Search

This study delves into optimizing production parameters and 3D printing (3Dp) conditions for alkaline‐treated 10% hemp fiber‐reinforced polycarbonate (PC) composites. Initially, composite filaments were extruded at 250°C (PCH250) and 230°C (PCH230) to assess the impact of varying melt mixing temperatures on thermal behavior. Thermal characterization was conducted using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC analysis indicated consistent glass transition temperatures (Tg) across pure PC and the composites, while TGA revealed minimal thermal degradation in PCH230 compared to pure PC. Subsequently, to ascertain the optimal 3D printing temperature, specimens were printed at temperatures elevated by 10°C relative to their melt mixing temperatures (PCH250/260 and PCH230/240), followed by mechanical evaluation via tensile testing. PCH230/240 exhibited superior mechanical properties, demonstrating a 12% increase in tensile strength and a 29% increase in Young's modulus compared to pure PC. Additional testing at 230°C printing temperature (PCH230/230) demonstrated enhanced mechanical strength over PCH250/260 but inferior performance relative to PCH230/240, attributed to incomplete interlayer adhesion observed through SEM analysis. Consequently, the optimal composite melt mixing temperature was determined to be 230°C, with an accompanying 3D printing temperature of 240°C for optimal mechanical performance. Highlights: 3D printable, 5% NaOH treated hemp fiber reinforced polycarbonate composite.Printing composite with 3D printing device at different temperatures230°C process temperature gives the best thermal properties.240°C 3Dp temperature provides the best mechanical and morphological properties. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The increased rate of postuse accumulation of the heteroatom‐containing plastic wastes, like polyethylene terephthalate (PET), polycarbonate (PC) and polyurethane (PU), in the environment propels the research for effective and sustainable valorization. In this study, PET from bottle waste, PC from compact discs, and PU from waste wind turbine blade were characterized and employed for fast pyrolysis experiments. Importantly, red mud (RM), a mixed oxide rich in Fe, Al, Si, Na, and Ca, was used as a catalyst for fast pyrolysis. The effects of temperature and feed/catalyst ratio on product yields were studied to elucidate the product formation mechanism. Benzoic acid and its derivatives, bisphenol‐A and oxygenated aromatics, and 4,4′‐methylenebisbenzamine were the major products obtained from the noncatalytic fast pyrolysis of PET, PC, and PU, respectively. The use of RM improved the yield of aromatic hydrocarbons from PET to 27.8 wt% at 550 °C, phenolics from PC to 46.6 wt% at 550  °C, and 4,4′‐methylenebisbenzamine to 34.9 wt% at 650 °C. The catalytic activity of RM is ascribed to the presence of active basic sites. The present study paves the path for the catalytic upcycling of challenging plastic wastes using industrial waste, like RM, as a sustainable catalyst from a circular economy viewpoint. [ABSTRACT FROM AUTHOR]

In initial experiments the effects of aromatic model substances on carbon nanotube (CNT) dispersions in dimethylformamide (DMF) were investigated. Electron‐deficient aromatics interact strongly with CNTs, causing increased agglomeration and sedimentation. Conversely, electron‐donating aromatics stabilize CNT dispersions in DMF. Polymers with electron‐deficient aromatics, such as polydinitrostyrene (PDNS), exhibit a concentration‐dependent effect: low concentrations lead to stabilization of dispersions, while higher concentrations lead to sedimentation. This suggests that such polymers can enhance attraction between the matrix of CNT‐reinforced polymers as well as stabilize the dispersed CNTs. Polycarbonate, modified with polydinitrocarbonate (PDNC) and reinforced with CNTs showed improved mechanical properties. The addition of 6 wt.% CNTs and 6 wt.% PDNC resulted in a notable improvement with a 22% increase in tensile strength, a 29% increase in flexural strength, a 39% increase in Young's modulus and a 47% increase in flexural modulus. This enhancement resulted in an overall mechanical performance comparable to the high‐performance polymer polyetherimide. However, there must be noted, that the addition of PDNC increases the CNT particle size, which can negatively affect mechanical properties. The results highlight the additive's dual role in enhancing adhesive interactions while potentially increasing CNT agglomerate sizes. Highlights: Interactions of CNTs dispersed in DMF and various aromatics were investigated.Polydinitrocarbonate (PDNC) was synthesized as a new additive for CNT‐composites.Polycarbonate/CNT‐composites were obtained using extrusion.Test specimens with CNT contents up to 6 wt.% were obtained.Mechanical properties of polycarbonate reached the level of polyetherimide. [ABSTRACT FROM AUTHOR]

A PPC‐dodecyl glucoside (PPC‐APG) polymer was synthesized by the terpolymerization of carbon dioxide (CO2), propylene oxide (PO), and the bio‐based monomer APG for the first time. The thermal stability and mechanical properties of PPC‐APG were significantly improved compared with those of conventional polypropylene carbonate (PPC), and its glass transition temperature (Tg) was increased by 14°C compared with that of PPC. The 5% heat loss temperature (Td,−5%) and total heat loss temperature (Td,max) of PPC‐APG were increased by 89.1 and 92.1°C, respectively, compared with those of PPC. The tensile strength of PPC‐APG was increased to 25.6 MPa, its elongation at break was decreased to 125.1%, and its thermal elongation and permanent deformation were reduced to 97.2% and 62.9%, respectively, which improved the processability of the material. In addition, the introduction of bio‐based monomers also rendered PPC‐APG functional, and its surface tension reached a maximum of 61.3 mN/m at a concentration of 0.05 g/mL, with a good degradability. The higher surface tension and enhanced degradability of PPC‐APG indicate its potential for application as a plastic printing substrate. [ABSTRACT FROM AUTHOR]

