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A new phenomenological constitutive model is proposed for the prediction of the tensile and compressive behavior of semi-crystalline and amorphous polymers. The new model modifies the phenomenological model previously proposed by Zhou and Mallick (ZM model) to correctly predict the complex behavior of thermoplastic materials including the linear viscoelastic deformation, the non-linear viscoelastic deformation, the yielding, the post-yield strain softening and the post-yield strain hardening. A validation activity based on literature data has been carried out for polyether-ether-ketone (PEEK) and polycarbonate (PC) materials. The new model proved effective in fitting with high accuracy all the phases of the flow stress behavior for the considered materials, across a wide range of strain rates and temperature conditions. Finally, the comparison with Zhu et al., Duan et al., Nasraoui et al., Mulliken- Boyce and Zhou-Mallick models showed the better fitting performance of the proposed phenomenological model. Highlights * Formulation of a new phenomenological model. * Validation on mechanical test of semi-crystalline and amorphous thermoplastics. * Comparison with different phenomenological models present in the literature. * Superior prediction results achieved compared to previously developed models. KEYWORDS constitutive model, mechanical behavior, polymers, strain rate, temperature, thermoplastics, visco-plastic model, 1 | INTRODUCTION The use of polymeric materials has been constantly rising in the automotive industry since the 1950s. This growth is even more relevant when expressed in terms of [...]

Fused filament fabrication (FFF), a known variation of fused deposition modeling (FDM), is a fast-growing additive manufacturing technique that is widely used in various industrial and technological applications owing to its ability to build functional parts with complex geometrical features in a reasonably good time. FFF utilizes a variety of thermoplastic materials such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), nylon (polyamide), and polycarbonate (PC) each offering distinct properties suitable for different applications. Polycarbonate is a high-performance polymer with engineering applications, but it is a less studied material with respect to the FFF process. The mechanical properties and dimensional accuracy of FFF-built parts are influenced by several process parameters, and choosing the best set of process parameters is essential for achieving the desired properties in the built parts. This study examined the effects of four critical process parameters (layer thickness, extrusion temperature, printing speed, and extrusion width) on the mechanical properties such as the tensile, flexural, and compression strengths of FFF-printed polycarbonate specimens. Tensile, flexural, and compressive tests were performed according to ASTM standards. Mathematical models based on dimensional analysis were developed to determine the correlation between the process parameters and mechanical properties of the printed specimen. The predicted models obtained showed a good correlation with the measured values and could be used to generalize the prediction for the process conditions of the FFF process. Validation tests were conducted to verify the developed mathematical models. The developed mathematical models provide a tool for optimizing the manufacturing parameters during the fused filament fabrication process. [ABSTRACT FROM AUTHOR]

A comparative study of the copolymerization of racemic propylene oxide (PO) with CO2 catalyzed by racemic (salcy)CoX (salcy = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = perfluorobenzoate (OBzF5) or 2,4-dinitrophenoxy (DNP)) in the presence of a [PPN]Cl ([PPN] = bis(triphenylphosphine)iminium) cocatalyst is performed in bulk at 21 °C and a 2.5 MPa pressure of CO2. The increase in the nucleophilicity of an attacking anion results in the increase in the copolymerization rate. Racemic (salcy)CoX provides a high selectivity of the copolymerization, which can be higher than 99%, and the living polymerization mechanism. Poly(propylene carbonate) (PPC) with bimodal molecular weight distribution (MWD) is formed throughout copolymerization. Both modes are living and are characterized by low dispersity, while their contribution to MWD depends on the nature of the attacking anion. The racemic (salcy)CoDNP/[PPN]DNP system is found to be preferable for the production of PPC with a high yield and selectivity. [ABSTRACT FROM AUTHOR]

We synthesized three poly(carbonate acetal) vitrimers (PCA-P, PCA-E, PCA-S) by condensing a waste polycarbonate-derived polyaldehyde (WPC-CHO) with pentaerythritol, erythritol, and D -sorbitol, using 0.5–4.0 mol% p-toluene sulfonic acid (pTSA) as a catalyst. Flexible PCA films emerged at pTSA concentrations ≥1 mol%, indicating a critical threshold of acid for effective condensation. The glass transition temperatures (Tg) of the films remained consistent across pTSA concentrations but varied based on the multi-alcohol structure, with Tg values of 178 °C for both PCA-P and PCA-S, and 142 °C for PCA-E, suggesting superior performance of pentaerythritol and D -sorbitol over erythritol as building blocks. Among these, the PCA-S series exhibited the best performance and utilized the least expensive starting materials, achieving the highest cost-performance index. The PCAs, featuring covalent adaptable polyacetal networks, facilitated thermal reprocessing through acetal metathesis. The second reprocessed PCA-P and PCA-S maintained similar thermal and mechanical properties to their original forms, demonstrating a closed-loop recycling. These polymers showed stability in THF/H2O (4/1) with 0.1–1.0 M H2SO4 at 25 °C, but can be degraded at 50 °C within 5 hours in both 0.5 M H2SO4 and HCl THF/H2O (4/1) solutions. NMR analysis of the degraded PCA-P confirmed the recovery of WPC-CHO and pentaerythritol. Furthermore, PCA-based carbon-fiber-reinforced plastics (CFRPs) were prepared, and the carbon fibers were successfully recovered after acid degradation without any loss to their structural or tensile integrity. [ABSTRACT FROM AUTHOR]

A new "cardo" bisphenol viz., 1-(2-(1,1-bis(4-hydroxyphenyl)-3-oxoisoindolin-2-yl)ethyl)-3,4-dimethyl-1H-pyrrole-2,5-dione (PPH-MA) was synthesized in a two-step reaction sequence starting from phenolphthalein. PPH-MA was utilized as a step-growth monomer for the synthesis of a homo- and fourco-polycarbonates bearing pendant 2,3-dimethylmaleimido groups (PC-MAs) via solution polycondensation of PPH-MA or various mol % compositions of PPH-MA and bisphenol-A, respectively, with triphosgene.1H NMR spectroscopy confirmed the chemical structure and composition of PC-MAs. Inherent viscosity and number average molecular weight values of PC-MAs were in the range 0.45–0.64 dL g−1 and 18,300 − 36,200 g mol−1, respectively, indicating the formation of polymers of medium to reasonably high molecular weights. Tough, transparent and flexible films of PC-MAs could be cast from chloroform solution. X-ray diffraction studies indicated the amorphous nature of PC-MAs. The 10% weight loss temperature (T10) values of PC-MAs were in the range 373–443 °C indicating their good thermal stability. [ABSTRACT FROM AUTHOR]

