Pub Date : 2026-03-01Epub Date: 2026-02-14DOI: 10.1016/j.polymertesting.2026.109109
Jingbo Ma , Yinting Guo
This study establishes a synergistic multi-component strategy to engineer fully bio-based, high-performance gelatin composite foams. By strategically integrating l-carrageenan(l-car), pectin, chitosan, sucrose, and microbial transglutaminase (mTG), we achieve tailored control over material properties. The incorporation of sucrose significantly enhanced thermal stability, elevating the melting point from 39.3 °C (pure gelatin) to 41.25 °C. Mechanically, all additives except mTG improved the compressive modulus and strength, with chitosan yielding the highest performance due to polyelectrolyte complex formation. Importantly, a quantitative power-law model reveals that foam expansion is governed by the competition between viscosity and gelation kinetics. These findings provide a versatile design paradigm for fabricating sustainable, tailorable bio-foams, offering a promising alternative to conventional polymer foams in packaging and insulation applications.
{"title":"Synergistic enhancement of foaming and thermal properties of gelatin based composite gel foam by blending biopolymers","authors":"Jingbo Ma , Yinting Guo","doi":"10.1016/j.polymertesting.2026.109109","DOIUrl":"10.1016/j.polymertesting.2026.109109","url":null,"abstract":"<div><div>This study establishes a synergistic multi-component strategy to engineer fully bio-based, high-performance gelatin composite foams. By strategically integrating l-carrageenan(l-car), pectin, chitosan, sucrose, and microbial transglutaminase (mTG), we achieve tailored control over material properties. The incorporation of sucrose significantly enhanced thermal stability, elevating the melting point from 39.3 °C (pure gelatin) to 41.25 °C. Mechanically, all additives except mTG improved the compressive modulus and strength, with chitosan yielding the highest performance due to polyelectrolyte complex formation. Importantly, a quantitative power-law model reveals that foam expansion is governed by the competition between viscosity and gelation kinetics. These findings provide a versatile design paradigm for fabricating sustainable, tailorable bio-foams, offering a promising alternative to conventional polymer foams in packaging and insulation applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109109"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404666","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 : 2026-03-01Epub Date: 2026-02-24DOI: 10.1016/j.polymertesting.2026.109122
Yanhui Wei , Zeyu Wang , Renyou Li , Meng Wang , Defeng Zang , Guochang Li
Insulation defects in high-voltage cable accessories easily induce partial discharge and even severe faults under sustained electrical stress, threatening cable line safe operation directly. However, existing defect detection methods are difficult to accurately identify early latent defects and are susceptible to electromagnetic interference. This study aims to clarify the influence law of insulation defects on ultrasonic characteristics, reveal the propagation mechanism of ultrasonic waves in insulating materials with defects, and establish a correlation relationship between ultrasonic characteristics and insulation performance. The research takes XLPE (cross-linked polyethylene), SIR (silicone rubber), and SEMI (semiconductive material) as objects, artificially prepares single-layer (XLPE, SIR) and double-layer composite (XLPE/SIR, XLPE/SEMI, SIR/SEMI) insulation samples with bubble defects. The experimental results show that samples with bubble defects produce obvious defect echoes, with amplitudes of 10% to 20% of the incident wave, and the ultrasonic amplitude attenuation of XLPE is greater than that of SIR. Defects cause the leakage current of insulating materials to increase by 67.22% to 81.49%, and the breakdown strength to decrease by 11.53% to 30.33%, which is closely related to the accumulation of charges at the defect site. The simulation results reveal that the semi-crystalline structure of XLPE enhances ultrasonic absorption attenuation, and the generation of defect echoes is due to the significant difference in acoustic impedance between the defect and the insulating material. The correlation relationship between ultrasonic characteristics and insulation performance in this study provides a theoretical basis for the early identification and state assessment of insulation defects in cable accessories.
