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Abstract Interfacial bond formation during sputter deposition of metal‐oxide thin films onto polycarbonate (PC) is investigated by ab initio molecular dynamics simulations and X‐ray photoelectron spectroscopy (XPS) analysis of PC|X interfaces (X = Al2O3, TiO2, TiAlO2). Generally, the predicted bond formation is consistent with the experimental data. For all three interfaces, the majority of bonds identified by XPS are (C─O)─metal bonds, whereas C─metal bonds are the minority. Compared to the PC|Al2O3 interface, the PC|TiO2 and PC|TiAlO2 interfaces exhibit a reduction in the measured interfacial bond density by 75 and ∼65%, respectively. Multiplying the predicted bond strength with the corresponding experimentally determined interfacial bond density shows that Al2O3 exhibits the strongest interface with PC, while TiO2 and TiAlO2 exhibit ∼70 and ∼60% weaker interfaces, respectively. This can be understood by considering the complex interplay between the metal‐oxide composition, the bond strength, and the population of bonds formed across the interface.

This paper presents numerical models of a 3D printed plastic joint applicable to the connection of wooden structures. The research presented provides a comparison of two alternative solutions for the geometry of the joint and results from several loading schemes and boundary conditions. Included are analyses evaluating the mechanical behaviour in a simple axial tensile test, a three-point bending test and, finally, a sensitivity analysis of the location susceptible to fatigue damage. The models include a 3D printed polycarbonate joint, wooden elements and steel shear pins. The combined model allows a deeper understanding of the interactions. Finite element method (FEM) software was used to develop the numerical models and suitably defined boundary conditions, and material properties of all parts were adopted. The simulation results show that the 3D joint exhibits a high resistance to tensile loading, while in the case of three-point bending, a higher susceptibility to fracture of the printed joint is observed. The sensitivity fatigue analysis identified critical areas on the 3D printed component that need to be improved before further development. These analyses provide important information for optimizing the design of 3D printed plastic joints intended for wooden structures.

Abstract Catalytic hydrogenolysis systems of C-O bonds in furan ring, tetrahydrofuran ring and tetrahydropyran ring in biomass-derived cyclic compounds are reviewed. Furfural or its hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol) have been frequently used as substrates for this type of reactions. Ring-opening of furfuryl alcohol over metal catalysts combined with basic components gives a mixture of 1,2-pentanediol, 1,5-pentanediol and other by-products. The selectivity much depends on catalysts and reaction conditions, and good 1,2-pentanediol selectivity can be obtained. For 1,5-pentanediol synthesis, more selective approaches have been reported such as Cu-zeolite catalysts for furfuryl alcohol hydrogenolysis in flow reactor and M-M’Ox-type (M: noble metal; M’: transition metal) supported catalysts or Ni-LnOx (Ln: rare earth element) catalysts for tetrahydrofurfuryl alcohol hydrogenolysis. The metal catalysts and M-M’Ox-type catalysts can be applied to ring-opening hydrogenolysis of other furan- and tetrahydrofuran-based compounds, respectively. Among the products of ring-opening hydrogenolysis of biomass-derived compounds, 1,5-pentanediol seems to be the most important because of the potential use as a monomer. The recent progress and reported properties of polymers using 1,5-pentanediol as a monomer are also summarized.

AbstractNanocomposite films (NC) of amorphous polycarbonate (PC), semicrystalline polyethylene oxide (PEO), and chromium oxide (Cr2O3) nanoparticles (NP) were synthesized. We believe that this study is novel in the area of the effect of laser radiation on such NC. The synthesized Cr2O3 had a nanonature of average particle size 29 nm, as indicated from the Rietveld refinement of the XRD scans. Samples of the PC-PEO/Cr2O3 NC films were irradiated with infrared energy fluences ranging from 5 to 95 Joule/cm2 (J/cm2) using an infrared pulsed laser. We used UV-vis spectroscopy and the International Commission on Illumination (CIE) color changes technique to investigate the resulting effects of the laser irradiation on the optical bandgap energy and color properties of the prepared films. As the laser fluence increased up to 95 J/cm2, the maximum fluence used, both the direct and indirect bandgaps decreased. The Urbach energy showed an opposite tendency; it increased from 0.32 to 0.56 eV. This can be attributed to the dominance of chain crosslinks that destroyed the ordered structure and thus increased the amorphous regions. Also, the optical dielectric loss (ε″) aided in detecting the nature of the microelectronic transitions. It was found that the PC/PEO/Cr2O3 NC films had direct allowed transitions. Additionally, the effect of laser irradiation on the absorbance, refractive index, real and imaginary dielectric parameters, and optical conductivity of the blend composite samples were studied. Moreover, the optical color changes between the pristine and the irradiated films were evaluated. The pristine blend film was uncolored. It showed significant color changes when irradiated with the laser at increasing fluences up to 95 J/cm2. The change in the optical properties of PC/PEO/Cr2O3 NC film suggested its usage as a promising candidate for future optoelectronics manufacturing. [ABSTRACT FROM AUTHOR]

As one of the five major engineering plastics, polycarbonate (PC) has been applied in many industrial fields. However, its poor wear‐ and UV‐ resistance greatly limit its further promotion. Inspired by the dual benefits of inorganic–organic hybrid filler, in this study, we developed a novel type of catechol group‐ and nano silica‐containing reinforcing filler (CFNS) for the preparation of wear‐ and UV‐resistant PC‐based composite films. With a low level of filler content (1%), the coefficient of friction (COF) was distinctly reduced from 0.14 (neat PC film) to 0.06 (composite film), benefiting from a wear‐resistant surface layer. On the basis of ensuring high and stable transmittance for visible light, the composite films also exhibit strengthened capacity of UV shielding for the waveband from 293 to 400 nm. In addition, the general performance of composite films including tensile strength, tensile modulus, and thermal stability have also been improved in different degrees. Therefore, the composite films reinforced by CFNS are highly promising for a wide range of applications, ascribed to their improved general properties as well as two additional functions of wear‐ and UV‐resistance. [ABSTRACT FROM AUTHOR]

