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We develop a static quantum embedding scheme that utilizes different levels of approximations to coupled cluster (CC) theory for an active fragment region and its environment. To reduce the computational cost, we solve the local fragment problem using a high-level CC method and address the environment problem with a lower-level Møller–Plesset (MP) perturbative method. This embedding approach inherits many conceptual developments from the hybrid second-order Møller–Plesset (MP2) and CC works by Nooijen [J. Chem. Phys. 111, 10815 (1999)] and Bochevarov and Sherrill [J. Chem. Phys. 122, 234110 (2005)]. We go beyond those works here by primarily targeting a specific localized fragment of a molecule and also introducing an alternative mechanism to relax the environment within this framework. We will call this approach MP-CC. We demonstrate the effectiveness of MP-CC on several potential energy curves and a set of thermochemical reaction energies, using CC with singles and doubles as the fragment solver, and MP2-like treatments of the environment. The results are substantially improved by the inclusion of orbital relaxation in the environment. Using localized bonds as the active fragment, we also report results for N=N bond breaking in azomethane and for the central C–C bond torsion in butadiene. We find that when the fragment Hilbert space size remains fixed (e.g., when determined by an intrinsic atomic orbital approach), the method achieves comparable accuracy with both a small and a large basis set. Additionally, our results indicate that increasing the fragment Hilbert space size systematically enhances the accuracy of observables, approaching the precision of the full CC solver. [ABSTRACT FROM AUTHOR]

In this research, the morphology, rheology, and mechanical performance of polyamide 6/polylactic acid/acrylonitrile-butadiene-styrene (PA6/ABS/PLA) ternary blends were studied. The optimum ABS percentage in PA6/ABS binary blend to achieve highly toughened blend was determined around 35 wt.%. The spreading coefficient ([S.sub.ij]) predictions showed that each of PLA and ABS can form separate phase in the PA6 matrix. The evaluation of the interfacial interactions in the ternary blends revealed a higher tendency of PLA to interact with PA6 chains ([S.sub.ij]:-1.20) rather than ABS ([S.sub.ij]:-0.20) which is in comply with higher work of adhesion of PLA/PA6 than PLA/ABS and PA6/ABS. By adding PLA to the binary blends of PA6/ABS, it was found that the ABS domain size decreased due to rheological change. The localization of each component in the ternary blends observed in SEM analysis was in agreement with spreading coefficient predictions. Morphological evaluations revealed higher interfacial interactions between PA6 and PLA in the blends with up to 20 wt.% PLA. The optimized blend ratio of ternary blends showed higher complex viscosity at low shear rates and higher values than the mixing rule prediction. The optimum flexural modulus of 2 GPa and impact resistance of 47 kJ/ m2 were achieved at 20 wt.% PLA in PA6/ABS/PLA ternary blend. Highlights * The optimum PA6/ABS blend ratio to achieve high toughness was determined. * The phase localization in the blends predicted via Spreading Coefficient. * The interaction of PA6 and ABS enhanced by the addition of PLA in the blends. * The mechanical properties of blends are correlated with rheological behavior. * The flexural modulus of blends was higher than Halpin-Tsai model predictions. KEYWORDS Halpin-Tsai model, morphology, PA6/ABS/PLA ternary blends, spreading coefficient, viscoelastic properties, 1 | INTRODUCTION Polyamide 6 (PA6) is an engineering plastic with high mechanical strength and good chemical resistance. However, its application is confined in some applications due to its poor [...]

Printability and interlayer adhesion are the most critical issues in 3D printing of immiscible polymer blends. It can affect structural integrity and mechanical performance of the printed parts. In this work, an effective strategy to improve the printability and interlayer adhesion of immiscible acrylonitrile-butadiene- styrene/polypropylene (ABS/PP) blends was implemented by introducing styrene-ethylene/butylene-styrene copolymer grafted with maleic anhydride (SEBS-gMA) as a compatibilizer. The printability of the developed blends was investigated using rheological properties such as absolute value of complex viscosity, loss tangent and die-swell ratio. Interestingly, it was found that the additive manufactured blends with 20 wt% SEBS-g-MA loading showed improved interlaminar shear strength, impact strength, Young's modulus and toughness as compared with the pure blend. Fractography analysis revealed that two different possible failure mechanisms, interface and matrix failure were apparent in the 3D printed samples with and without SEBS-g-MA content. This work provides a promising pathway to fabricate the complex structures from polymer blends with improved mechanical properties and surface finish. Highlights * This study demonstrated improved interlayer adhesion at the printed interface of immiscible ABS/PP blends in presence of SEBS-g-MA. * The printability of the developed blends was predicted from rheological properties. * Additive manufactured blends with SEBS-g-MA loading showed improved mechanical performance. KEYWORDS ABS, interlaminar shear strength, interlayer adhesion, PP, printability, 1 | INTRODUCTION Additive Manufacturing (AM) is a revolutionizing fabrication technique in which the selected material is deposited layer-by-layer in accordance with computeraided design (CAD).1 Several AM processes are commercially [...]

Hydrogen with small molecule size under high pressure can permeate most materials, being a challenge for rubber sealing materials used in hydrogen storage. The volume expansion of rubber materials due to high-pressure hydrogen is an Important indicator of their degradation and failure. Here, both microscopic calculations and experimental investigations of the nitrile rubber were conducted to evaluate the relation between the structure features and the expansion performance. Three factors, the acrylonitrile amount, the chain length, and the crosslinking degree, were considered to impact on the expansion of the nitrile rubber. Current study indicates that the increasing of acrylonitrile amount can result in the reduction of the volume expansion, owing to the preferential interactions between hydrogen and the butadiene group of nitrile rubber. Both of the chain length and the crosslinking degree are positively proportional to the chain elongation and then the volume of the nitrile rubber. Especially, the amount of acrylonitrile was found to be a key factor for evaluating the expansion of nitrile rubber under high-pressure hydrogen. This study performs microscopic calculations and macroscopic experiments to investigate the expansion of nitrile rubber, which is expected to be used in designing the sealing rubber material for high-pressure hydrogen storage applications. Highlights * Acrylonitrile determines the expansion performance of NBR within highpressure hydrogen. * Short chain and low crosslinking density suppressed the expansion of NBR. * Evaluating the expansion of nitrile rubber exposed to high-pressure hydrogen. KEYWORDS high-pressure hydrogen, molecular dynamic calculation, NBR O-rings, volume expansion, 1 | INTRODUCTION Hydrogen as a fuel is a good candidate for meeting the rapidly growing demand for energy in an environmentally friendly way. (1-3) However, the low-volume energy density [...]

