickness for aged powder compared to virgin powder. Moreover, the aging is associated with distinct influences on the burning behavior during cone calorimetry testing. While aged flame retardant additives cause a steep increase of HRR within the first seconds of ignition, followed by a decline and plateau formation, aged PA12 shows a slower increase in HRR, followed by a plateau formation on a higher HRR level.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109048"},"PeriodicalIF":6.0,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-12DOI: 10.1016/j.polymertesting.2025.109040
Min Woo Kim , Hyeonjeong Kim , Jaegeun Lyu , Howon Choi , Juyoung Kim , Donghoon Lee , Dae Young Lim , Ji Ho Youk , Youngho Eom , Han Gi Chae
Para
aramid (p-aramid) fibers, traditionally used in bulletproof vests because of their exceptional strength and modulus, are now widely utilized in optical cables and the aerospace industry. This growing demand driven by advanced applications requires precise performance grading to meet diverse operational requirements. This study proposes a rational copolymerization strategy for tailoring the properties of p-aramid copolymer (co-p-aramid) fibers by adjusting the ratio of 3,4′-oxydianiline (3,4′-ODA) and 4,4′-oxydianiline (4,4′-ODA). While 3,4′-ODA enhances mechanical strength, 4,4′-ODA improves thermo-chemical stability. For high-strength applications, co-p-aramid fibers synthesized with 3,4′-ODA as the sole comonomer achieve a tensile modulus and tensile strength of 80.4 and 3.1 GPa, respectively. For superior thermo-chemical resistance, fibers with a 3,4′-ODA:4,4′-ODA molar ratio of 2:8 exhibit the highest stability, with a decomposition temperature of 484.1 °C, which is 25.7 °C higher than that of the sole 3,4′-ODA-based fiber. Further, these fibers demonstrate strong chemical durability, retaining 42 % and 98 % of their tensile strength and modulus, respectively, after 24 h in 60 wt% nitric acid, whereas the latter retains only 15 % and 61 %. These findings confirm that molecular design using positional isomers effectively fine-tunes the performance of co-p-aramid fibers, establishing a foundation for developing customized high-performance fibers.
{"title":"Tailored performance optimization of p-aramid copolymer fibers: From strength to thermo-chemical durability","authors":"Min Woo Kim , Hyeonjeong Kim , Jaegeun Lyu , Howon Choi , Juyoung Kim , Donghoon Lee , Dae Young Lim , Ji Ho Youk , Youngho Eom , Han Gi Chae","doi":"10.1016/j.polymertesting.2025.109040","DOIUrl":"10.1016/j.polymertesting.2025.109040","url":null,"abstract":"<div><h3>Para</h3><div>aramid (<em>p</em>-aramid) fibers, traditionally used in bulletproof vests because of their exceptional strength and modulus, are now widely utilized in optical cables and the aerospace industry. This growing demand driven by advanced applications requires precise performance grading to meet diverse operational requirements. This study proposes a rational copolymerization strategy for tailoring the properties of <em>p</em>-aramid copolymer (<em>co</em>-<em>p</em>-aramid) fibers by adjusting the ratio of 3,4′-oxydianiline (3,4′-ODA) and 4,4′-oxydianiline (4,4′-ODA). While 3,4′-ODA enhances mechanical strength, 4,4′-ODA improves thermo-chemical stability. For high-strength applications, <em>co</em>-<em>p</em>-aramid fibers synthesized with 3,4′-ODA as the sole comonomer achieve a tensile modulus and tensile strength of 80.4 and 3.1 GPa, respectively. For superior thermo-chemical resistance, fibers with a 3,4′-ODA:4,4′-ODA molar ratio of 2:8 exhibit the highest stability, with a decomposition temperature of 484.1 °C, which is 25.7 °C higher than that of the sole 3,4′-ODA-based fiber. Further, these fibers demonstrate strong chemical durability, retaining 42 % and 98 % of their tensile strength and modulus, respectively, after 24 h in 60 wt% nitric acid, whereas the latter retains only 15 % and 61 %. These findings confirm that molecular design using positional isomers effectively fine-tunes the performance of <em>co</em>-<em>p</em>-aramid fibers, establishing a foundation for developing customized high-performance fibers.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109040"},"PeriodicalIF":6.0,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-12DOI: 10.1016/j.polymertesting.2025.109039
Sung Nam Moon , Jin Woo Song , Sang Yup Kim , Woo Il Lee
This study investigates the deformation behavior of spin-coated polystyrene (PS) thin films under nanoscale confinement during thermal nanoimprint lithography (T-NIL). As film thickness approaches the radius of gyration (), polymer flow is significantly suppressed, and deformation resistance increases even under moderate imprinting pressures. To quantify this behavior, a semi-empirical model is developed that incorporates three physically meaningful parameters: bulk-limit deformability, critical cavity size linked to coil dimensions and entanglement thresholds, and confinement-induced resistance scaling. Experimental results reveal a sharp rise in the confinement-induced resistance scaling parameter below ∼7 , indicating strong confinement effects associated with reduced segmental mobility and disrupted entanglement networks. Complementing this framework, an apparent viscosity model is constructed based on modified Poiseuille flow. The apparent viscosity exhibits an inverse power-law dependence on film thickness, closely mirroring the classical scaling law of viscosity with molecular weight () in entangled polymer melts. Together, these models provide predictive insight into deformation resistance in confined polymer systems and offer quantitative guidelines for NIL process optimization. Beyond NIL, the findings contribute to a broader understanding of rheological behavior in polymer thin films under geometric confinement.
{"title":"Confinement-induced flow resistance in polystyrene thin films: A semi-empirical framework for nanoimprint lithography","authors":"Sung Nam Moon , Jin Woo Song , Sang Yup Kim , Woo Il Lee","doi":"10.1016/j.polymertesting.2025.109039","DOIUrl":"10.1016/j.polymertesting.2025.109039","url":null,"abstract":"<div><div>This study investigates the deformation behavior of spin-coated polystyrene (PS) thin films under nanoscale confinement during thermal nanoimprint lithography (T-NIL). As film thickness approaches the radius of gyration (<span><math><mrow><msub><mi>R</mi><mi>g</mi></msub></mrow></math></span>), polymer flow is significantly suppressed, and deformation resistance increases even under moderate imprinting pressures. To quantify this behavior, a semi-empirical model is developed that incorporates three physically meaningful parameters: bulk-limit deformability, critical cavity size linked to coil dimensions and entanglement thresholds, and confinement-induced resistance scaling. Experimental results reveal a sharp rise in the confinement-induced resistance scaling parameter below ∼7 <span><math><mrow><msub><mi>R</mi><mi>g</mi></msub></mrow></math></span>, indicating strong confinement effects associated with reduced segmental mobility and disrupted entanglement networks. Complementing this framework, an apparent viscosity model is constructed based on modified Poiseuille flow. The apparent viscosity exhibits an inverse power-law dependence on film thickness, closely mirroring the classical scaling law of viscosity with molecular weight (<span><math><mrow><mi>η</mi><mo>∼</mo><msup><mi>M</mi><mn>3.4</mn></msup></mrow></math></span>) in entangled polymer melts. Together, these models provide predictive insight into deformation resistance in confined polymer systems and offer quantitative guidelines for NIL process optimization. Beyond NIL, the findings contribute to a broader understanding of rheological behavior in polymer thin films under geometric confinement.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109039"},"PeriodicalIF":6.0,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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