AbstractAdditives, such as bisphenol A (BPA) that are added to packaging material to enhance functionality may migrate into food products creating a concern for food safety. BPA has been linked to various chronic diseases, such as: diabetes, obesity, prostate cancer, impaired thyroid function, and several other metabolic disorders. To safeguard consumers, BPA migration limits have been defined by regulatory bodies. However, it is important to address the underlying factors and mechanisms so that they can be optimized in order to minimize BPA migration. In this review, we determine the relative importance of the factors, i.e. temperature, contact time, pH, food composition, storage time and temperature, package type, cleaning, and aging, and packaging damage that promote BPA migration in foods. Packaging material seems to be the key source of BPA and the temperature (applied during food production, storage, can sterilization and cleaning processes) was the critical driver influencing BPA migration. [ABSTRACT FROM AUTHOR]

AbstractPolycarbonate/poly(methyl methacrylate)/polyethylene oxide (PC/PMMA/PEO) blends were formed using a casting technique. Samples from the prepared PC/PMMA/PEO films were irradiated with γ ray doses ranging from 20 to 180 kGy. UV-vis spectroscopy was used to explore the resulting effects of the γ ray irradiation on the optical properties of the prepared films. The impact of the γ ray irradiation on the light absorbance, transmission, refractive index, extinction coefficient, dielectric constant and optical conductivity of the PC/PMMA/PEO blend films was examined. The absorbance of the blend films increased as it was irradiated with the γ ray doses up to 180 kGy, the maximum dose used. The increase in absorbance was associated with a decrease in the direct bandgap from 4.52 to 4.20 eV, and an increase of Urbach energy from 0.37 to 0.87 eV. Also, we used the optical dielectric loss (ε”) to detect the type of microelectronic transition for the PC/PMMA/PEO blend films, which was found to be a direct allowed transition. Moreover, the optical color changes between the pristine and the irradiated films were assessed using the International Commission on Illumination color differences technique. The pristine film was uncolored. It showed significant color alterations when irradiated with γ radiation up to 180 kGy. The induced enhancement in the optical properties indicated that the γ radiation is a useful tool that would allow the application of the resulting PC/PMMA/PEO blend films in optoelectronic devices. [ABSTRACT FROM AUTHOR]

The paper deals with the high-speed formation of nanocomposite structures on a polycarbonate matrix with a metal film affected by pulsed laser radiation at a wavelength of 1064 nm. Studied is the micro- and nanosized ordering depending on the laser power. Based on confocal laser scanning microscopy and using the area similarity method, structural groups and fractal dimensions are determined, and 2D-to-3D structure transition is studied herein. [ABSTRACT FROM AUTHOR]

The immobilization of gold nanoparticle (AuNP) linear surface assemblies on polycarbonate (PC) melt surface via molding is investigated. The order of the particle assemblies is preserved during the molding process. The assemblies on PC exhibit plasmonic coupling features and dichroic properties. The structure of the assemblies is quantified based on Scanning Electron Microscopy (SEM) and image analysis data using an orientational order parameter. The transfer process from mold to melt shows high structural fidelity. The order parameter of around 0.98 reflects the orientation of the lines and remains unaffected, independent of the injection direction of the melt relative to the particle lines. This is discussed in the frame of fountain flow during injection molding. The particles were permanently fixed and withstood the injection molding process, detachment of the substrate, and extraction in boiling ethanol. The plasmonic particles coupled strongly within the dense nanoparticle lines to produce anisotropic optical properties, as quantified by dichroic ratios of 0.28 and 0.52 using ultraviolet–visible–near-infrared (UV–Vis–NIR) spectroscopy. AuNP line assemblies on a polymer surface may be a basis for plasmonic devices like surface-enhanced Raman scattering (SERS) sensors or a precursor for nanowires. Their embedding via injection molding constitutes an important link between particle-self-assembly approaches for optically functional surfaces and polymer processing techniques. [ABSTRACT FROM AUTHOR]

The preparation of CO2-containing polymers with improved degradation properties is still very challenging. An elegant method for preparing these polymers is to use CO2-containing monomers in ring-opening polymerizations (ROP) which are particularly gentle and energy-saving methods. However, cyclic carbonates are required for this which are not readily available. This paper therefore aims to present the optimization and comparison of two synthesis methods to obtain cyclic carbonates for ROP. Within this work, cyclic styrene carbonate was synthesized from readily available raw materials by using a Jacobsen catalyst for the reaction of styrene oxide and carbon dioxide or an organocatalyst for the transesterification of methyl carbonate with 1-phenyl-1,2-ethanediol. The latter performed with 100% selectivity to the desired styrene carbonate, which was succesfully tested in ROP, producing an amorphous thermoplastic polymer with a TG of 185 °C. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenolysis systems of C-O bonds in furan ring, tetrahydrofuran ring and tetrahydropyran ring in biomass-derived cyclic compounds are reviewed. Furfural or its hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol) have been frequently used as substrates for this type of reactions. Ring-opening of furfuryl alcohol over metal catalysts combined with basic components gives a mixture of 1,2-pentanediol, 1,5-pentanediol and other by-products. The selectivity much depends on catalysts and reaction conditions, and good 1,2-pentanediol selectivity can be obtained. For 1,5-pentanediol synthesis, more selective approaches have been reported such as Cu-zeolite catalysts for furfuryl alcohol hydrogenolysis in flow reactor and M-M'Ox-type (M: noble metal; M': transition metal) supported catalysts or Ni-LnOx (Ln: rare earth element) catalysts for tetrahydrofurfuryl alcohol hydrogenolysis. The metal catalysts and M-M'Ox-type catalysts can be applied to ring-opening hydrogenolysis of other furan- and tetrahydrofuran-based compounds, respectively. Among the products of ring-opening hydrogenolysis of biomass-derived compounds, 1,5-pentanediol seems to be the most important because of the potential use as a monomer. The recent progress and reported properties of polymers using 1,5-pentanediol as a monomer are also summarized. [ABSTRACT FROM AUTHOR]

