Polymer Testing最新文献_第2页

A clearer understanding of the dynamic structuring of different natural rubber genotypes on a macroscopic and mesoscopic scale by asymmetrical-flow field-flow fractionation (A4F) analysis 通过非对称流场-流分馏（A4F）分析，在宏观和中观尺度上更清晰地了解不同天然橡胶基因型的动态结构

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-19 DOI: 10.1016/j.polymertesting.2024.108614

{"title":"A clearer understanding of the dynamic structuring of different natural rubber genotypes on a macroscopic and mesoscopic scale by asymmetrical-flow field-flow fractionation (A4F) analysis","authors":"","doi":"10.1016/j.polymertesting.2024.108614","DOIUrl":"10.1016/j.polymertesting.2024.108614","url":null,"abstract":"<div><div>Unlike synthetic elastomers, the structure of natural rubber (NR) evolves (dynamic structuring) and so do its properties during the storage before reaching an industrial mixer. In the rubber industry this is known as storage hardening. NR samples from three genotypes (GT1, RRIM600 and PB235) were subjected to different levels of structuring by varying the structuring time (t) on phosphorus pentoxide (0 < t < 28 h). Storage hardening (ΔP) of the samples was then determined by measuring the increase in Wallace plasticity (P) (macro-scale) and by analyzing their mesostructure (meso-scale) using asymmetrical flow field flow fractionation (A4F). Monitoring ΔP as a function of structuring time revealed a diversity of behaviors specific to the genotype from which the rubber originated. For example, NR samples from genotypes GT1 and PB235 exhibited different kinetics for t < 12 h, an increase in ΔP with structuring time, but reached the same final plateau (t > 12 h). An A4F analysis of the samples was used to quantify the fraction of microaggregates smaller than 1 μm (microgel<sub><1μ</sub>). The microgel<sub><1μ</sub> rate decreased with structuring time to varying extents depending on the genotype. A very significant negative relationship was found between ΔP and the microgel<sub><1μ</sub> rate, indicating that the NR samples that hardened the most contained the lowest microgel<sub><1μ</sub> rate, but the highest macrogel rate.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531601","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}

引用次数: 0

XPS analysis of damp heat aged and fractured polymer/glass laminates 湿热老化和断裂聚合物/玻璃层压板的 XPS 分析

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-19 DOI: 10.1016/j.polymertesting.2024.108617

{"title":"XPS analysis of damp heat aged and fractured polymer/glass laminates","authors":"","doi":"10.1016/j.polymertesting.2024.108617","DOIUrl":"10.1016/j.polymertesting.2024.108617","url":null,"abstract":"<div><div>Essential for the durability of photovoltaic (PV) modules is the polymeric encapsulant. In addition to the well-established ethylene vinyl acetate copolymers (EVA), polyolefin elastomers (POE) are gaining market relevance. The main objective of this paper was to elucidate the ageing and degradation mechanisms of PV relevant glass laminates based on UV-transparent EVA and POE encapsulants by X-ray photoelectron spectroscopy (XPS).</div><div>Special focus was given to the polymer/glass interfaces. Therefore, glass laminates were damp heat aged and debonded by monotonic compressive shear testing. Subsequently, the polymer side of the fractured surfaces was characterized by XPS and Fourier-transform infrared spectroscopy (FTIR). The polar EVA encapsulant revealed more pronounced deterioration than the less polar POE material.</div><div>Significant differences were already discernible after 1kh of damp heat exposure. The diffusion of Na ions from the glass substrate into the polymer matrix and the formation of Na salts at the interface were ascertained for EVA and to a less extent also for POE. While EVA laminates failed primarily close to the interface, but still within the EVA material, glass residues were detected on the fractured POE surfaces indicating interface-near glass corrosion and a fracture path propagating back and forth within POE and glass.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531600","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}

引用次数: 0

Insights on the polymerization kinetics of non-isocyanate polyurethanes (NIPU) using in situ NMR spectroscopy 利用原位核磁共振光谱深入了解非异氰酸酯聚氨酯 (NIPU) 的聚合动力学

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-19 DOI: 10.1016/j.polymertesting.2024.108615