We describe a method to run simulations of ground or excited state dynamics under extremely high pressures. The method is based on the introduction of a fictitious ideal gas that exerts the required pressure on a molecular sample and is therefore called XP‐GAS (eXtreme Pressure by Gas Atoms in a Sphere). The algorithm is most suitable for approximately spherical clusters of molecules described by quantum chemistry methods, Molecular Mechanics or mixed QM/MM approaches. We compare the results obtained by the algorithm here presented and by the XP‐PCM approach, based on a continuum description of the environment. As a test case, we study the conformational dynamics of 1,3‐butadiene either as an isolated molecule ("naked" butadiene) or embedded in a cluster of argon atoms, under pressures up to 15 GPa. Overall, our results show that the XP‐GAS QM/MM simulation method is in good agreement with the XP‐PCM QM/Continuum model (Cammi model) in describing the effect of the pressure on static properties as the equilibrium geometry of butadiene in the ground state. Furthermore, the comparison of XP‐GAS simulations with naked butadiene and butadiene in argon shows the importance, for XP‐GAS and related methods, of a realistic representation of the medium in modelling pressure effects. [ABSTRACT FROM AUTHOR]

Products made from light olefins play an important role in our daily lives. Traditional light olefins production based on steam cracking and fluid catalytic cracking suffer from high energy consumption and CO2 emissions. Thereby, the continually increasing demand for light olefins needs to be met through more environmentally sustainable procedures. On‐purpose production routes are preferred choice among petrochemicals manufacturers, being energy efficient and having lower carbon footprint. Among them, oxidative dehydrogenation (ODH) of light paraffins is a thermodynamically favourable exothermic process as compared to non‐oxidative routes. They can be operated at lower temperatures and have propensity of low coke deposition on catalyst, thereby resisting rapid catalyst deactivation. Herein, we have analysed various catalytic systems utilised in the oxidative dehydrogenation process. We have reviewed role of support, chemical composition of catalyst, presence of dopant, oxidation state of active metal, controlled surface modification by oxidative and reductive pretreatments, and reaction factors for each system. The performance of various catalytic systems for ODH of ethane, propane and butane in the presence of O2, CO2, N2O and special oxidants have been reviewed. A short critical overview on emerging on‐purpose routes for the production of renewable 1,3 butadiene has also been discussed. [ABSTRACT FROM AUTHOR]

The study presents the chemiluminescence based (CL) evaluation of the recyclability of linear styrene block copolymers. This analysis can provide insight into the material's degradation state and predict its suitability for further recycling cycles, helping to avoid unnecessary energy consumption during processing.The thermal stability of four similar copolymer structures − styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS) copolymers with different styrene/butadiene ratios, and styrene-ethylene-butadiene-styrene (SEBS) − was studied using isothermal and non-isothermal chemiluminescence (CL). The activation energies for oxidative degradation were calculated based on oxidation induction times indicated by the CL intensities evolution. The results, which highlight the influence of molecular structure on stability under aging conditions, as presented by the calculated for the activation energy (kJ mol−1), show the following sequence: SBS (styrene 30%) (117 kJ mol−1) ≈ SIS 120 (kJ mol−1) < SBS (styrene 40%) (176 kJ mol−1) < SEBS (180 kJ mol−1). The CL data were correlated with infrared (IR) spectroscopy and differential scanning calorimetry (DSC) data, providing a comprehensive understanding of the thermal stability and degradation mechanisms during recycling proces. The sequence of the composing units determines the degradation process, with weaker points predominantly attacked in the linear moieties of isoprene, butadiene, and vinyl segments. The experimental data indicate that SIS and SBS (30% styrene) copolymers degrade the fastest likely due to the rapid accumulation of hydroperoxide radicals. The SEBS copolymer also experiences significant degradation, but this occurs at higher temperatures (above 220 ⁰C) and progresses more gradually once it begins. In contrast, the SBS copolymer with 40% styrene content degrades more slowly and exhibits minimal mass loss, primarily due to the formation of less reactive keto degradation products. [ABSTRACT FROM AUTHOR]

This paper utilizes the Wohler curve and the J-integral principle to predict the service life of purposely-damaged acrylonitrile butadiene styrene (ABS) specimens. The hardness of single- and double-notched specimens was measured using the J-integral, facilitating a comparison between two different types of defects. By analyzing the Wohler curve, we were able to examine the decline in the service life of the ABS specimens over various time intervals. According to the comparison, a hole with a single internal notch flaw is not as detrimental as one with two notch defects. [ABSTRACT FROM AUTHOR]

This article explores the fatigue characteristics of acrylonitrile butadiene styrene (ABS) components fabricated using fused filament fabrication (FFF) additive manufacturing technology. ABS is frequently used as a polymeric thermoplastic material in open-source FFF machines for a variety of engineering applications. However, a comprehensive understanding of the mechanical properties and execution of FFF-processed ABS components is necessary. Currently, there is limited knowledge regarding the fatigue behavior of ABS components manufactured using FFF AM technology. The primary target of this study is to evaluate the results of part-build directions and build orientation angles on the tensile fatigue behavior exhibited by ABS material. To obtain this target, an empirical investigation was carried out to assess the influence of building angles and orientation on the fatigue characteristics of ABS components produced using FFF. The test samples were printed in three distinct directions, including Upright, On Edge, and Flat, and with varying orientation angles ([0°, 90°], [15°, 75°], [30°, 60°], [45°]), using a 50% filling density. The empirical data suggest that, at each printing angle, the On-Edge building orientation sample exhibited the most prolonged vibrational duration before fracturing. In this investigation, we found that the On-Edge printing direction significantly outperformed the other orientations in fatigue life under cyclic loading with 1592 loading cycles when printed with an orientation angle of 15°–75°. The number of loading cycles was 290 and 39 when printed with the same orientation angle for the Flat and Upright printing directions, respectively. This result underscores the importance of orientation in the mechanical performance of FFF-manufactured ABS materials. These findings enhance our comprehension of the influence exerted by building orientation and building angles on the fatigue properties of FFF-produced test samples. Moreover, the research outcomes supply informative perspectives on the selection of building direction and building orientation angles for the design of 3D-printed thermoplastic components intended for fatigue cyclic-loading applications. [ABSTRACT FROM AUTHOR]

Deep eutectic electrolytes (DEEs) have attracted significant interest due to the unique physiochemical properties, yet challenges persist in achieving satisfactory Li anode compatibility through a binary DEE formula. In this study, we introduce a nonflammable binary DEE electrolyte comprising of lithium bis(trifluoro‐methane‐sulfonyl)imide (LiTFSI) and solid butadiene sulfone (BdS), which demonstrates enhanced Li metal compatibility while exhibiting high Li+ ion migration number (0.52), ionic conductivity (1.48 mS ⋅ cm−1), wide electrochemical window (~4.5 V vs. Li/Li+) at room temperature. Experimental and theoretical results indicate that the Li compatibility derives from the formation of a LiF‐rich SEI, attributed to the undesirable adsorption and deformation of BdS on Li surface that facilitates the preferential reactions between LiTFSI and Li metal. This stable SEI effectively suppresses dendrites growth and gas evolution reactions, ensuring a long lifespan and high coulombic efficiency in both the Li||Li symmetric cells, Li||LiCoO2 and Li||LiNi0.8Co0.1Mn0.1O2 full cells. Moreover, the BdS eutectic strategy exhibit universal applicability to other metal such as Na and Zn by pairing with the corresponding TFSI‐based salts. [ABSTRACT FROM AUTHOR]