Incremental sheet forming represents a relatively recent technology, similar to the layered manufacturing principle of the rapid prototype approach; it is very suitable for small series production and guarantees cost-effectiveness because it does not require dedicated equipment. Research has initially shown that this process is effective in metal materials capable of withstanding plastic deformation but, in recent years, the interest in this technique has been increasing for the manufacture of complex polymer sheet components as an alternative to the conventional technologies, based on heating–shaping–cooling manufacturing routes. Conversely, incrementally formed polymer sheets can suffer from some peculiar defects, like, for example, twisting. To reduce the risk of this phenomenon, the occurrence of failures and poor surface quality, a viable way is to choose toolpath strategies that make the tool/sheet contact conditions less severe; this represents one of the main goals of the present research. Polycarbonate sheets were worked using incremental forming; in detail, cone frusta with a fixed-wall angle were manufactured with different toolpaths based on a reference and a stair strategy, in lubricated and dry conditions. The forming forces, the forming time, the twist angle, and the mean roughness were monitored. The analysis of the results highlighted that a stair toolpath involving an alternation of diagonal up and vertical down steps represents a useful strategy to mitigate the occurrence of the twisting phenomenon in incremental formed thermoplastic sheets and a viable way of improving the process towards a green manufacturing process. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research 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.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research 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.)

This study aims to investigate the effects of different hydroxy-terminated silicones on the properties of polycarbonate-silicone copolymers (ICS-PC) by introducing flexible and hydrophobic silicone into isosorbide-based polycarbonate through melt transesterification- polycondensation method. Through compatibility and transesterification experiments, it is confirmed that the alcohol-hydroxyl polydimethylsiloxane (a-PDMS) has higher reactivity and silicone conversion than the phenol-hydroxyl polydimethylsiloxane (p-PDMS), but the conversion does not exceed 81%. Polyether-modified silicone (PEMS) exhibits better compatibility and higher reactivity, thus resulting in higher conversion that can reach 86%. Effects of the type and content of silicone on the glass transition temperature (Tg), optical transparency, saturated water absorption, and mechanical strength of ICS-PCs were also discussed. It is found that p-PDMS has higher Tg, hydrophobicity, and mechanical strength with similar silicone content, but the total transmittance does not exceed 60%. In contrast, the PEMS system exhibits better optical transparency due to its improved compatibility with the PC matrix, with a total transmittance of up to 73%, Tg exceeding 150 °C while maintaining excellent flexibility and hydrophobicity. These results are helpful to further improve the comprehensive properties of bio-based polycarbonates. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the contribution of tool wear and process parameters to the shape defects induced by the micro-machining of glassy polymers such as polycarbonate. An experimental approach is proposed in this study using an instrumented orthogonal cutting configuration. Diamond inserts have been considered as a cutting tool and have been subjected to different levels of accelerated wear. The worn tools were first characterized to identify the wear mechanisms that occurred on the active cutting zone and were then used to perform orthogonal cutting experiments on polycarbonate. Micro-cutting depth values (3–20 µm) were considered to respect the micro-machining configuration. Chip morphology, cutting forces, and machined surfaces' topography have been acquired to analyze and assess the effectively removed material depth regarding the theoretical cutting depth for each worn tool. Results show that the increase of the cutting edge radius is the main wear mechanism that occurred in the diamond inserts. This tool wear evolution was found to be the most influential factor on the induced shape defect by increasing the elastic deformation of polycarbonate rather than its shear when using micro-cutting depths, which induces a spring-back of polycarbonate after cutting. [ABSTRACT FROM AUTHOR]

We have investigated a simple two-step method for the hydrophilic modification of polycarbonate using polyethyleneimine (PEI) and poly(acrylic acid-co-maleic acid) (PAcM). While PEI or PAcM can improve the hydrophilicity, much better hydrophilicity is obtained by treating polycarbonate with PEI and then PAcM. While a higher treating temperature generally leads to a lower contact angle, the reaction time does not play an important role (e.g., between 15 and 90 min). Meanwhile, increasing the concentration of PEI or PAcM can generate better hydrophilicity. Superhydrophilicity is obtained with a contact angle of 3° while maintaining the transparency of polycarbonate. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) emerges a broad application and development prospects in the joining of dissimilar materials. Friction stir lap welding (FSLW) of 6061-T6 aluminium (Al) alloy sheet with different depths groove pretreatment and polycarbonate (PC) sheets is investigated. Weld surface defects are studied by visual inspection. The analyses of microstructures and mechanical tensile properties of the dissimilar joints are carried out by optical microscopy (OM) and tensile tests. Results indicate that the groove depth is a significant factor affecting the welding surface morphology. Tensile strength reaches the maximum with the average value of 29.05 MPa at the groove depth of 0.2 mm, which is equivalent to 58% of the PC base material strength. Microstructure analysis indicates that the molten PC and Al alloy fragments flow along the groove at the action of the pin tool. Simultaneously, Al alloy fragments are inserted into the molten PC material. The two materials form a compact mixed structure, which improves the tensile strength. [ABSTRACT FROM AUTHOR]