{"title":"Ultrasonic characteristics of compound interface defects of high voltage cable accessory and its correlation with insulation properties","authors":"Yanhui Wei , Zeyu Wang , Renyou Li , Meng Wang , Defeng Zang , Guochang Li","doi":"10.1016/j.polymertesting.2026.109122","DOIUrl":"10.1016/j.polymertesting.2026.109122","url":null,"abstract":"<div><div>Insulation defects in high-voltage cable accessories easily induce partial discharge and even severe faults under sustained electrical stress, threatening cable line safe operation directly. However, existing defect detection methods are difficult to accurately identify early latent defects and are susceptible to electromagnetic interference. This study aims to clarify the influence law of insulation defects on ultrasonic characteristics, reveal the propagation mechanism of ultrasonic waves in insulating materials with defects, and establish a correlation relationship between ultrasonic characteristics and insulation performance. The research takes XLPE (cross-linked polyethylene), SIR (silicone rubber), and SEMI (semiconductive material) as objects, artificially prepares single-layer (XLPE, SIR) and double-layer composite (XLPE/SIR, XLPE/SEMI, SIR/SEMI) insulation samples with bubble defects. The experimental results show that samples with bubble defects produce obvious defect echoes, with amplitudes of 10% to 20% of the incident wave, and the ultrasonic amplitude attenuation of XLPE is greater than that of SIR. Defects cause the leakage current of insulating materials to increase by 67.22% to 81.49%, and the breakdown strength to decrease by 11.53% to 30.33%, which is closely related to the accumulation of charges at the defect site. The simulation results reveal that the semi-crystalline structure of XLPE enhances ultrasonic absorption attenuation, and the generation of defect echoes is due to the significant difference in acoustic impedance between the defect and the insulating material. The correlation relationship between ultrasonic characteristics and insulation performance in this study provides a theoretical basis for the early identification and state assessment of insulation defects in cable accessories.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109122"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404671","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 : 2026-03-01Epub Date: 2026-02-10DOI: 10.1016/j.polymertesting.2026.109110
Oumaima Belcadi , Leila Khalij , Christophe Gautrelet , Catherine Legrand , Nicolas Desilles , Hassan El Minor , Fatima Ezzahra Arrakhiz
This study investigates vibration-induced fatigue of polypropylene (PP) reinforced with argan nut shell (ANS) particles. Specimens were designed by finite-element modal and harmonic analyses to target resonant frequency while limiting self-heating. Fatigue tests using a vibration shaker setup were used to evaluate fatigue performance based on S-N curves and the Basquin's equation.
The results showed that the incorporation of ANS particles reduces fatigue resistance at high stress levels but improves it at low stress levels. Differential scanning calorimetry confirmed the nucleating effect of the particles through an increase in crystallinity, while dynamic mechanical analysis revealed a reduction in damping performance. These combined effects result in a stiffer material with reduced energy dissipation ability.
Scanning electron microscopy (SEM) was used to observe crack initiation and propagation at the matrix-particle interface, revealing that the main fracture mechanisms were interfacial decohesion, void formation, and micro-shear bands. These findings emphasized the dual role of ANS particles: while they enhance stiffness and fatigue stability at low stress levels, they also make the material more brittle and cause local stress concentration.
{"title":"Vibration-induced fatigue behavior and damage mechanisms of polypropylene-argan nut shell composites","authors":"Oumaima Belcadi , Leila Khalij , Christophe Gautrelet , Catherine Legrand , Nicolas Desilles , Hassan El Minor , Fatima Ezzahra Arrakhiz","doi":"10.1016/j.polymertesting.2026.109110","DOIUrl":"10.1016/j.polymertesting.2026.109110","url":null,"abstract":"<div><div>This study investigates vibration-induced fatigue of polypropylene (PP) reinforced with argan nut shell (ANS) particles. Specimens were designed by finite-element modal and harmonic analyses to target resonant frequency while limiting self-heating. Fatigue tests using a vibration shaker setup were used to evaluate fatigue performance based on S-N curves and the Basquin's equation.</div><div>The results showed that the incorporation of ANS particles reduces fatigue resistance at high stress levels but improves it at low stress levels. Differential scanning calorimetry confirmed the nucleating effect of the particles through an increase in crystallinity, while dynamic mechanical analysis revealed a reduction in damping performance. These combined effects result in a stiffer material with reduced energy dissipation ability.</div><div>Scanning electron microscopy (SEM) was used to observe crack initiation and propagation at the matrix-particle interface, revealing that the main fracture mechanisms were interfacial decohesion, void formation, and micro-shear bands. These findings emphasized the dual role of ANS particles: while they enhance stiffness and fatigue stability at low stress levels, they also make the material more brittle and cause local stress concentration.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109110"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404746","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}