Herein, we report a highly selective production route for butadiene from γ‐valerolactone over zeolite catalysts. The catalytic performance of eight zeolites with different framework topologies were compared, revealing that zeolites with narrower 10‐membered ring channels exhibit enhanced selectivity of butadiene. Specifically, ZSM‐35 and ZSM‐22, featuring the narrowest 10‐membered ring channels, demonstrate the highest butadiene selectivity to 61 % and 59 %, respectively. Notably, surface passivation of ZSM‐35 leads to a remarkable increase in butadiene selectivity to 82 %, maintaining a 99 % conversion. Additionally, we propose a reaction network and identify cyclopentenone as a key intermediate in the transformation of γ‐valerolactone to butadiene. Both experimental and theoretical results conclude that confinement effect of 10‐membered ring channels improves the selectivity of butadiene. [ABSTRACT FROM AUTHOR]

Architected metamaterials are known as materials with unique mechanical and topological behavior. This paper presents architected twist-compression metamaterials, which twist around their axis under compression, for energy absorption and effective mechanical properties. The proposed metastrcutures are designed through novel generative algorithms that enable the parametric design in which the geometrical parameters of the produced metastructures are tunable. Several experimental tests were carried out to determine accurate material properties for the finite element analysis and to evaluate the capability of the presented metastructures. Specimens printed from acrylonitrile butadiene styrene (ABS) using fused deposition modeling techniques (FDM). To evaluate the effect of geometrical parameters on the properties of the twist-compression metastructures a four-step parametric study was conducted by virtue of the verified finite element models. These finite element models contain damage criteria to model the failure behavior of the metastrucutures under quasi-static loading. The influencing geometrical parameters on the mechanical properties, as well as energy absorption capacity, have been considered via numerical and experimental analysis. Obtained results showed some unique features of these structures in elastic and plastic behaviors. [ABSTRACT FROM AUTHOR]

Abstract The study presents the chemiluminescence based (CL) evaluation of the recyclability of linear styrene block copolymers. This analysis can provide insight into the material’s degradation state and predict its suitability for further recycling cycles, helping to avoid unnecessary energy consumption during processing.The thermal stability of four similar copolymer structures − styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS) copolymers with different styrene/butadiene ratios, and styrene-ethylene-butadiene-styrene (SEBS) − was studied using isothermal and non-isothermal chemiluminescence (CL). The activation energies for oxidative degradation were calculated based on oxidation induction times indicated by the CL intensities evolution. The results, which highlight the influence of molecular structure on stability under aging conditions, as presented by the calculated for the activation energy (kJ mol−1), show the following sequence: SBS (styrene 30%) (117 kJ mol−1) ≈ SIS 120 (kJ mol−1)

To make advanced treatment of wastewater from butadiene-based PA66 salt production, the research of ozone catalyst was conducted, and a combined process of high-efficiency sedimentation+pre-ozone catalytic oxidation+two-stage pre-denitrification+post-ozone catalytic oxidation was introduced. The results showed that the treatment effect of the whole process was in a relatively stable condition. The effluent with COD≤40 mg/L, NH3-N≤2 mg/L, and TN≤5 mg/L was better than first class A effluent index of Pollutant Emission Standards for Urban Sewage Treatment Plants(GB 18918-2002). In the process of bacterial culture, post-ozone catalytic oxidation had NH3-N removal rate of 81.1% and TN removal rate of 63.7%, showing great performance in NH3-N and TN removal. Meanwhile, pre-ozone catalytic oxidation had a better performance in COD removal, and the mass ratio between ozone consumption and COD removal was 1.64∶1. The operating cost of the whole process for treating wastewater from PA66 salt producted by butadiene was 4.86 yuan/t. The whole process was cost-effective compared to deep treatment project. It provides reference for similar wastewater treatment.

A cobalt-catalyzed three-component assembly of substituted aryl oximes with dienes and formaldehyde via C–H bond activation is described. This protocol affords highly regio- and chemoselective substituted homoallylic alcohols with moderate-to-excellent yields. The scope of this protocol has been extensively explored with various substituted aryl ketoximes and aldoximes. Butadiene and internally substituted dienes are also well compatible for this transformation. A plausible reaction mechanism is proposed to account for the present reaction and is supported by deuterium labeling studies. [ABSTRACT FROM AUTHOR]

The influence of acetone vapor bath smoothing on the fatigue lives of 3D printed acrylonitrile butadiene styrene test specimens was investigated using a rotating bending cantilever beam test. The results show that the vapor bath treatment improved the fatigue life by a factor of two on average, but the variability in the specimen lifetime increased. Investigation of the fracture surface via optical and scanning electron microscopy reveals a complex fracture path with crack nucleation at multiple sites. Based on the observations from the study, suggestions are made to improve the fatigue lives of 3D printed ABS polymer components. [ABSTRACT FROM AUTHOR]

1,3-Butadiene (BD) is classified as a human carcinogen, and occupational exposure should be minimized. This study examined the effectiveness of personal protective equipment (PPE) during the clean-up and repair of a storage tank containing sludge contaminated with BD. A total of 66 workers participated, providing repeat urine samples before and after the shift. Overall, 1286 samples were analyzed for 1,2-dihydroxy-4-(N-acetylcysteinyl)butane (DHBMA) and the isomers 2-hydroxy-1-(N-acetylcysteinyl)-3-butene and 1-hydroxy-2-(N-acetylcysteinyl)-3-butene (MHBMA). Both DHBMA and MHBMA are urinary metabolites of BD and serve as biomarkers for recent BD exposure. Established correlations between the urinary concentrations of these biomarkers and airborne BD levels allowed for exposure assessment. However, conclusions regarding the exceedances of occupational exposure limits can vary depending on whether DHBMA or MHBMA levels are considered. This study investigated this discrepancy by estimating the apparent urinary half-lives of DHBMA and MHBMA using sequential individual post- and pre-shift samples. The results indicated that the longer urinary half-life of MHBMA (19.7 ± 3.1 h) led to its accumulation during the work week, in contrast to DHBMA, which has a shorter half-life (10.3 ± 1.9 h) and showed limited accumulation. When the kinetic information was used to adjust for the MHBMA build-up over the week, the discrepancy with DHBMA resolved, confirming that exposure limit values were not exceeded and validating the effectiveness of the PPE used. In the context of biomonitoring, this study provides valuable insights into biomarker selection based on specific objectives. MHBMA is recommended for scenarios with uncertain exposure timing and activities, whereas DHBMA is the preferred biomarker for evaluating the effectiveness of protective measures in known exposure settings. [ABSTRACT FROM AUTHOR]

