Pub Date : 2025-10-25DOI: 10.1016/j.polymertesting.2025.109018
Yiwei Fang , Jinxuan Ding , Wanchuan Liu , Damien Crowley , Justin Antonette , Haoyan Fang , Aniket Raut , David Sprouster , Xiaoyang Liu , Yu-Chung Lin , Dilip Gersappe , Miriam Rafailovich
Biopolymers such as xanthan gum (XG) and locust bean gum (LBG) hold great potential as eco-friendly alternative soil binders. In this work, we investigated the impact of XG/LBG mixtures on the unconfined compressive strength (UCS) of sand. The high strength of dry biopolymer/sand arises from the cohesion between solid polymer films and sand particles which supported by work of adhesion calculation and soil mechanics measurement. LBG exhibits much lower sand reinforcement efficacy because polymers unevenly distributed within sand matrix. The formation of a core-shell structure in LBG/sand is an interplay of surface free energy and viscoelastic properties of polymer solutions. This structure is altered when LBG mixed with XG at varying ratios as those physical properties changed due to the complexity of polymer chains association. By probing these factors, we aim to elucidate the role of surface energies and polymer physics in governing the strength of the sand/polymer network, thereby contributing to a more comprehensive understanding polymer-sand interface. The low strength of gels (G’ ∼10Pa) cannot solely account for the increased UCS of wet sand over 10 kPa. Instead, the high strength of biopolymer/sand is more likely derived from the granular particles with biopolymers as solid glue.
{"title":"Interplay of surface energy and rheology in biopolymer soil enhancement","authors":"Yiwei Fang , Jinxuan Ding , Wanchuan Liu , Damien Crowley , Justin Antonette , Haoyan Fang , Aniket Raut , David Sprouster , Xiaoyang Liu , Yu-Chung Lin , Dilip Gersappe , Miriam Rafailovich","doi":"10.1016/j.polymertesting.2025.109018","DOIUrl":"10.1016/j.polymertesting.2025.109018","url":null,"abstract":"<div><div>Biopolymers such as xanthan gum (XG) and locust bean gum (LBG) hold great potential as eco-friendly alternative soil binders. In this work, we investigated the impact of XG/LBG mixtures on the unconfined compressive strength (UCS) of sand. The high strength of dry biopolymer/sand arises from the cohesion between solid polymer films and sand particles which supported by work of adhesion calculation and soil mechanics measurement. LBG exhibits much lower sand reinforcement efficacy because polymers unevenly distributed within sand matrix. The formation of a core-shell structure in LBG/sand is an interplay of surface free energy and viscoelastic properties of polymer solutions. This structure is altered when LBG mixed with XG at varying ratios as those physical properties changed due to the complexity of polymer chains association. By probing these factors, we aim to elucidate the role of surface energies and polymer physics in governing the strength of the sand/polymer network, thereby contributing to a more comprehensive understanding polymer-sand interface. The low strength of gels (G’ ∼10Pa) cannot solely account for the increased UCS of wet sand over 10 kPa. Instead, the high strength of biopolymer/sand is more likely derived from the granular particles with biopolymers as solid glue.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109018"},"PeriodicalIF":6.0,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419582","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 : 2025-10-24DOI: 10.1016/j.polymertesting.2025.109014
A. Vaz-Romero , A. Montoya , J.P. Fernández-Blázquez , S.C. Cifuentes
In this work, we investigate the elastocaloric performance (eCE) of thermoplastic polyurethane (TPU) processed via Selective Laser Sintering (SLS), an additive manufacturing technique with significant yet underexplored potential in this field. A comprehensive experimental methodology was developed, which combines mechanical testing of V-notched specimens, infrared thermography, and in situ SAXS/WAXS analysis to simultaneously track mechanical, thermal, and structural evolution under cyclic loading. The experimental results reveal reversible adiabatic temperature changes of up to 5 °, associated with strain-induced crystallization (SIC) and directional structural orientation. The use of a localized notched geometry (V-notched) enhanced the elastocaloric response at moderate global strains. Numerical modeling further confirmed the development of stress states favorable for SIC. These findings validate the elastocaloric functionality of SLS-printed TPU and offer new insights into processing–structure–property relationships. This work represents a step forward in the development of scalable, environmentally friendly cooling devices based on polymeric materials.
