Polymer Testing最新文献

{"title":"Facile grafting method achieves Unprecedented dispersion stability of carbon black in PP fiber","authors":"Yaoming Wang ,&nbsp;Guihao Liu ,&nbsp;Yuqing Liu ,&nbsp;Yiqing Zhang ,&nbsp;Guangtao Chang ,&nbsp;Ruoxin Li","doi":"10.1016/j.polymertesting.2025.108698","DOIUrl":"10.1016/j.polymertesting.2025.108698","url":null,"abstract":"<div><div>Carbon black (CB) offers valuable properties, but its tendency to agglomerate hinders its full potential in polymer applications. This study presents a novel and straightforward graft modification method to overcome this limitation. By covalently bonding organic functional groups to the CB surface, the surface energy of carbon black was significantly reduced and enhanced its compatibility with organic PP polymers. Characterization techniques (FTIR, XPS, Raman, TGA, etc.) confirm successful grafting and demonstrate excellent dispersion stability of modified CB in organic media. The modified CB exhibits uniform dispersion and reduced particle size within polypropylene (PP) fibers, leading to tensile strength increased dramatically from 103 MPa (unmodified) to 517 MPa (modified). Moreover, the strain reached 1086 %, exceeding both unmodified CB or commercial CB concentrate modified polypropylene (PP) fibers by 31 % and 11 %, respectively. This method represents a significant advancement over existing techniques by providing a straightforward and efficient approach to developing high-strength polypropylene fibers with exceptional tensile and strain characteristics for coloring synthetic fiber applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108698"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fiber Bragg grating in-situ detection method for curing characteristics of GIS epoxy/Al2O3 composite insulation materials","authors":"Yingying Zhang,&nbsp;Yanpeng Hao,&nbsp;Zikui Shen,&nbsp;Dongyuan Du,&nbsp;Hongru Mi","doi":"10.1016/j.polymertesting.2025.108701","DOIUrl":"10.1016/j.polymertesting.2025.108701","url":null,"abstract":"<div><div>Excessive residual strain generated by curing shrinkage of epoxy/Al₂O₃ composite insulation materials can reduce the mechanical properties of gas-insulated metal-enclosed switchgear (GIS) insulators. The process and formula optimization of insulators lack effective detection methods. A thermocouple-compensated fiber Bragg grating in-situ detection method for seven high-temperature curing characteristics is proposed. The curing shrinkage characteristics and residual strain generation mechanism of this material cured at 114 °C are studied. The cured residual strain is calculated by the total central wavelength shift of the grating and the thermocouple temperature change inside the sample at the end of the curing process. The curing degree, curing initiation time, and curing completion time are calculated by the temperature inside the sample and the surface temperature of the mold based on the law of thermal equilibrium. Gel time, gel temperature, and glass transition temperature are detected by linear fitting and differential analysis of the strain variation with temperature inside the sample based on the thermal expansion coefficient. Differential scanning calorimetry and SB(<em>m</em>, <em>n</em>) autocatalytic reaction model are used to calculate the curing kinetic equation and to comparatively verify the glass transition temperature and curing degree. The differences between the two test results of the glass transition temperature, curing initiation time, and curing completion time are 0.39 %, 11.2 %, and 17.6 %, respectively. The proposed method can be used for detecting and evaluating the processes and formulations of GIS insulators in the same batch of production samples and optimizing the processes and formulations.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108701"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy evolution characteristics and failure mechanism of coal confined by CFRP jackets subjected to different loading rates","authors":"Qingwen Li ,&nbsp;Mengjiao Xu ,&nbsp;Wenxia Li ,&nbsp;Chuangchuang Pan ,&nbsp;Mengmeng Yu","doi":"10.1016/j.polymertesting.2025.108723","DOIUrl":"10.1016/j.polymertesting.2025.108723","url":null,"abstract":"<div><div>To reveal the improvement effects of Carbon fiber reinforced polymer (CFRP) jackets on the strength and deformation characteristics of coal samples, and the energy transformation mechanism during the failure process of coal samples under different loading rates. In this study, uniaxial compression tests were conduct on 28 coal samples, the results indicated that both the loading rate and the number of CFRP layers significantly influenced the energy evolution process of the coal samples. The total energy growth ratio of coal samples confined by single and double layer of CFRP jackets ranging from 11.86 to 23.46 and 32.002–56.066, respectively, with the total energy at failure of the double layer samples being 1.8 times that of the single layer