Polymer Testing最新文献

{"title":"Advancing thermal stability in natural ester oil-paper insulation systems via precision nanostructuring with parylene films: Experimental and molecular-level comprehensive assessment","authors":"","doi":"10.1016/j.polymertesting.2024.108592","DOIUrl":"10.1016/j.polymertesting.2024.108592","url":null,"abstract":"<div><div>The oil-paper insulation system in eco-friendly fire-retardant transformers depends on hydrophilic natural ester insulating oil. Moisture within the system synergistically interacts with aging, worsening oil-paper insulation degradation and hastening overall system aging. Chemical vapor deposition was used to create parylene surface-modified insulating paper as a strategy to inhibit moisture-induced aging in natural ester oil-paper insulation. The effectiveness of the approach was identified by a comprehensive assessment of the physicochemical and electrical properties of the parylene surface-modified insulating paper. The findings from accelerated thermal aging at 130 °C for 90 days on the natural ester oil-paper insulation system reveal the outstanding lipophilic and hydrophobic properties while maintaining electrical characteristics of the parylene surface-modified insulating paper. After 90 days of aging, the parylene surface-modified insulating paper exhibited a 56.76 % higher degree of polymerization and a 19.36 % significantly lower moisture content than conventional cellulose insulating paper. In the natural ester oil-paper insulation system, the parylene surface-modified insulating paper led to a notable 63 % reduction in insulating oil acid value, a 60.50 % decrease in dielectric loss, and a substantial 20.35 % increase in AC breakdown voltage. Molecular-level investigations revealed the inhibitory mechanism of the parylene film, offering a promising solution to enhance the thermal stability and aging resistance of natural ester oil-paper insulation systems.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561036","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 titanate coupling agent on antioxidant property and UV blocking property of PBAT/lignin composite films","authors":"","doi":"10.1016/j.polymertesting.2024.108613","DOIUrl":"10.1016/j.polymertesting.2024.108613","url":null,"abstract":"<div><div>PBAT is the largest amount of biomass-degradable plastics on the market at present, and its application in related fields is limited due to its defects such as poor weather resistance. In this study, the surface modification of lignin by titanate coupling agent was realized by the melt extrusion reaction method of non-catalytic system, and the PBAT/cotton straw lignin composite film was prepared by melt blending and blow molding with PBAT at a certain ratio. The structure and properties of the specimens were analyzed before and after the artificial accelerated aging test using characterization means such as DSC, SEM, IR, transmittance and mechanical properties. The results showed that the tensile strength and elongation at break ratios of the composite film increased by 36.99 % and 34.31 %, respectively, compared with the pure PBAT film when the titanate coupling agent modified lignin was 10 %; the retained value of elongation at break of the specimen on the sixth day of thermo-oxidative light aging increased by 13.33 %; and the UV transmittance at 500 nm was reduced by 96.95 %; And through the comprehensive evaluation system of material stability, the temperature aging kinetic model was established and a temperature sensitivity analysis was performed, and it was found that the specimen with 10 % lignin content had a significant reduction in temperature sensitivity. The composite film developed in this study maintains the fully biodegradable properties of PBAT while introducing the characteristics of functional modifiers, which provides a new idea to broaden the application in the field of packaging and helps to reduce the production cost.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561035","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":"Inverse vulcanized sulfur-styrene polymers as effective plasticizers for polystyrene","authors":"","doi":"10.1016/j.polymertesting.2024.108625","DOIUrl":"10.1016/j.polymertesting.2024.108625","url":null,"abstract":"<div><div>Inverse vulcanized polymers have demonstrated significant potential as alternatives to conventional petrochemical polymers in various applications, including environmental remediation, where they are used to absorb heavy metals and pollutants from water and soil, and energy devices, such as in the development of high-capacity lithium-sulfur batteries. Despite their promise in these areas, the full application scope of these sulfur-based polymers remains unexplored. There is substantial potential for their use in other fields, such as advanced material coatings, medical devices, and as additives to improve the properties of existing polymers, yet these possibilities have not been thoroughly investigated. This study presents a sulfur-based polymer, synthesized via the inverse vulcanization of sulfur and styrene and partially crosslinked with divinylbenzene, as a novel plasticizer for polystyrene (PS). This polymer