Durable protein-resistant materials that perform reliably under physiological conditions are essential for medical and marine applications, where surface interactions with the fouling environment determine functionality. While zwitterionic polymers have shown excellent antifouling properties, their widespread application is limited by high cost, poor mechanical durability, and complex synthesis. In this study, we present a new class of polyurethane (PU) coatings incorporating a mixture of commercially available ionic chain extenders—2,2-bis(hydroxymethyl)propionic acid (DMPA) and N-methyldiethanolamine (MDEA)—as a durable and cost-effective alternative. By introducing equal amounts of positively and negatively charged monomers as separate functional groups, rather than covalently linked zwitterionic units, we demonstrate a simple and effective strategy for designing biocompatible and antifouling coatings. Mixing independent ionic monomers as separate groups (rather than covalently linked zwitterionic units) represents a new design concept that has not been systematically explored for either thermoplastic or thermoset PUs. The resulting uniform distribution of charged groups enables hydration-driven surface rearrangement that minimizes protein adsorption while preserving mechanical integrity. Polyurethanes with 10% charged-group content, optimized in both thermoplastic and thermoset architectures, exhibit excellent biocompatibility, enhanced mechanical performance, and reduced material cost compared to zwitterionic systems. Spectroscopic (ATR-FTIR, NMR) and morphological (AFM) analyses confirm the uniform integration of charged groups, promoting hydration-driven surface rearrangement. Thermoset PUs, in particular, combine high tensile strength (>12 MPa), remarkable flexibility (>900% elongation), and low water uptake (<5 wt%). Both material types exhibit strong biocompatibility, hemocompatibility, and excellent protein adsorption resistance (∼95% decrease). This work provides a simple yet effective approach for developing robust, biocompatible materials for protein-resistant coatings.
{"title":"A mixed-charged monomer approach to robust protein-resistant polyurethane coatings","authors":"Fatemeh Jafari , Alireza Mahjub , Helma Vakili , Hassan Ghermezcheshme , Atefeh Zarepour , Ali Zarrabi , Atefeh Derakhshani , Hossein Ghanbari , Hesam Makki","doi":"10.1016/j.polymertesting.2026.109137","DOIUrl":"10.1016/j.polymertesting.2026.109137","url":null,"abstract":"<div><div>Durable protein-resistant materials that perform reliably under physiological conditions are essential for medical and marine applications, where surface interactions with the fouling environment determine functionality. While zwitterionic polymers have shown excellent antifouling properties, their widespread application is limited by high cost, poor mechanical durability, and complex synthesis. In this study, we present a new class of polyurethane (PU) coatings incorporating a mixture of commercially available ionic chain extenders—2,2-bis(hydroxymethyl)propionic acid (DMPA) and N-methyldiethanolamine (MDEA)—as a durable and cost-effective alternative. By introducing equal amounts of positively and negatively charged monomers as separate functional groups, rather than covalently linked zwitterionic units, we demonstrate a simple and effective strategy for designing biocompatible and antifouling coatings. Mixing independent ionic monomers as separate groups (rather than covalently linked zwitterionic units) represents a new design concept that has not been systematically explored for either thermoplastic or thermoset PUs. The resulting uniform distribution of charged groups enables hydration-driven surface rearrangement that minimizes protein adsorption while preserving mechanical integrity. Polyurethanes with 10% charged-group content, optimized in both thermoplastic and thermoset architectures, exhibit excellent biocompatibility, enhanced mechanical performance, and reduced material cost compared to zwitterionic systems. Spectroscopic (ATR-FTIR, NMR) and morphological (AFM) analyses confirm the uniform integration of charged groups, promoting hydration-driven surface rearrangement. Thermoset PUs, in particular, combine high tensile strength (>12 MPa), remarkable flexibility (>900% elongation), and low water uptake (<5 wt%). Both material types exhibit strong biocompatibility, hemocompatibility, and excellent protein adsorption resistance (∼95% decrease). This work provides a simple yet effective approach for developing robust, biocompatible materials for protein-resistant coatings.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109137"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404668","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 : 2026-03-01Epub Date: 2026-02-25DOI: 10.1016/j.polymertesting.2026.109125
Changjin Yang , Ruocan Liu , Yubao Chen , Xijuan Li , Shuangquan Liao , Lingxue Kong , Zheng Peng , Jihua Li
Natural rubber (NR) owes its exceptional mechanical properties to strain-induced crystallization (SIC), a phenomenon strongly influenced by molecular structure. Mastication, a crucial processing step, reduces raw NR molecular weight via chain scission, yet its effects on SIC and mechanical performance remain incompletely understood. This study systematically investigates how mastication-induced molecular weight reduction modulates SIC and the mechanical properties of NR. We varied mastication degrees (via controlled passes on a two-roll mill) to obtain NR samples with different molecular weights. SIC behavior was characterized using in-situ wide-angle X-ray scattering (WAXS). Mechanical properties, including static tensile, hardness, and tear strength, were also evaluated. Results of cure characteristics showed that reducing molecular weight via mastication prolongs scorch time TS1 and cure time T90 while regulating cure rate index. Results of WAXS showed that reducing molecular weight hinders SIC. Specifically, samples with higher molecular weight (less intensive mastication) exhibited more extensive and rapid SIC under tension, correlating with superior tensile strength, tear resistance, and modulus. In contrast, lower molecular weight (more intensive mastication) improved processability but compromised SIC-driven mechanical performance. This work establishes a clear mechanistic link between mastication-induced molecular weight changes, SIC, and mechanical properties of NR. These findings offer practical guidelines for optimizing mastication processes to balance NR processability and mechanical performance, thereby advancing the design of high-performance NR products for diverse industrial applications.