Double metal cyanide (DMC) complexes represent a unique family of materials with an open framework structure. The main current application of these complexes in chemical industry is their use as catalysts (DMCCs) of the ring-opening polymerization of propylene oxide (PO), yielding branched polyols, highly demanded in production of polyurethanes and surfactants. The actual problem of chemical fixing carbon dioxide from the atmosphere gave new impetus to the development of DMCCs, which turned out to be effective in oxirane/CO2 copolymerization. In recent years, new types and formulations of DMCCs were created, so that greater understanding of the reaction mechanisms was achieved and new fields of catalytic applications were found. In the present review, we summarized background and actual information about the synthesis, structure, and mechanisms of the action of DMCCs, as well as their application in the development of new materials and fine chemicals. [ABSTRACT FROM AUTHOR]

Different polyurethanes (PUs) were synthesized with polycarbonate polyols of molecular weights of 500, 1000, and 2000 Da. Their self-healing abilities at 20 °C were tested, and their structural, thermal, and mechanical properties were analyzed. The PUs made with polycarbonates of molecular weights 500 (YC500) and 1000 Da (YC1000) exhibited self-healing at 20 °C, and the self-healing time of YC1000 was the shortest. The absence of crystallinity and the low degree of micro-phase separation favored self-healing at 20 °C in YC500. However, the presence of tack and the existence of allophanate species and urethane–carbonate and urea–carbonate hydrogen bonds disfavored self-healing. Consequently, the self-healing time at 20 °C of YC500 was longer than expected. On the other hand, YC1000 exhibited an "equilibrium" between urethane-carbonate and urea–carbonate hydrogen bonds and carbonate–carbonate interactions among the soft segments, so a particular structural order was produced that was associated with its fastest self-healing at 20 °C. The PU made with the polycarbonate of molecular weight 2000 Da did not exhibit self-healing at 20 °C because of its significant micro-phase separation, the presence of semi-crystalline soft domains, and the lower density of hydrogen bonds. [ABSTRACT FROM AUTHOR]

A homo- and three co-polycarbonates (PC-NBs) bearing pendant norbornenyl groups were synthesized via solution polycondensation of triphosgene with 4, 4'-(bicyclo (2.2.1) hept-5-en-2 yl methylene) bis (2-methoxyphenol) (BPA-NB) or various mol % compositions of BPA-NB and bisphenol-A, respectively. 1H-NMR spectroscopy confirmed the chemical structure and composition of PC-NBs. Inherent viscosity and number-average molecular weight (Mn) values of PC-NBs were in the range 0.44 – 0.64 dL g−1 and 21,800 – 34,100 g mol−1, respectively, indicating the formation of polymers of medium to reasonably high molecular weights. Tough, transparent, and flexible films of PC-NBs could be cast from chloroform solution. X-Ray diffraction studies indicated the amorphous nature of PC-NBs. Glass transition temperature (Tg) values, determined by DSC analysis, of PC-NBs were in the range 154 – 175°C and Tg values increased with the increase in mol % of BPA-NB. The post-polymerization modification of a representative PC-NB was demonstrated using 3,6-diphenyl-1,2,4,5-tetrazine via tetrazine-ene reaction. [ABSTRACT FROM AUTHOR]

The combination of the best properties of Polycarbonate (PC) and Acrylonitrile-butadiene-styrene (ABS) has resulted in the development of commercially available PC/ABS blends that have been found to be useful in many molding applications. PC has excellent mechanical and optical properties, but predominant use of bisphenol A in PC synthesis raises concerns regarding its potential environmental harm. In this study, we have studied the alternative for the PC/ABS blend by replacing PC with the bio-based PC and ABS with the Acrylonitrile-styrene-acrylate (ASA). A blend of bio-based PC and ASA was prepared by the melt blending techniques and investigated mechanical, thermal, and degradation (hydrolytic and soil burial degradation) properties. [ABSTRACT FROM AUTHOR]

Antibiotic resistance has been threatening public health for a long period, while the COVID pandemic aggravated the scenario. To combat antibiotic resistance strains, host defense peptides (HDPs) mimicking molecules have attracted considerable attention. Herein, we reported a series of polycarbonates bearing cationic lysine amino acid residues that could mimic the mechanism of action of HDPs and possess broad‐spectrum antimicrobial activity. Moreover, those polymers had negligible toxicity toward red blood cells and mammalian cells. The membrane‐disruption mechanism endows the lysine‐containing polycarbonates with low possibility of resistance development and the fast killing kinetics, making them promising candidates for antimicrobial development. [ABSTRACT FROM AUTHOR]

Gut microbiome composition is tied to diseases ranging from arthritis to cancer to depression. However, mechanisms of action are poorly understood, limiting development of relevant therapeutics. Organ‐on‐chip platforms, which model minimal functional units of tissues and can tightly control communication between them, are ideal platforms to study these relationships. Many gut microbiome models are published to date but devices are typically fabricated using oxygen permeable polydimethylsiloxane, requiring interventions to support anaerobic bacteria. To address this challenge, a platform is developed where the chips are fabricated entirely from gas‐impermeable polycarbonate without tapes or gaskets. These chips replicate polarized villus‐like structures of the native tissue. Further, they enable co‐cultures of commensal anaerobic bacteria Blautia coccoides on the surface of gut epithelia for two days within a standard incubator. Another complication of commonly used materials in organ‐on‐chip devices is high ad‐/absorption, limiting applications in high‐resolution microscopy and biomolecule interaction studies. For future communication studies between gut microbiota and distal tumors, an additional polycarbonate chip design is developed to support hydrogel‐embedded tissue culture. These chips enable high‐resolution microscopy with all relevant processing done on‐chip. Designed for facile linking, this platform will make a variety of mechanistic studies possible. [ABSTRACT FROM AUTHOR]