{"title":"Strain-induced crystallization and elastocaloric response in SLS-printed thermoplastic polyurethane","authors":"A. Vaz-Romero , A. Montoya , J.P. Fernández-Blázquez , S.C. Cifuentes","doi":"10.1016/j.polymertesting.2025.109014","DOIUrl":"10.1016/j.polymertesting.2025.109014","url":null,"abstract":"<div><div>In this work, we investigate the elastocaloric performance (eCE) of thermoplastic polyurethane (TPU) processed via Selective Laser Sintering (SLS), an additive manufacturing technique with significant yet underexplored potential in this field. A comprehensive experimental methodology was developed, which combines mechanical testing of V-notched specimens, infrared thermography, and in situ SAXS/WAXS analysis to simultaneously track mechanical, thermal, and structural evolution under cyclic loading. The experimental results reveal reversible adiabatic temperature changes of up to 5 °<span><math><mi>C</mi></math></span>, associated with strain-induced crystallization (SIC) and directional structural orientation. The use of a localized notched geometry (V-notched) enhanced the elastocaloric response at moderate global strains. Numerical modeling further confirmed the development of stress states favorable for SIC. These findings validate the elastocaloric functionality of SLS-printed TPU and offer new insights into processing–structure–property relationships. This work represents a step forward in the development of scalable, environmentally friendly cooling devices based on polymeric materials.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109014"},"PeriodicalIF":6.0,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145369846","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 : 2025-10-23DOI: 10.1016/j.polymertesting.2025.109015
C. Reinhards – Hervás , J. Rodríguez , A. Rico
The poroviscoelastic behavior of polyacrylamide (PAAm) and PAAm/alginate hydrogels is investigated through torsional and spherical indentation tests across multiple scales. The results reveal that both hydrogel types exhibit mechanical responses governed by viscoelastic and poroelastic mechanisms, with their relative contributions depending on contact scale and time. Torsional tests, which exclude fluid flow, showed purely viscoelastic relaxation, with increased stiffness and reduced relaxation in hydrogels with higher crosslinking density or alginate content. In indentation tests, relaxation time increased with contact size, indicating strong poroelastic influence. A constrained fitting model was applied to decouple both contributions and extract key material parameters such as diffusivity and relaxation modulus. Increased crosslinking enhanced both stiffness and diffusivity, while alginate addition improved stiffness but reduced diffusivity and Poisson's ratio. The consistency between results from both testing modes validates the proposed separation approach. Overall, this work demonstrates that multiscale poroviscoelastic characterization enables accurate understanding of the mechanical behavior of complex hydrogels.
{"title":"Poroviscoelastic characterization of polyacrylamide–alginate hydrogels across a broad range of length scales using torsional and depth sensing indentation tests","authors":"C. Reinhards – Hervás , J. Rodríguez , A. Rico","doi":"10.1016/j.polymertesting.2025.109015","DOIUrl":"10.1016/j.polymertesting.2025.109015","url":null,"abstract":"<div><div>The poroviscoelastic behavior of polyacrylamide (PAAm) and PAAm/alginate hydrogels is investigated through torsional and spherical indentation tests across multiple scales. The results reveal that both hydrogel types exhibit mechanical responses governed by viscoelastic and poroelastic mechanisms, with their relative contributions depending on contact scale and time. Torsional tests, which exclude fluid flow, showed purely viscoelastic relaxation, with increased stiffness and reduced relaxation in hydrogels with higher crosslinking density or alginate content. In indentation tests, relaxation time increased with contact size, indicating strong poroelastic influence. A constrained fitting model was applied to decouple both contributions and extract key material parameters such as diffusivity and relaxation modulus. Increased crosslinking enhanced both stiffness and diffusivity, while alginate addition improved stiffness but reduced diffusivity and Poisson's ratio. The consistency between results from both testing modes validates the proposed separation approach. Overall, this work demonstrates that multiscale poroviscoelastic characterization enables accurate understanding of the mechanical behavior of complex hydrogels.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"153 ","pages":"Article 109015"},"PeriodicalIF":6.0,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419609","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 : 2025-10-20DOI: 10.1016/j.polymertesting.2025.109005
Yao Yang , Zhennuo Shi , Ruqing Bai , Weihu Yang , Jifang Zhou , Li Wang
In this study, a shape-memory 3D scaffold with photothermal capability to heal bone defect was developed by a multifunctional porous composite network. The fabrication contains in-situ polymerization with gas foaming process, by incorporating surface-modified iron oxide nanoparticles (functionalized by polydopamine) into a biodegradable polyurethane matrix derived from poly(propylene glycol) and poly(ε-caprolactone) precursors. Enhanced osteoinductive signaling through these bioactive surface, enabling controlled mineralization and cell-matrix interactions. Robust osteogenic differentiation of mesenchymal stem cells across interconnected networks. Reversible shape memory transition (melting transition at 37 °C) enabling minimally invasive deployment through 4 mm diameter cannulas. Synergistic therapeutic effects combining localized heat shock protein induction with sustained bioactive ion release. This programmable biomatrix platform addresses critical unmet needs in complex craniofacial and orthopedic reconstruction by integrating shape-morphing delivery, spatially controlled thermotherapy, and sequential bone regeneration cues within a single implantable system.
