Polymer Testing最新文献

{"title":"Modelling the curing kinetics of DGEBA-MTHPA with DMP-accelerator concentration dependence","authors":"H. Möllers ,&nbsp;C. Schmidt ,&nbsp;D. Meiners","doi":"10.1016/j.polymertesting.2025.108726","DOIUrl":"10.1016/j.polymertesting.2025.108726","url":null,"abstract":"<div><div>The curing of epoxy anhydride systems is often modelled using various phenomenological models. These models give a relationship between the cure rate and the temperature and degree of cure of the resin. Typically, epoxy anhydride systems are used in combination with an accelerator to lower the cure temperature and speed up the cure process. In this study, the influence of 2,4,6-Tris(dimethylaminomethyl)phenol (DMP) accelerator on the cure kinetics of a Bisphenol A diglycidyl ether (DGEBA or BADGE)-Methyltetrahydrophthalic anhydride (MTHPA) mixture was investigated using isothermal and dynamic modulated differential scanning calorimetry (MDSC) measurements. As expected, the accelerator increased the cure rate and lowered the reaction start temperature. The Kamal-Sourour model, incorporating a Fournier diffusion factor, was successfully fitted to the MDSC data. The Kamal-Sourour parameters indicate that the accelerator primarily affects the non-autocatalytic part of the reaction. Increasing the accelerator concentration also resulted in earlier vitrification of the resin up to 6 % degree of cure and 3–4% higher achievable cure degrees at isothermal temperatures. The effect of the accelerator was integrated into the Kamal-Sourour model, yielding a set of parameters that can be used to calculate the cure rate as a function of temperature, cure degree, and accelerator concentration with a mean error of 3.5 %.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"143 ","pages":"Article 108726"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137204","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":"Microstructure regulation and fabrication of epoxy-based conductive films with excellent electrical and thermal conductivity, adhesion, toughness, and flexibility","authors":"Hongming Yang,&nbsp;Li Zhang,&nbsp;Rong Chen,&nbsp;Shaoyun Guo","doi":"10.1016/j.polymertesting.2024.108657","DOIUrl":"10.1016/j.polymertesting.2024.108657","url":null,"abstract":"<div><div>The electrically conductive adhesive films (ECAFs) are new materials used for large-format bonding in microelectronics packaging. However, improving its electrical and thermal conductivity, adhesion, and flexibility simultaneously has been a challenge. In this study, silver powder with different particle sizes and poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) were used to create a high-efficient multi-scale conductive bridge structure. This reduced the volume resistivity from 7.30 × 10⁻⁴ Ω cm to 3.80 × 10⁻⁴ Ω cm, with lower silver powder content. The thermal conductivity improved from 9.074 W/m·K to 9.124 W/m·K, and adhesion performance between the epoxy matrix and the metal increased from 6.85 MPa to 8.08 MPa. Furthermore, the addition of hydroxyl-functionalized polyurethane materials enhanced the toughness without significantly affecting its electrical, thermal, and adhesion properties. This study successfully prepared epoxy-based conductive adhesive films with a combination of electrical conductivity, thermal conductivity, adhesion, and flexibility, while significantly reducing costs due to the reduction in silver powder content.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108657"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170978","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":"O2-self-supplying and glutathione-depleting scaffold for synergistic cancer therapy","authors":"Jiajia Zeng ,&nbsp;Chongxian He ,&nbsp;Xinna Bai ,&nbsp;Cijun Shuai ,&nbsp;Hao Pan","doi":"10.1016/j.polymertesting.2024.108656","DOIUrl":"10.1016/j.polymertesting.2024.108656","url":null,"abstract":"<div><div>Photodynamic therapy (PDT) has great potential for tumor therapy because of its non-invasive and high selectivity. However, the therapeutic effect of PDT is critically restricted by hypoxia and glutathione (GSH) overexpression in the tumor microenvironment (TME). In this work, CeO₂ with catalase and peroxidase dual enzyme activities was loaded on Ti₃C₂ nano-sheet, and the nanosystem was then introduced in poly-L-lactic acid (PLLA) and prepared into bone scaffold using selective laser sintering technology. Specifically, CeO₂ alleviates hypoxia through its catalase enzyme activity, which promotes the continuous photodynamic process. CeO₂ also consumes over-expressed GSH through its redox reaction and amplifies the oxidative stress in TME, thus improving the curative effect of PDT. On the other hand, the photothermal effect of scaffold can not only generate heat to kill tumor cells, but also enhance the activity of nanoenzyme, and the catalase activity enhanced by photothermal effect is fed back to PDT, forming a two-way promotion. The results indicated that the concentration of oxygen in PLLA/Ti₃C₂-CeO₂ scaffold group was 9.76 mg/L higher, and the concentration of singlet oxygen (¹O₂) and hydroxyl radical (·OH) was respectively increased by 60 % and 170 %, compared with the PLLA/Ti₃C₂ scaffold. Moreover, the PLLA/Ti₃C₂-CeO₂ scaffold showed a higher GSH consumption rate, indicating that it could consume the overexpressed GSH. Therefore, the Ti₃C₂ nano-sheet loaded with CeO₂ could combine the dual enzyme activities, photodynamic and photothermal effect to enhance the tumor therapy with a tumor growth inhibitory effect of approximately 88.8 %. In summary, introducing the Ti₃C₂ nanosystem loaded with nanozyme into PLLA scaffold is a promising strategy to develop bone scaffold with multimodal anti-tumor function.