{"title":"The impact of mastication-induced molecular weight reduction on the strain-induced crystallization and mechanical properties of natural rubber","authors":"Changjin Yang , Ruocan Liu , Yubao Chen , Xijuan Li , Shuangquan Liao , Lingxue Kong , Zheng Peng , Jihua Li","doi":"10.1016/j.polymertesting.2026.109125","DOIUrl":"10.1016/j.polymertesting.2026.109125","url":null,"abstract":"<div><div>Natural rubber (NR) owes its exceptional mechanical properties to strain-induced crystallization (SIC), a phenomenon strongly influenced by molecular structure. Mastication, a crucial processing step, reduces raw NR molecular weight via chain scission, yet its effects on SIC and mechanical performance remain incompletely understood. This study systematically investigates how mastication-induced molecular weight reduction modulates SIC and the mechanical properties of NR. We varied mastication degrees (via controlled passes on a two-roll mill) to obtain NR samples with different molecular weights. SIC behavior was characterized using in-situ wide-angle X-ray scattering (WAXS). Mechanical properties, including static tensile, hardness, and tear strength, were also evaluated. Results of cure characteristics showed that reducing molecular weight via mastication prolongs scorch time T<sub>S1</sub> and cure time T<sub>90</sub> while regulating cure rate index. Results of WAXS showed that reducing molecular weight hinders SIC. Specifically, samples with higher molecular weight (less intensive mastication) exhibited more extensive and rapid SIC under tension, correlating with superior tensile strength, tear resistance, and modulus. In contrast, lower molecular weight (more intensive mastication) improved processability but compromised SIC-driven mechanical performance. This work establishes a clear mechanistic link between mastication-induced molecular weight changes, SIC, and mechanical properties of NR. These findings offer practical guidelines for optimizing mastication processes to balance NR processability and mechanical performance, thereby advancing the design of high-performance NR products for diverse industrial applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109125"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404669","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 : 2026-03-01Epub Date: 2026-03-02DOI: 10.1016/j.polymertesting.2026.109136
Jiahui Zhang, Minqiao Ren, Yutao Wang, Junpeng Zheng, Shijun Zhang, Longgui Zhang, Juan Li
Strain-induced crystallization (SIC) could be promoted by the presence of physical entanglement network within polymer systems with high regularity in molecular chain structure. However, such effect is not fully investigated within systems with lower chain structural regularity and inferior crystallization ability. In this study, hydrogenated nitrile butadiene rubber (HNBR) samples with varying molecular weights but share a similar acrylonitrile content of 37 wt% were used to investigate the influence of molecular weight on stretching orientation and SIC behaviors of HNBR by using polarized Fourier transform infrared spectroscopy (polarized FTIR) and two dimensional wide angle X-ray diffraction (2D WAXD) technique. Different chemical units within HNBR chain exhibited similar orientation degrees during stretching, implying a uniform orientation of molecular chains under strain. A positive correlation was obtained between the degree of whole chain orientation and molecular weight of HNBR. HNBR samples with Weight-average Molecular Weight (MW) of 14.6 × g/mol and 32.5 × g/mol could not crystallize under strain. When MW was high enough (52.7 × g/mol), SIC occurred and presenting improved crystallization ability, where the crystal was composed of hydrogenated butadiene–acrylonitrile alternating copolymer segments. Higher degree of molecular chain orientation under strain induced by physical entanglement network of long-chain molecules was thought to account for the enhancement of SIC in HNBR-37.