AbstractIn order to find an optimal antibacterial agent for Polycarbonate (PC), five quaternary fluoroalkyl phosphonium salts (FAPS) with iodine anions (PPICF-13), tetrafluoroborate (FB-PPCF-13), trifluoromethanesulfonate (TFMS-PPCF-13), methanesulfonate (MS-PPCF-13), and p-toluenesulfonate (pTS-PPCF-13), each with a side chain of 13 fluorine atoms, were incorporated were incorporated into PC with a mass ratio of 2.5 wt.%. The influence of the counter anions on the rheological properties, mechanical properties, appearance and light transmittance, antibacterial activity and cytotoxicity of the antibacterial PCs were investigated. The results showed that all the FAPS could impart PC with above 90% of antibacterial degree. The melt flow rate of the PC was increased due to the plasticizing effect of FAPS. The incorporation of up to 2.5 wt.% FAPS had no negative influence on the flexural strength, flexural modulus and tensile strength of the PC, but reduced the impact strength of the PC to varying degrees, depending on the counter anion. All five of the FAPS influenced the appearance and light transmittance of PC, and the TFMS-PPCF-13, MS-PPCF-13 and pTS-PPCF-13 samples appeared to have less impact on these properties than PPICF-13 and FB-PPCF-13. All antibacterial PCs; except for the antibacterial PC containing PPICF-13, exhibited no cytotoxicity. Considering all the properties, the antibacterial PC containing TFMS-PPCF-13 showed the optimal comprehensive properties based on this research. [ABSTRACT FROM AUTHOR]

New and simple ligand design strategies for the preparation of versatile metal-based catalysts capable of operating under greener and eco-friendly conditions in several industrially attractive processes are in high demand for society development. We present the first nucleophilic addition of an organolithium to ketenimines which incorporates a stereogenic centre in an N-donor atom to prepare new enantiopure NNN-donor scorpionates. We have also verified its potential utility as a valuable scaffold for chirality induction through the preparation of inexpensive, non-toxic and asymmetric zinc complexes. The pro-ligands and the corresponding zinc-based complexes have been characterized by X-ray diffraction studies. DFT studies were carried out to rationalize the different complexation abilities of these pro-ligands. These complexes have proved to act as highly efficient catalysts for a variety of sustainable bioresourced processes that are industrially attractive, with a wide substrate scope. Thus, complex 7 behaves as a highly efficient initiator for the well-behaved living ring-opening polymerization (ROP) of rac-lactide under very mild conditions. The PLA materials produced exhibited enhanced levels of isoselectivity, comparable to the highest value reported so far for zinc-based catalysts (Pi = 0.88). In addition, the combination of 7 with onium halide salts functioned as a very active and selective catalyst for CO2 fixation into five-membered cyclic carbonates through the cycloaddition of CO2 into epoxides under very mild and solvent-free conditions, reaching very good to excellent conversions (TOF = 227 h−1). Furthermore, this bicomponent system exhibits a broad substrate scope and functional group tolerance, including mono- and di-substituted epoxides, as well as the very challenging bio-renewable tri-substituted terpene-derived cis/trans-limonene oxide, whose reaction proceeds with high stereoselectivity. Finally, complex 7 also achieved high activity and selectivity as a one-component initiator for the synthesis of poly(cyclohexene carbonate)s via ring-opening copolymerization (ROCOP) of cyclohexene oxide and CO2 under very soft conditions, affording materials with narrow dispersity values. [ABSTRACT FROM AUTHOR]

Various excellent catalysts have been explored for the methanolysis of polycarbonate (PC), but it is still challenging to develop green and economical catalysts for solvent-free PC methanolysis to recover both bisphenol A (BPA) and dimethyl carbonate (DMC). Herein, green, efficient and solvent-free degradation of PC to BPA and DMC was achieved using urea as a cheap green catalyst. At 140 °C for 3 h, PC was completely degraded to BPA and DMC with yields of 93.4% and 74.7%, respectively. A possible catalytic degradation mechanism of PC was proposed by kinetic experiments and NMR, where urea, methanol and carbonate formed a six-membered ring in the reaction. It was found that the increase of urea concentration significantly reduced the activation energy, which was attributed to the fact that the increase of urea concentration made the six-membered ring easier to form and activated the carbonate bond. The degradation system can be reused directly up to 10 times and 100% degradation rate can be maintained. This work provides a simple, green and economical method for industrial PC recycling. [ABSTRACT FROM AUTHOR]

The use of alkaline earth‐abundant metal catalysts as alternatives to transition metal catalysts in the depolymerization of plastic waste is a very important research area. In this work, the first method is described for the conversion of polyesters into value‐added compounds catalyzed by a magnesium catalyst. It is demonstrated that the commercially available, inexpensive and air‐stable, alkaline earth magnesium catalyst Mg(OTf)2 efficiently promotes the reductive depolymerization of several polyesters using pinacolborane (HBpin) as the reducing agent with good to excellent yields. This catalyst also remains very active in at least 12 consecutive polycaprolactone (PCL) reductive depolymerization reactions with yields between 89% and 81%. This magnesium catalyst is also efficient in the reductive depolymerization of the polycarbonate poly(bisphenol A carbonate) (PC.BPA). Furthermore, it is found that Mg(OTf)2 also successfully catalyzes the methanolysis of polyesters and polycarbonates at moderate temperature with excellent yields. [ABSTRACT FROM AUTHOR]

This study investigates the challenges and potential of conventional injection molding for producing thick-walled optical components. The research primarily focuses on optimizing process parameters and mold design to enhance product quality. The methods include software simulations and experimental validation using polycarbonate test samples (optical lenses). Significant parameters such as melt temperature, mold temperature, injection pressure, and packing pressure were varied to assess their impact on geometric accuracy and visual properties. The results show that lower melt temperatures and higher mold temperatures significantly reduce the occurrence of dimensional defects. Additionally, the design of the gate system was found to be crucial in minimizing defects and ensuring uniform material flow. Effective packing pressure was essential in reducing volumetric shrinkage and sink marks. Furthermore, we monitored the deviation between the predicted and actual defects relative to the thickness of the sample wall. After optimization, the occurrence of obvious defects was eliminated across all sample thicknesses (lenses), and the impact of the critical defect, the sink mark on the planar side of the lens, was minimized. These findings demonstrate the substantial potential of conventional injection molding to produce high-quality thick-walled parts when these parameters are precisely controlled. This study provides valuable insights for the efficient design and manufacturing of optical components, addressing the growing demand for high-performance thick-walled plastic products. [ABSTRACT FROM AUTHOR]