This paper aimed to determine the susceptibility of polycarbonate and polymethylmethacrylate to corrosion cracking under specific operating conditions. The tests included static tensile and flexure, impact strength, and microscopic examination. Due to the synergistic effect of tensile stresses and seawater environment, numerous cracks are observed. Moreover, aging conditions did not significantly reduce the strength properties of the tested specimens; thus, higher resistance to stress corrosion cracking does not have a close relationship with the material's mechanical properties. [ABSTRACT FROM AUTHOR]

The study investigated the properties of alkali-treated hemp fiber-reinforced polycarbonate (PC) composites that can be formed by 3D printers for architectural applications. To determine the optimum alkali treatment to be applied to the fibers, the properties of the samples treated with 5% and 7% sodium hydroxide (NaOH) at both ambient temperature (AT) and 120 °C (HT) were determined by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). It was determined that the alkali treatment that gave the optimum result was 5% HT. Composite specimens with fiber/matrix ratios of 10/90, 20/80, and 30/70 were prepared in filament form to be printed in a 3D printer as alkali-treated and untreated. These composites were characterized by conducting tensile strength, FTIR, differential scanning calorimetry (DSC), TGA, and scanning electron microscopy (SEM) analyses. Tensile strength results revealed the highest mechanical performance for 5% NaOH alkali-treated and 10 wt.% hemp fiber-reinforced PC composites. DSC results showed that slight changes occurred in the glass transition temperature values. Furthermore, SEM analysis showed that 5% NaOH-treated hemp fibers have better interfacial bonding with the PC matrix than untreated fibers. As a result, more natural and sustainable materials have been obtained for architectural applications without significantly decreasing in PC properties. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

AbstractIn our research described in this article, we used a solution casting technique to prepare a blend film containing polycarbonate (PC), poly (methyl methacrylate) (PMMA), and polystyrene (PS) polymers. Samples from the prepared PC/PMMA/PS films were irradiated with γ ray doses ranging from 20 to 160 kGy. We used UV-vis spectroscopy to investigate the resulting effects of the γ ray irradiation on the optical properties of the prepared films. When the γ ray dose was increased up to 160 kGy, the maximum dose used, the direct bandgap was decreased from 3.68 to 2.90 eV, associated with an increase of Urbach energy from 0.82 to 1.03 eV. Also, we used the optical dielectric loss (ε″) to detect the type of microelectronic transition for the PC/PMMA/PS blend films, which was found to be a direct allowed transition. The γ ray effects on the absorbance, extinction coefficient, refractive index, dielectric parameters, optical conductivity and the nonlinear parameters of the blend films were studied. The enhancement in the optical properties indicated that the γ radiation is a useful tool that allows the application of the resulting PC/PMMA/PS blend films in optoelectronic devices. [ABSTRACT FROM AUTHOR]

This study investigates the adhesion properties of polycarbonate (PC) and liquid silicone rubbers (LSR) through surface activation using ultraviolet C (UVC) radiation. While self-adhesive LSRs adhere easily to certain thermoplastic composites such as polybutylene terephthalate (PBT) and polyamides (PAs), bonding to PC typically requires surface treatment due to the lack of compatible functional groups. Previous methods like plasma or flame treatment have been effective, but the use of UVC radiation for surface activation remains unexplored. Through experiments, it was found that UVC surface activation, particularly with ozone-generating lamps, significantly enhances the peel strength between PC and self-adhesive LSRs. The study evaluates the impact of different irradiation times and lamp configurations on peel resistance, surface energy, and composite stability. Results show that UVC/ozone (wavelengths 254 nm and 185 nm) activation increases peel resistance, with distinct differences observed between LSR types. Additionally, the study examines the stability of UVC activation over time and under various storage conditions, highlighting its effectiveness for up to 36 months at room temperature. Furthermore, the relationship between surface energy and peel strength is analyzed, finding that UVC/ozone activation increases surface energy but does not consistently correlate with improved adhesion. The study concludes with a comparison of UVC/ozone activation to alternative surface treatment methods, emphasizing its advantages such as cost-effectiveness and stability while considering limitations regarding substrate compatibility and occupational safety aspects. Overall, UVC/ozone surface activation presents a promising approach for enhancing adhesion in PC–LSR composite systems and holds potential for applications across various industries. [ABSTRACT FROM AUTHOR]

The impact protection applications of polycarbonate (PC) products are gradually increasing. Due to the high sensitivity of PC to notches, research on notch impacts has become very important. In this paper, the impact performance of PC with two different molecular weights under different notch states was investigated. Three notch size factors, namely notch tip radius, notch angle, and notch center depth, were selected to design orthogonal experiments and research impact toughness. Subsequently, a single-factor study was conducted on the impact radius at the tip of the notch, which was the most important factor affecting the impact performance. Research shows that the brittle–ductile-transition tip radius of high-molecular-weight PC is 0.15 mm, and it has a higher impact toughness than low-molecular-weight PC during the brittle fracture process. The brittle–ductile-transition tip radius of lower molecular weight is 0.25 mm, while low-molecular-weight PC has a higher impact toughness during the ductile fracture process. The brittle and ductile fracture mechanisms of PC with different molecular weights were analyzed by observing the stress changes and cross-sectional morphology. [ABSTRACT FROM AUTHOR]