{"title":"Effect of molecular weight on the molecular chain orientation and strain-induced crystallization behaviors of HNBR under uniaxial stretching","authors":"Jiahui Zhang, Minqiao Ren, Yutao Wang, Junpeng Zheng, Shijun Zhang, Longgui Zhang, Juan Li","doi":"10.1016/j.polymertesting.2026.109136","DOIUrl":"10.1016/j.polymertesting.2026.109136","url":null,"abstract":"<div><div>Strain-induced crystallization (SIC) could be promoted by the presence of physical entanglement network within polymer systems with high regularity in molecular chain structure. However, such effect is not fully investigated within systems with lower chain structural regularity and inferior crystallization ability. In this study, hydrogenated nitrile butadiene rubber (HNBR) samples with varying molecular weights but share a similar acrylonitrile content of <span><math><mo>∼</mo></math></span>37 wt% were used to investigate the influence of molecular weight on stretching orientation and SIC behaviors of HNBR by using polarized Fourier transform infrared spectroscopy (polarized FTIR) and two dimensional wide angle X-ray diffraction (2D WAXD) technique. Different chemical units within HNBR chain exhibited similar orientation degrees during stretching, implying a uniform orientation of molecular chains under strain. A positive correlation was obtained between the degree of whole chain orientation and molecular weight of HNBR. HNBR samples with Weight-average Molecular Weight (MW) of 14.6 × <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> g/mol and 32.5 × <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> g/mol could not crystallize under strain. When MW was high enough (52.7 × <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> g/mol), SIC occurred and presenting improved crystallization ability, where the crystal was composed of hydrogenated butadiene–acrylonitrile alternating copolymer segments. Higher degree of molecular chain orientation under strain induced by physical entanglement network of long-chain molecules was thought to account for the enhancement of SIC in HNBR-37.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109136"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404674","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 : 2026-03-01Epub Date: 2026-02-25DOI: 10.1016/j.polymertesting.2026.109126
Phillipp A.B. Braeuer , Leo A. Bahr , Edgar Mayer , Maximilian Marschall , Michael Schmidt , Stefan Will
The absorption of laser energy during laser transmission welding (LTW) of certain thermoplastics such as isotactic polypropylene (iPP) affects their three-phase morphology (TPM) – comprised of crystalline (CF), mobile amorphous (MAF) and rigid-amorphous phase fractions (RAF) – and thus their mechanical properties, which are relevant for their production, processing and application. Therefore, this study serves to establish a spatially resolved and quantitative diagnostic to generate deeper insights into the cause-and-effect relationships between LTW parameters and the resulting TPM in iPP. Raman spectroscopy is developed as a quantitative TPM measurement technique in iPP. To that end, in situ Raman measurements are performed during the melting and crystallization of iPP. A spectral reconstruction routine is applied to the spectra to create a setup-independent Raman peak model. Furthermore, an improved Raman TPM model is established via model selection leveraging the Bayesian Information Criterion. The developed models are then applied to determine the effect of different LTW line energies on the local TPM in iPP welds using spatially resolved Raman microscopic line-focus mapping. Compared to the laser-unaffected iPP, the weld core shows a decrease in the CF, but an increase in the RAF and MAF contributions. For high line energies this effect is less pronounced as the system is given more time for crystallization after melting. In effect, higher line energies are advantageous to achieve a similar TPM in both the weld core and adjacent non-irradiated iPP.