Incremental sheet forming has been largely investigated in the last two decades because of its versatility and cost-effectiveness, which make it viable for manufacturing highly customized parts as well as small- and medium-sized batches. This process allows for reaching greater formability compared to conventional sheet-forming processes. In contrast, it is affected by defects like twisting, which strongly influence the geometric accuracy of the formed parts. These aspects are dramatically accentuated when forming soft materials like thermoplastics. With these premises, the following research aims to investigate the effects of the toolpath strategy on the occurrence of failures and defects in the incremental sheet forming under very severe process conditions. Cone frusta with a fixed wall angle were obtained by thin polycarbonate sheets, imposing four unidirectional helical trajectory-based toolpaths, one traditional, and three stair strategies. The analysis of the forming forces, the evaluation of the worked surfaces, and the monitoring of the defectiveness highlight the advantages of a stair toolpath strategy in terms of reduced twisting and loading and high surface quality, regardless of the lubrication conditions. [ABSTRACT FROM AUTHOR]

Adhesive joints play a crucial role in enhancing the structural integrity and performance of 3D printed parts. The purpose of this study is to investigate the failure load and behavior of polycarbonate (PC) single lap joints (SLJs) produced by fused deposition modeling (FDM) using experimental and finite element analysis (FEA) methods. The FEA of joints presents a new approach by integrating PC substrates with Hill yield criterion, transversely isotropic material and adhesive layer with cohesive zone modeling (CZM). The study focused on the effect of printing angles (0°, 45°, and 90°) and overlap lengths (12.5 and 25 mm) on the performance of SLJs. The influence of 3D printing parameters on the mechanical behavior of PC joints was investigated by tensile testing of SLJs. The experimental failure load was 1586 N for a 12.5 mm joint at 90° and 4115 N for a 25.4 mm joint at 0°. Comparison of the experimental and FEA failure loads of the joints showed maximum and minimum differences of 11.98% and 1.34%, respectively. This result showed that the proposed model is applicable for determining the joint strength as a function of the printing angle and monitoring the joint damage behavior. [ABSTRACT FROM AUTHOR]

The effects of triethyl citrate (TEC) on the viscoelastic properties of a copolycarbonate comprising isosorbide and 1,4-cyclohexanedimethanol (ISB-PC) were studied in both the molten and solid states. TEC acted as an antiplasticizer for ISB-PC and increased its modulus in the glassy state, as demonstrated in blends comprising 5 and 10 wt% TEC. Because antiplasticization reduces the free volume fraction, the water content of the copolycarbonate films, which is known to affect various properties, decreased following the addition of TEC. Furthermore, TEC greatly decreased the zero-shear viscosity. The experimental values were much lower than those predicted by the Berry–Fox formula. In other words, a small amount of TEC greatly enhances the flowability of ISB-PC. [ABSTRACT FROM AUTHOR]

Endocrine disruptive compounds are natural or anthropogenic environmental micropollutants that alter the function of the endocrine system ultimately damaging the metabolism. Bisphenol A (BPA) is the most common of these pollutants and it is often used in epoxy coatings and polycarbonates as a plasticizer. Therefore, monitoring BPA levels in different environments is very important and challenging. In recent years, an increasing number of BPA detection methods have been proposed. This article presents a critical review of aptamer-based electrochemical, fluorescence-based, colorimetric, and several other BPA detection platforms published in the last decade. Furthermore, a statistical evaluation has been made using principle component analysis showing analytical performance parameters do not create very different clusters. Comparisons to other BPA detection methods are also presented so that the reader has an overall literature overview. [ABSTRACT FROM AUTHOR]

Luminescent polymer composites based on polycarbonate and polystyrene doped with boron difluoride β-ketoiminates have been synthesized. The luminescence properties of 12 dyes with various substituents have been studied. The effect of the boron difluoride β-ketoiminate concentration on the spectral properties of the samples has been studied. It has been found that the studied dyes exhibit monomer luminescence even with a tenfold increase in the luminophore concentration (from 0.05 to 0.5%). It has been revealed that composites containing boron difluoride 3-amino-1-phenyl-2-buten-1-onate (1a) and boron difluoride 3-methylamino-1-phenyl-2-buten-1-onate (2a) dyes in polystyrene exhibit exciplex luminescence. [ABSTRACT FROM AUTHOR]

The characterization of the impact strength and structure of bisphenol A polycarbonate aged in 65°C H2SO4 aqueous solutions (pH = 4.5) and in distilled water, both at 65°C, was carried out by means of impact testing, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Polarizing Microscopy (POM) and Scanning Electron Microscopy (SEM) measurements. The results were as follows: the impact strength increased a little (from 71 to 76.3 kJ/m2) after being aged 1 day in the H2SO4 aqueous solution. Microvoids were formed on the surface of the PC in both the aqueous solution and distilled water aging, and the size and number of the microvoids increased substantially with the increase of aging time. The glass transition temperature showed a slight decrease after aging. In both liquids, the degradation mechanism was ascribed to the hydrolysis of ester groups in both aqueous solutions aging. However, the hydrolysis rate of PC aged in hot water was higher than that of the sample aged in the H2SO4 aqueous solution in the first day of aging. In addition, a ductile failure to brittle failure transition was observed for both H2SO4 solution and hot water aging. [ABSTRACT FROM AUTHOR]

The melt deposition modeling method (FDM) is one of the increasingly widespread additive manufacturing methods, known as 3D printing, based on the layered assembly of material filaments. However, it is seen that the parts produced with FDM in the aviation industry do not have the desired dimensional and geometric tolerance values. For this reason, different manufacturing methods are used to bring the parts produced by the FDM method to the desired tolerance values. In this study, experiments were carried out to improve the tolerance values of the holes on the plates made of polycarbonate material, which is widely used in prototyping and production tools (welding, drilling, fixing) with FDM, and the optimum processing parameters were determined using the integrated design of experiment and TOPSIS methods. According to the obtained results, the optimum drilling parameters for the plate without pre-drilling case could be obtained by selecting HSS as the drill material, using cutting fluid, and setting the feed rate to 390.9091 mm/min and the spindle speed to 1000 rpm. For the pre-drilled plate, the optimum drilling parameters were again obtained by selecting the drill material HSS, using cutting fluid and applying the feed rate to 369.6970 mm/min and the spindle speed to 781.8182 rpm. [ABSTRACT FROM AUTHOR]