AbstractContributing to the confinement safety evaluation of glove boxes (GBs) connected to high-efficiency particle air filters for radioactive materials under fire accidents, combustion tests of a flammable polymer, i.e., polymethyl methacrylate (PMMA), and a flame retardant polymer, i.e., polycarbonate (PC), as typical GB panel resins have been conducted with an engineering-scale combustion apparatus. Combustion properties such as the mass loss rate (MLR) and the heat release rate (HRR) of PMMA and PC were investigated in the combustion tests. From our results, the relationships of MLR and HRR to the surface area of the plate type of PMMA and PC were deduced. [ABSTRACT FROM AUTHOR]

Boron nitride nanotubes (BNNTs) are among the most effective additives for producing polymeric nanocomposites that exhibit high thermal conductivity but remain electrically nonconductive. However, the main challenge in the fabrication of such composites comes from the low dispersibility of BNNTs in polymeric matrices. This research aims to establish guidelines for controlling the morphology of nanocomposite, thereby adjusting their thermal conductivity and heat dissipation rate for optimized heat management applications. Two mixing methods, solvent and melt mixings, have been employed to incorporate noncovalently functionalized BNNTs (poly-(3-hexyl-thiophene) (P3HT)-BNNTs) into a polycarbonate matrix, and the effects of processing conditions on the morphology of the nanocomposites have been decoupled and analyzed systematically. Smaller microscale agglomerations of BNNTs with better dispersion were observed with the melt mixing method, whereas the solvent mixing method maintained a higher aspect ratio of BNNTs. Although improved thermal conduction was evident, thermal conductivity in either mixing method did not change significantly up to 5 wt % BNNT; however, the heat dissipation rate of the melt-mixed samples was around twice higher. This indicates that the heat dissipation rate is sensitive to the morphology and length of the nanotubes in the samples. UV–vis-NIR spectroscopy and enhanced truncated-correlation photothermal coherence tomography (eTC-PCT) studies revealed that the higher heat dissipation rate of the melt-mixed samples is attributable to better dispersion and distribution of BNNTs that were enhanced by their smaller agglomeration sizes and aspect ratios. [ABSTRACT FROM AUTHOR]

A novel functional polycarbonate (PAGC), characterized by the presence of double bonds within its side chain, was successfully synthesized through a ternary copolymerization of propylene oxide (PO), allyl glycidyl ether (AGE), and carbon dioxide (CO2). Polyhedral oligomeric silsesquioxanes octamercaptopropyl (POSS-SH) was employed as a crosslinking agent, contributing to the formation of organic–inorganic hybrid materials. This incorporation was facilitated through thiol-ene click reactions, enabling effective interactions between the POSS molecules and the double bonds in the side chains of the polycarbonate. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed a homogeneous distribution of silicon (Si) and sulfur (S) in the polycarbonate matrix. The thiol-ene click reaction between POSS-SH and the polycarbonate led to a micro-crosslinked structure. This enhancement significantly increased the tensile strength of the polycarbonate to 42 MPa, a notable improvement over traditional poly (propylene carbonate) (PPC). Moreover, the cross-linked structure exhibited enhanced solvent resistance, expanding the potential applications of these polycarbonates in various plastic materials. [ABSTRACT FROM AUTHOR]

Diphenyl carbonate is one of the raw materials used for the synthesis of polycarbonate, and its green and clean production is of great importance to the non-phosgene process for polycarbonate. The production of diphenyl carbonate by transesterification is its representative process route and is considered to be one of the typical examples of a green and sustainable process for chemicals. Since the discovery of the transesterification catalyst for diphenyl carbonate in the 1970s, researchers have been committed to improving its catalytic activity and selectivity and, correspondingly, the reaction engineering process. However, thermodynamic limitations, low activity, low selectivity, and limited stability have been bottlenecks that the transesterification catalyst has not been able to completely overcome, and the improvement of the catalyst is still ongoing. Therefore, this review takes the transesterification reaction of dimethyl carbonate and phenol as a model reaction and, based on a review of the progress in catalyst research on catalytic reaction processes, tries to clarify the structure–activity relationship between catalytic active sites and catalytic performance in homogeneous and heterogeneous catalytic processes and provides an overview of the progress in catalyst synthesis and modification. [ABSTRACT FROM AUTHOR]

This research focuses on studying of the process of glycolysis of polycarbonate (PC) catalyzed by zinc chloride. The degradation of polyester into monomers (bisphenol A, or BPA, and ethylene carbonate, or EC), which may then interact with one another to generate the matching ethers, was discovered to be the process. As a result, the optimal conditions for the depolymerization of PC to obtain bisphenol A and ethylene carbonate with the highest yield were therefore identified as 190 °C, a molar ratio of 11 between EG and PC, and a mass concentration of 0.4% ZnCl2. A scheme of PC glycolysis has been proposed, and a mathematical model adequately describing the experimental data has been developed. [ABSTRACT FROM AUTHOR]

Today, the removal of dyes as one of the most important pollutants in water resources using polymeric nanofibers and silicate-based materials has received a great deal of attention owing to their high specific surface area and active surface, respectively. This study aims to develop a polycarbonate (PC) nanofibrous adsorbent modified with 10 (%w/v) of carbonized vermiculite (CVMT) for elimination of Congo red (CR) from aqueous solutions. The field-emission scanning electron microscopy results show the electrospun nanofibrous sample with an average diameter of 235.8 nm. Prior to CVMT incorporation into PC nanofibers, the specific surface area of the sample is 6.4 m2/g and this value shows a slight increase up to 8.5 m2/g after the addition of CVMT. By adjusting the operational parameters such as pH of 3, adsorbent amount of 0.08 g, and CR initial concentration of 100 ppm, the adsorption capacity is about 42 mg/g. In the following, the pseudo-first-order kinetic equation besides the Freundlich model confirms that the adsorption process of CR is controlled by physisorption onto the heterogeneous surface of the nanofibrous adsorbent. Eventually, thermodynamic studies reveal the enthalpy of 14.92 kJ/mol and entropy of 0.055 kJ/mol, thereby suggesting endothermic and random adsorption process. [ABSTRACT FROM AUTHOR]