Compatibility of polycarbonate (PC) and polymethyl methacrylate (PMMA) alloys was improved by using a transesterification catalyst (SnCl2·2H2O). Modified PC/PMMA alloys exhibit single Tg, and their initial island phase existing in the SEM were transformed into uniform surface. Besides, the transmittance of the modified alloys was increased from original 40% to 85%. Moreover, PC/PMMA alloys and PC foams with micro‐cellular and nano‐cellular structures were prepared by solid‐state CO2 foaming in the presence of transesterification catalyst. Distinctively, there are obvious nano‐cellular structures existing in the PC samples, but no related nanostructures were found in PMMA samples, after treated by same amount of catalyst and foaming process for pure PC and PMMA matrix. Furthermore, the effects of foaming temperature and segment structure on their foaming behavior were also studied. Additionally, a uniaxial stress experiment was conducted at a specific temperature to simulate the biaxial stress during the foaming process for discovering the mechanism of nanopore formation. Therefore, the concept of nano‐cellular structures will point out a direction for the development of high‐performance, heat insulation PC materials of the next generation. Highlights: Transesterification catalysts enhanced compatibility between PC and PMMA.Nanopore structures were successfully constructed in PC foams.Segment stretching was the main reason for the formation of nanopores. [ABSTRACT FROM AUTHOR]

This study focuses on the experimental investigation of the mechanical properties of PBT/PC blends with varying compositions. The studied mechanical properties include tensile strength, elongation, tensile modulus, impact strength, and Shore hardness of PBT/PC blends with different PC contents. PBT, characterized by its semi‐crystalline and tough nature, contrasts with PC, known for its impact resistance and hardness. Achieving an optimal blend composition proves to be crucial for attaining the best combination of these properties. The tensile strength of the PBT/PC 30/70 blend increased by approximately 24%, with Shore hardness also experienced a 12% enhancement compared to pure PBT. This improvement is attributed to the presence of PC segments in the blend structure. Conversely, an increase in PC content led to the elongation and impact strength of the blends peaking in the PBT/PC 70/30 blend. Notably, the impact strength of the PBT/PC blend with 30% PC increased by about three times compared to PBT and 18% more than pure PC. Scanning Electron Microscopy (SEM) analysis revealed that PBT and PC segments disperse at lower PC content, while at higher content, phase separation becomes prominent. Fourier Transform Infrared Spectroscopy (FTIR) analysis indicates direct transesterification between PBT and PC, resulting in the formation of a long‐chain blend structure with random copolymer blocks. The transesterification mechanism is also supported by Differential Scanning Calorimetry (DSC) results, wherein a reduction in the crystallization temperature (Tc) and an increase in the glass transition temperature (Tg) is observed. The study concludes that the volume of these segments and their bonding play a decisive role in determining the mechanical properties. The bonding mechanism elucidated through FTIR and SEM provides valuable insights into the fabrication and property engineering of PBT/PC blends. [ABSTRACT FROM AUTHOR]

We prepared yttria‐stabilized zirconia (YSZ) and titania crystalline thin films on polycarbonate (PC) substrates by the sol‐gel transfer technique that we have developed recently. Precursor gel films were deposited by spin‐coating on a polyimide/polyvinylpyrrolidone mixture layer on Si(100) substrates, and then were calcined at 600°C. The spin‐coating and the calcination were cycled, followed by final firing at 600–1000°C, to obtain 140–190 nm thick, YSZ and titania crystalline thin films. The film densification progressed as the final firing temperature increased, where the porosity calculated from the refractive index decreased down to a few percent. The film thus obtained was heated at 190°C on a hot plate, and a PC substrate was pressed on the film to transfer it to the PC substrate. The transferability quantified by image analysis of the film area was found to be significantly different between the YSZ and titania films. In the case of YSZ films, the area of silicon that was fractured and adhered to the transferred film increased significantly with increasing firing temperature, leading to a decrease down to 0% in the fraction of the successful transfer area without such a damage. On the other hand, the fraction of the successful transfer area remained around 90% irrespective of the firing temperature for the titania films. The surface of the titania films that were fired at 800–1000°C and transferred to PC substrates had voids of several tens nm scale, which may have been formed during anatase‐to‐rutile phase transformation. We thought that the reduced titania/Si(100) contact area due to such void formation facilitated the delamination of the titania films from Si(100) substrates. High temperature firing, which promotes crystallization and densification of films, thus affects differently the film transferability to plastic substrates, depending on the type of films. The work also suggested possible use of titania films as release‐assisting layers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

La(III)‐catalyzed depolymerization of polycarbonates produces the raw carbonates and diols by transesterification without the use of bases, ionic liquids or additives. Poly(bisphenol A carbonate) (1 a) is depolymerized by [La(acac)3] (acac: acetylacetonate) (1 mol %) in MeOH at 135 °C for 20 min to give dimethyl carbonate (2 a) (95 %) and bisphenol A (3 a) (93 %). This reaction can also be carried out in the air using MeOH as received and on a 10 gram‐scale. A commercial compact disk (CD) can also be depolymerized quantitatively. Depolymerization of 1 a in EtOH or 1,2‐propanediol produces corresponding carbonate with 3 a. Poly(ethylene carbonate) (1 b) and poly(propylene carbonate) (1 c) are converted into dimethyl carbonate and corresponding glycols in high yields in MeOH. The kinetic study suggests the surface reaction mechanism for the La(III)‐catalyzed depolymerization of 1 a. [ABSTRACT FROM AUTHOR]

Highlights Various sizing agents were prepared to enhance the interfacial properties between aramid fiber (AF) and polycarbonate (PC), as well as to enhance the mechanical properties of AF/PC composites. It was found that PC sizing agent, P‐GO sizing agent, and PSi‐GO sizing agent effectively coated the surface of AF from the FTIR and XPS and SEM results. The IFSS and mechanical properties of composites reinforced with fibers treated by the sizing agents exhibited significant improvement, as well as their single fiber tensile strength also improved. Specifically, when AF was treated with PSi‐GO sizing agent, the interfacial shear properties between AF and PC increased by a remarkable 78.69%, reaching 22.89 MPa compared to the original AF/PC composite, the tensile strength of the single‐filament exhibited an increment of 12.4% to 26.4 cN/dtex. Moreover, the tensile strength, flexural strength, and impact strength of the composite increased by 5.43%, 77.74%, and 54.71%, respectively. These improvement can be attributed to the GO with a higher concentration of chemical groups and excellent dispersion with modified with the silane agent. These findings suggest that coating the AF with sizing agents can effectively enhance its interfacial adhesion with the matrix, which is useful for its application as the reinforcement in the composites. Adding GO to the sizing agent to change the Aramid fabric surface properties. Silane coupling agent was used to improve the dispersion of GO on the fiber surface. GO modified sizing agent can improve the flexural strength, tensile strength, and interlaminar shear strength of the composites. [ABSTRACT FROM AUTHOR]