A CO2‐based thermoplastic elastomer, poly(propylene carbonate)‐multiblock‐polyamide6 (PPC‐mb‐PA6) copolymer, was constructed through coupling amorphous/soft PPC blocks with crystalline/hard PA6 blocks. The PPC‐mb‐PA6 copolymers with different block length pairs were designed and synthesized, and then fully characterized by structural, thermal, and mechanical analysis. The proton nuclear magnetic resonance (1H‐NMR), diffusion ordered spectroscopy (DOSY), heteronuclear multiple‐bond correlation (HMBC) and gel permeation chromatography (GPC) results confirm that the multiblock sequence structure of PPC‐mb‐PA6. The differential scanning calorimetry (DSC) tests show that all PPC‐mb‐PA6s possess melting points around 179–206°C. The thermal and mechanical analysis indicates improved service temperatures (T5% up to 270°C) and tensile strength ranging from 15.8 to 39.6 MPa with higher PA6 content. The dynamic mechanical analysis demonstrates excellent shape memory effect of PPC‐mb‐PA6 with thermal stimuli responsiveness derived from the micro phase separation between soft PPC and hard PA6 domains. And the characteristic strain fixity parameter (Rf) and deformation recovery rate (Rr) are 98% and 100%, respectively, which are comparable with other excellent shape memory polymers. [ABSTRACT FROM AUTHOR]

Physical aging refers to relaxation of the polymer glassy state toward the amorphous state and this phenomenon affects their physical‐mechanical properties. This work investigates the effect of physical aging on polymer scratch behavior and visibility. It was shown that mechanical properties were significantly modified over the aging time, especially the yield stress, in turn affecting polymer scratch behavior. As a matter of fact, the critical load for the onset of scratch visibility was shown to increase with the aging, thus improving sensitivity of polymer to scratches. Such behavior was strictly related to the yield stress increase with the aging time. The usefulness of the present work is highlighted, and some future perspectives are discussed. [ABSTRACT FROM AUTHOR]

Polybutadiene grafted methyl methacrylate copolymer (PBL‐g‐MMA, MB) with core‐shell structure was prepared by emulsion polymerization. Without adding compatibilizers, PC/ABS composites were blended with polycarbonate (PC) and SAN. The effects of methacrylate butadiene (MB) on mechanical properties, flow properties, and thermal properties of PC/ABS composites were investigated. The results show that the addition of MB has obvious toughening effect on PC/ABS, effectively improving the mechanical properties and melt flow rate (MFR) of PC/ABS composites, and hence significantly improving the processability of PC/ABS composites. When the amount of MB is 12 phr, the notched impact strength of PC/ABS blend can reach up to 430 J/m. This is several times more than pure PC resin. The scanning electron microscope (SEM) analysis results show that the compatibility of PC/ABS and the impact strength of PC/ABS blend are improved with the increase of MB dosage. With the increase of MB content, the softening temperature of Vicat first decreased and then increased. It increased with the increase of PC content. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the compatibility and performance of PLA/PC blends by investigating the effects of Cloisite 20A nanoclay (NC) and Joncryl chain extender (CE). PLA/PC blends with varying NC and CE loadings were prepared, and the optimal formulation was identified. The optimal NC and CE content were then used to produce PLA/PC blends with varying PC ratios. The test specimens were produced by mixing the mixture in a twin‐screw micro compounder and subsequent injection molding into dog bone specimens to investigate the thermal, mechanical, and morphological properties of the blends. Scanning electron microscopy and dynamic mechanical analysis confirmed the immiscibility of the unmodified blend, but significant improvements in blend morphology were observed with high NC/CE ratios. The presence of NC/CE resulted in reduced droplet size of dispersed PC phase and a new intermediate glass transition temperature (Tg) in DMA, suggesting partial miscibility. The highest thermal stability improvement was achieved with 5 wt% NC alone or a combination of 5 wt% NC and 1 wt% CE. Composites containing NC/CE showed the most significant improvements in composite properties, demonstrating their effectiveness as compatibilizers and improved compatibility in PLA/PC blends. These results indicate that the use of NC/CE is a promising method for expanding the applicability of PLA/PC blends. [ABSTRACT FROM AUTHOR]

A novel dithiocarbamate polymer (TTDP) derived from bis(2‐aminothiazole) sulfide was synthesized through a straightforward process. The synthesis involved the initial conversion of 2‐aminothiazole into its bis(sulfide), subsequent reaction with chloroacetyl chloride, and final copolymerization with disodium ethylene bisdithiocarbamate. TTDP boasts a high percentage of functional groups containing sulfur, nitrogen, and oxygen, contributing to its hydrophilicity, strong chelation capacity with metal cations, and compatibility with other polymers. Therefore, it was used as a strong candidate for making membranes in water media. According to this, TTDP was blended in ratios 1, 2, 5, and 10 wt% with polyvinyl chloride (PVC; 15 wt%), 2 wt% of polyethylene glycol 4000 in N,N‐dimethylacetamide as polymeric membranes for water‐based applications. The blended membranes were prepared using the casting and immersion precipitation method. The blended membrane showed high fluxes, up to 1052 L/m2 h for 2 wt% of TTDP (in comparison to the bare membrane's 459 L/m2h). Notably, they demonstrated an excellent protein solution flux of 222–269 L/m2 h at 3 bar with 96%–98% bovine serum albumin rejection. Furthermore, these membranes showed remarkable efficacy in removing cadmium ions (up to 98.96% for 5 and 10 wt% TTDP) and synthetic dye methyl orange (up to 84.03% for 2 wt% TTDP). [ABSTRACT FROM AUTHOR]

As the application of polycarbonate (PC) in various fields continues to expand, the requirements for its flame retardancy are becoming increasingly stringent. To enhance the flame retardancy of PC, employing multi‐element synergistic effects and developing novel flame retardants are considered as vital strategies. This work introduces a blend of 1,3‐Benzenedisulfonic acid dipotassium salt (KSP) and three types of phenyl polysiloxanes, namely Octaphenylcyclotetrasiloxane (P4), Octaphenylsilsesquioxane (OPS), and ladder‐like Polyphenylsesquioxane (L‐PPSQ), into PC to create composites. The thermal stability and combustion properties of these composites were characterized using thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 vertical burning, and cone calorimetry tests. Composites with phenyl polysiloxanes achieved a UL‐94 V‐0 flame retardant rating for 1.6 mm thickness sample and reduced the peak heat release rate by 30%–45%. PC composites with 3% OPS and 0.03% KSP achieved optimal performance, howing a LOI of 34.5%, a 45.4% reduction in peak heat release, and a 40.5% reduction in total smoke release. The flame‐retardant mechanism was analyzed using scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and pyrolysis‐gas chromatography‐mass spectrometry (Py‐GC‐MS). [ABSTRACT FROM AUTHOR]