ones. The number of CFRP layers significantly enhances the total energy at the peak point and its growth ratio of the coal samples. At the minimum (maximum) loading rate, the growth ratio of the dissipation energy rate at the peak point decreases with the increase of CFRP layers. Additionally, the value at the maximum rate is approximately 6.03–8.87 times greater than that at the minimum rate. The elastic energy consumption ratio exhibited a ‘fishhook-shaped’ trend as axial deformation increased. The use of CFRP jackets can effectively improve the energy storage mechanism of coal samples. Therefore, studying the energy dissipation and failure behavior of CFRP confined coal samples subjected to different loading rates is crucial for reducing the risk of accidents caused by coal pillar instability.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108723"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complex cure kinetics of self-healing copolyester vitrimers via isothermal thermogravimetric analysis","authors":"Louis O. Vaught ,&nbsp;Jacob L. Meyer ,&nbsp;Omar El Arwadi ,&nbsp;Tanaya Mandal ,&nbsp;Ahmad Amiri ,&nbsp;Mohammad Naraghi ,&nbsp;Andreas A. Polycarpou","doi":"10.1016/j.polymertesting.2025.108724","DOIUrl":"10.1016/j.polymertesting.2025.108724","url":null,"abstract":"<div><div>Thermogravimetric Analysis (TGA) is a valuable tool for studying chemical reactions that release volatile compounds. Constant-temperature TGA can be particularly useful for polymer cure reactions with complex, time-evolving phenomenology, by ensuring time and temperature effects remain separable. In this work, a compound isothermal TGA methodology is developed to study the cure process of high-performance vitrimers known as Aromatic Thermosetting coPolyesters (ATSP). By fitting observed mass loss to a nondimensional phenomenological model with generalized terms and introducing additional nonphysical terms to account both known and suspected non-cure behaviors, changes in cure kinetics were evaluated across a wide range of temperatures (210°C–380 °C). The activation of the added nonphysical terms was used to differentiate between expected cure behavior (240°C–340 °C), and cures involving precursor decomposition (&gt;340 °C). An unexpected cure-like reaction below cure temperature (&lt;240 °C) was hypothesized to correspond to self-healing bond exchange, which is well-understood to cause changes in molecular weight in thermoplastic polyesters. This was directly validated via evolved gas analysis, and activation energies were calculated for the cure-dominant region of the reaction. These activation energies were found to be similar across different polymer formulations. When combined with significant observed mass loss below the expected cure temperature and findings in prior work, this indicates that the apparent cure process may be driven by thermodynamically-favorable bond exchange reactions.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108724"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143313090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of hard segment content on the phase separation and properties of hydroxyl-terminated polybutadiene thermoplastic polyurethane","authors":"Boxin Liu ,&nbsp;Zhihao Niu ,&nbsp;Zhanglei Wang ,&nbsp;Yimin Wang ,&nbsp;Hua Zou ,&nbsp;Xiuying Zhao ,&nbsp;Shikai Hu","doi":"10.1016/j.polymertesting.2024.108681","DOIUrl":"10.1016/j.polymertesting.2024.108681","url":null,"abstract":"<div><div>Thermoplastic polyurethane (TPU) possesses a distinctive microphase separation structure resulting from the thermodynamic incompatibility between its soft and hard segments. The content of hard segments is a significant factor that impacts the micromorphology and associated properties of TPU. In this study, hydroxyl-terminated polybutadiene thermoplastic polyurethanes (HTPB-TPUs) were synthesized using a two-step method in which hydroxyl-terminated polybutadiene, toluene diisocyanate, and 1,4-butanediol were incorporated. These HTPB-TPUs were designed to lack hydrogen bonding between the soft and hard segments. The structure and properties of the HTPB-TPUs were comprehensively evaluated. The results demonstrated a noticeable influence of the hard segment content on the degree of microphase separation. A combination of analytical techniques was employed to elucidate the effect of hard segment content on phase separation. Additionally, all-atom molecular dynamics simulations were conducted to determine the number of hydrogen bonds. These simulations served to verify the impact of the hard segment content on phase separation. Furthermore, the relationship between the hard segment content and the mechanical properties was elucidated by examining the phase separation phenomenon. This study provides valuable insights into the interaction between the structure and properties of TPU, laying a foundation for future investigations in this area.