In present work, using the double layer ONIOM methodology, we simulated the stages of initiation and growth of the polymer chain during the polymerization of butadiene on a neodymium‐based Ziegler–Natta catalyst. The DFT methods B3LYP and PBE0 in combination with the Def2‐TZVP atomic basis set were used as high‐level methods in ONIOM. Grimme's semi‐empirical XTB1 method was used as a low‐level method. In our previous work, the mechanism of butadiene polymerization on a neodymium‐containing Ziegler–Natta catalyst was studied in detail. The polymerization activation energy of 61 kJ/mol was found to be slightly higher than the experimentally determined values of this parameter. In the present work, the influence of a high‐level method and a model of taking into account dispersion interactions on the quality of calculation of activation parameters of the polymerization reaction was studied. Experimental activation energy for the polymerization of dienes in the presence of Ziegler–Natta catalysts is in the range of 30–60 kJ/mol, but neodymium‐based catalysts have an activation energy somewhat closer to the lower limit of this range. For comparison, semi‐empirical Grimme models D3 and D4 were used. It has been established that the both models reveal within the B3LYP method the activation energy practically the same, while within the PBE0 method it decreases to 41 kJ/mol. Thus, using the PBE0 as a high‐level method within the ONIOM methodology and taking into account dispersion interactions within the D4 model leads to results in much better agreement with experimental data. [ABSTRACT FROM AUTHOR]

The main objective of the Steam Cracker is to produce monomers prone to polymerization. The drawback is that polymerization can occur in the Steam Cracker itself. The main monomers fouling precursor is Butadiene. All along the separation process, Butadiene concentration and process temperature change. This implies step changes in polymer structure and fouling level. Several techniques are used to control this fouling, including oxygen ingress control, the use of additives such as antioxidants and free radical scavengers. By a catalytic effect, the metal surfaces can also be a polymerization initiator. The objective of passivation is to modify the Carbon Steel surface into stable magnetite and maghemite. Using electrochemistry to characterize different Carbon Steel samples, we were able to improve our passivation procedure. And when applying metal passivation, we were able to increase run length of Depropanizer reboilers limiting the fouling rate and its impact on operation. [ABSTRACT FROM AUTHOR]

Acrylonitrile butadiene styrene (ABS) is a polymer used for diverse applications such as automobile parts, electronic components, and consumer goods owing to properties like high impact strength, lightweight nature, and chemical resistance. However, the extensive use of ABS polymer generates a significant amount of waste, which has environmental repercussions due to improper disposal, such as landfilling and incineration, which severely threaten the ecosystems around us. Recycling ABS waste reduces the burden on landfills and enables us to reuse waste ABS, which aligns with the principles of sustainability. This article discusses the processes involved in recycling ABS waste, including collection, segregation, recycling technologies, preparation of blends, and applications of recycled ABS. Mechanical and chemical recycling technologies are comprehensively covered as these are the two main recycling technologies employed for ABS waste recycling. This review attempts to cover recent ABS recycling techniques and highlight the significance of ABS plastic recycling for the circular economy. Recycling ABS waste is vital in extending its lifespan, leading to more cost-effective and resource-efficient industrial processes. Embracing the transformative potential of ABS waste unlocks many possibilities and opportunities for innovation while upholding sustainability principles. [ABSTRACT FROM AUTHOR]

In this work, a series of nickel-containing samples of carbon xerogels (Ni@CX) were synthesized by introducing nickel acetate into a solution of precursors (resorcinol and formaldehyde), joint polycondensation, and subsequent pyrolysis in an atmosphere of argon. The samples were tested in the selective hydrogenation reaction of 1,3-butadiene. It was shown that catalysts prepared without the addition of complexing agents contained nickel nanoparticles (4–7 nm) stabilized in a carbon matrix. The Ni@CX catalyst made it possible to achieve a selectivity of 93% for butenes at a conversion of 94% and a temperature of 200°C, while the selectivity for the formation of butenes in the presence of an impregnated reference sample was lower than 1%, although it provided a conversion of 100% already at 75°C. It was supposed that the selectivity of catalysts prepared by the joint synthesis increased due to the blockage of nonselective catalytic sites by carbon of the support. [ABSTRACT FROM AUTHOR]

The article focuses on synthesising a new nanocomposite incorporating ZnS filler and investigating its structure, optical properties and specific electrical conductivity. In this study, expanded perlite (EP) and butadiene rubber (BR) underwent simultaneous oxidative chlorophosphorylation and subsequent hydrolysis. ZnS nanoparticles were then grown on the crosslinked/ion-exchange composite (EP-PhBR) using the Successive Ionic Layer Adsorption and Reaction (SILAR) method, resulting in the ZnS/EP-PhBR nanocomposite. The structure of the nanocomposite was characterised through UV-Vis spectroscopy and X-ray diffraction analysis. Embedding ZnS nanoparticles in EP-PhBR caused a reduction in the optical band gap from 3.18 eV to 3.045 eV, signifying increased disorder in ZnS nanoparticles due to alterations in the nanocomposite's intermolecular structure. XRD studies revealed cubic crystal-structured ZnS nanoparticles with an average size of approximately 3 nm in the ZnS/EP-PhBR nanocomposite. The specific electrical conductivity (σ) at ambient temperature demonstrated the enhanced crystallinity of EP-PhBR, attributed to interfacial interactions with ZnS nanoparticles and the developed nanolayers. The ZnS/EP-PhBR nanocomposite exhibited favourable properties, making it a promising material for photocatalysis and solar cell applications. [ABSTRACT FROM AUTHOR]