{"title":"A biomimetic composite scaffold with near-infared light controlled shape-memory properties for bone defect healing","authors":"Yao Yang , Zhennuo Shi , Ruqing Bai , Weihu Yang , Jifang Zhou , Li Wang","doi":"10.1016/j.polymertesting.2025.109005","DOIUrl":"10.1016/j.polymertesting.2025.109005","url":null,"abstract":"<div><div>In this study, a shape-memory 3D scaffold with photothermal capability to heal bone defect was developed by a multifunctional porous composite network. The fabrication contains in-situ polymerization with gas foaming process, by incorporating surface-modified iron oxide nanoparticles (functionalized by polydopamine) into a biodegradable polyurethane matrix derived from poly(propylene glycol) and poly(ε-caprolactone) precursors. Enhanced osteoinductive signaling through these bioactive surface, enabling controlled mineralization and cell-matrix interactions. Robust osteogenic differentiation of mesenchymal stem cells across interconnected networks. Reversible shape memory transition (melting transition at 37 °C) enabling minimally invasive deployment through 4 mm diameter cannulas. Synergistic therapeutic effects combining localized heat shock protein induction with sustained bioactive ion release. This programmable biomatrix platform addresses critical unmet needs in complex craniofacial and orthopedic reconstruction by integrating shape-morphing delivery, spatially controlled thermotherapy, and sequential bone regeneration cues within a single implantable system.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 109005"},"PeriodicalIF":6.0,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363552","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 : 2025-10-20DOI: 10.1016/j.polymertesting.2025.109016
Ana Clelia Babetto , Lívia Maria Garcia Gonçalves , Eliada Andrade Silva , Benedito Santos Lima Neto , Andreia de Araújo Morandim-Giannetti , Sílvia Helena Prado Bettini
Lignin, a high-volume byproduct of the pulp and paper industry, contains sterically hindered phenolic hydroxyl groups that enable antioxidant activity in polymer systems. This study investigates the potential of three eucalyptus-derived lignins, referred to as L1, L2, and L3, extracted from black liquor via acid precipitation under varying conditions, as primary antioxidants in polypropylene (PP). The lignins exhibited distinct pH values: L1 (3.35), L2 (3.68), and L3 (7.97). A comprehensive characterization, combining structural, chemical, and molecular analyses, was performed to correlate intrinsic features with antioxidant efficiency in PP. Although extraction conditions influenced purity and functionality, only detailed characterization allowed reliable prediction of stabilization performance. Lignins with acidic pH values (L1 and L2) showed higher purity and a greater concentration of sterically hindered phenolic groups, correlating with enhanced antioxidant activity. Oxidative induction time (OIT), rotational rheometry, and size exclusion chromatography (SEC) confirmed the superior performance of L1 and L2. At 2000 ppm, PP-lignin formulations containing L1 or L2 exhibited significantly higher OIT values, viscosities, and molar masses compared to PP with conventional synthetic antioxidants. Structural differences between syringyl and guaiacyl units in L1 and L2 further influenced stabilization during high-temperature processing, with L2 demonstrating exceptional performance under elevated temperature, oxygen, and shear. This work highlights the importance of combining extraction strategies with advanced lignin characterization to predict antioxidant efficiency, while introducing methodologies that correlate rheological behavior with molar mass distribution. These findings support lignin's application as a cost-effective, bio-based, and high-performance antioxidant additive for recycled polypropylene.