{"title":"Determination of the local three-phase morphology in laser transmission weld seams of isotactic polypropylene by Raman microscopic line-focus mapping","authors":"Phillipp A.B. Braeuer , Leo A. Bahr , Edgar Mayer , Maximilian Marschall , Michael Schmidt , Stefan Will","doi":"10.1016/j.polymertesting.2026.109126","DOIUrl":"10.1016/j.polymertesting.2026.109126","url":null,"abstract":"<div><div>The absorption of laser energy during laser transmission welding (LTW) of certain thermoplastics such as isotactic polypropylene (iPP) affects their three-phase morphology (TPM) – comprised of crystalline (CF), mobile amorphous (MAF) and rigid-amorphous phase fractions (RAF) – and thus their mechanical properties, which are relevant for their production, processing and application. Therefore, this study serves to establish a spatially resolved and quantitative diagnostic to generate deeper insights into the cause-and-effect relationships between LTW parameters and the resulting TPM in iPP. Raman spectroscopy is developed as a quantitative TPM measurement technique in iPP. To that end, <em>in situ</em> Raman measurements are performed during the melting and crystallization of iPP. A spectral reconstruction routine is applied to the spectra to create a setup-independent Raman peak model. Furthermore, an improved Raman TPM model is established via model selection leveraging the Bayesian Information Criterion. The developed models are then applied to determine the effect of different LTW line energies on the local TPM in iPP welds using spatially resolved Raman microscopic line-focus mapping. Compared to the laser-unaffected iPP, the weld core shows a decrease in the CF, but an increase in the RAF and MAF contributions. For high line energies this effect is less pronounced as the system is given more time for crystallization after melting. In effect, higher line energies are advantageous to achieve a similar TPM in both the weld core and adjacent non-irradiated iPP.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109126"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404676","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 : 2026-03-01Epub Date: 2026-02-25DOI: 10.1016/j.polymertesting.2026.109132
Bincan Deng , Fernando López Lasaosa , Dingding Chen , Caimiao Zheng , Yiyan He , Chen Xuan , Yuwen Cui , Manuel Doblaré
- Hyaluronic acid methacrylate (HAMA)/gelatin methacrylate (GelMA) hybrid hydrogels are extensively utilized in biomanufacturing and tissue engineering, where their rheological properties are determinants of bioprintability and functional performance. However, optimizing these behaviors remains challenging due to the complex nonlinearity and high-dimensional design space defined by hydrogel concentration and temperature. Compared with previous machine-learning studies on hydrogel systems that primarily perform forward prediction of rheological or mechanical properties, here we introduce an interactive Bayesian optimization (IBO) framework that integrates Bayesian optimization with both an environment model and a discriminative model to optimize concentration–temperature values to achieve a target viscosity. The multilayer perceptron–based environment model here proposed exhibits high predictive performance (R2 ≥ 0.994, RMSE = 4.68), while the support vector machine–based discriminator achieved F1 > 0.95 and AUC >0.998 in distinguishing thermosensitive regions. Through feedback-driven iterations, IBO improved efficiency and robustness in targeting viscosity, with its mean value converging from 66.01 ± 8.76 Pa s to 51.81 ± 4.38 Pa s across three rounds, reaching a qualified rate of 80%. Even under a constrained HAMA content of 0.40% (w/v), IBO generated near-target viscosities (47.64–49.64 Pa s). These results collectively demonstrate that IBO can efficiently navigate complex, nonlinear rheological landscapes and reliably converge toward user-defined performance targets with low experimental data cost, while maintaining robustness under practical formulation constraints, thereby enabling efficient and directed formulation design. Overall, IBO provides an efficient, reliable, and scalable paradigm for viscosity-guided formulation design of HAMA/GelMA hybrid hydrogels, with potential applicability to soft matter and polymer systems. These findings can further assist in developing hydrogel formulations with improved printability and performance in biomanufacturing and related biomedical applications.