{"title":"Insights on the polymerization kinetics of non-isocyanate polyurethanes (NIPU) using in situ NMR spectroscopy","authors":"","doi":"10.1016/j.polymertesting.2024.108615","DOIUrl":"10.1016/j.polymertesting.2024.108615","url":null,"abstract":"<div><div>An <em>in situ</em> characterization method using liquid Nuclear Magnetic Resonance (NMR) spectroscopy has been developed to aid the preparation of highly reactive non-isocyanate polyurethanes (NIPUs) from cyclic carbonate aminolysis. Using this methodology, the aminolysis kinetics and the final polymer structure of a model NIPU obtained by reaction of a 5-membered bis-cyclic carbonate (5CC) and 1,4-diaminobutane have been fully investigated, as a function of the type and concentration of the aminolysis catalyst, and the reaction temperature. Several catalysts already reported in NIPUs syntheses, including 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), have been compared. The kinetics of the 5CC hydrolysis side reaction was also studied. With an activation energy of 29.7 kJ mol<sup>−1</sup>, TBD was clearly the most efficient catalyst used, allowing 5CC conversion ratio of up to 100 % using a concentration of 0.35 eq<sub>5CC</sub>. However, under these experiment conditions, TBD concentration also showed to have a non-negligible influence on the hydrolysis rate, representing between 6 and 14 % of the initial 5CC concentrations, at 353 K. Neither the catalyst or the temperature seemed to affect the polymer structure, with secondary hydroxyl-containing isomer proportions of (70 ± 6) %. Finally, this <em>in situ</em> NMR method is paving the way for rapid screening of innovative catalysts for sustainable NIPU synthesis.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531121","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}

引用次数: 0

Solvent-free synthesis of bio-based non-isocyanate polyurethane (NIPU) with robust adhesive property and resistance to low temperature 无溶剂合成生物基非异氰酸酯聚氨酯 (NIPU)，具有良好的粘合性和耐低温性

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-19 DOI: 10.1016/j.polymertesting.2024.108616

{"title":"Solvent-free synthesis of bio-based non-isocyanate polyurethane (NIPU) with robust adhesive property and resistance to low temperature","authors":"","doi":"10.1016/j.polymertesting.2024.108616","DOIUrl":"10.1016/j.polymertesting.2024.108616","url":null,"abstract":"<div><div>Non-isocyanate polyurethane (NIPU) adhesives represent a cutting-edge advancement in adhesive technology, poised to significantly diminish the dependency on isocyanate-based PU within the industry. In the context of the increasing scarcity of petroleum-based resources and the growing imperative for sustainable environmental practices, the pursuit of a comprehensively sustainable, bio-derived non-isocyanate polyurethane (NIPU) adhesive has swiftly become a pivotal area of interest within the scientific research community. In this study, the cashew phenol cyclic carbonate (CPCC) was synthesized through the addition polymerization process involving cashew phenol glycidyl ether (602A) with carbon dioxide (CO<sub>2</sub>), followed by a curing step utilizing a diamine extracted from biomass-derived oils to produce bio-based NIPU at ambient temperature. The synthesized NIPU adhesive demonstrated remarkable thermal stability and exceptional adhesion to a variety of substrate materials. Notably, the adhesive showcased superior bonding efficacy at ultra-low temperatures, with steel bonding strength reaching up to 7.78 MPa at -37°C. This study presents an efficient and accelerated synthesis approach for the preparation of bio-based NIPU, offering a significant contribution to the field. Moreover, it provides a valuable reference for future advancements in NIPU adhesive technology, particularly for applications requiring robust bonding at low-temperature environments.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531602","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}

引用次数: 0

Char, gas, and action: Transfer of the flame-retardant modes of action in epoxy resins and their fiber-reinforced composites 炭、气体和作用：环氧树脂及其纤维增强复合材料阻燃作用模式的转移

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-15 DOI: 10.1016/j.polymertesting.2024.108610

{"title":"Char, gas, and action: Transfer of the flame-retardant modes of action in epoxy resins and their fiber-reinforced composites","authors":"","doi":"10.1016/j.polymertesting.2024.108610","DOIUrl":"10.1016/j.polymertesting.2024.108610","url":null,"abstract":"<div><div>Flame retardants are often developed for epoxy resins and then transferred into their fiber-reinforced composites with uncertain results. Understanding this transfer in detail represents a critical scientific challenge. This study systematically compares epoxy resins with their glass-fiber reinforced composites, focusing on bisphenol A diglycidyl ether with the hardener dicyandiamide, the flame retardants melamine polyphosphate, ammonium polyphosphate, and silane ammonium polyphosphate, along with inorganic silicate. The research investigates changes in pyrolysis (thermogravimetry), flammability (UL 94, limiting oxygen index), and fire behavior (cone calorimeter) while also examining the flame-retardant modes of action and overall fire performance. The findings reveal that alterations in the amount of fuel, thermal properties, melt flow, and protective layer significantly impact ignition, flammability, and fire load, with a critical reduction in carbonaceous char within the composites preventing intumescence. This study quantifies the effects and provides a fundamental scientific understanding of the complex transfer process of flame retardants from resins to composites, offering essential insights that are of major importance for developing more effective flame-retardant materials.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531128","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}