Seeking high‐performance photoresists is an important item for semiconductor industry due to the continuous miniaturization and intelligentization of integrated circuits. Polymer resin containing carbonate group has many desirable properties, such as high transmittance, acid sensitivity and chemical formulation, thus serving as promising photoresist material. In this work, a series of aqueous developable CO2‐sourced polycarbonates (CO2‐PCs) were produced via alternating copolymerization of CO2 and epoxides bearing acid‐cleavable cyclic acetal groups in the presence of tetranuclear organoborane catalyst. The produced CO2‐PCs were investigated as chemical amplification resists in deep ultraviolet (DUV) lithography. Under the catalysis of photogenerated acid, the acetal (ketal) groups in CO2‐PC were hydrolysed into two equivalents of hydroxyl groups, which change the exposed area from hydrophobicity to hydrophilicity, thus enabling the exposed area to be developed with water. Through normalized remaining thickness analysis, the optimal CO2‐derived resist achieved a remarkable sensitivity of 1.9 mJ/cm2, a contrast of 7.9, a favorable resolution (750 nm, half pitch), and a good etch resistance (38 % higher than poly(tert‐butyl acrylate)). Such performances outperform commercial KrF and ArF chemical amplification resists (i.e. polyhydroxystyrene‐derived and polymethacrylate‐based resists), which endows broad application prospects in the field of DUV (KrF and ArF) and extreme ultraviolet (EUV) lithography for nanomanufacturing. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the bisphenol A (BPA) release from four CAD/CAM splint materials: three polycarbonate‐based (DD BioSplint C, Splint Plus Biostar, Temp Premium Flexible) and one polymethylmethacrylate‐based (Temp Basic) material. From each material, ten cylindrical samples (n = 40) were immersed in high‐performance liquid chromatography (HPLC) grade water following ISO 10993‐12 and incubated for 24 h in an incubation shaker at 37°C and 112 rpm. Following BPA derivatization, analysis was performed by high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS). After 24 h of incubation, all investigated materials released significant amounts of BPA compared to water blanks. The material‐dependent elution increased in the following order: DD BioSplint C < Splint Plus Biostar < Temp Basic < Temp Premium Flexible. Subtracting extraneous BPA, the concentrations ranged between 2.27 ng/mL and 12.65 ng/mL. After extrapolating the concentrations in relation to the average surface area of occlusal splints, the amount of BPA per mL exceeded the Tolerable Daily Intake (TDI) set by the European Union for a person weighing 70 kg by 1.32–6.16 times. Contrary to the release from previously investigated materials, BPA elution from CAD/CAM splint materials was highly elevated. Considering the increasing adaptation of CAD/CAM techniques, elution from them may represent a relevant BPA source in daily dental practice. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Improper end‐of‐life treatments of C−O‐linked plastics have caused serious environmental crises and resource waste. One effective method to solve this issue is the catalytic alcoholysis of these plastics. Traditional homogeneous catalysts or metal‐based heterogeneous catalysts for alcoholysis have some drawbacks, such as difficulty in complete separation, environmental threats, and economic burden. Thus, finding a green, low‐cost, recyclable, and highly efficient catalyst substitute is critical. Here, we reported that polymeric carbon nitride nanosheets can serve as a metal‐free heterogeneous catalyst for the methanolysis of polycarbonate, polyethylene terephthalate, and polylactic acid. The catalyst exhibits remarkable performance and could be reused at least four times. NHx was found to be the predominant active site of the catalyst by characterization and experiments. These results show promise for the design of metal‐free heterogeneous catalysts to depolymerize C−O‐linked plastics. [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]

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]

Polycarbonate (PC) is a thermoplastic engineering plastic with excellent properties, and its excellent dielectric properties have broad application prospects in the field of electronics. In this paper, bisphenol Z (BPZ) and diphenyl carbonate (DPC) are used as raw materials to synthesize special polycarbonate (BPZ‐PC) by melt transesterification. The effects of catalyst type, catalyst dosage, molar ratio of raw materials, transesterification reaction time and vacuum degree, polycondensation reaction temperature and time on the molecular weight of the product are investigated, and the optimal reaction conditions are obtained. The chemical structure of the product is verified by FTIR, 1H‐NMR and 13C‐NMR spectra tests. The thermal properties, mechanical properties, optical properties and dielectric properties of BPZ‐PC are evaluated. Therefore, due to its excellent performance, BPZ‐PC, a high‐performance low‐dielectric polycarbonate, can be widely used in high‐frequency communication, microelectronics, and aerospace industries. [ABSTRACT FROM AUTHOR]

Stimulus‐responsive drug carriers have significant potential for enabling smart drug delivery within the intricate microenvironment of tumors. However, a single stimulus source and complex synthesis process limit its application. In this study, we successfully synthesized a pH/GSH‐stimulated responsive polycarbonate (PSSA) through ring‐opening polymerization and post‐esterification reactions. PSSA can self‐assemble into homogeneous and stable micelles, effectively encapsulating the anticancer drug doxorubicin (DOX). The carbon backbone of PSSA contains disulfide and acetal linkages, which allow for extensive responsiveness to changes in pH and GSH. This results in variations in particle size and micellar morphology. The micelles loaded with DOX demonstrate responsive drug‐releasing properties when stimulated by pH/GSH. The dual‐response micelles exhibit superior drug release compared to single stimulus sources. The blank micelles are non‐cytotoxic, while the DOX‐loaded micelles show dose‐dependent cytotoxicity towards HepG2 cells. Importantly, DOX‐loaded micelles enable precise intracellular drug release by responding to the microenvironment of tumor cells. Therefore, this dual‐responsive micellar nano‐carrier, which maintains extracellular stability but activates intracellular drug release, presents a novel approach for smart anti‐tumor drug delivery applications. [ABSTRACT FROM AUTHOR]