透明质酸甲基丙烯酸酯(HAMA)/明胶甲基丙烯酸酯（GelMA）混合水凝胶广泛应用于生物制造和组织工程，其流变性能是生物可打印性和功能性能的决定因素。然而，由于复杂的非线性和由水凝胶浓度和温度定义的高维设计空间，优化这些行为仍然具有挑战性。与之前针对水凝胶系统的机器学习研究主要进行流变学或力学性质的前向预测相比，本研究引入了一种交互式贝叶斯优化（IBO）框架，该框架将贝叶斯优化与环境模型和判别模型相结合，以优化浓度-温度值以实现目标粘度。本文提出的基于多层感知器的环境模型具有较高的预测性能（R2 ≥ 0.994,RMSE = 4.68），而基于支持向量机的鉴别器在区分热敏区域时达到F1 >； 0.95和AUC >；0.998。通过反馈驱动迭代，IBO提高了瞄准粘度的效率和鲁棒性，三轮迭代的平均值从66.01 ± 8.76 Pa s收敛到51.81 ± 4.38 Pa s，合格率达到80%。即使在限制HAMA含量为0.40% （w/v）的情况下，IBO也能产生接近目标的粘度（47.64-49.64 Pa s）。这些结果共同表明，IBO可以有效地导航复杂的非线性流变景观，并以较低的实验数据成本可靠地收敛于用户定义的性能目标，同时在实际配方约束下保持鲁棒性，从而实现高效和定向的配方设计。总的来说，IBO为黏度导向的HAMA/GelMA混合水凝胶配方设计提供了一种高效、可靠、可扩展的范例，具有适用于软物质和聚合物体系的潜力。这些发现可以进一步帮助开发在生物制造和相关生物医学应用中具有更好的可打印性和性能的水凝胶配方。
{"title":"An interactive Bayesian optimization framework for intelligent design of HAMA/GelMA hybrid hydrogels","authors":"Bincan Deng , Fernando López Lasaosa , Dingding Chen , Caimiao Zheng , Yiyan He , Chen Xuan , Yuwen Cui , Manuel Doblaré","doi":"10.1016/j.polymertesting.2026.109132","DOIUrl":"10.1016/j.polymertesting.2026.109132","url":null,"abstract":"<div><div>- Hyaluronic acid methacrylate (HAMA)/gelatin methacrylate (GelMA) hybrid hydrogels are extensively utilized in biomanufacturing and tissue engineering, where their rheological properties are determinants of bioprintability and functional performance. However, optimizing these behaviors remains challenging due to the complex nonlinearity and high-dimensional design space defined by hydrogel concentration and temperature. Compared with previous machine-learning studies on hydrogel systems that primarily perform forward prediction of rheological or mechanical properties, here we introduce an interactive Bayesian optimization (IBO) framework that integrates Bayesian optimization with both an environment model and a discriminative model to optimize concentration–temperature values to achieve a target viscosity. The multilayer perceptron–based environment model here proposed exhibits high predictive performance (R<sup>2</sup> ≥ 0.994, RMSE = 4.68), while the support vector machine–based discriminator achieved F1 > 0.95 and AUC >0.998 in distinguishing thermosensitive regions. Through feedback-driven iterations, IBO improved efficiency and robustness in targeting viscosity, with its mean value converging from 66.01 ± 8.76 Pa s to 51.81 ± 4.38 Pa s across three rounds, reaching a qualified rate of 80%. Even under a constrained HAMA content of 0.40% (w/v), IBO generated near-target viscosities (47.64–49.64 Pa s). These results collectively demonstrate that IBO can efficiently navigate complex, nonlinear rheological landscapes and reliably converge toward user-defined performance targets with low experimental data cost, while maintaining robustness under practical formulation constraints, thereby enabling efficient and directed formulation design. Overall, IBO provides an efficient, reliable, and scalable paradigm for viscosity-guided formulation design of HAMA/GelMA hybrid hydrogels, with potential applicability to soft matter and polymer systems. These findings can further assist in developing hydrogel formulations with improved printability and performance in biomanufacturing and related biomedical applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109132"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404613","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 : 2026-03-01Epub Date: 2026-02-27DOI: 10.1016/j.polymertesting.2026.109134
Tianyu Gao , Hui Yan , Kehai Long , Wenjun Xu , Hao Wang , Xinyuan Long , Yifan Li , Zheng Qin
This study quantifies how architecture and fillers govern the compressive and energy-absorption behavior of LCD-photopolymerized P-type TPMS lattices. Specimens with unit-cell sizes of 10–20 mm and volume fractions of 10–30% were LCD-printed. Carbon fibers and nano-hydroxyapatite were added as fillers. Mechanical response was evaluated by compression testing and supported by numerical simulations. Unfilled lattices showed overall geometric integrity with localized microporosity and a three-stage stress–strain response dominated by plastic dissipation. Increasing volume fraction raised compressive modulus, yield/ultimate strengths, and energy absorption; the l = 16.7 mm, 30% configuration provided the best overall performance. Under cyclic loading, higher volume fraction increased hysteretic energy at identical maximum strain, while 30% volume-fraction specimens exhibited reduced residual strain at higher maximum strains. Fillers yielded distinct reinforcement profiles. At equal contents, 50-mesh carbon fibers most effectively enhanced energy absorption via plateau extension; 500-mesh fibers primarily delivered modest strength gains; HAP (Hydroxyapatite)increased compressive modulus and ultimate strength with content but decreased yield strength, indicating toughness loss due to particle effects. Simulations reproduced the experimental trends and key stress-localization features. These findings provide design guidance for selecting unit-cell size, volume fraction, and filler systems to enhance strength and energy absorption of LCD-printed TPMS-P lattices within manufacturability constraints.