{"title":"Can all lignins act as an antioxidant for polypropylene?","authors":"Ana Clelia Babetto , Lívia Maria Garcia Gonçalves , Eliada Andrade Silva , Benedito Santos Lima Neto , Andreia de Araújo Morandim-Giannetti , Sílvia Helena Prado Bettini","doi":"10.1016/j.polymertesting.2025.109016","DOIUrl":"10.1016/j.polymertesting.2025.109016","url":null,"abstract":"<div><div>Lignin, a high-volume byproduct of the pulp and paper industry, contains sterically hindered phenolic hydroxyl groups that enable antioxidant activity in polymer systems. This study investigates the potential of three eucalyptus-derived lignins, referred to as L1, L2, and L3, extracted from black liquor via acid precipitation under varying conditions, as primary antioxidants in polypropylene (PP). The lignins exhibited distinct pH values: L1 (3.35), L2 (3.68), and L3 (7.97). A comprehensive characterization, combining structural, chemical, and molecular analyses, was performed to correlate intrinsic features with antioxidant efficiency in PP. Although extraction conditions influenced purity and functionality, only detailed characterization allowed reliable prediction of stabilization performance. Lignins with acidic pH values (L1 and L2) showed higher purity and a greater concentration of sterically hindered phenolic groups, correlating with enhanced antioxidant activity. Oxidative induction time (OIT), rotational rheometry, and size exclusion chromatography (SEC) confirmed the superior performance of L1 and L2. At 2000 ppm, PP-lignin formulations containing L1 or L2 exhibited significantly higher OIT values, viscosities, and molar masses compared to PP with conventional synthetic antioxidants. Structural differences between syringyl and guaiacyl units in L1 and L2 further influenced stabilization during high-temperature processing, with L2 demonstrating exceptional performance under elevated temperature, oxygen, and shear. This work highlights the importance of combining extraction strategies with advanced lignin characterization to predict antioxidant efficiency, while introducing methodologies that correlate rheological behavior with molar mass distribution. These findings support lignin's application as a cost-effective, bio-based, and high-performance antioxidant additive for recycled polypropylene.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 109016"},"PeriodicalIF":6.0,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363547","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 : 2025-10-17DOI: 10.1016/j.polymertesting.2025.109007
Pan Li , Ying-Xuan Zhang , Rui-Xin Jia , Sheng-Jian Zhang , Li-Jun Fu , Shu-Wei Yuan , Yu Lin , Wei-Hong Ji , Yue Liu , T. Tafsirojjaman
Conventional monitoring methods for steel cables often face limitations, such as insufficient measurement accuracy and suboptimal long-term reliability. Additionally, the inherent corrosion susceptibility of steel cables poses significant compatibility challenges with standard installation procedures for Fiber Bragg Grating (FBG) sensors. To address these issues, this study leverages the superior corrosion resistance and enhanced sensor compatibility of carbon fiber reinforced polymer (CFRP) composites. Specifically, smart CFRP strands were developed by embedding FBG sensors within the core of CFRP rods, followed by an extensive investigation of their fundamental mechanical properties. Smart composite cables were then fabricated by integrating these CFRP strands with conventional steel strands, imparting self-sensing capabilities to the hybrid system. This innovative configuration not only enhances the measurement accuracy of cable force monitoring but also significantly improves the long-term durability of embedded FBG sensors, thus achieving effective coupling between structural load-bearing and sensing functions. Quasi-static tensile tests conducted at 10 %–40 % of the maximum cable force (FCmax) revealed a linear correlation coefficient of 0.99 between FBG wavelength shifts and axial strains, with total monitoring errors confined to below 11.5 % (hysteresis error ξH ≤ 10 %, linearity error ξL ≤ 3 %, repeatability error ξR ≤ 6.6 %). Notably, under ultimate loading conditions, the monitoring accuracy remained at 99.2 %, with sensors maintaining functionality until CFRP strand fracture, thereby validating the system's reliability for cable force monitoring in bridge engineering. Field validations conducted on the Liuheng Highway Bridge (Ningbo-Zhoushan Port) and the Anluo Yellow River Bridge demonstrated excellent monitoring performance, highlighting the system's promising potential for infrastructure health monitoring applications.