The development of fifth‐generation technology has resulted in increased demand for materials with low dielectric losses and superior thermal and mechanical properties. However, ensuring the widespread use of such materials by investigating their aging mechanisms and operating lifetimes remains challenging. In this study, a glass‐fiber (GF)‐reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite is designed and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Based on the general Peck model, the composite maintains a high level of quality for over 10 years, including under harsh conditions of 40 °C and 80% relative humidity. The aging mechanism is primarily ascribed to cracking between the GF fibers and matrix, the breaking of chemical bonds, the generation of new cross‐linked domains, and physical aging. These findings provide valuable insights into the long‐term utilization of ASA/GF/PC composites in harsh environments. [ABSTRACT FROM AUTHOR]

A nitrogen‐rich DOPO‐based phosphoramide (DPAPZ) was synthesized using aminopyrazine and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as raw materials, and blended with polycarbonate (PC) through melting method. The chemical structure of DPAPZ was validated by FTIR, 1H NMR and 31P NMR. The presence of DPAPZ endowed PC/DPAPZ composites with better fire safety and smoke suppression. With the incorporation of 6 wt% DPAPZ, PC/DPAPZ‐6 composite reached UL‐94 V‐0 rating and 30.2% of limiting oxygen index value. Simultaneously, the peak of heat release rate and total heat release of PC/DPAPZ‐6 were reduced by 44.8% and 47.0% as compared with the pure PC, respectively. The DPAPZ displayed bi‐phase flame retardant roles. In the gas phase, the decomposition of DPAPZ released phosphorus‐containing free radicals acting as the quencher of reactive H·/OH· and nonflammable NH3 diluting O2/combustible volatiles. In the condensed phase, the phosphorus‐containing components were dehydrated into metaphosphoric acid or polymetaphosphate covering the surface to protect the PC matrix from further combustion, and to promote the formation of a dense carbon layer to interrupt the transmission of O2 and volatiles between the combustion zone and the inner. The tensile strength of the composites displayed almost no change but the elongation at break decreased slightly with the addition of DPAPZ. [ABSTRACT FROM AUTHOR]

This work describes a novel method for the efficient reductive depolymerization of polyester and polycarbonate plastic waste using pinacolborane (HBpin) catalyzed by Zn(OAc)2.2H2O and Zn(OTf)2. This method is applied to a variety of plastic waste and has the advantages of combining the use of non‐toxic, cheap, and commercially available catalysts with a mild, easy‐to‐handle reducing agent, with excellent yields, under mild reaction conditions. [ABSTRACT FROM AUTHOR]

When exposed to the open air, the wood can change its physical and structural properties due to the combined effect of ultraviolet radiation, oxygen, humidity, atmospheric pollutants, and microorganisms. The demand for durable coatings with application to wooden structures or pieces is always a relevant topic. Waterborne polyurethane (WPU) dispersions as wood protective coatings might be attractive, especially outdoors. In this work, WPU dispersions have been synthesized from isophorone diisocyanate and different ratios of polypropylene glycol and polycarbonate (PC) diol. Synthesized polyurethanes were applied to wood surfaces as a coating. The results showed that the partial and total replacement of polypropylene glycol (PPG) by PC influences the mechanical, thermal, and structural properties of the films obtained from aqueous polyurethane dispersions. In addition, a simple and promising methodology based on Fourier‐transform infrared (FTIR) spectra was proposed to determine the polycarbonate content in poly(carbonate‐ether‐urethane). The synthesized coatings reduced water absorption by the wood, especially the one with a 25:75 polycarbonate to PPG ratio. The applied coating does not impact the final color of the wood, allowing a natural aging effect. Polyurethanes are promising for use as coatings for wood. [ABSTRACT FROM AUTHOR]

To understand the interfacial bond formation between polycarbonate (PC) and magnetron‐sputtered metal nitride thin films, PC | X interfaces (X = AlN, TiN, (Ti,Al)N) are comparatively investigated by ab initio simulations as well as X‐ray photoelectron spectroscopy. The simulations predict significant differences at the interface as N and Ti form bonds with all functional groups of the polymer, while Al reacts selectively only with the carbonate group of pristine PC. In good agreement with simulations, experimental data reveal that the PC | AlN and the PC | (Ti,Al)N interfaces are mainly defined by interfacial C─N bonds, whereas for PC | TiN, the interface formation is also characterized by numerous C─Ti and (C─O)─Ti bonds. Bond strength calculations combined with the measured interfacial bond density indicate the strongest interface for PC | (Ti,Al)N followed by PC | AlN, whereas the weakest is predicted for PC | TiN due to its lower density of strong interfacial C─N bonds. This study shows that the employed computational strategy enables prediction of the interfacial bond formation between PC and metal nitrides and that it is reasonable to assume that the research strategy proposed herein can be readily adapted to other organic | inorganic interfaces. [ABSTRACT FROM AUTHOR]

The consequences of light‐induced oxidation of polycarbonate on its permeability to oxygen were deeply investigated. Polymer films were sequentially photoaged, resulting in the sequential appearance and growth of oxidation products at the surface of the exposed side up to a limit value, owing to the progressive yellowing of the film during the photoageing process. Such effect restricts drastically the oxidation process to the film surfaces. The observed decrease in oxygen permeability consecutive to exposure of only one side of the film results principally from a decrease in oxygen solubility into the polymer, with a minor reduction of its diffusion ability. This was explained by the increase of the polymer polarity owing to the appearance of several types of polar chemical groups (namely CO and OH) as well as the occurrence of cross‐linking upon photodegradation. This decrease in oxygen permeability is then a positive feature in the case of applications for packaging and medical components. No further decrease in oxygen permeability was observed when the second side of the films was photooxidized, which can be explained by a "funnel effect" type between sorption, diffusion and desorption steps. [ABSTRACT FROM AUTHOR]