blend was prepared using an internal mixer to replace conventional organic-based plasticizers. The selected system was designed to maximize miscibility. Both virgin and plasticized PS were injection molded for comprehensive characterization. Differential Scanning Calorimetry (DSC) confirmed the complete consumption of sulfur, revealing a significant reduction in the glass transition temperature of PS upon the addition of the sulfur-based plasticizer. Morphological analysis showed a homogeneous surface with uniform single-phase morphology, indicating full miscibility of the blend. Tensile tests demonstrated enhanced ductility and reduced stiffness in plasticized PS, with strain at maximum tensile strength and elongation at break increasing by 22.0 % and 28.1 %, respectively. The plasticizer also improved the toughness of PS by 25.2 %. Rheological assessments corroborated the plasticization effect and confirmed the blend's full miscibility. Contact angle measurements indicated increased hydrophilicity of the plasticized PS samples. This newly developed sulfur-based plasticizer proved to be highly effective for PS, showcasing competitive efficiency comparable to commercial plasticizers. This advancement paves the way for new applications in the expanding field of sulfur-based polymers.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571703","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":"Characterization of CL-20/HMX cocrystallization and its effects on GAP-based propellants during thermal aging process","authors":"","doi":"10.1016/j.polymertesting.2024.108623","DOIUrl":"10.1016/j.polymertesting.2024.108623","url":null,"abstract":"<div><div>The incorporation of HMX and CL-20 as component particles can greatly improve the energy efficiency of composite propellants. Nevertheless, the occurrence of cocrystallization arises when HMX and CL-20 exists together. Further investigation is needed to determine the effects of the CL-20/HMX cocrystallization on the aging features of the propellants. The present study examines the evolutionary trends and effects of the CL-20/HMX cocrystal on the process of solid propellant aging. Experimental thermal aging studies were carried out on GAP-based composite propellants at temperatures of 60 °C/180-day and 70 °C/90-day. An investigation of density bottle, differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, and uniaxial tensile testing were performed on the samples. The results indicate that the cocrystallization behaviours of CL-20/HMX undergo three distinct stages during propellant aging. The reaction rate accelerates most during the middle aging stage. As the GAP-based propellant ages, the recently developed cocrystal structure deteriorates the interfacial characteristics between the propellant particles and the matrix, leading to the formation of cavities inside the material. This will further enhance the decrease in elastic modulus, ultimate strength, and maximum elongation of the propellants. Among them, the most notable distinction from the aging behaviours of propellants without the addition of particles is the increase of the elastic modulus. Furthermore, a strong linear correlation was observed between variation of the elastic modulus and the cocrystal content of CL-20/HMX. This correlation offers a reliable indicator for monitoring the extent of cocrystallization phenomena.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578635","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":"Correlations between molecular weight, mechanical properties and morphology of micro-injection molded polyoxymethylene (POM)","authors":"","doi":"10.1016/j.polymertesting.2024.108626","DOIUrl":"10.1016/j.polymertesting.2024.108626","url":null,"abstract":"<div><div>Polyoxymethylene (POM) is a fast crystallizing polymer, whose structure is highly dependent on the processing conditions and is showing a broad range of mechanical properties. Three POM materials with different molecular weights were selected and a design of experiments (DoE) was performed varying melt temperature, mold temperature, and injection speed. In combination with increased viscosity at higher molecular weights, the flow resistance and shear stresses will also increase at a certain injection speed and geometric conditions. Thereby, the range of morphological differences depends not only on the process boundary conditions but also on the rheological conditions. This aspect is particularly relevant for micro-injection molded parts, as the acting cooling and shearing rates are much higher than in standard injection molding. A specially designed tensile rod with a radially symmetric cross section was utilized for the experiments, which offers advantages in terms of a symmetric flow and cooling behavior. The morphology was studied with thin sections from the center of the sample. Differential Scanning Calorimetry (DSC) was used to study the crystallinity of the samples and the mechanical properties were determined by a tensile test using an adopted optical extensometer. The mechanical properties of low molecular weight POM are only to a minor extent affected by the process variations. However, higher molecular weight POM is greatly affected in terms of its skin layer formation and improved mechanical properties favored by a low injection velocity.