{"title":"Smart carbon fiber reinforced polymer (CFRP) strand: Mechanical properties, self-sensing characteristics, and engineering applications","authors":"Pan Li , Ying-Xuan Zhang , Rui-Xin Jia , Sheng-Jian Zhang , Li-Jun Fu , Shu-Wei Yuan , Yu Lin , Wei-Hong Ji , Yue Liu , T. Tafsirojjaman","doi":"10.1016/j.polymertesting.2025.109007","DOIUrl":"10.1016/j.polymertesting.2025.109007","url":null,"abstract":"<div><div>Conventional monitoring methods for steel cables often face limitations, such as insufficient measurement accuracy and suboptimal long-term reliability. Additionally, the inherent corrosion susceptibility of steel cables poses significant compatibility challenges with standard installation procedures for Fiber Bragg Grating (FBG) sensors. To address these issues, this study leverages the superior corrosion resistance and enhanced sensor compatibility of carbon fiber reinforced polymer (CFRP) composites. Specifically, smart CFRP strands were developed by embedding FBG sensors within the core of CFRP rods, followed by an extensive investigation of their fundamental mechanical properties. Smart composite cables were then fabricated by integrating these CFRP strands with conventional steel strands, imparting self-sensing capabilities to the hybrid system. This innovative configuration not only enhances the measurement accuracy of cable force monitoring but also significantly improves the long-term durability of embedded FBG sensors, thus achieving effective coupling between structural load-bearing and sensing functions. Quasi-static tensile tests conducted at 10 %–40 % of the maximum cable force (FC<sub>max</sub>) revealed a linear correlation coefficient of 0.99 between FBG wavelength shifts and axial strains, with total monitoring errors confined to below 11.5 % (hysteresis error ξ<sub>H</sub> ≤ 10 %, linearity error ξ<sub>L</sub> ≤ 3 %, repeatability error ξ<sub>R</sub> ≤ 6.6 %). Notably, under ultimate loading conditions, the monitoring accuracy remained at 99.2 %, with sensors maintaining functionality until CFRP strand fracture, thereby validating the system's reliability for cable force monitoring in bridge engineering. Field validations conducted on the Liuheng Highway Bridge (Ningbo-Zhoushan Port) and the Anluo Yellow River Bridge demonstrated excellent monitoring performance, highlighting the system's promising potential for infrastructure health monitoring applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 109007"},"PeriodicalIF":6.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363553","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 : 2025-10-17DOI: 10.1016/j.polymertesting.2025.109013
Tomaž Kek, Zoran Bergant, Roman Šturm
The acoustic and mechanical behavior of basalt fiber-reinforced bio-epoxy laminates under different loading angles are investigated, with a focus on damage evolution description through acoustic emission (AE) monitoring. Laminates with different fiber orientations, quasi-isotropic [45/–45/0/90]2S and angle-ply [45/–45]4S were tested using an adapted Arcan fixture for simultaneous AE monitoring. A novel ellipsoidal visualization method is introduced to represent AE signal parameters, enabling a more intuitive interpretation of parameter magnitudes and trends. The study demonstrates that these ellipsoidal AE patterns enhance early damage detection and reveal shifts in AE responses corresponding to various stress states. The integration of AE monitoring with digital image correlation (DIC) and microscopy analysis provides complementary insights into failure mechanisms. Neural network classification of AE signals by normalized force regions confirms strong discriminative capability, particularly in the nonlinear loading phase where significant energy release events occur. The AE parameter transitions near peak load show consistent trends across both laminate types, with differences observed in the intensity of parameter shifts. The findings highlight the potential of AE monitoring as advanced diagnostics in sustainable fiber-reinforced composites.