Herein, the six‐membered sulfur‐containing cyclic carbonates was successfully synthesized from d‐ and l‐xylose through an environmental friendly process by employing carbonyl sulfide (COS) as a sustainable C1‐carbonation agent. The ring‐opening polymerization of the monomers were rapidly initiated by bifunctional organocatalysts and alkali metal alkoxides, respectively, under ambient reaction conditions. The resultant sulfur‐containing polycarbonates exhibit high‐temperature resistance and good optical properties. This work furnishes an original and practical strategy for utilizing COS as a sulfur feedstock in biopolymer synthesis. [ABSTRACT FROM AUTHOR]

Poly(isosorbide carbonate) (PIC) is an example of the shift from fossil to bio‐based feedstocks in polymeric materials. However, the naturally high hygroscopicity of isosorbide may lead to the bad dimensional stability of its polymers, limiting its application. This work aims to develop a series of isosorbide‐based copolycarbonates by introducing hydrophobic groups, such as alkane chains and aromatic rings, into the polymer backbone via one‐pot melt polycondensation. As expected, the molecular structure and steric hindrance of the comonomer have a remarkable effect on the water absorption of the copolycarbonates. Among the comonomers, tricyclo[5.2.1.0(2,6)]decanedimethanol with an alkane skeleton bridge effectively reduces the saturation water absorption by 61% compared to PIC. The water absorption mechanism and kinetics of the copolycarbonates are investigated. Moreover, the incorporation of comonomers in PIC not only exhibits stronger hydrophobicity, but also significantly improves its optical properties. Copolycarbonates obtained have a light transmittance of 92% and a refractive index of 1.5394, which are higher than those of PIC, along with better thermal stability, flexibility, and lower glass transition temperature. This work provides a new strategy for the design of isosorbide‐based polycarbonates for use in optics. [ABSTRACT FROM AUTHOR]

Polymer scratch mechanics has been widely studied. However, the physics behind scratch visibility is still not well understood. Scratch deformation mechanisms certainly affect visibility but also other material properties, such as roughness, color, or gloss. This work relates to methods to quantitatively evaluate the effect of sample color on polymer scratch and mar induced visibility, aiming at linking scratch behavior with the underlying physics. A custom‐built black box was utilized for the analysis of samples possessing different colors and surface finishing. Automatic image analysis was performed through a commercial software to quantify the onset of visibility in terms of a critical load above which the scratch becomes visible. Trained surveyors visually quantified said critical load. White color was shown to delay the onset of visibility by reducing the contrast between the damaged and undamaged area. For instance, the critical load for the onset of visibility for a white polycarbonate copolymer was nearly twice the value reported for its black variant. Consistent results were obtained for all tested samples. Similar findings were reported for the mar phenomenon, highlighting how white color can also mask a different type of damage. The usefulness of the present work and some future perspectives are discussed. [ABSTRACT FROM AUTHOR]

This study addresses the effect of the coatings prepared from aramid nanofibers (ANFs) on the surface treatment of aramid fiber and reinforced polycarbonate (PC) composite (AF/PC). Aramid fiber's smooth, inert surface bonds poorly with polycarbonate. In this research, the PC‐ANF coating was made by the PC/CH2Cl2 solution, which was modified by aramid nanofibers to improve the interfacial adhesion and compatibility of aramid fiber/PC composites. What's more, the silane (KH570) was added to improve the dispersion and interfacial strength of ANF and PC. The results showed the water contact angle of the aramid fiber modified by PSi‐ANF coating was reduced, indicating the modified fiber has a better wettability. The interfacial bonding strength between PC and aramid fiber increased by 77.2%. The AF/PC composites were prepared by hot‐compression, which the aramid fiber wovens treated with P‐ANF coating, PSi‐ANF coating. The tensile strength, flexural strength, interlaminar shear strength, and impact strength of the AF/PC composite reinforced by AF treated with PSi‐ANF containing 2.0 wt% ANF increased by 62.0%, 81.9%, 49.5%, and 27.6%, respectively. Therefore, this study demonstrates that incorporating ANF interphase may offer an innovative and practical way for enhancing the interface bonding properties of aramid‐reinforced composites. [ABSTRACT FROM AUTHOR]

Photochromism has been used as an attractive method to enhance the authentication of commercially available goods. It has been fundamental to enhance the engineering procedure of the authentication materials to introduce a mechanically reliable authentication nanofibrous film. In this context, we develop a mechanically reliable and photoluminescent electrospun nanofibrous polycarbonate film immobilized with lanthanide‐doped aluminate nanoparticles (NPs) by the electrospinning method for authentication purposes. The prepared composite film displayed photochromism by changing color from transparent under daytime light to green under ultraviolet light. To guarantee the transparency of the electrospun nanofibrous film, the strontium aluminate pigment must be presented in the nano‐scaled particle form to improve its distribution without forming aggregates in the electrospun polycarbonate nanofibrous bulk. The pigment‐polycarbonate nanofibers showed an emission band at 512 nm upon excitation at 374 nm. The pigment‐polycarbonate nanofibers showed an improved hydrophobicity with raising the pigment ratio without adverse influences on their inherent appearance and mechanical characteristics. When excited with UV light, the transparent films had rapid and reversible photochromism without fatigue. The nanofibrous mats displayed elasticity and flexibility. The present approach can be described as a competent method for the preparation of diverse anticounterfeiting materials. [ABSTRACT FROM AUTHOR]