引用次数: 0

The Effects of Loading Angles on the Failure of Cross-Ply Notched Bio-Basalt Composites 加载角度对交叉层缺口生物钴复合材料失效的影响

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-11 DOI: 10.1016/j.polymertesting.2024.108609

{"title":"The Effects of Loading Angles on the Failure of Cross-Ply Notched Bio-Basalt Composites","authors":"","doi":"10.1016/j.polymertesting.2024.108609","DOIUrl":"10.1016/j.polymertesting.2024.108609","url":null,"abstract":"<div><div>A cross-ply basalt V-notched butterfly specimens were subjected to pure tension, combined tension-shear, and shear stress-strain state using a modified Arcan test fixture with loading angles from 0° to 90° with 15° increment. Multiaxial stress and strain states were studied using the principal stress and strain ratio, from which the principal angle was determined and used to represent principal states in the gauge section. The quasi-elastic to non-linear transition stresses were determined for each loading angle. In biaxial stress-strain states and pure shear, the deformation and consequently the shear-induced damage start to accumulate significantly. Also, in biaxial stress-strain states between 15°-75°, the shift from tension-shear to pure shear was observed after the transition to the non-linear part of the stress-strain curve. The digital image correlation (DIC) images and microscopic evaluation show that a large extent of damage is the consequence of the shear deformation after the rotation of 0° clamped fibres, while the 90° fibres maintained their original straight form. In off-axis tests, the principal strain axis rotates towards the weakest material axis even at small off-axis angles. This causes a transition from a tension-shear biaxial state in the linear loading part to shear in the non-linear part, leading to irreversible damage beyond the transition point.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433247","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}

引用次数: 0

Ultra-strength and anti-freezing zwitterionic hydrogels with high ion conductivity: Effect of the hydrophobic monomer in hydrogels mechanical properties 具有高离子传导性的超强度抗冻齐聚物水凝胶：疏水单体对水凝胶机械性能的影响

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-10 DOI: 10.1016/j.polymertesting.2024.108607

{"title":"Ultra-strength and anti-freezing zwitterionic hydrogels with high ion conductivity: Effect of the hydrophobic monomer in hydrogels mechanical properties","authors":"","doi":"10.1016/j.polymertesting.2024.108607","DOIUrl":"10.1016/j.polymertesting.2024.108607","url":null,"abstract":"<div><div>Zwitterionic hydrogels have emerged as a promising option due to their remarkable ionic conductivity. However, these hydrogels often suffer from poor mechanical properties due to their super hydrophilicity. Herein, we propose the use of a rigid aryl imidazolium monomer (AIm) for crosslinking with poly(vinyl alcohol) (PVA) to create a unique zwitterion hydrogel. Chlorosulfonic acid acts as an agent to introduce anionic groups, facilitating the transfer of Zn<sup>2</sup>⁺ ions in zwitterionic hydrogel. We achieve extraordinary mechanical properties by incorporating an optimal amount of AIm into the PZW2 hydrogel (tensile stress 0.9 MPa and stretch 1400 %). Above all, the PZW2 hydrogel exhibits remarkable resistance to freezing, remaining unfrozen even at up to −80 °C. This anti-freezing property is attributed to the cation-dipole interactions and the presence of ZnCl<sub>2</sub>, effectively preventing water from freezing within the hydrogel structure. Furthermore, the PZW2 hydrogel demonstrates a high ionic conductivity of 4.34 S m<sup>−1</sup> at room temperature. This can be attributed to the presence of anionic and cationic charges within the PZW2 hydrogel, which facilitates the transfer of ions through a hopping mechanism. The PZW2 hydrogel demonstrates better performance compared to most antifreeze conductive hydrogels. At −20 °C, it achieves an impressive ionic conductivity of 2.73 S m<sup>−1</sup> and retains outstanding mechanical characteristics with a stretchability of 1000 %. Ultimately, the PZW2 hydrogel demonstrates a sensitive response performance with a gauge factor of 1.59, making it highly suitable for potential sensor applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441331","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}

引用次数: 0

Rheological analysis of network structure of raw natural rubber prepared by different processing techniques 不同加工技术制备的天然生橡胶网络结构的流变学分析