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108681"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study on taper preparation techniques for direct internal structure analysis of organic coatings applied on galvanized steel","authors":"D. Leidlmair ,&nbsp;J. Duchoslav ,&nbsp;S. Keppert ,&nbsp;G. Mayr ,&nbsp;J.D. Pedarnig ,&nbsp;H. Groiss ,&nbsp;B. Strauß ,&nbsp;G.M. Wallner ,&nbsp;D. Stifter","doi":"10.1016/j.polymertesting.2025.108716","DOIUrl":"10.1016/j.polymertesting.2025.108716","url":null,"abstract":"<div><div>Depth-resolved analysis of organic coatings delivers crucial information on the interior material structure, <em>e.g.,</em> on the formation of chemical gradients or on the impact of degradation processes. However, assessing the complex internal composition of modern heterogeneous paint systems requires a careful selection of suitable depth profiling methods. In this work, a comparative examination of four state-of-the-art preparation techniques for depth-resolved analysis, exemplified on a high-build polyester-polyurethane coating system applied on galvanized steel, is reported. The fabrication of wedge-shaped tapers by applying mechanical polishing, cryo-ultra-low-angle microtomy (cryo-ULAM), a standardised paint borer, and Ar⁺-ion flat milling was comprehensively evaluated with respect to determining preparation artefacts including smearing, plastic deformation or alterations of the exposed internal coating chemistry induced by the different techniques. To this purpose, 3D topographical imaging, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed to examine the resulting surface morphology of extended sections down to the steel substrate, which showed the displacement of material for the paint borer sections, while the polished samples contained grooves and smearing artefacts. Furthermore, correlative elemental and chemical analysis by Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) allowed to determine the impact of the respective preparation process on the bulk and surface chemistry of the exposed areas, <em>e.g.</em>, the loss of chemical information after Ar⁺-ion flat milling. Overall, the fabrication of extended tapers for depth profiling by cryo-ULAM is favourably recommended by the comprehensive in-depth investigation performed in this study, which serves as a valuable basis for the future internal structure analysis of organic coatings.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108716"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring the repair process of internal microdamages in thermoplastic composites using optical coherence tomography","authors":"Pinbo Huang ,&nbsp;Changhao Wang ,&nbsp;Weirui Zhang ,&nbsp;Zihao Ni ,&nbsp;Rufeng You","doi":"10.1016/j.polymertesting.2025.108689","DOIUrl":"10.1016/j.polymertesting.2025.108689","url":null,"abstract":"<div><div>The reliability of composite structures critically depends on effective damage repair. This study employs optical coherence tomography (OCT), a non-destructive imaging technique capable of generating cross-sectional images of translucent materials, to investigate the repair of early-stage microdamage in thermoplastic composites. Using electrical resistance heating, the healing of a microscale void in a carbon fiber-reinforced ethylene-vinyl acetate (EVA) polymer sample was monitored through OCT-derived scattered light intensity and phase difference measurements. Firstly, the void healing process was observed using a self-developed OCT system. Repair parameters, including initiation and completion times, were then estimated from the scattered light intensity changes in the defective region. Additionally, phase-contrast imaging was utilized to analyze phase difference patterns, enabling the computation of displacement fields across the defective cross-section and providing quantitative insights into the healing dynamics. The findings demonstrate the efficacy of OCT in monitoring and characterizing the repair processes of composite materials, highlighting its potential as a valuable tool in structural health assessment.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108689"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular origin of asymmetric yield surface of crosslinked epoxy polymers","authors":"Jinyoung Kim ,&nbsp;Kyeongmin Hong ,&nbsp;Yong-Seok Choi ,&nbsp;Dayoung Jang ,&nbsp;Jang-Woo Han ,&nbsp;Hyungbum Park","doi":"10.1016/j.polymertesting.2025.108710","DOIUrl":"10.1016/j.polymertesting.2025.108710","url":null,"abstract":"<div><div>In this study, we investigate the multiaxial mechanical behavior of thermosetting epoxy polymers and explore the asymmetry between tension and compression in their yield surfaces at the molecular level using molecular dynamics simulations, complemented by experimental validation through polymer synthesis. After constructing an atomistic-scale amorphous epoxy system based on molecular dynamics simulations, we derived equivalent stress–strain curves and yield surfaces as functions of the degree of crosslinking