{"title":"Ellipsoidal acoustic emission patterns in basalt bio-epoxy laminates under different loading angles","authors":"Tomaž Kek, Zoran Bergant, Roman Šturm","doi":"10.1016/j.polymertesting.2025.109013","DOIUrl":"10.1016/j.polymertesting.2025.109013","url":null,"abstract":"<div><div>The acoustic and mechanical behavior of basalt fiber-reinforced bio-epoxy laminates under different loading angles are investigated, with a focus on damage evolution description through acoustic emission (AE) monitoring. Laminates with different fiber orientations, quasi-isotropic [45/–45/0/90]<sub>2S</sub> and angle-ply [45/–45]<sub>4S</sub> were tested using an adapted Arcan fixture for simultaneous AE monitoring. A novel ellipsoidal visualization method is introduced to represent AE signal parameters, enabling a more intuitive interpretation of parameter magnitudes and trends. The study demonstrates that these ellipsoidal AE patterns enhance early damage detection and reveal shifts in AE responses corresponding to various stress states. The integration of AE monitoring with digital image correlation (DIC) and microscopy analysis provides complementary insights into failure mechanisms. Neural network classification of AE signals by normalized force regions confirms strong discriminative capability, particularly in the nonlinear loading phase where significant energy release events occur. The AE parameter transitions near peak load show consistent trends across both laminate types, with differences observed in the intensity of parameter shifts. The findings highlight the potential of AE monitoring as advanced diagnostics in sustainable fiber-reinforced composites.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 109013"},"PeriodicalIF":6.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363554","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 : 2025-10-16DOI: 10.1016/j.polymertesting.2025.109008
Wenyang Zhang , Wei Cai , Jin Chen , Yongli Liu , Lingzhi Li , Jiangao Shi , Yanfeng Niu
The gel-spun ultrahigh molecular weight polyethylene (UHMWPE) fiber has attracted widespread attention due to its low density and superior high strength and modulus. However, its limited antibacterial properties impede its development and high-end application in fields like ocean engineering and medical health. This study investigates the structure and properties of UHMWPE fibers modified with polypropylene-grafted poly(hexamethylene guanidine) (PP-g-PHMG). We show that PP-g-PHMG migrates from the UHMWPE matrix to the fiber surface during the super-stretching process, thus enriching the surface with PP-g-PHMG on the UHMWPE fibers. The resulting UHMWPE fibers added with a small amount of PP-g-PHMG (UPE-10 %) exhibit excellent antibacterial properties while maintaining their mechanical strength with minimal compromise. This study provides a method for preparing antibacterial UHMWPE fibers that effectively balance desirable traits, including tensile strength and excellent antibacterial properties. A schematic diagram was proposed to describe the surface enrichment behavior of PP-g-PHMG modified UHMWPE fibers and their antibacterial properties.
{"title":"Surface enrichment behavior and properties of polypropylene-grafted poly(hexamethylene guanidine) modified ultrahigh molecular weight polyethylene fibers","authors":"Wenyang Zhang , Wei Cai , Jin Chen , Yongli Liu , Lingzhi Li , Jiangao Shi , Yanfeng Niu","doi":"10.1016/j.polymertesting.2025.109008","DOIUrl":"10.1016/j.polymertesting.2025.109008","url":null,"abstract":"<div><div>The gel-spun ultrahigh molecular weight polyethylene (UHMWPE) fiber has attracted widespread attention due to its low density and superior high strength and modulus. However, its limited antibacterial properties impede its development and high-end application in fields like ocean engineering and medical health. This study investigates the structure and properties of UHMWPE fibers modified with polypropylene-grafted poly(hexamethylene guanidine) (PP-<em>g</em>-PHMG). We show that PP-<em>g</em>-PHMG migrates from the UHMWPE matrix to the fiber surface during the super-stretching process, thus enriching the surface with PP-<em>g</em>-PHMG on the UHMWPE fibers. The resulting UHMWPE fibers added with a small amount of PP-<em>g</em>-PHMG (UPE-10 %) exhibit excellent antibacterial properties while maintaining their mechanical strength with minimal compromise. This study provides a method for preparing antibacterial UHMWPE fibers that effectively balance desirable traits, including tensile strength and excellent antibacterial properties. A schematic diagram was proposed to describe the surface enrichment behavior of PP-<em>g</em>-PHMG modified UHMWPE fibers and their antibacterial properties.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 109008"},"PeriodicalIF":6.0,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363550","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 : 2025-10-15DOI: 10.1016/j.polymertesting.2025.108995
Eva Munio , Frédéric Coste , Martina Ridlova , Nicolas Gallienne , Emmanuel Richaud
Understanding the ignition behaviour of polymers in oxygen-enriched atmospheres is critical for safety in various high-performance demanding applications. This work presents a novel experimental approach using a laser source for controlled, localized energy deposition to simulate ignition events. Coupled with thermal and high-speed cameras, this technique allows for the detailed monitoring of material changes and ignition time in pressurized oxygen environment. This methodology was employed to investigate the influence of thermo-oxidative ageing at 80 and 100 °C, on the ignition properties of polychloroprene (CR). To understand the ageing mechanisms, a multi-scale characterization combining DSC, DMA, and swelling tests was performed. The results indicate that the ageing process involves first antioxidant consumption together with plasticizer evaporation. Crosslinking occur when antioxidants are totally consumed. These physico-chemical modifications significantly alter the material’s ignition behaviour. Plasticizer loss reduces the reactivity of the gas phase generated during heating, while the formation of a crosslinked network inhibits thermal decomposition pathways, thus limiting the release of flammable volatiles and ultimately enhancing the ignition resistance of the aged material.