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586798","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 the spatial distribution of metallic fibers on the electromagnetic shielding of thermoplastic composites","authors":"","doi":"10.1016/j.polymertesting.2024.108611","DOIUrl":"10.1016/j.polymertesting.2024.108611","url":null,"abstract":"<div><div>In this work the effect of the morphology of fiber-filled thermoplastic composites has been studied. Two molds with the same thickness and different filling configurations have been used for the preparation of the samples that afterwards have been tested to obtain their electromagnetic Shielding Effectiveness (SE). The selected molds produce two completely different patterns of filling. In one of them, the pattern is mainly radial, as the gate is located in the center of the mold. In the other one, there are two entrances in a side of the mold, and this produces a weld line in the center of the plate. The effect of the radial distribution and the existence of a weld line has been studied against the shielding effectiveness, measured using a device formed by a stainless-steel cube with an opening in one of the faces to allow the SE measurement of representative plates. It has been observed from the shielding results that the main parameter to consider is the even and high-density distribution of the fibers, measured both by discreet methods (i.e. TGA and density measurements) and a continuous method like the grey scale analysis of tomography scans. It is finally concluded that the material's density distribution and not the existence of a weld line in the plate is the key factor to take into consideration when analyzing the shielding characteristics of fiber-filled thermoplastic composites.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538362","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":"The comparison of eight different common in vitro and ex vivo environments with in vivo conditions applying model collagen samples: Correlation possibilities and their limits","authors":"","doi":"10.1016/j.polymertesting.2024.108621","DOIUrl":"10.1016/j.polymertesting.2024.108621","url":null,"abstract":"<div><div>New biomaterials are routinely evaluated for their degradation behaviour in the real body environment. Following the 3R strategy, <em>in vitro</em> simulated body conditions are often preferred. No studies that simultaneously compare such conditions with the real body environment have been conducted to date. Model porous collagen scaffolds were exposed for 21 days to eight different environments: simple salt-based and enzymatic media, human blood plasma, cell culture media with and without human fibroblasts and <em>ex vivo</em> model cortical bone, and subsequently compared with an <em>in vivo</em> environment represented by a pig peritoneum. The mechanical properties of the scaffolds were then determined via uniaxial compression testing, and the structural properties via the micro-CT, weight loss, infrared spectroscopy, X-ray diffraction and histological methods. Interestingly, the various analysed simulated body conditions caused differing alterations in the collagen scaffold characteristics when compared with the real body environment. The mechanical properties were similar during the first 7 days of incubation but diverged after 14 and 21 days. The structural properties varied significantly after just 7 days of incubation. The histological evaluation of the scaffolds exposed to the cellular, <em>ex vivo</em> and <em>in vivo</em> conditions revealed the poor ability of cells to completely populate the scaffolds, accompanied by the massive ingrowth of connective tissue into the <em>in vivo</em> exposed scaffolds, which resulted in their variable global behaviour. In conclusion, the value of <em>in vitro</em> simulated body environments lies in their screening capacity and feasibility; however, direct extrapolation to real body conditions needs to be verified going forward.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538361","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":"Towards quantitative microplastic analysis using pyrolysis-gas chromatography coupled with mass spectrometry","authors":"","doi":"10.1016/j.polymertesting.2024.108620","DOIUrl":"10.1016/j.polymertesting.2024.108620","url":null,"abstract":"<div><div>Microplastic pollution from everyday plastic items has increased tremendously worldwide. Pyrolysis gas chromatography coupled to mass spectrometry (Py-GC/MS) has been widely investigated for the qualitative and quantitative analysis of microplastics in environmental samples. However, there are several pitfalls to consider when developing an appropriate protocol for their analysis. This study aimed at the development of an in-house database of primary (single) polymers, binary (two) polymers and tertiary (three) polymer mixtures. In this context the potential occurrence of gas phase reactions during pyrolysis of binary and tertiary polymers were investigated. Further, different diluters were tested for the accurate preparation of calibration standards for quantification purposes.