Friction stir lap welding (FSLW) of dissimilar acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) was conducted using a double-pin tool. The formation process of the weld and the influences of rotational speed on the microstructure and mechanical property were investigated. It was found that the weld was generated accompanying with the closure of old cavities in the front of the pins and the simultaneous regeneration of new cavities in the rear of the pins. Annular material flow on the vertical and horizontal directions occurred during FSLW. With the increase of the rotational speed, the PC anchors resulted from the upflow of plasticized PC layer and the shoulder affected zone both enlarged. Microstructure analysis of the weld nugget showed that PC was fragmented into lamellar, columnar, and spherical particles and their dimensions decreased when rotational speed increased. Lap-shear tensile tests showed that the weld strength increased with higher rotational speed and the maximum strength of the weld produced under 800 r/min reached 19.38 MPa, which was comparable to the ABS/PC welds produced by a tapered pin under the optimal parameters. Through the further optimization of such FSLW process, it was potential to join dissimilar polymeric components in future industrial manufacturing field. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC) is an essential thermoplastic renowned for its clarity and durability, making it widely used across various applications. Since its introduction in 1953, polycarbonate (PC) has rapidly emerged as [...]

Synthesis of polycarbonates (PCs) from isosorbide (ISB) monomers has been recently investigated. However, compared to bisphenol A, PCs face challenges in commercialization because their high rigidity renders it difficult to increase their molecular weight, resulting in high brittleness. To address these limitations, a flexible co‐monomer, ethoxylated ISB (EI5), was mixed with ISB to produce ISB/EI5‐based PCs. The structures of the ISB/EI5‐based PCs were controlled by varying the ISB/EI5 ratio from 100/0 to 60/40 mol%. Films were fabricated, and their thermal, optical, and mechanical properties and degradability were investigated. With increasing EI5 content, the thermal processability of the ISB/EI5‐based PCs improved, and the produced films exhibited excellent visible light transmittance and UV‐blocking effects. The mechanical properties of the ISB/EI5‐based PCs indicated sufficient tensile strength (σ = 89.7–72.9 MPa), competitive to that of commercial PC, and the properties could be controlled by adjusting the ISB/EI5 ratio. The contact angle and hydrolysis behavior of the ISB/EI5‐based PC films indicated increased surface hydrophilicity and increased degradation rate with increasing EI5 content. In conclusion, the structural control of the ISB/EI5‐based PCs enhanced their moldability and degradability, suggesting their potential commercial utilization. [ABSTRACT FROM AUTHOR]

The ternary copolymerization of a series of cyclic anhydrides with epoxides and carbon dioxide using dinuclear [OSSO]‐type chromium (III),1, and ‐iron(III), 2, complexes (0.1 mol %) in combination with (bis(triphenylphosphine)iminium chloride) (PPNCl, 0.5–1.0 mol with respect to catalyst) as co‐catalyst is reported in this study. The results have yielded copolymers with polyester and polycarbonate segments with high molecular weights and narrow dispersity. The catalytic systems 1–2/PPNCl were tested in the copolymerization of different epoxides, such as propylene oxide (PO), cyclohexene oxide (CHO), and vinylcyclohexene oxide (VCHO), with a variety of cyclic anhydrides, such as phthalic (PA), diglycolic (DGA) and succinic (SA), with CO2 pressure of 20 bar, temperature range of 45–80 °C in 24 h. Anhydride reaction, affording the polyester segments, exceeded the conversion of 99 % in all the explored cases. On the other hand, in the case of epoxide copolymerization with CO2, for the propylene oxide (PO) reaction, the selectivity towards polypropylene carbonate (PPC) without polyether linkage consistently was >99 %. For the terpolymerization of PO, CO2 and diglycolic anhydride (DGA), a notable epoxide conversion of 86 %, selectively to polycarbonate, with TOF value as high as 36 h−1, was achieved. [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]

Plastics are versatile materials, offering lightweight, durable, and affordable solutions across various industries. However, their non‐degradable nature poses challenges by end of their life. This study presented an innovative carbonyl extraction method to utilize waste poly(bisphenol A carbonate) (PC) as reaction precursor to synthesis of activated furan as precursor for photoswitchable Stenhouse adducts. This innovative chemical strategy not only generated N,N'‐functionalized barbiturates but also provided an eco‐friendly and cost‐effective alternative to traditional synthesis methods. The method presented hereby not only promotes sustainability by repurposing waste polycarbonate as carbonyl equivalent under green conditions but also yielded reusable bisphenol A (BPA). Furthermore, the derived activated furans exhibited their functionality by forming colored donor‐acceptor Stenhouse adducts (DASAs) on aminated polymer surfaces. This work demonstrated a transition from a linear plastics economy toward a circular one, highlighting the potential of plastic waste as a resource for creating materials with improved properties. [ABSTRACT FROM AUTHOR]

The results of the measurements of spall strength of polycarbonate at a maximum compression stress of 0.6 GPa in the initial temperature range of 20–185°C are presented. It has been found a significant decrease in the spall strength when the polycarbonate reached the glass transition temperature. The strain rates in the plastic compression wave are determined depending on the maximum stress under single and stepwise shock compression. The dependences of the shock wave velocity Us—mass velocity up in the range of maximum shock compression stresses up to 0.8 GPa at different temperatures are constructed. [ABSTRACT FROM AUTHOR]

New expanding spherical cavity model (ECM) for conical indentation is proposed. For polymeric materials description, the model incorporates isotropic non-monotonic strain hardening. For capturing the indentation size effect (ISE), the model incorporates the strain gradient dependence in yield strength based on lower-order strain gradient plasticity assumptions. Specifically, the forward gradient of the equivalent (accumulated) plastic strain is utilized as a non-local part of the yield strength. To predict the indentation depth-dependent hardness based on the proposed model, it is sufficient to numerically integrate one nonlinear ODE of the first order, and then calculate the definite integral. For the local perfect plasticity model, the hardness is obtained as an analytical expression that differs from known ECMs. The hardness estimate obtained numerically using the proposed model is compared with the experimental ISE data for polycarbonate (PC) and polymethyl methacrylate (PMMA). For the local perfect plasticity model, the formula obtained in the study is compared with the experimental data on the hardness of preliminary work-hardened materials. In both cases, the model shows good agreement with the experimental data. Fitting the experimental data on ISE, we found that intrinsic length scale of PMMA should be near 3 microns and near 9 microns for PC. [ABSTRACT FROM AUTHOR]