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-10 DOI: 10.1016/j.polymertesting.2024.108608

引用次数: 0

Flexible and innovative PVA/ZrO2/g-C3N4/CNT nanocomposites film for optoelectronic applications 用于光电应用的柔性创新 PVA/ZrO2/g-C3N4/CNT 纳米复合薄膜

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-05 DOI: 10.1016/j.polymertesting.2024.108604

{"title":"Flexible and innovative PVA/ZrO2/g-C3N4/CNT nanocomposites film for optoelectronic applications","authors":"","doi":"10.1016/j.polymertesting.2024.108604","DOIUrl":"10.1016/j.polymertesting.2024.108604","url":null,"abstract":"<div><div>This study successfully prepared polyvinyl alcohol (PVA) polymer films doped with ZrO<sub>2</sub>/(g-C<sub>3</sub>N<sub>4</sub>/CNT) nanofillers using the solution casting technique. The crystal structure of the nanocomposite films was characterized by X-ray diffraction (XRD), revealing the semi-crystalline nature of PVA and an average ZrO<sub>2</sub> crystallite size of 13.17 nm. Fourier-transform infrared (FTIR) spectroscopy confirmed the chemical composition and functional groups present in the nanocomposites. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed uniform dispersion of the nanofillers without noticeable phase separation, with EDX confirming the successful incorporation of ZrO<sub>2</sub>, g-C<sub>3</sub>N<sub>4</sub>, and CNT into the PVA matrix. X-ray photoelectron spectroscopy (XPS) further validated the elemental composition and chemical states, indicating the presence of carbon, oxygen, nitrogen, and zirconium. Optical analysis demonstrated that increasing ZrO<sub>2</sub>/(g-C<sub>3</sub>N<sub>4</sub>/CNT) content reduced the direct and indirect band gaps from 5.41 eV to 5.25 eV and from 5.18 eV to 4.92 eV, respectively. In addition, the single-oscillator energy (<em>E</em><sub><em>0</em></sub>) and dispersion energy (<em>E</em><sub><em>d</em></sub>) increased, while the static refractive index (n<sub>0</sub>) decreased. Improvements were also observed in linear optical susceptibility (χ<sup>(1)</sup>) and third-order nonlinear optical susceptibility (χ<sup>(3)</sup>), enhancing the polarizability of the polymer molecules. These results indicate that PVA films doped with ZrO<sub>2</sub>/(g-C<sub>3</sub>N<sub>4</sub>/CNT) hold promise for optoelectronic applications due to their enhanced optical properties.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421854","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}

引用次数: 0

Characterization of the in-situ degradation process of P3HT:PCBM based on hyperspectral and neural networks 基于高光谱和神经网络的 P3HT:PCBM 原位降解过程表征

IF 5 2区材料科学

Polymer Testing Pub Date : 2024-10-04 DOI: 10.1016/j.polymertesting.2024.108606

{"title":"Characterization of the in-situ degradation process of P3HT:PCBM based on hyperspectral and neural networks","authors":"","doi":"10.1016/j.polymertesting.2024.108606","DOIUrl":"10.1016/j.polymertesting.2024.108606","url":null,"abstract":"<div><div>In situ online observation of surface morphology during degradation processes is of paramount importance for exploring the stability of organic photovoltaic materials. In this study, we designed an in situ online characterization system based on hyperspectral and neural network technologies, and observed the degradation processes of P3HT:PCBM thin film materials. The system is capable of collecting hyperspectral image data from 101 channels within the 400–700 nm wavelength range for characterizing detailed surface features of materials. Additionally, to automate the processing of hyperspectral image data, we designed a spectral image segmentation algorithm based on neural networks and proposed a foreground attention mechanism to improve the segmentation accuracy of the algorithm. The experimental results indicate that the system can achieve high spectral characterization of P3HT:PCBM thin film materials and automate image data processing through artificial intelligence algorithms, with an image segmentation accuracy of 99.62 %. Furthermore, owing to the higher spectral resolution of this system and its computer-assisted analysis capabilities for material image data, not only are the in-situ variations in size, density, and formation rate of aggregates formed during the thermal degradation process of P3HT:PCBM thin film materials experimentally analyzed, but also the fluorescence changes at the edges of aggregates during the photodegradation process are revealed. The reliable code can be found at the following link: <span><span>https://github.com/HyperSystemAndImageProc/IONFMDP-UHHNN</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421851","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}

引用次数: 0