</div><div>Seven different polymers were included in this study, which were chosen due to their prevalence in daily plastic appliances. For each single polymer specific peaks could be identified and recommendation for quantifier analytes given. The analysis of binary polymer mixtures revealed gas phase reactions for PET with PVC, PVC with MDI-PU and PE with PVC. For these binary polymers, several different novel pyrolysis products, specific for the according binary polymer mixture, could be identified. These results confirmed that especially PVC exhibits strong interactions during co-pyrolysis with ester- and ether-based polymers. Similar results were obtained for tertiary polymers.</div><div>For accurate preparation of calibration standards different diluters (silica, deactivated silica, calcium carbonate, THF and HFIP) were tested. It was observed that deactivated silica had only an influence on the pyrolysis of PET. Whereas, dilution with silica affected PA-6/66, PE, PET and MDI-PU. Only PVC was not influenced by dilution with silica.</div><div>In conclusion, our results highlight the necessity of an international standard of reference material as well as a standardized analytical protocol for the analysis and quantification of polymers in environmental samples. It is crucial to use diluters suitable for the specific polymer, to exclude potential interactions of diluters with the polymer. The present work has to be seen as a foundation, but future work is needed to adequately address the quantification of polymers in environmental samples.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531604","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":"Biocompatible and hydrophilic copper-complexed polyvinyl alcohol coating for antifogging surfaces","authors":"","doi":"10.1016/j.polymertesting.2024.108619","DOIUrl":"10.1016/j.polymertesting.2024.108619","url":null,"abstract":"<div><div>Visibility is decreased when fog accumulates on the clear surface of optical devices. It is quite desirable to design the surface with antifogging properties. The current study used a dip coating process to prepare copper-incorporated polyvinyl alcohol (PVA) hydrophilic coating on the hydroxylated glass substrate. The formation of the PVA-Cu complex by the hydroxyl group was determined by FTIR and XPS methods. The surface morphology, adhesion test, wettability behavior, and cytotoxicity were investigated by SEM, cross-cut tape, contact angle measurement, and MTT experiment. By varying the CuCl₂ concentration (0.0125–0.0625 M), the durability and adhesion of the coating were improved, as evidenced by its minimal mass loss and water uptake. The optimum coating condition showed a thickness of about 24.0 ± 0.7 μm and a good optical transmittance of over 90 %. Below 0.0375 M, the coating stability and water resistance could not be achieved due to the weak complexation of Cu with the PVA coating. In contrast, the PVA-Cu₃ coating (0.0375 M, Cu²⁺ ions) was identified as an optimized condition for improved antifogging performance due to the effective complexation of Cu with the PVA matrix while maintaining the hydrophilicity and wettability behavior. Furthermore, no cytotoxicity was observed by L929 cell lines in response to the prepared coating. The current study results revealed that the adhesive, hydrophilic PVA-Cu_x coating with a contact angle of less than 62° might demonstrate strong antifogging properties and find its usage for endoscopic applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531127","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":"Complexes of polymeric acids and short polyamines as binary stimulus-sensitive systems","authors":"","doi":"10.1016/j.polymertesting.2024.108618","DOIUrl":"10.1016/j.polymertesting.2024.108618","url":null,"abstract":"<div><div>Stimulus-sensitive polymers are of great interest due to their unusual properties in solution and diverse applications. Copolymers with different groups (hydrophilic, hydrophobic and ionizable) are typical stimulus-sensitive polymers, and varying the copolymer composition allows the pH and thermal sensitivity to be adjusted for a particular application. We found that complexes of polymeric acids with short methylated polyamines having trimethylene insertions between amine groups exhibit stimulus-sensitive properties in aqueous media at moderate pH and temperature. The position of the lower critical temperature of the solution depends on the ratio of polyacid to polyamine and on the pH. The complex of poly(acrylic acid) and pentaamine was found to be electrosensitive: exposure to an electric field with reversible polarity (8 Hz) led to precipitation of the polymer. These binary stimulus-sensitive compositions consist of two simple substances and are a promising alternative to copolymer-based systems, since the adjustment of properties does not require the synthesis of new substances and expensive toxicological studies in the case of biomedical applications.</div></div>","PeriodicalId":20628,"journal":{"name":"Polymer Testing","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531603","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}