Background: Surface‐guided radiotherapy (SGRT) is adopted by several institutions; however, reports on the phantoms used to assess the precision of the SGRT setup are limited. Purpose: The purpose of this study was to develop a phantom to verify the accuracy of the irradiation position during skin mark‐less SGRT. Methods: An acrylonitrile butadiene styrene (ABS) plastic cube phantom with a diameter of 150 mm on each side containing a dummy target of 15 mm and two types of body surface‐shaped phantoms (breast/face shape) that could be attached to the cube phantom were fabricated. Films can be inserted on four sides of the cubic phantom (left, right, anterior and posterior), and the center of radiation can be calculated by irradiating the dummy target with orthogonal MV beams. Three types of SGRT using a VOXELAN‐HEV600M (Electronics Research&Development Corporation, Okayama, Japan) were evaluated using this phantom: (i) SGRTCT—a SGRT set‐up based solely on a computed tomography (CT)‐reference image. (ii) SGRTCT + CBCT—a method where cone beam computed tomography (CBCT) matching was performed after SGRTCT. (iii) SGRTScan—a resetup technique using a scan reference image obtained after completing the (ii) step. Results: Both the breast and face phantoms were recognized in the SGRT system without problems. SGRTScan ensure precision within 1 mm/1° for breast and face verification, respectively. All SGRT methods showed comparable rotational accuracies with no significant disparities. Conclusions: The developed phantom was useful for verifying the accuracy of skin mark‐less SGRT position matching. The SGRTScan demonstrated the feasibility of achieving skin‐mark less SGRT with high accuracy, with deviations of less than 1 mm. Additional research is necessary to evaluate the suitability of the developed phantoms for use in various facilities and systems. This phantom could be used for postal surveys in the future. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The utilization of carbon dioxide (CO2) as a C1 feedstock is consistently attractive, especially in the preparation of sustainable polymeric materials. In this contribution, a terpolymer of CO2, 1,3‐butadiene (BD) and epoxide is synthesized by scandium triflate catalyzed cationic ring‐opening copolymerization of α‐ethylidene‐δ‐vinyl‐δ‐valerolactone (EVL), an intermediate derived from CO2 and BD, with epoxides. The obtained terpolymer with a CO2 content of 22 mol% has a number‐average molecular weight (Mn) up to 7.8 kg/mol and a dispersity (Đ) of 2.4. The reactivity ratios of EVL and cyclohexene oxide (CHO) are determined as 0.01 and 1.07, respectively, suggesting random characteristic of the terpolymer. The preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated crosslinking. The yielded networks are fluorescent and degradable. This method offers enhanced versatility to the synthesis and additional functionalization of CO2‐based polymers. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the tire–road-wear particles (TRWPs) and suspended dust generated based on the nominal maximum aggregate size (NMAS) of the polymer-modified stone mastic asphalt (SMA) mixtures indoors. The SMA mixtures containing styrene butadiene styrene (SBS) polymer and the NMASs of 19, 13, 10, 8, and 6 mm were used. Dust was generated from the wear of the tires and the pavement inside the indoor chamber by using the laboratory tire–road-wear particle generation and evaluation tester (LTRWP tester) developed by Korea Expressway Corporation (KEC). In this method, a cylindrical asphalt-mixture specimen rotates in the center, and a load is applied using three tires on the sides of the test specimen. During the test, a digital sensor was used to measure the concentration for each particle size. After the test was completed, the dust was collected and weighed. According to the test results, the generated TRWP emissions were reduced by approximately 0.15 g as the NMAS of the SMA mixture decreased by 1 mm. TRWP emissions decreased by 20% when using the 6 mm SMA mixture compared to the 13 mm SMA mixture. For practical application, a predicted equation of TRWP emissions estimation was developed by using the concentration of suspended dust measured by the digital sensor in the LTRWP tester. LTRWP can be used as an indoor test method to evaluate pavement and tire materials to reduce the amount of dust generated from tire and pavement wear. [ABSTRACT FROM AUTHOR]

The rapid advancement of polymer composites, particularly those reinforced with hybrid kenaf, has positioned them as viable structural materials across diverse industries such as automotive, defense, aerospace, marine, construction, and naval. Despite their growing popularity, recent advances in kenaf yarn‐reinforced thermoplastic acrylonitrile butadiene styrene (ABS) composites for structural applications need more comprehensive coverage in the literature. This article addresses this gap by critically examining the influence of quasi‐isotropic stacking orientation on water absorption, flexural strength, and impact properties in kenaf yarn fiber‐reinforced ABS composites. Prepared using hand layup and compression molding techniques, the composites featured varying stacking orientations, including 0°/0°/0°/0°, 0°/90°/0°/90°, −45°/90°/0°/45°, 90°/−45°/0°/45°, 90°/0°/45°/−45°, and 0°/45°/−45°/90° for kenaf yarn reinforced ABS. The findings reveal that the 0°/45°/−45°/90° configuration offers the best overall mechanical properties and water penetration resistance among quasi‐isotropic stacking sequences, exhibiting low water uptake and higher tensile and flexural strengths of 35.3 and 85.4 MPa, respectively, compared to other sequences. This suggests that incorporating ±45° plies contributes to a balanced distribution of mechanical strength and modulus across different directions, making the 0°/45°/−45°/90° configuration ideal for high‐strength structural applications in kenaf yarn/ABS composites. Highlights: Fiber stacking orientation is the key factor affecting the mechanical performance of kenaf‐based composites.Using the hand layup technique, six stacking orientations (0°/0°/0°/0°, 0°/90°/0°/90°, −45°/90°/0°/45°, 90°/−45°/0°/45°, 90°/0°/45°/−45°, and 0°/45°/−45°/90°) were employed to create kenaf fiber‐reinforced ABS composites.A quasi‐isotropic sequence of 0°/45°/−45°/90° allows the least water penetration due to the strategic placement of ±45° plies in the middle layers of composites.0°/45°/−45°/90° configuration offers the best flexural and tensile properties due to better force distribution within the ±45° plies in the middle layers.Under surface morphological analysis, the optimal fiber stacking sequence contributes to fewer voids and fiber pull‐outs. [ABSTRACT FROM AUTHOR]

The improvement of the structure-property relation in nanocomposites between different polymer matrices and the embedded nano-additives has become a strategic blueprint for many academic counterparts around the globe. In this work, different loadings of graphene oxide (GO) varied from 1.0 to 3.0 wt. % were mixed with acrylonitrile butadiene styrene (ABS) using solution casting approach. The resulted nanocomposites underwent to spectral, structural, morphological, mechanical, thermal and thermomechanical tests. Different kinds of instruments associated with each test were employed to draw a professional conclusion about the potential improvement in structure-property relation. The targeted improvement was achieved as spectral, structural and morphological investigations confirmed the interaction, structural variation, and good dispersion of GO in ABS; respectively. Furthermore, as GO loadings went higher, the mechanical, thermal, and thermomechanical performances for the nanocomposites were improved compared to the neat polymer. Young's modulus, tensile strength, thermal decomposition, and visco-elastic properties showed an enhancement compared to the neat polymer. The mechanical and thermomechanical performances for the nanocomposites recorded significant promotions. [ABSTRACT FROM AUTHOR]