through biaxial deformation analysis. The results show that increasing the degree of crosslinking leads to an increase in equivalent stress in all loading directions, resulting in an expansion of the yield surface. Notably, a more accelerated expansion of the yield surface in the biaxial compression direction was observed at higher degrees of crosslinking, which is attributed to a deformation mechanism that more effectively accommodates stress in this loading direction. This unique deformation behavior is attributed to high non-bonded stress arising from reduced polymer chain mobility by crosslinking effect. To experimentally validate the deformation mechanisms, epoxy polymer samples were synthesized, and uniaxial tensile and plane-strain compression (PSC) tests were conducted to obtain stress–strain profiles and yield surfaces according to different degrees of cure. These results provide fundamental insights into the distinct mechanical properties of polymer materials, such as the asymmetry of the yield surface, by revealing their behavior at the molecular level.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108710"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating cyclic creep behavior of silicone-based thermoplastic elastomers for morphing control surface applications","authors":"Jeong-Hwan Yoon ,&nbsp;Min-Jun Gim ,&nbsp;Ye-Won Park ,&nbsp;Yeon-Jee Cho ,&nbsp;Kyoung-Ho Shin ,&nbsp;Jae-Won Lee ,&nbsp;Hui-Yeol Yun","doi":"10.1016/j.polymertesting.2025.108722","DOIUrl":"10.1016/j.polymertesting.2025.108722","url":null,"abstract":"<div><div>The development of morphing control surfaces in automotive applications has necessitated the development of advanced elastomeric materials with high resilience and elastic recovery under cyclic deformation. In this study, the suitability of silicone-based thermoplastic vulcanizate (TPV-Si) and silicone-based thermoplastic polyurethane (TPU-Si) materials as morphing surface skins was investigated. A new cyclic creep test method for simulating real-world operational conditions for morphing control surfaces was proposed to evaluate the performance of these materials. The Norton-Bailey model was employed to analyze the test results to characterize the creep behavior across different strain levels, focusing on the primary and secondary deformation phases. The results revealed distinct differences in the elastic recovery capabilities and durability of TPV-Si and TPU-Si, offering insights into material selection for enhanced durability in morphing-controlled surface applications. This analysis highlighted the superior performance of TPU-Si under high-strain conditions, making it a promising candidate for automotive morphing technology.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108722"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage evolution and toughening mechanism in brick-and-mortar structure: Essential role of interface thickness ratio","authors":"Tian Qiu,&nbsp;Chengyu Guan,&nbsp;Lihong Liang","doi":"10.1016/j.polymertesting.2025.108725","DOIUrl":"10.1016/j.polymertesting.2025.108725","url":null,"abstract":"<div><div>The brick-and-mortar structure, known for its excellent mechanical properties, holds significant potential in biomimetic design. However, the effect of the interface on damage evolution and toughening mechanism remains unclear. This study employed 3D printing to fabricate brick-and-mortar structures with different interface thickness ratios and examined their mechanical properties and damage evolution through quasi-static tensile tests and digital image correlation (DIC) technology. The results indicate that increasing the interface thickness ratio reduces yield strength, fracture strength, and elastic modulus while increasing fracture strain. Higher interface thickness ratios also intensify interface damage, increase separation length, and cause the fracture mode of the brick-and-mortar structure to transition from hard phase fracture to pull-out fracture, significantly enhancing ductility. To elucidate the effect of interface thickness on elastic modulus, theoretical models based on tension-shear chain (TSC), shear-lag (SL), and strain gradient theory based on shear-lag (SGSL) models were applied and validated with experimental data. At higher thickness ratios, tensile deformation is dominated by the hard phase, necessitating a larger aspect ratio to counteract the low modulus of the interface. To achieve optimal mechanical performance, the study introduced an optimal aspect ratio and explored the synergistic optimization of interface thickness and the aspect ratio of the hard phase. The optimal aspect ratio can effectively compensate for the low modulus of the interface, thereby optimizing the balance between mechanical strength and toughness. These findings provide a reference and basis for future biomimetic material design.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108725"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}