The melt fluidity of polycarbonate (PC) significantly influences the processing, while the melt viscosity depends on the molecular structure. Specifically, the melt viscosity increases sharply with the increase of polymerization degree. However, the influence mechanism of alkali metal catalysts on the fluidity by affecting the molecular structure remains unclear. Herein, high and low concentrations of NaOH catalysts were used to synthesize PC with different polycondensation degrees. The effect of NaOH catalyst content on the molecular structure and thus melt fluidity of PC were systematically characterized and discussed employing NMR spectroscopy, absolute and relative molecular weight, intrinsic viscosity, melt flow index, and thermal analysis. The results show that a random branched structure of the PC molecular chain caused by excess NaOH improves the melt flowability. However, the residual NaOH promotes the degradation of carbonate bonds during thermal processing, resulting in poor PC stability. Based on the above discussion, empirical fitting equations are proposed to describe the relationship between molecular structure and flow properties, which provides a new way to judge PC performance. [ABSTRACT FROM AUTHOR]

Transforming renewable resources into functional and degradable polymers is driven by the ever‐increasing demand to replace unsustainable polyolefins. However, the utility of many degradable homopolymers remains limited due to their inferior properties compared to commodity polyolefins. Therefore, the synthesis of sequence‐defined copolymers from one‐pot monomer mixtures is not only conceptually appealing in chemistry, but also economically attractive by maximizing materials usage and improving polymers' performances. Among many polymerization strategies, ring‐opening (co)polymerization of cyclic monomers enables efficient access to degradable polymers with high control on molecular weights and molecular weight distributions. Herein, we highlight recent advances in achieving one‐pot, sequence‐controlled polymerizations of cyclic monomer mixtures using a single catalytic system that combines multiple catalytic cycles. The scopes of cyclic monomers, catalysts, and polymerization mechanisms are presented for this type of sequence‐controlled ring‐opening copolymerization. [ABSTRACT FROM AUTHOR]

In this work, multiple rheological and molecular structure characterization methods are utilized to investigate the melt post‐polycondensation (MPP) process of polycarbonate (PC) at high temperatures (260–300°C) under a nitrogen atmosphere. We find some unexpected phenomena that the complex viscosity of PC melt rise rapidly and it reaches an extraordinarily high value of about 106 Pa·s during the MPP process of 10 h at 300°C. Dissoluble PC and insoluble gel residue are separated and both fractions are analyzed by gel permeation chromatography, 1H‐NMR, and pyrolysis‐gas chromatography mass spectrometry. Results show that the molecular weight of dissoluble PC significantly increases at the early stage of the reaction (less than 1 h). After that, it continues to reduce due to the occurrence of branching reactions and degradation reactions caused by high temperature reactions for a long time. Chemical structure analysis indicates that the same two branched structures are discovered in both dissoluble PC and insoluble gel residue, the changes in structures indicate that no new structures are formed during the crosslinking reaction. According to this study's results, we clearly understand the correlation between the rheological properties and structural changes for PC in the MPP progress. [ABSTRACT FROM AUTHOR]

Dielectric capacitors have a high power density, and are widely used in military and civilian life. The main problem lies in the serious deterioration of dielectric insulation performance at high temperatures. In this study, a polycarbonate (PC)‐based energy storage dielectric was designed with BN/SiO2 heterojunctions on its surface. Based on this structural design, a synergistic suppression of the carrier injection and transport was achieved, significantly improving the insulating properties of the polymer film. In particular, the composite film achieves optimal high‐temperature energy‐storage properties. The composite film can withstand an electric field intensity of 760 MV m−1 at 100°C and obtain an energy storage density of 8.32 J cm−3, while achieving a breakthrough energy storage performance even at 150°C (610 MV m−1, 5.22 J cm−3). Through adjustment of the heterojunction structure, free adjustment of the insulation performance of the material can be realized; this is of great significance for the optimization of the material properties. [ABSTRACT FROM AUTHOR]

To fabricate polycarbonate (PC) composites with high mechanical and optical properties, PC composite films reinforced by cellulose nanocrystals esterified using palmitoyl chloride (palmitoylated cellulose nanocrystal [PAL‐CNCs]) were fabricated by casting‐evaporation and characterized by several techniques. It was shown that the PAL‐CNCs with a substitution degree of 0.43 and the crystalline index of 53.3% were better dispersed in chloroform and tetrahydrofuran, and achieved a water contact angle of 81.0°. The crystallite size and crystalline index of the PC in the composite film significantly increased to more than 5.2 nm and 51.5%, respectively, after the incorporation of the PAL‐CNCs. The PC composite film had an increase of 91.4% in tensile strength, 84.1% in Young's modulus, and a decrease of 5% in impact strength. Meanwhile, its UV–Vis‐light transmittance was above 90%. Therefore, the palmitoylated ‐CNCs were a better candidate for engineering PC composites with high mechanical performance and transparency. [ABSTRACT FROM AUTHOR]

Exposure to shear flow produced by a pressure‐driven capillary rheometer provides a concentration gradient without phase separation in miscible polymer blends of bisphenol‐A polycarbonate containing low‐molecular‐weight poly(methyl methacrylate) (PMMA). The strand surface extruded from the rheometer contains a large amount of PMMA. However, the strand is transparent because there is no light scattering due to phase separation. The segregation behavior, that is, enrichment of the PMMA content at the strand surface, is enhanced when the molecular weight of PMMA is low. Furthermore, the segregation is also enhanced at high temperatures and at high shear rates. By contrast, the die length barely affects the degree of segregation. The segregation phenomenon should be noted because it may facilitate the modification of the surface properties of various products. [ABSTRACT FROM AUTHOR]

Polymer films are widely used in various industries, and incorporation of nanofillers into polymer films can give much more versatility in their applications. Polymer/carbon nanotubes (CNTs) composite films with good electrical conductivity can easily find applications in anti‐static or electrostatic discharge (ESD) protection. In the present study, efforts were devoted to investigate novel ultrasound‐assisted twin‐screw extrusion technology on improving the dispersion and distribution of single‐walled carbon nanotubes (SWNTs) in polycarbonate (PC) composites films via extrusion process. As a key processing parameter, effect of screw configuration on the performance of the composite films were systematically studied. Electrical, rheological, morphological and mechanical properties were characterized to illustrate the processing‐structure–property relationship during continuous film casting of PC/SWNTs composites with ultrasound‐assisted twin‐screw extruder. Results indicated that the screw configuration containing more kneading blocks led to better SWNTs dispersion and distribution, while the effect of ultrasound was more prominent in screw design with less kneading blocks. [ABSTRACT FROM AUTHOR]