{"title":"Study on the reinforcement mechanism of LCD photopolymerization 3D-printed triply periodic minimal surface structures doped with carbon fiber and hydroxyapatite","authors":"Tianyu Gao , Hui Yan , Kehai Long , Wenjun Xu , Hao Wang , Xinyuan Long , Yifan Li , Zheng Qin","doi":"10.1016/j.polymertesting.2026.109134","DOIUrl":"10.1016/j.polymertesting.2026.109134","url":null,"abstract":"<div><div>This study quantifies how architecture and fillers govern the compressive and energy-absorption behavior of LCD-photopolymerized P-type TPMS lattices. Specimens with unit-cell sizes of 10–20 mm and volume fractions of 10–30% were LCD-printed. Carbon fibers and nano-hydroxyapatite were added as fillers. Mechanical response was evaluated by compression testing and supported by numerical simulations. Unfilled lattices showed overall geometric integrity with localized microporosity and a three-stage stress–strain response dominated by plastic dissipation. Increasing volume fraction raised compressive modulus, yield/ultimate strengths, and energy absorption; the l = 16.7 mm, 30% configuration provided the best overall performance. Under cyclic loading, higher volume fraction increased hysteretic energy at identical maximum strain, while 30% volume-fraction specimens exhibited reduced residual strain at higher maximum strains. Fillers yielded distinct reinforcement profiles. At equal contents, 50-mesh carbon fibers most effectively enhanced energy absorption via plateau extension; 500-mesh fibers primarily delivered modest strength gains; HAP (Hydroxyapatite)increased compressive modulus and ultimate strength with content but decreased yield strength, indicating toughness loss due to particle effects. Simulations reproduced the experimental trends and key stress-localization features. These findings provide design guidance for selecting unit-cell size, volume fraction, and filler systems to enhance strength and energy absorption of LCD-printed TPMS-P lattices within manufacturability constraints.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109134"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404672","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}
Understanding adhesion between fiber and matrix at elevated temperatures is essential for improving the mechanical performance of polymer-based composites, especially with thermoplastic matrices. However, detailed characterization of polymer surface tension and its polar and dispersive components as a function of temperature remains limited. In this work, reliable methods were set using the Wilhelmy plate and pendant drop approaches to investigate these properties against temperature. First, experimental procedures were developed, optimized, and validated through cross-comparison with reference liquids of known surface tension and components. Accurate and reproducible measurements were secondly achieved across a range of elevated temperatures for liquid polymers (polyethylene glycol, bio-based epoxy) and for molten thermoplastics (polypropylene, polylactic acid). The results reveal a linear decrease in surface tension with increasing temperature and contribute to a better understanding of fiber wetting phenomena. Additionally, a procedure was set to determine polymer dispersive and polar components as a function of temperature. Due to the volatility and thermal limitation of n-hexane used in interfacial tension measurements, alternative probe liquids were systematically evaluated. Silicone and paraffin oil were identified and validated as suitable replacements, enabling reliable measurements with polymers at high temperatures. These key findings demonstrate robust methodology for high-temperature surface characterization and provide essential data to understand fiber–matrix adhesion under realistic processing conditions.
{"title":"Estimation of the surface tension and dispersive and polar components of polymers as a function of temperature for composite manufacturing applications","authors":"Rami Alawar , Pierre-Jacques Liotier , Romain Ravel , Monica Francesca Pucci","doi":"10.1016/j.polymertesting.2026.109112","DOIUrl":"10.1016/j.polymertesting.2026.109112","url":null,"abstract":"<div><div>Understanding adhesion between fiber and matrix at elevated temperatures is essential for improving the mechanical performance of polymer-based composites, especially with thermoplastic matrices. However, detailed characterization of polymer surface tension and its polar and dispersive components as a function of temperature remains limited. In this work, reliable methods were set using the Wilhelmy plate and pendant drop approaches to investigate these properties against temperature. First, experimental procedures were developed, optimized, and validated through cross-comparison with reference liquids of known surface tension and components. Accurate and reproducible measurements were secondly achieved across a range of elevated temperatures for liquid polymers (polyethylene glycol, bio-based epoxy) and for molten thermoplastics (polypropylene, polylactic acid). The results reveal a linear decrease in surface tension with increasing temperature and contribute to a better understanding of fiber wetting phenomena. Additionally, a procedure was set to determine polymer dispersive and polar components as a function of temperature. Due to the volatility and thermal limitation of n-hexane used in interfacial tension measurements, alternative probe liquids were systematically evaluated. Silicone and paraffin oil were identified and validated as suitable replacements, enabling reliable measurements with polymers at high temperatures. These key findings demonstrate robust methodology for high-temperature surface characterization and provide essential data to understand fiber–matrix adhesion under realistic processing conditions.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"156 ","pages":"Article 109112"},"PeriodicalIF":6.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147404748","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号