This work proposes for the first time protecting–reflecting on both sides of plated mirrors and a solution to polycarbonate surface vulnerability to weathering and scratching using tungsten disulfide (WS2) by mechanical polishing. The ability of the dynamic chemical plating (DCP) technique to deposit Ag films at the nanometer scale on a polycarbonate (PC) substrate and its characteristics to be metallized is also shown. These deposits hold significant promise for concentrated solar power (CSP) applications. Complementarily, the application of WS2 as a reflective film for CSP by mechanical polishing on smooth polycarbonate surfaces is both novel and practical. This technique is innovative and scalable without needing reactants or electrical potential, making it highly applicable in real-world scenarios, including, potentially, on-site maintenance. The effects of surface morphology and adhesion, and the reflectivity parameters of the silver metallic surfaces were investigated. Wettability was investigated because it is important for polymeric surfaces in the activation and metal deposition immediately after redox reactions. The flame technique improved wettability by modifying the surface with carbonyl and carboxyl functional groups, with PC among the few industrial polymers that resisted such a part of the process. The change in the chemical composition, roughness, and wettability of the surfaces effectively improved the adhesion between the Ag film and the PC substrate. However, it did not significantly affect the adhesion between PC and WS2 and showed its possible implementation as a first surface mirror. Overall, this work provides a scalable, innovative method for improving the durability and reflectivity of polycarbonate-based mirrors, with significant implications for CSP applications. [ABSTRACT FROM AUTHOR]

The steep increase in carbon dioxide (CO2) emissions has created great concern due to its role in the greenhouse effect and global warming. One approach to mitigate CO2 levels involves its application in specific technologies. In this context, CO2 can be used for a more sustainable synthesis of polycarbonates (CO2-PCs). In this research, CO2-PC films and composites with multiwalled carbon nanotubes (MWCNTs, ranging from 0.2 to 7.0 wt.%) have been prepared to achieve more sustainable multifunctional sensing devices. The inclusion of the carbonaceous fillers allows for the electrical conductivity to be enhanced, reaching the percolation threshold (Pc) at 0.1 wt.% MWCNTs and a maximum electrical conductivity of 0.107 S·m−1 for the composite containing 1.5 wt.% MWCNTs. The composite containing 3.0 wt.% MWCNTs was also studied, showing a stable and linear response under temperature variations from 40 to 100 °C and from 30 to 45 °C, with a sensitivity of 1.3 × 10−4 °C−1. Thus, this investigation demonstrates the possibility of employing CO2-derived PC/MWCNT composites as thermoresistive sensing materials, allowing for the transition towards sustainable polymer-based electronics. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printing with polycarbonate (PC) plastic occurs in manufacturing settings, homes, and schools. Emissions generated during printing with PC stock and bisphenol-A (BPA), an endocrine disrupter in PC, may induce adverse health effects. Inhalation of 3D printer emissions, and changes in endocrine function may lead to cardiovascular dysfunction. The goal of this study was to determine whether there were any changes in markers of peripheral or cardiovascular dysfunction in animals exposed to PC-emissions. Male Sprague Dawley rats were exposed to PC-emissions generated by 3D printing for 1, 4, 8, 15 or 30 d. Exposure induced a reduction in the expression of the antioxidant catalase (Cat) and endothelial nitric oxide synthase (eNos). Endothelin and hypoxia-induced factor 1α transcripts increased after 30 d. Alterations in transcription were associated with elevations in immunostaining for estrogen and androgen receptors, nitrotyrosine, and vascular endothelial growth factor in cardiac arteries of PC-emission exposed animals. There was also a reduction eNOS immunostaining in cardiac arteries from rats exposed to PC-emissions. Histological analyses of heart sections revealed that exposure to PC-emissions resulted in vasoconstriction of cardiac arteries and thickening of the vascular smooth muscle wall, suggesting there was a prolonged vasoconstriction. These findings are consistent with studies showing that inhalation 3D-printer emissions affect cardiovascular function. Although BPA levels in animals were relatively low, exposure-induced changes in immunostaining for estrogen and androgen receptors in cardiac arteries suggest that changes in the action of steroid hormones may have contributed to the alterations in morphology and markers of cardiac function. [ABSTRACT FROM AUTHOR]

The production and application of biodegradable polycarbonate have been significantly facilitated by the scale production of dimethyl carbonate which is the downstream of carbon dioxide. Hence, the progress in current research of novel biodegradable aliphatic poly(butylene carbonate) (PBC) modification has been reviewed. The mechanism of monomer structure (i. e. linear aliphatic monomer, cyclic aliphatic monomer, and aromatic monomer) and blending compatibility effect on thermal properties, crystallization, and tensile properties of PBC were analyzed. In addition, the application and development were also prospected according to the structure-properties relationship of PBC-based copolycarbonate and PBC-based blends. [ABSTRACT FROM AUTHOR]

Aliphatic polycarbonates have been explored as environmentally benign alternatives to aromatic polycarbonates. Improvements to the glass transition temperature (Tg) of aliphatic polycarbonates have been pursued by several groups. We recently showed that attaching a pendant aromatic group to poly(TMC) can enhance the Tg. Also, we have shown that para substituents on the pendant group have an impact on the Tg. Here, we have explored the role of bulky pendant groups and the effect of substituent position on the pendant aromatic ring. We prepared novel naphthalene‐derived poly(TMC)s as well as 2‐Br‐substituted poly(PhTMC). The 2‐bromophenyl derivative showed a Tg of 69.5 °C which represents a nominal increase in comparison to the 4‐bromo derivative that we reported earlier. This suggests that the position of the substituent does not have a critical impact on Tg. With naphthalene derivatives, the increase in steric bulk led to an increase in Tg. Increase of chain length beyond fifty monomer units had a minimal impact on Tg. Finally, when 4‐bromonaphthyl moiety was the pendant group, we observed a Tg of 97 °C. This demonstrates that Tg can be varied significantly by modifying the pendant groups. We have also shown that the 1,3‐diols used in our polymer are non‐cytotoxic. [ABSTRACT FROM AUTHOR]