The presence of polymer material filaments plays a crucial role in the realm of 3D printing. These filaments are utilized in 3D printing to create prototype products efficiently and cost-effectively. However, ensuring the production of high-quality prototype products necessitates the use of superior filaments characterized by consistent diameter and a round cross-section. Filaments are typically manufactured through an extrusion process using either a single screw extruder or a twin extruder. In this research, a DIY single-screw extruder was developed specifically for filament production. The main objective of this study is to generate quality filaments by optimizing the extruder parameters for various polymer materials. Three different polymers; Ethylene-vinyl Acetate (EVA), Polypropylene (PP), and Acrylonitrile Butadiene Styrene (ABS) were employed in this study. The research aimed to assess the melt flow index (MFI) to demonstrate viscous behavior and establish the ideal parameters for each material in the extrusion process. A total of 27 EVA material filament samples, 26 PP filament samples, and 26 ABS filament samples were successfully produced. Through analysis, optimal settings were identified for EVA, PP, and ABS filaments, resulting in high-quality production. The recommended parameters for producing quality EVA filaments included a temperature of 160°C, screw speed of 400 rpm, and take-up speed of 400 rpm. For PP filaments, the optimal settings comprised a temperature of 230°C, screw speed of 700 rpm, and take-up speed of 250 rpm. Lastly, ABS filament production was optimized with a temperature of 210°C, screw speed of 300 rpm, and take-up speed of 100 rpm. This project's outcomes are anticipated to have significant implications for future advancements in filament manufacturing processes. [ABSTRACT FROM AUTHOR]

Safety and reliability are the major challenges to face for the development and acceptance of hydrogen technology. It is therefore crucial to deeply study material compatibility, in particular for tribological components that are directly in contact with hydrogen. Some of the most critical parts are sealing materials that need increased safety requirements. In this study, the fretting behavior of several elastomer materials were evaluated against 316L stainless steel in an air and hydrogen environment up to 10 MPa. Several grades of cross-linked hydrogenated acrylonitrile butadiene (HNBR), acrylonitrile butadiene (NBR) and ethylene propylene diene monomer rubbers (EPDM) were investigated. Furthermore, aging experiments were conducted for 7 days under static conditions in 100 MPa of hydrogen followed by rapid gas decompression. Fretting tests revealed that the wear of these compounds is significantly affected by the hydrogen environment compared to air, especially with NBR grades. After the aging experiment, the friction response of the HNBR grades is characterized by increased adhesion due to elastic deformation, leading to partial slip. [ABSTRACT FROM AUTHOR]

The use of polymers is desirable in the industries where weight reduction and corrosion resistance are required, such as in the automotive industry where weight reduction directly relates to fuel conservation. Acrylonitrile butadiene styrene (ABS) is a type of polymer used in aerospace, railway, automotive, and consumer goods industries. This research article investigates the use of friction stir welding (FSW) to join ABS polymer. Compared to traditional metal-based products, polymers offer better formability, design flexibility, and ease of processing. The process parameters were optimized based on tensile strength using Taguchi's L18 orthogonal array (OA). A maximum tensile strength of 19.4 MPa was obtained at a tool rotational speed of 224 rpm, a tool travel speed of 40 mm/min, external heat of 45 °C, and a tool shoulder diameter of 16 mm. Transmission electron microscopy was used to analyze the microstructural characteristics, while Vickers microhardness tester and tensometer were used to examine the mechanical properties. The strength of the joint was affected due to the butadiene rubber particles breaking or weakening in the stir zone). Moreover, to identify the location of failure, three additional tensile coupons were taken from Experiment No. 13, and a 1-mm-deep notch was machined in all of them at the Center, AS, and RS. The findings revealed that the tensile coupon with the notch at RS had a tensile strength of 19.4 MPa, which is 60% relative to the base material. The retreating side of Experiment No. 13 exhibited a Vickers microhardness of 14.3 HV, which was higher than the base material's Vickers microhardness of 13.8 HV, indicating that it became harder. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The calendering process of pole piece is a key step affecting the performance of the power battery. In the calendaring process, rubber roller materials will produce hysteresis heat, resulting in rolling resistance, which will lead to energy loss. The thermo-mechanical coupling model for calendering rubber roller has been established and the effects of materials, calendering speeds, and roller structure shape on the viscoelastic temperature rise of rubber roller were analyzed. Solution-polymerized styrene-butadiene rubber (SSBR) materials with different fillers have the greatest impact on temperature rise, followed by the roller shape, and calendering speed is smaller. The loss modulus of SSBR filled with white carbon black studied was smaller, and the temperature rise at high speed was 14.5[degrees]C higher than that at low speed. The optimized roller shape has a temperature rise of 10.4[degrees]C lower than the original shape. The research results could provide reference for the calendering rubber roller design of pole piece and similar processing. Highlights * A thermo-mechanical coupling model of calendering rubber roller was established. * The rubber roller made of SSBR-VN3 has a lower temperature rise. * Optimized structure reduced contact pressure by 28.1% and temperature rise by 10.4[degrees]C. KEYWORDS battery pole piece calendaring, FEM, hysteresis temperature rise, rubber roller, thermomechanical coupling model, 1 | INTRODUCTION With the increasingly serious problems of environmental pollution and energy shortage, especially with the development of science and technology and the process of modernization, the consumption of [...]

Photoinduced Pd‐catalyzed bisfunctionalization of butadienes with a readily available organic halide and a nucleophile represents an emerging and attractive method to assemble versatile alkenes bearing various functional groups at the allylic position. However, enantiocontrol and/or diastereocontrol in the C−C or C−X bond‐formation step have not been solved due to the open‐shell process. Herein, we present a cascade asymmetric dearomatization reaction of indoles via photoexcited Pd‐catalyzed 1,2‐biscarbonfunctionalization of 1,3‐butadienes, wherein asymmetric control on both the nucleophile and electrophile part is achieved for the first time in photoinduced bisfunctionalization of butadienes. This method delivers structurally novel chiral spiroindolenines bearing two contiguous stereogenic centers with high diastereomeric ratios (up to >20 : 1 dr) and good to excellent enantiomeric ratios (up to 97 : 3 er). Experimental and computational studies of the mechanism have confirmed a radical pathway involving excited‐state palladium catalysis. The alignment and non‐covalent interactions between the substrate and the catalyst were found to be essential for stereocontrol. [ABSTRACT FROM AUTHOR]

In this work, the incorporation of halloysite nanotubes (HNTs) and polyphenylene ether-grafted maleic anhydride copolymer (FB) into acrylonitrile butadiene styrene (ABS)/polyphenylene oxide (PPO) blend has been investigated to enhance the compatibility and performance of the blends. ABS/PPO blend (AP) with the weight ratio of ABS/PPO = 70/30 with 5 wt% loading of FB and different weight contents of HNTs were elaborated by melt blending process, and their properties were studied. The SEM observation revealed that AP blend exhibited dispersed phases of PPO droplets with apparent gaps between PPO and ABS phases, indicating poor adhesion between the polymers in the blend. As the compatibilizer, FB effectively enhanced the inter-phase interaction, minimizing the formation of interfacial gaps, evidenced by the SEM images, leading to the adhesion between ABS, PPO, and HNTs phases. As a result, the mechanical performance of the AP blend was significantly improved with the addition of FB and HNTs. At 5 wt% of HNT, the AP/FB/HNT blend exhibited the tensile strength of 37.47 MPa and flexural strength of 59.09 MPa compared to 26.60 MPa and 39.45 MPa of neat AP, respectively. The glass transition temperature of the modified blends showed shifts compared to the neat AP, which indicates the improvement in miscibility of the modified-AP blends. The thermal stability and flame resistance of the blends were also enhanced with the introduction of HNTs and FB, evidenced by the V-1 rating in the UL-94 test and the increase in limiting oxygen index (LOI). These results demonstrated that the incorporation of HNTs and FB is a promising and straightforward method to improve the properties of ABS/PPO blends. [ABSTRACT FROM AUTHOR]