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108656"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173202","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":"Nano silica and meso silica extracted from rice husk waste utilized for enhancing leather properties","authors":"Ebtasam ,&nbsp;Md. Nahid Bin Hasan ,&nbsp;Rupok Kumar Nayak ,&nbsp;Md. Ahsanul Haque Milon ,&nbsp;Md. Farhad Ali","doi":"10.1016/j.polymertesting.2024.108680","DOIUrl":"10.1016/j.polymertesting.2024.108680","url":null,"abstract":"<div><div>The final stage of the leather manufacturing process, known as leather finishing, is what gives leather its final qualities and aesthetic appeal. Applying solvents and binders that can interact with crust leather's surface to change its chemical composition and enable the fixation of colors and dyes is the finishing process. To obtain great performance, the finishing must be extremely compatible. Therefore, this study focused on the extraction of the nanoparticles from rice husk waste for using in leather finishing which can be the sustainable materials that not only enhance the quality and performance of leather but also led to the waste minimization. The highly active, polar, porous, and huge interior area of biogenic silica nanoparticles and mesoparticles make them an excellent substitute for manufactured silica. Meso-silica and nano silica has been extracted from the rice husk by sol-gel method. A comprehensive array of assessments, encompassing FTIR, TGA, SEM, DLS, XRD, Zeta Potential, water vapor permeability, tensile strength, color rub fastness, color fastness to water, finish film adhesion test, adhesion strength of finish film, resistance to water spotting, heat resistance test, lastometer test, percentage of silica yield and percentage of elongation at break was conducted to thoroughly evaluate the performance of meso silica, nano silica and leather finished with both the nano particles as well as without nanoparticles. The performance of leather finished with nanoparticles also compared with each other and conventionally finished leather. The findings revealed satisfactory physical and analytical characteristics of the nano silica and meso silica finished leather.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108680"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173211","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":"Influence of different type of impermeable phase on the permeability of PLA films: Nanofillers versus crystalline phase","authors":"Aurore Jullin ,&nbsp;Guillaume Sudre ,&nbsp;Nicolas Hascoët ,&nbsp;Francisco Chinesta ,&nbsp;Eliane Espuche","doi":"10.1016/j.polymertesting.2024.108682","DOIUrl":"10.1016/j.polymertesting.2024.108682","url":null,"abstract":"<div><div>Different amorphous PLA-based nanocomposites series allowing to vary the nanofiller shape from spherical (hydrophobic/hydrophilic silica, silver), to tubular (halloysites) and lamellar (montmorillonite, graphene) have been prepared for filler content up to 15 vol%. In parallel, a semi-crystalline PLA films series has been prepared by annealing amorphous PLA films from the glassy state with the aim to achieve different degree of crystallinity. The polymer chains mobility and the impermeable domains (either filler domains or crystalline phase) contained in each membrane have been characterized in detail. Membranes water vapor and oxygen permeability coefficients have been determined with the aim to evidence the governing factors for barrier properties. For nanocomposite membranes, the matrix microstructure and chain mobility were not significantly affected by the addition of fillers, so the barrier properties were mainly governed by the filler domains size and dispersion. For semi-crystalline membranes, the increase in crystallinity led to a decrease of the amorphous chains mobility (<em>MAF</em>) which was found to also influence the permeability. Theoretical models were used to describe the evolution of the experimental relative permeability and an equivalence diagram was proposed to have a direct comparison of the effect of fillers and crystallinity on the permeability.