This paper reviewed the research progress in high-temperature-resistant modification of polycarbonate at home and abroad in recent years from two aspects: chemical and physical modifications. [ABSTRACT FROM AUTHOR]

In the present study, the low pollution acidic potassium permanganate system has been used in the study of its micro‐etching effect on polycarbonate‐acrylonitrile butadiene styrene (PC‐ABS). Prior to micro‐etching using a N methyl pyrrolidone (NMP)‐glycol butyl ether solution was used as the swelling system of PC‐ABS. Reasonable swelling conditions were determined, a 2‐min expansion period at a temperature of 35°C with an NMP concentration of 80%. After the swelling processes, the effects of the volume ratio of VH2O:VH2SO4, micro‐etching temperature, and micro‐etching duration on the PC‐ABS surface morphology, surface roughness, surface hydrophilicity, and peel strength, have been investigated. It was finally determined that the best micro‐etching effect could be obtained by reacting at VH2O:VH2SO4 = 1:2 and a temperature of 60°C for 25 min. The surface of the PC‐ABS copolymers was characterized by x‐ray photoelectron spectroscopy, atomic force microscopy, and Fourier‐transform infrared spectroscopy. The results showed that the micro‐etching process changed the morphology of the PC‐ABS surface and generated cavities. In addition, the surface roughness increased from the initial Ra = 9.69 to Ra = 197 nm. Also, the water contact angle on the PC‐ABS surface decreased from 92.2° to 28.6°, and the peel strength increased to 0.98 kN/m. [ABSTRACT FROM AUTHOR]

DNA extraction yield from drinking water distribution systems and premise plumbing is a key metric for any downstream analysis such as 16S amplicon or metagenomics sequencing. This research aimed to optimize DNA yield from low-biomass (chlorinated) reverse osmosis-produced tap water by evaluating the impact of different factors during the DNA extraction procedure. The factors examined are (1) the impact of membrane materials and their pore sizes; (2) the impact of different cell densities; and (3) an alternative method for enhancing DNA yield via incubation (no nutrient spiking). DNA from a one-liter sampling volume of RO tap water with varying bacterial cell densities was extracted with five different filter membranes (mixed ester cellulose 0.2 µm, polycarbonate 0.2 µm, polyethersulfone 0.2 and 0.1 µm, polyvinylidene fluoride 0.1 µm) for biomass filtration. Our results show that (i) smaller membrane pore size solely did not increase the DNA yield of low-biomass RO tap water; (ii) the DNA yield was proportional to the cell density and substantially dependent on the filter membrane properties (i.e., the membrane materials and their pore sizes); (iii) by using our optimized DNA extraction protocol, we found that polycarbonate filter membrane with 0.2 µm pore size markedly outperformed in terms of quantity (DNA yield) and quality (background level of 16S gene copy number) of recovered microbial DNA; and finally, (iv) for one-liter sampling volume, incubation strategy enhanced the DNA yield and enabled accurate identification of the core members (i.e., Porphyrobacter and Blastomonas as the most abundant indicator taxa) of the bacterial community in low-biomass RO tap water. Importantly, incorporating multiple controls is crucial to distinguish between contaminant/artefactual and true taxa in amplicon sequencing studies of low-biomass RO tap water. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) is often used to create designs inspired by topology optimization and biological structures, yielding unique cross-sectional geometries spanning across scales. However, manufacturing defects intrinsic to AM can affect material properties, limiting the applicability of a uniform material model across diverse cross-sections. To examine this phenomenon, this paper explores the influence of specimen size and layer height on the compressive modulus of polycarbonate (PC) and thermoplastic polyurethane (TPU) specimens fabricated using fused filament fabrication (FFF). Micro-computed tomography imaging and compression testing were conducted on the printed samples. The results indicate that while variations in the modulus were statistically significant due to both layer height and size of the specimen in TPU, variations in PC were only statistically significant due to layer height. The highest elastic modulus was observed at a 0.2 mm layer height for both materials across different sizes. These findings offer valuable insights into design components for FFF, emphasizing the importance of considering mechanical property variations due to feature size, especially in TPU. Furthermore, locations with a higher probability of failure are recommended to be printed closer to the print bed, especially for TPU, because of the lower void volume fraction observed near the heated print bed. [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]

Polycarbonate (PC) is an amorphous polymer that is an extremely robust material with a high tenacity, and thus suitable for a lightweight construction with glass‐like transparency. Due to these advantageous properties, PC is often used in industry for example in medical devices, automotive headlamps, sporting equipment, electronics, and a variety of other products. PC is often subjected to uniaxial and biaxial loading conditions. Therefore, reliable material models have to take into account the various resulting experimental effects. For those reasons, we investigate PC specimens under uniaxial and biaxial loading by using different stretch rates and loading scenarios. In addition to that, we propose methods for optical measurement of local stretches to obtain the approximated local true stress. In future work, the displacement fields and the resulting reaction forces will be used for parameter identification of constitutive equations. [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]

The present paper aims to design a tunable polymeric multilayer dielectric reflector (PMD) to eliminate escape-cone effects in luminescent solar concentrators (LSCs). The PMD structure consisted of periodically and quasi-periodically stacked layers of polycarbonate (PC) and polymethyl methacrylate (PMMA). Monte Carlo and Transfer Matrix analysis demonstrated that the transmission band gap of a periodic reflector (PR) exhibited a narrow bandwidth and experienced a blue shift with increasing incident angles, resulting in a limited overlap with the dye emission band and inadequate capture of escape cone emissions. Conversely, the quasi-periodic reflector (QPR) achieved a broader transmission band gap, leading to complete overlap and higher efficiency. Furthermore, PMDs enhanced sunlight absorption in LSCs by reflecting transmitted solar photons through the LSC and increased reabsorption losses by minimizing escape cone losses. The results show optical efficiency of 12% and 33% for the LSC with PR and QPR, respectively. Additionally, investigations into optimal dye concentration revealed a change in concentration when PMDs are applied, allowing the system to select a lower optimal concentration to mitigate reabsorption losses. [ABSTRACT FROM AUTHOR]