To study the variation laws and effects of asphalt mastic under the cooperative interaction of different temperatures and humidities, cyclic conditions for different temperature ranges were set to conduct indoor experimental simulations of thermal–humidity coupling cycles. Firstly, the macroscopic performance changes in styrene butadiene styrene polymer (SBS)-modified asphalt mastic were evaluated by the penetration test, softening point test, ductility test, Brookfield rotational viscosity test, and double-edge notched tensile (DENT) test; then, the mechanism of performance changes was explored from the perspective of chemical composition by combining this with Fourier transform infrared spectroscopy (FTIR). The research results show that with the increase in thermal–humidity coupling cycles, SBS-modified asphalt mastic exhibited aging phenomena such as hardening and embrittlement, and its macroscopic performance deteriorated; under the same test conditions, the interval with a higher temperature difference had a greater impact on the performance of the mastic; the sulfoxide index (IS=O) of SBS-modified asphalt mastic increases after thermal–humidity coupling cycles, while the isoprene index (IB) decreases. [ABSTRACT FROM AUTHOR]

Biocomposites made from natural fibers have attracted significant attention in recent years owing to the global concern regarding plastic accumulation. In this investigation, ramie fiber was employed as a natural fiber reinforcement in the acrylonitrile butadiene styrene (ABS) matrix to enhance the biodegradability of the polymer composite. ABS/ramie fiber composites were prepared by compression molding with various wt% (5, 10, 15, and 20 wt %) of ramie fibers within the ABS matrix. Subsequently, the biodegradability, water absorption, mechanical properties, viscoelastic behavior, and thermal characteristics of the prepared composites were evaluated. The biodegradation test results demonstrated that there was a positive correlation between the concentrations of fibers in neat ABS. The maximum biodegradation of the composites was 2.56% at 20 wt% ramie fibers in the ABS matrix. Moreover, an increase in the wt% of ramie fiber led to an increase in water absorption. Although the tensile strength and impact strength decreased with increasing fiber content, the tensile modulus of the ABS/ramie fiber composites initially increased up to 5 wt% fiber and then started decreasing, and the natural fibers in ABS reduced the viscoelastic properties. The objective of developing ABS/ramie fiber composites is to utilize them as environmentally sustainable materials in automotive manufacturing industry. [ABSTRACT FROM AUTHOR]

Porous materials that could recognize specific molecules from complex mixtures are of great potential in improving the current energy‐intensive multistep separation processes. However, due to the highly similar structures and properties of the mixtures, the design of desired porous materials remains challenging. Herein, a sulfonate‐functionalized metal–organic framework ZU‐609 with suitable pore size and pore chemistry is designed for 1,3‐butadiene (C4H6) purification from complex C4 mixtures. The sulfonate anions decorated in the channel achieve selective recognition of C4H6 from other C4 olefins with subtle polarity differences through C−H⋅⋅⋅O−S interactions, affording recorded C4H6/trans‐2‐C4H8 selectivity (4.4). Meanwhile, the shrunken mouth of the channel with a suitable pore size (4.6 Å) exhibits exclusion effect to the larger molecules cis‐2‐C4H8, iso‐C4H8, n‐C4H10 and iso‐C4H10. Benefiting from the moderate C4 olefins binding affinity exhibited by sulfonate anions, the adsorbed C4H6 could be easily regenerated near ambient conditions. Polymer‐grade 1,3‐butadiene (99.5 %) is firstly obtained from 7‐component C4 mixtures via one adsorption‐desorption cycle. The work demonstrates the great potential of synergistic recognition of size‐sieving and thermodynamically equilibrium in dealing with complex mixtures. [ABSTRACT FROM AUTHOR]

This study investigated how printing conditions influence the fracture behaviour of 3D-printed acrylonitrile butadiene styrene (ABS) under tensile loading. Dog-bone-shaped ABS specimens were produced using the fusion filament fabrication technique, with varying printing angles. Tensile tests were conducted on pre-notched specimens with consistent pre-notch lengths but different orientations. Optical and scanning electron microscopies were employed to analyse crack propagation in the pre-notched specimens. In order to support experimental evidence, finite element computation was implemented to study the damage induced by the microstructural rearrangement of the filaments when subject to tensile loading. The findings revealed the simple linear correlation between the failure properties including elongation at break and maximum stress in relation to the printing angle for different pre-notch lengths. A more progressive damage was found to support the ultimate performance of the studied material. This experiment evidence was used to build a damage model of 3D-printed ABS that accounts for the onset, growth, and damage saturation. This damage modelling is able to capture the failure properties as a function of the printing angle using a sigmoid-like damage function and a modulation of the stiffness within the raster. The numerical results demonstrated that damage pattern develops as a result of the filament arrangement and weak adhesion between adjacent filaments and explains the diffuse damage kinetics observed experimentally. This study concludes with a topological law relating the notch size and orientation to the rupture properties of 3D-printed ABS. This study supports the idea of tailoring the microstructural arrangement to control and mitigate the mechanical instabilities that lead to the failure of 3D-printed polymers. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

3D printing of carbon fiber (CF)-reinforced thermoplastics has been reported for manufacturing economical consumer products. But hitherto, very little has been reported on 3D-printed hybrid composite structures prepared by sandwiching CF in the layer-by-layer manufactured functional prototype. The present work reports the 3D printing of CF sandwiched acrylonitrile butadiene styrene (ABS) (by varying the CF layers from 1 to 3) composite structure. The 3D printing parameters like the number of CF layers, the orientation angle of layers, and the printing temperature of the nozzle were designed by Taguchi L9 orthogonal array. The mechanical properties obtained (ultimate tensile strength (UTS): 58.51 MPa, modulus of toughness (MT): 1.566 MPa, and Young's modulus (E): 1009.994 MPa) were optimized to ascertain the acceptable strength of functional parts for commercial 3D printing applications. The parametric optimization highlighted that the acceptable orientation angle of CF in ABS matrix is 0°. Along with 03 numbers of CF layers and 250 °C printing nozzle temperature, functional parts with acceptable mechanical properties may be fabricated. The morphological analysis of the fractured surface outlined that the 3 layers of CF correspond to acceptable mechanical properties in the 3D-printed functional prototype. The mechanical and morphological results are supported by x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrometric analysis. [ABSTRACT FROM AUTHOR]