In this study, we added a small amount of polycarbonate (PC), ranging from 1 to 9 wt%, to the composites of styrene–acrylonitrile copolymer (SAN) and multiwalled carbon nanotube (MWNT). When two types of SANs having 24 and 32 wt% AN (SAN24 and SAN32) were used, we found that the resistivity of the SAN/MWNT (0.5 wt%) composites significantly decreased with the addition of 1–3% of PC, and the effect was more pronounced in the case of SAN32. Transmission electron microscopy (TEM) images revealed that MWNTs, which were uniformly distributed on the pure SAN, tended to agglomerate and form an interconnected structure when an appropriate amount of PC was added. The reduced resistivity of the composites is mainly attributed to the connectivity of MWNTs facilitating electron transport. It is worth noting that the network structure disappears when the amount of PC exceeds 5 wt%, where the size of PC domains grows, and most of the MWNTs are entrapped in the PC phase, resulting in an increased resistivity of the composite. The rheological investigation of the composites revealed that the storage moduli of the composites were sensitive to the state of MWNT distribution, which was greatly altered by the type of SAN and the amount of PC. [ABSTRACT FROM AUTHOR]

The results of thermogravimetric and Fourier transform infrared (FTIR) analysis of polymer composite materials (PCMs) based on polyethylene (PE) and polycarbonate (PC) are presented and compared to PE and PC polymers. Empirical data are obtained for mathematical modeling, including the amount of solid residue upon pyrolysis, volatile yield, and ash content of the studied PCMs and polymers. The results of the mathematical modeling of the pyrolysis process at a temperature of 600°C are presented to quantitatively assess the composition of pyrolysis gas. [ABSTRACT FROM AUTHOR]

Abstract Conductive fillers‐embedded plastic polymer hybrid composites are crucial electronic materials in modern technologies owing to their tunable conductive properties, low density, and corrosion resistance. However, the application of traditional rigid inorganic conductive fillers‐embedded plastic composites is constrained by their subpar electrical conductivity and mechanical properties. Consequently, liquid metals (LMs) including gallium and gallium‐based alloys, have recently emerged as the preferred conductive flexible fillers over traditional rigid fillers. This work employs a solvent evaporation method and phase separation‐induced conductivity mechanism. The resulting flexible and electrically conductive LM‐polycarbonate (PC) film circuits demonstrate ultrahigh metallic conductivity, robust mechanical performance, excellent solvent recyclability, and notable processability. The fluidic nature of LMs and the superior mechanical properties of the PC polymer confer high electrical stability and durability to the LM‐PC film circuits under diverse mechanical forces and environmental conditions. The LM‐PC film circuits are exceedingly promising and apt for use as flexible conductors in contemporary electrical applications, including electricity transmission and underwater working.

The article presents a study of the rheological properties and morphology of a mixture of multicomponent waste polymer compositions of polyamide 6 (PA6GF30) and polycarbonate (PC) from automotive parts. A comparative analysis of the melt flow rate of the obtained mixture was carried out depending on the content of its components. The compatibility of the components in the mixture and their distribution in the obtained polymer composition were studied. The effect of the composition of the secondary multicomponent mixture on the physical and mechanical properties is demonstrated. The possibility of reusing multicomponent polymer waste with the predicted main parameters of the technological process of injection molding is shown.

IntroductionAdditive manufacturing (AM) is a revolutionary technology transforming traditional production processes by providing exceptional mechanical characteristics.MethodsThe present study aims explicitly to predict the hardness of Polycarbonate (PC) parts produced using AM. The objectives of this study are: (1) To investigate the process parameters that impact the ability to estimate the hardness of PC materials accurately, and (2) To develop a best-performing ML model from a range of models that can reliably predict the hardness of additively manufactured PC parts. Initially, fused filament fabrication (FFF), the most affordable AM technique, was used for the manufacturing of parts. Four process parameters, infill density, print direction, raster angle, and layer thickness, are selected for investigation. A heatmap is generated to obtain the influence of process parameters on hardness. Then, machine learning (ML) techniques create a range of predictive models that can predict hardness value considering the level of process parameters.ResultsThe developed ML models include Linear Regression, Decision Tree, Random Forest, K-nearest neighbor, Support Vector Regression, AdaBoost, and Artificial Neural Network. Further, an investigation has been done that includes choosing and improving ML algorithms and assessing the models’ performance.DiscussionPrediction plots, residual plots, and evaluation metrics plots are prepared to gauge the performance of the developed models. Thus, the research enhances AM capabilities by applying predictive modeling to process parameters and improving the quality and reliability of fabricated components.