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108682"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173125","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":"In situ wear test of acrylonitrile butadiene rubber in a low pressure hydrogen environment","authors":"Byeong-Lyul Choi ,&nbsp;Myung-Chan Choi ,&nbsp;Sang Koo Jeon ,&nbsp;Un bong Baek ,&nbsp;Byoung-Ho Choi","doi":"10.1016/j.polymertesting.2024.108683","DOIUrl":"10.1016/j.polymertesting.2024.108683","url":null,"abstract":"<div><div>Polymers are increasingly being used in hydrogen environments because of their potential for high durability and cost-effectiveness in applications such as fuel cells and hydrogen storage systems. However, the interactions between polymers and hydrogen, particularly under varying pressure conditions, can significantly affect their performance, leading to challenges in material selection and design. Hence, this study investigated the tribological behavior of acrylonitrile butadiene rubber (NBR) in low-pressure hydrogen environments and focused on the effects of different filler types and contents, including carbon black and silica. Using a custom-designed in situ tribometer, wear tests were conducted to evaluate the friction and wear characteristics of the NBR composites in hydrogen, helium, and ambient air atmospheres. The findings indicated that the filler type and content critically influenced the tribological performance of NBR, with carbon black-filled NBR showing higher friction coefficients and wear rates and silica-filled NBR exhibiting superior wear resistance and lower friction. These results emphasize the importance of optimizing the filler selection to enhance the durability and effectiveness of NBR in hydrogen-rich environments. Therefore, the results of this study provide valuable insights for the development of robust sealing materials for hydrogen energy applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108683"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173177","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":"Prediction of influence of helical structure on shape memory behavior of thermosetting resin useing molecular dynamics simulation","authors":"Shuaijiang Ma ,&nbsp;Qi Zhang ,&nbsp;Xuyan Li ,&nbsp;Jilei Xu ,&nbsp;Ping Chen","doi":"10.1016/j.polymertesting.2024.108671","DOIUrl":"10.1016/j.polymertesting.2024.108671","url":null,"abstract":"<div><div>The deformation process of helical structure is analogous to the stretching of spring which has shape memory capability. We propose introducing helical structure molecules into thermosetting resin matrix to investigate the influence of helical structure molecules on the shape memory properties of the resin matrix. The effects of helical structure on the thermomechanical properties and shape memory properties of epoxy and bismaleimide resins were analyzed by molecular dynamics. The results indicated that the introduction of helical structure molecules could enhance the tensile properties of thermosetting resin crosslinking network to some extent, and also reduce residual strain in the network. The epoxy resin and bismaleimide resin cell both contain one helical molecule, with mass fractions of 6.15 % and 5.95 %, respectively. The introduction of one helical structure additionally enhanced the shape memory recovery ratio of epoxy resin and bismaleimide resin by 12.63 % and 12.76 %, respectively, while promoting a faster shape recovery response in the crosslinking network.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108671"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173203","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":"Sensitivity of the particle size determined inline by Photon Density Wave Spectroscopy with respect to sample properties and measurement settings during emulsion copolymerization reactions","authors":"Usue Olatz Aspiazu ,&nbsp;Sebastian Zimmermann ,&nbsp;Marvin Münzberg ,&nbsp;Jose Ramon Leiza ,&nbsp;Maria Paulis","doi":"10.1016/j.polymertesting.2024.108668","DOIUrl":"10.1016/j.polymertesting.2024.108668","url":null,"abstract":"<div><div>Photon Density Wave spectroscopy (PDWS) is one of the few real-time and inline submicron particle size monitoring techniques that are commercially available nowadays. In this work, a sensitivity analysis of the PDWS results with respect to relevant sample properties and measurement settings is carried out. It is investigated how the distances between the emission and detection fibers together with the laser modulation frequencies, and uncertainties of the input parameters (refractive index, density, and solids content of the dispersed phase) needed for data analysis affect the reduced scattering coefficients and particle diameters obtained from inline PDWS measurements. The seeded semibatch emulsion copolymerization of methyl methacrylate (MMA, 51 w-%), butyl acrylate (BA, 47 w-%), and methacrylic acid (MAA, 2 w-%) is used as a model system. It is shown that the careful selection of measurement distances and modulation frequencies increases the accuracy of the particle size determination by PDWS. Furthermore, it is observed that the obtained particle sizes are more sensitive to uncertainties of the refractive index and solids content than to uncertainties of the density of the disperse phase.