{"title":"Thermal ageing of polychloroprene - Effect on laser induced ignition","authors":"Eva Munio , Frédéric Coste , Martina Ridlova , Nicolas Gallienne , Emmanuel Richaud","doi":"10.1016/j.polymertesting.2025.108995","DOIUrl":"10.1016/j.polymertesting.2025.108995","url":null,"abstract":"<div><div>Understanding the ignition behaviour of polymers in oxygen-enriched atmospheres is critical for safety in various high-performance demanding applications. This work presents a novel experimental approach using a laser source for controlled, localized energy deposition to simulate ignition events. Coupled with thermal and high-speed cameras, this technique allows for the detailed monitoring of material changes and ignition time in pressurized oxygen environment. This methodology was employed to investigate the influence of thermo-oxidative ageing at 80 and 100 °C, on the ignition properties of polychloroprene (CR). To understand the ageing mechanisms, a multi-scale characterization combining DSC, DMA, and swelling tests was performed. The results indicate that the ageing process involves first antioxidant consumption together with plasticizer evaporation. Crosslinking occur when antioxidants are totally consumed. These physico-chemical modifications significantly alter the material’s ignition behaviour. Plasticizer loss reduces the reactivity of the gas phase generated during heating, while the formation of a crosslinked network inhibits thermal decomposition pathways, thus limiting the release of flammable volatiles and ultimately enhancing the ignition resistance of the aged material.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"152 ","pages":"Article 108995"},"PeriodicalIF":6.0,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363551","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 : 2025-10-14DOI: 10.1016/j.polymertesting.2025.109006
Vincent Boulic , Dhahabia Abdallah Boina , Mariapaola Staropoli , Stephan Westermann , Pierre Verge , Daniel Frederick Schmidt , Frédéric Addiego
Vitrimers are a type of crosslinked polymer that can undergo mechanical recycling – one of the simplest and most efficient reprocessing methods. An easy way to implement this method consists of grinding the vitrimer into millimeter-sized particles, followed by compression-molding at a temperature high enough to both exceed the glass transition temperature and enable rapid associative covalent bond exchange, but low enough to avoid thermal degradation. In spite of the facile nature of the process, many open questions remain, including how reconsolidation occurs and how the reconsolidated material behaves. This study uses a design-of-experiments approach to investigate the structural rearrangements of a polybenzoxazine (PBz) vitrimer during mechanical recycling as a function of reprocessing parameters. Through the application of micro-computed X-ray tomography (μCT), it is found that particle size is the most important factor controlling porosity, followed by the compression-molding temperature. However, if the compression-molding temperature and/or time are too high, this can induce cracks in the material due to degradation. The mechanisms of pore closure have been investigated as a function of time by considering the correlation between pore volume and sphericity, with three successive steps revealed. It is further demonstrated that increasing the dynamic bond content in the vitrimer significantly decreases the porosity after reprocessing. Overall, this work shows that, under well-defined preparation and reprocessing conditions, pore-free recycled vitrimers can be obtained, which is highly desirable to retain the mechanical properties of the non-recycled vitrimer.
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