Abstract Rechargeable polymer‐based solid‐state batteries with metallic lithium anodes and LiNixMnyCo1−x−yO2 (NMC)‐based cathodes promise safer high‐energy‐density storage solutions than existing lithium‐ion batteries, but have shown challenging to realize. The failure mechanisms that have been suggested for these battery cells have mostly been related to the use of a metallic lithium anode and formation of dendrites during cycling. Here, we approach the issue of using solid polymer electrolytes (SPEs) vs. NMC cathodes by employing a range of materials based on poly(ϵ‐caprolactone‐co‐trimethylene carbonate) (PCL‐PTMC) with different salts under various cycling conditions. It is seen that although the ionic conductivity of the electrolyte can be improved by exchanging the lithium salt, it does not immediately correlate to better cycling performance. However, increasing the temperature during battery cycling to improve the ion transport kinetics lowers the polarization of the battery cell and full capacity can be achieved at an upper voltage cut‐off that is appropriate for the polymer electrolyte. For these electrolytes, the limit is demonstrated to be 4.4 V vs. Li+/Li, and cycling with NMC‐111 cathodes is thereby possible provided that the upper cut‐off is limited to below this limit.

Purpose – This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the I-Optimal design. Design/methodology/approach – I-optimal design methodology is used to plan the experiments by means of Minitab-17.1 software. Samples are manufactured using Stratsys FDM 400mc and tested as per ISO standards. Additionally, an artificial neural network model was developed and compared to the regression model in order to select an appropriate model for optimisation. Finally, the genetic algorithm (GA) solver is executed for improvement of tensile strength of FDM built PC components. Findings – This study demonstrates that the selected process parameters (raster angle, raster to raster air gap, build orientation about Y axis and the number of contours) had significant effect on tensile strength with raster angle being the most influential factor. Increasing the build orientation about Y axis produced specimens with compact structures that resulted in improved fracture resistance. Research limitations/implications – The fitted regression model has a p-value less than 0.05 which suggests that the model terms significantly represent the tensile strength of PC samples. Further, from the normal probability plot it was found that the residuals follow a straight line, thus the developed model provides adequate predictions. Furthermore, from the validation runs, a close agreement between the predicted and actual values was seen along the reference line which further supports satisfactory model predictions. Practical implications – This study successfully investigated the effects of the selected process parameters - raster angle, raster to raster air gap, build orientation about Y axis and the number of contours - on tensile strength of PC samples utilising the I-optimal design and ANOVA. In addition, for prediction of the part strength, regression and ANN models were developed. The selected ANN model was optimised using the GA-solver for determination of optimal parameter settings. Originality/value – The proposed ANN-GA approach is more appropriate to establish the non-linear relationship between the selected process parameters and tensile strength. Further, the proposed ANN-GA methodology can assist in manufacture of various industrial products with Nylon, polyethylene terephthalate glycol (PETG) and PET as new 3DP materials.

Mechanical behavior of press-induced deformation of polycarbonate at intermediate strain rates was studied by finite element method. Based on DSGZ constitutive model, polycarbonate cylindrical uniaxial compression finite element simulation was carried out. Effectiveness of the model for prediction of compressive mechanical response was verified by contrast of simulated and experimental results, calculation of prediction accuracy of model, and analyzation of multi-physics distribution in material after compressive deformation. Mechanical evolution rule of polycarbonate plates was obtained by simulation of the solid-state deformation in lateral restricted mode. The results show that simulated stress-strain curves is in good agreement with that acquired from experiment in the process of uniaxial compressive deformation, and stress-strain relationship in compressive elastic-plastic deformation can accurately predicted by DSGZ model relatively. The overall deformation of material was uniform, and the sensitivity of stress response to temperature is higher than that of strain rate in cylindrical uniaxial compressive deformation and press-induced deformed simulation. Mechanical behavior of press-induced deformation of polycarbonate was reflected by simulated results, which can be an important basis for engineering realization of press-induced deformation of polycarbonate, and provide strong support for material strengthening and its application in aircraft cockpit transparencies.

Objective: This systematic review examines the efficacy and biocompatibility of orthodontic clear aligner tooth aligners constructed from polyethylene terephthalate glycol (PeT-G), polypropylene (PP), polycarbonate (PC), thermoplastic polyurethanes (TPUs), and ethylene-vinyl acetate (EVA). Materials and Methods: To find relevant papers published through September 2021, PubMed was searched extensively. Randomized clinical trials (RCTs) and observational studies assessing the effectiveness and biocompatibility of the aligner materials were included. Data were extracted independently, and the quality of included research was appraised using relevant procedures. The research variability necessitated a narrative synthesis. Results: Five studies were included for comparison. All materials were biocompatible; however, PeT-G and EVA aligners caused the least tissue irritation. Patients preferred TPU aligners for initial comfort and PeT-G aligners for transparency and endurance. Conclusion: Biocompatible PeT-G, PP, PC, TPU, and EVA tooth aligners fix malocclusions. Aligner materials should be chosen based on patient preferences, treatment goals, and material qualities. For stronger proof, a longer-term study is needed.

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Microplastics (MPs) are a pervasive pollutant in the marine environment. Pantai Teluk Likas in Sabah, Malaysia is one of the most visited beaches where tourism, recreational, and fisheries activities are high in this area. Hence, the area suffers from severe pollution, particularly from plastics. This study aims to quantify the microplastic composition in terms of color, shapes, and polymer types in marine bivalves (Anadara granosa, Glauconome virens, and Meretrix lyrata) and water column samples from Pantai Teluk Likas. All samples were digested using sodium hydroxide (NaOH) and incubated in the oven for at least 48 h. Serial filtration was done for each sample before they were observed under the dissecting microscope. The microplastics were identified and counted based on their physical attributes which were colors and shapes. The functional group of the polymers was determined using FTIR spectroscopy. Microplastics were found present in all samples collected. G. virens had the highest abundance of microplastics at 113.6 ± 6.5 particles/g followed by M. lyrata at 78.4 ± 3.7 particles/g. On the contrary, A. granosa had the least microplastics with an abundance of 24.4 ± 0.6 particles/g. Meanwhile, 110.0 ± 36.2 particles/L of microplastics were found in water column samples from Pantai Teluk Likas. Based on the analysis, fibers were the most common shape in bivalves, while fibers and films were common in the water column. In terms of colors, black, blue, and red were a few of the most abundant colors observed in both samples. The most common polymer detected in all bivalve species and water column samples is polycarbonate (PC), followed by polymethyl methacrylate (PMMA). Future study that focuses on the correlation between microplastic abundance in the marine biota and the water column is recommended to better understand microplastic availability and exposure. [ABSTRACT FROM AUTHOR]