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108668"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173200","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":"Designing and study of composites reinforced with shredded corn stalks using a variety of matrices based on dammar, epoxy and acrylic resins","authors":"Cosmin Mihai Mirițoiu ,&nbsp;Dan Dobrotă ,&nbsp;Daniela Popa","doi":"10.1016/j.polymertesting.2024.108672","DOIUrl":"10.1016/j.polymertesting.2024.108672","url":null,"abstract":"<div><div>The primary goal of this research was to develop and evaluate environmentally friendly composite materials. Shredded corn stalks, regarded as both renewable resources and industrial by-products, were employed as the main reinforcement. Several synthetic resins were used as matrices, including one epoxy resin and two types of acrylic resins, as well as hybrid resins incorporating natural Dammar resin as a significant component. A range of composites was manufactured and tested for properties such as tensile, compressive, and flexural strength, vibration resistance, Shore D hardness, and water absorption. Under the tensile test, the samples reinforced only with shredded corn stalks exhibited strength values below 7 MPa and elongation at break below 2.5 %. From the perspective of compressive strength, values ranging between 9 and 23.5 MPa were obtained, exceeding the tensile strength values. In fact, the tensile strength is 3–3.6 times lower compared to the compressive strength (by comparing materials of the same type). For the samples reinforced only with shredded corn stalks, the flexural strength was the lowest, with values ranging between 0.98 and 3 MPa. When comparing compressive and flexural strengths, it is observed that the compressive strength is 7.8–9.2 times higher. To increase the tensile and flexural strengths, facets made of a mixed fiber composition of 70 % silk and 30 % linen were applied. Following the addition of facets composed of 70 % silk and 30 % linen, tensile strength increased by 9.5–13.3 times, and flexural strength increased by 8.7–17.8 times. Furthermore, a greater proportion of natural Dammar r. esin improved the ductility of the composites but resulted in a decrease in overall strength. As a practical application of the study, a shelf and a cupboard door were constructed from the developed materials. The research ultimately emphasizes the promising mechanical properties of these composites, indicating their potential for use in the furniture industry, particularly in the production of chipboard.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108672"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173209","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 mobility and dielectric properties of dendronized side chain liquid crystalline polyamines with benzoate groups as lateral spacers","authors":"Xavier Montané ,&nbsp;Robert Graf ,&nbsp;Borja Pascual-José ,&nbsp;Roberto Teruel-Juanes ,&nbsp;Jordi Guardià ,&nbsp;Marta Giamberini ,&nbsp;José Antonio Reina ,&nbsp;Amparo Ribes-Greus","doi":"10.1016/j.polymertesting.2024.108658","DOIUrl":"10.1016/j.polymertesting.2024.108658","url":null,"abstract":"<div><div>Dendronized polymers are suitable candidates for the preparation of biomimetic membranes for ion transport in fuel cells, which is nowadays a sustainable way of producing electrical energy. To prepare materials for these high-technology applications, it is necessary to understand the role of the different parts that make up these supramolecular structures. Another key factor is optimizing the preparation processes to ensure the materials achieve their maximum performance potential. Following these premises, in this work we report on the characterization of side chain liquid crystalline polyamines synthesized by chemical modification of poly[2-(aziridin-1-yl)ethanol] (PAZE) with lateral benzoate groups and the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy]benzoate (TAP) by using the following techniques: liquid and solid-state Nuclear Magnetic Resonance (NMR), Differential Scanning Calorimetry (DSC), Polarized Optical Microscopy (POM) and Dielectric Thermal Analysis (DETA). This in-depth investigation allowed us to understand the effect of parameters that could influence the organization of the different parts of the resulting supramolecular structures and their dynamics: introduction of benzoate lateral spacers, grafting with different amounts of TAP mesogenic group, and the thermal treatment used in the orientation of the polymer chains. NMR investigations confirmed that the melting of both copolyamines took place thanks to the mobility gained by the aliphatic tails of the TAP dendron between 256 and 272 K. Furthermore, the evaluation of variable temperature ¹³C solid-state NMR experiments proved that the clearing transition was related to the aromatic moieties of these polyamines. DETA studies of oriented and non-oriented membranes corroborated that the application of the thermal treatment increased the temperatures of the detected transitions: γ-relaxation, α_Tg and α_Clear. The results obtained demonstrated that the adjustment of the aforementioned parameters is essential for designing membranes intended for ion transport applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":"142 ","pages":"Article 108658"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171841","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}