Production and consumption of poly(bisphenol‐A carbonate) resins are seeing a worldwide increase. However, their usage lifetimes are short and their final disposition as landfills pose environmental and health risks, due to the release of toxic bisphenol‐A (BPA). The development of alternative recycling routes is thus becoming subject of increasing interest. In this review, the main recycling processes of poly(bisphenol‐A carbonate) are described and critically compared, with special focus on the chemical mechanisms. While mechanical recycling is possible, the end products are restricted only to polymer blends, whose main mechanical properties decrease with each compounding cycle. In turn, chemical recycling can produce BPA monomer and a variety of by‐products that can be used in different industries, including the polymeric field, as synthesis reagents and precursors. The operation conditions of each method are reviewed, as well as the different results obtained in terms of product yield, composition, selectivity and reaction times. Reaction mechanisms are described in detail and a view on the usability of each end product is offered. [ABSTRACT FROM AUTHOR]

Summary: Polycarbonate (PC) is a polymer containing Bisphenol A (BPA) monomers in its structure. It is frequently used in manufacturing consumer goods such as food storage containers, reusable water bottles, infant feeding bottles, microwave containers and microwaveable cups. Under varying pH and temperature conditions, additives used in the plastic manufacture can leach in trace levels into the food in contact and negatively affect human health over time. Therefore, quantitative determination of BPA in food can be of great significance. The present study analysed the migration of BPA in coffee from different qualities of polycarbonate microwaveable cups under the influence of microwave heating by reversed‐phase ultra‐high‐performance liquid chromatography (UHPLC). The amount of BPA detected in samples ranged from undetected to 391.105 ± 0.05 μg kg−1. Results obtained indicate that BPA migration is minimal in good‐quality polycarbonate cups. Poor‐quality cups are accelerated time‐dependent; increased contact duration between polycarbonate and hot contact medium leads to more significant BPA migration. Furthermore, the BPA leaching process is enhanced during microwave heating due to high temperatures reached in a short time. [ABSTRACT FROM AUTHOR]

Poly(cyclopentene carbonate) (PCPC) produced by copolymerization of CO2 and cyclopentene oxide (CPO) is a promising but challenging chemical recyclable polymer that has high potential in minimizing plastic pollution and maximizing CO2 utilization. Currently, problems remain to be solved, include low reactivity of toxic metal catalysts, inevitable byproducts, and especially the ambiguous mechanism understanding. Herein, we present the first metal‐free access to PCPC by using a series of modular dinuclear organoboron catalysts. PCPC was afforded in an unprecedented catalytic efficiency of 1.0 kg of PCPC/g of catalyst; while the depolymerization of PCPC abides by a combination pathway of random chain scission and chain unzipping, returning CPO in near‐quantitative yield (>99 %). The preparation and depolymerization of PCPC along with in depth understanding of related mechanisms would be helpful for further development of advanced catalysts and recyclable plastics. [ABSTRACT FROM AUTHOR]

In order to increase the applicability of wollastonite (Wo) in polycarbonate (PC) polymer, surface modification of Wo was carried out using different modifiers containing silane coupling agent KH570, stearic acid (SA), and sodium dodecylbenzene sulfonate. The physical, physic‐chemical, and application properties of modified Wo were evaluated. Results showed that KH570 modified Wo had narrower particle size distribution, higher absolute zeta potential and were more evenly distributed. Scanning electron microscope study confirmed their changes in morphology and aspect ratio during the modification process. The tensile strength of Wo/PC composites, in which KH570‐modified Wo was used were superior to those in which original Wo or other modifiers modified samples were used. The maximum tensile strength of 65 ± 1 MPa was obtained by adding 15 wt% KH570‐modified Wo. Thermal analysis indicated that adding Wo to the polycarbonate increased the residue content but decreased the thermal decomposition temperature and glass transition temperature slightly, regardless of unmodified or modified Wo. These results indicated that the well‐modified Wo mineral had the potential to replace expensive carbon and glass fibers as fillers in polycarbonate products. [ABSTRACT FROM AUTHOR]

Reduction of CO2 emission is an important issue all over the world, and the development of effective transformation methods of CO2 into valuable chemicals is highly desirable. Among various potential products derived from CO2, polymers are one of the promising target chemicals in terms of the production amount and CO2 fixation to solid materials. Therefore, the direct synthesis of polycarbonates from CO2 has recently attracted much attention because polycarbonates including polycarbonate diols are useful engineering plastics and intermediates for polyurethanes. There are many reports on the synthesis of polycarbonates from CO2 and cyclic ethers such as epoxides and oxetanes, however, the reports on the synthesis from CO2 and diols are limited. In this review, we summarize the recent progress of direct polycarbonate synthesis from CO2 and diols and explain the potential and issues for industrialization based on the characteristics of the reaction systems. [ABSTRACT FROM AUTHOR]

The significant development of catalytic biomass conversion has provided a large library of chemicals ready for subsequent upgrading to polymerisable monomers for the design and preparation of sustainable polymers. In this study, hydroxyethylation of eugenol by using green ethylene carbonate as alkylation reagent and cheap tetrabutylammonium iodide ionic liquids as green solvents and catalysts produced 2‐(4‐allyl‐2‐methoxyphenoxy)ethan‐1‐ol with a 85% yield, which could be used to construct an in situ CO2 capture and conversion system by taking the reversible chemistry of alcoholic compounds with CO2 in the presence of superbases, on which α,ω‐diene functionalized carbonate monomers were successfully prepared and were applied in thiol‐ene click and acyclic diene metathesis polymerisation (ADMET), producing a series of poly(thioether carbonate)s and unsaturated aromatic aliphatic polycarbonates with moderate molecular weights and satisfactory thermal properties. The structures of the formed CO2 reversible ILs, the polymerisable monomers and the corresponding polymers were fully characterized by various technologies. [ABSTRACT FROM AUTHOR]