The research presented in this article aimed to investigate the differences in mechanical properties between solid structural timber and the same reinforced element in three different ways. A three-point bending test was performed on wood elements reinforced with carbon-fiber-reinforced polymer (CFRP), 3D printed polycarbonate (3DPC) lamellas, and 3D printed polycarbonate with carbon fiber (3DPCCF) lamellas. In this comparison, the bending strength was large for CFRP samples, which have 8% higher performance than samples with 3DPCCF and 19% higher performance than samples with 3DPC. Conversely, when factoring in theoretical manufacturing costs, the performance of 3DPCCF is almost three times that of CFRP and 3DPC. In addition, 3D materials can be used for more complicated reinforcement shapes than those discussed in the paper. [ABSTRACT FROM AUTHOR]

We developed a series of Zn(II)-Co(III) double metal cyanide (DMC) catalysts with exceptional activity for the ring-opening polymerization of various cyclic monomers by employing diverse organophosphorus compounds as complexing agents (CAs). The chemical structure and composition of DMC catalysts were investigated by commonly used analysis such as infrared and X-ray photoelectron spectroscopies, and elemental analysis combining with in situ NMR analysis to determine the complexation types of organophosphorus compounds the catalyst framework. The resulting catalysts exhibited very high turnover frequencies (up to 631.4 min−1) in the ring-opening polymerization (ROP) of propylene oxide and good efficiency for the ROP of ε-caprolactone. The resultant polyester polyols are suitable to use as an macroinitiator to produce well-defined poly(ester ether) triblock copolymers of 1800–6600 g mol−1 and dispersity of 1.16–1.37. Additionally, the DMC catalysts bearing organophosphorus compounds CAs exhibited remarkable selectivity for the copolymerization of PO with CO2, yielding poly(ether carbonate) polyols with carbonate contents up to 34.5%. This study contributes to the development of efficient DMC catalytic systems that enable the synthesis of high-quality polyols for various applications. [ABSTRACT FROM AUTHOR]

Environmental damage caused by waste plastics and downstream chemical breakdown products is a modern crisis. Endocrine‐disrupting bisphenol A (BPA), found in breakdown products of poly(bisphenol A carbonate) (PC), is an especially pernicious example that interferes with the reproduction and development of a wide range of organisms, including humans. Herein we report a single‐stage thiocracking method to chemically upcycle polycarbonate using elemental sulfur, a waste product of fossil fuel refining. Importantly, this method disintegrates bisphenol A units into monoaryls, thus eliminating endocrine‐disrupting BPA from the material and from any potential downstream waste. Thiocracking of PC (10 wt%) with elemental sulfur (90 wt%) at 320 °C yields the highly crosslinked network SPC90. The composition, thermal, morphological, and mechanical properties of SPC90 were characterized by FT‐IR spectroscopy, TGA, DSC, elemental analysis, SEM/EDX, compressive strength tests, and flexural strength tests. The composite SPC90 (compressive strength = 12.8 MPa, flexural strength = 4.33 MPa) showed mechanical strengths exceeding those of commercial bricks and competitive with those of mineral cements. The approach discussed herein represents a method to chemically upcycle polycarbonate while deconstructing BPA units, and valorizing waste sulfur to yield structurally viable building materials that could replace less‐green legacy materials. [ABSTRACT FROM AUTHOR]

Chemical recycling polymer waste is a highly required technology to follow the current carbon‐neutral trend. Here, we present practical recycling methods for poly (bisphenol A carbonate) (PC) and poly(ϵ‐caprolactone) (PCL). PC can be converted to bisphenol A and urea with excellent product yield at 80 °C via ammonolysis using ammonium salt (ammonium‐formate or ‐carbonate) instead of liquid ammonia that is usually used in previous PC recycling. PCL can be converted to methyl 6‐hydroxy‐hexanoate monomer with excellent yield at 80 °C via methanolysis catalyzed by KOH. [ABSTRACT FROM AUTHOR]

Crossbow-related injuries resulting in serious and mortal consequences have increased in recent years, and although significant research exists for both injury and fatality on the human body, limited data exists on the lethality of the bolt and the failure modes of protective materials. This paper concerns itself with the experimental validation of four differing crossbow bolt geometries, their effects on material failure and potentially lethality. During this study, four different types of crossbow bolt geometries were tested against two protection mechanisms that differed in mechanical properties, geometry, mass and size. The results show that at 67 ms−1, ogive, field and combo tips do not provide lethal effect at 10-m range, whilst a broadhead tip will perforate both the para-aramid and a reinforced area of polycarbonate material consisting of two 3-mm plates at 63–66 ms−1. Although perforation was apparent with a more honed tip geometry, the chain mail layering within the para-aramid protection and friction caused by polycarbonate petalling on the arrow body reduced the velocity enough to demonstrate the materials under test are effective at withstanding crossbow attack. Subsequent calculation of the maximum velocity that arrows could achieve if fired from the crossbow within this study shows results close to the overmatch value of each material and therefore a requirement to advance the knowledge in this field to influence the development of more effective armour protection mechanisms. [ABSTRACT FROM AUTHOR]