In this study, a novel iron-based catalyst system, Fe(acac)3/(isocyanoimino) triptenylphosphorane (IITP)/AlR3, was employed for the synthesis of syndiotactic 1,2-polybutadiene in hexane. This catalyst system exhibits remarkably high catalytic activity, achieving a polymerization activity of 762 kgpolymer·molcatalyst−1·h−1 at 50 °C with a [BD]/[Fe] molar ratio of 20000. Furthermore, living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene polymerization. These characteristics were well demonstrated by a narrow molecular weight distribution (PDI≈2.0) of the resulting polybutadiene and a linear relationship between–ln(1 − c) and polymerization time as well as number average molecular weight and polymer yield. The resultant polymer showed a 1,2-selectivity of approximately 76% and stereoregularity ranging from 62% to 73%(rrrr). Additionally, through kinetic studies on polymerization reaction, an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol−1, which suggests that high polymerization temperature favors efficient polymerization. [ABSTRACT FROM AUTHOR]

Prior studies into fatigue crack growth (FCG) in fibre-reinforced polymer composites have shown that the two methodologies of Simple-Scaling and the Hartman–Schijve crack growth equation, which is based on relating the FCG rate to the Schwalbe crack driving force, Δκ, were able to account for differences observed in the measured delamination growth curves. The present paper reveals that these two approaches are also able to account for differences seen in plots of the rate of crack growth, da/dt, versus the range of the imposed stress intensity factor, ΔK, associated with fatigue tests on different grades of high-density polyethylene (HDPE) polymers, before and after electron-beam irradiation, and for tests conducted at different R ratios. Also, these studies are successfully extended to consider FCG in an acrylonitrile butadiene styrene (ABS) polymer that is processed using both conventional injection moulding and additive-manufactured (AM) 3D printing. [ABSTRACT FROM AUTHOR]

The greenness of naphtha‐ and bioethanol‐based butadiene was compared using green metrics (GM) and life cycle assessment (LCA). GM provide predominantly qualitative results, showing advantages for bioethanol‐based butadiene. LCA indicates benefits of bioethanol‐based butadiene in terms of global warming and fossil resource consumption, but drawbacks in acidification, eutrophication, radiation, land use, ozone depletion, particulate matter, ozone formation, metal depletion, and freshwater consumption. When comparing both assessment approaches used, LCA offers a more comprehensive environmental assessment while GM is limited to a smaller section of the value chain but address additional aspects such as safety of chemicals. [ABSTRACT FROM AUTHOR]

This study investigates the catalytic conversion of ethanol using a modified saponite in both an ohmic and a conventional reactor. For testing in the ohmic reactor the catalyst is stacked in between conductive graphite fleece or formed to conductive pellets. The influence on catalytic activity and axial temperature profiles was examined. Catalytic tests in the ohmic reactor showed comparable results to the conventional reactor. Additionally heating profiles of different conductive materials where taken, within uniform heating was reached with the carbon fleeces. [ABSTRACT FROM AUTHOR]

We report efficacious vibration damping of carbon black reinforced nitrile butadiene rubber‐polyvinyl chloride blend (NVC) vulcanizates in a constrained layer damping (CLD) configuration. The objective is to compare numerical simulations using finite element method (FEM) and the widely used Ross‐Kerwin‐Ungar (RKU) model with the experimental results. NVC blend (50:50 by weight), was compounded with carbon black as reinforcing filler and vulcanized using a sulfur‐based curative system. Significant reinforcement and toughening were observed for the carbon black reinforced vulcanizates compared to the pristine blend. The viscoelastic properties of the vulcanizates were assessed using dynamic mechanical analysis (DMA), exploring their behavior concerning temperature variations and different frequencies to generate the Prony series coefficients for input in FEM analysis. Vibration damping experiments were conducted using the Oberst beam method in a single cantilever mode, with steel as the vibrating substrate, aluminum as the constraining layer, and the NVC vulcanizates as viscoelastic materials (VEM). Numerical simulations were performed using FEM to analyze mode shapes and frequency response function (FRF), and the RKU model was employed to quantify CLD system loss factors (SLF). The salient finding of this study was the observed SLF values in the range of 0.08–0.20 in the frequency regime of 200–2000 Hz. These values qualify the studied material as effective VEMs for CLD treatment of structural vibrations. This study supports design optimization efforts in a wide range of engineering applications where effective vibration damping is critical. Highlights: Enhancement of NVC blend properties through carbon black reinforcement.Detailed analysis of viscoelastic behavior using DMA.Validation of findings through experimental modal analysis.Promising results in terms of system loss factors for CLD applications. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental investigation of the mechanical characteristics of 3D-printed acrylonitrile butadiene styrene (ABS) and its modifications reinforced with different types of short-fiber fillers: carbon, glass, and basalt. Elastic modulus, tensile and bending strength, as well as fracture toughness were determined in series of mechanical tests for samples produced with different manufacturing parameters, such as nozzle diameter and infill angle. It was found that the use of ABS filament reinforced with the short fibers can significantly improve the mechanical properties of 3D-printed devices when the infill angle is oriented along the vector of the applied load. In such a case, the elastic modulus and tensile strength can be increased by more than 1.7 and 1.5 times, respectively. The use of a larger nozzle diameter led to the growth of tensile strength by an average of 12.5%. When the macroscopic load is applied along the normal to the printed layers, the addition of short fibers does not give much gain in mechanical properties compared to pure ABS, which was confirmed by both standard tensile and fracture toughness tests. The surface of the fractured samples was examined using scanning electronic microscopy, which allowed us to make conclusions on the type of defects as well as on the level of adhesion between the polymeric matrix and different types of short fibers. [ABSTRACT FROM AUTHOR]

Temperature is very important in the fabrication of products developed for different applications, considering the widespread use of additive manufacturing (AM) technology. Thermal properties seriously affect the mechanical properties of products. In this study, the effect of printing nozzle temperature changes on the dimensional and mechanical properties of samples fabricated with acrylonitrile butadiene styrene (ABS) material was investigated. This material can be preferred over foam material for drone and model aircraft areas due to its low density. A total of thirty-six tensile test samples (ISO527–type1A) were fabricated with fused filament fabrication (FFF), one of the AM methods, and their dimensional properties (length, width, thickness, and mass) were determined. During the fabrication process, the nozzle temperature of the 3D (three-dimensional) printer was increased from 220 °C to 270 °C in 10 °C increments. All samples were subjected to tensile testing, and stress–strain values were measured. Analysis of variance (ANOVA) was applied to examine the effect of nozzle temperature change on the findings obtained as a result of the experimental study. The printing nozzle temperature significantly affected both the mechanical strength and dimensional properties of the samples. The samples showed lower viscosity and less hardness at higher nozzle temperatures. The mass and density of the samples decreased with increasing temperature. The tensile strength value decreased by 41.52%. [ABSTRACT FROM AUTHOR]