The effect of physical aging of the partially miscible blend of polycarbonate:polystyrene (PC:PS) at temperatures near the glass transition temperature (Tg) of the PS was studied as a function of time. For this purpose, blends of PC and PS with different ratios were elaborated and characterized using SEM, FTIR, DSC, and DMA techniques. The results indicated the presence of weak interaction upon blending with a maximum of interaction for the 50:50 blend. The effect of physical aging on the latter was then investigated via DMA, DSC, and NMR analyses. The DMA results showed that both phases were sensitive to aging. The effect was found to be strongly dependent on both the temperature and time. The aging of PC:PS blend was also found to trap stress during the process which induced an instability in the viscoelastic behavior. The latter was found to be associated with a phase‐separation morphology of the blend and influenced by its composition. The NMR analysis also showed a pronounced distortion of the conformation combined with increasing molecular motion. These effects were found to be important for aging below the PS's Tg. [ABSTRACT FROM AUTHOR]

The effects of annealing conditions and molecular weight on the energies required for cracking and plastic deformation were investigated by the essential work of fracture (EWF) method. We found that the energy required for plastic deformation, βwp, regardless of the molecular weight, decreased upon annealing, and the energy required for cracking, we, did not change. On the basis of these results, it is suggested that annealing affects βwp because the density fluctuation is amplified by annealing, and as a result, the strain in the plastic region is concentrated. Moreover, both βwp and we increased with the molecular weight because the increase of molecular weight increases the number of entanglements formed by a molecular chain. In addition, comparing the values of the J‐integral (Jc), we found that we obtained from the EWF and Jc was almost the same, indicating that we obtained from the EWF also involves the energy required for plastic deformation when the deformation around the notch changes from biaxial stretching to uniaxial stretching. [ABSTRACT FROM AUTHOR]

ZnO nanoparticles were functionalized with amine groups and incorporated into a thin‐film nanocomposite (TFN) membrane. Polycarbonate (PC) membranes were coated with polyvinyl alcohol (PVA)/ZnO‐NH2 solution using the dip‐coating method. All prepared membranes were applied for the removal of humic acid (HA) in a submerged membrane system at vacuum trans‐membrane pressure (TMP) of 0.3 and 0.6 bar. Attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) and field‐emission scanning electron microscopy (FESEM) images confirmed the formation of PVA/ZnO‐NH2 top layer on the PC support membrane. The addition of nanoparticles caused the hydrophilicity and surface roughness of TFN membranes to increase. HA filtration experiments revealed that at lower vacuum TMP, the TFN with 0.05 wt.% of ZnO‐NH2 nanoparticles showed higher permeate flux. However, at higher vacuum TMP permeate flux significantly decreased. HA rejection did not change with added nanoparticles. As a final result, when vacuum TMP increased from 0.3 to 0.6 bar, rejection of HA slightly increased from 98.3% to 99.1% and 98.3% to 99.3% for thin film composite and TFN with 0.05 wt.% of nanoparticles, respectively. [ABSTRACT FROM AUTHOR]

In this work, four new mononuclear Cr(III) complexes (2–5) bearing bis‐thioether‐diphenolate, [OSSO]‐type ligands, were synthesized and characterized. These complexes in combination with bis(triphenylphosphine)iminium chloride (PPNCl) promoted the coupling of CO2 with epoxides. Depending on the type of substrate and the conditions, the reaction results in the selective formation of either polycarbonate or cyclic carbonate. For example, the reactions in the presence of complex 2 led to the exclusive formation of poly(cyclohexene carbonate, PCHC) from cyclohexene oxide (CHO) (TOF up to 39 h−1, at T=45–100 °C, time=24 h, pCO2=20 bar, epoxide/2 (mol/mol)=1000, and PPNCl/2=0.5–2.0 mol %). Under the same conditions and PPNCl/2=0.5–5.0 mol %, the reactions of CO2 with styrene oxide (SO), epichlorohydrin (ECH), 1,2 epoxydodecane (EDD), and allyl glycidyl ether (AGE) have shown selective conversion to the corresponding cyclic carbonates (TOF up to 41 h−1). [ABSTRACT FROM AUTHOR]

In this study, acrylonitrile‐butadiene‐styrene and polycarbonate substrates plastics were coated with aluminum by physical vapor deposition method in order to determine which one is a better choice for outdoor reflector technology. This investigation has been done by applying the coating on a reflector that is already been used in the lighting industry. Scraping test, caustic soda and caustic potash test, reflection efficiency performance test and surface roughness test methods were used to determine the selection. Coatings on acrylonitrile‐butadiene‐styrene and polycarbonate plastic materials were characterized by scanning electron microscopy and energy dispersive x‐ray spectrometry. Although acrylonitrile‐butadiene‐styrene plastic material is easier for injection molding and cheaper than polycarbonate material, the results showed that polycarbonate plastic material is more efficient than acrylonitrile‐butadiene‐styrene plastic material, especially in terms of surface roughness and reflection efficiency. [ABSTRACT FROM AUTHOR]

Carbon dioxide utilization is considered an effective strategy to mitigate the carbon footprint of chemical industry. Among other uses, the incorporation of carbon dioxide into cyclic organic carbonates (COCs) and aliphatic polycarbonates (APCs) has received great attention in the field of homogeneous catalysis. After few decades of research activity, a wide range of metal‐based catalytic systems has been reported to promote this reaction. Nonetheless, a better comprehension of the apparently simple reaction mechanism of such transformations has been reached only in recent years. This, in turn, allowed for the design of new catalytic systems guided by a clearer mechanistic picture. In this review, we present the most recent advancements in this field, distinguishing between catalysts for COCs and APCs production classified on the bases of their ligand structures. [ABSTRACT FROM AUTHOR]