Polycarbonate Material Research Articles

RESEARCH OF THE RESISTANCE OF POLYCARBONATE SAMPLES MADE BY FDM TECHNOLOGY TO ABRASIVE ACTION

The article deals with the investigation of tribological properties of polycarbonate (PC) material produced by 3D printing using Fused Deposition Modelling (FDM) technology under different layer deposition strategies and their subsequent testing for abrasive wear. The aim of the experiment was to compare the effect of different layer deposition strategies in the FDM process on the abrasive wear of the material at specified process parameters, which were defined according to ASTM G65 standardized tests. Based on these tests, the different strategies were compared and evaluated in terms of their ability to resist abrasive wear, providing insight into the effect of different orientations and layer arrangements on the tribological properties of 3D printed polycarbonate.

Environmental stress cracking of silver‐coated polycarbonate

AbstractThis study investigates the effect of silver coating on the environmental stress crack resistance (ESCR) of Lexan EXL9330 polycarbonate under exposure to anti‐corrosion oil and mechanical strain. Polycarbonates, known for their durability and versatility, are susceptible to environmental stress cracking (ESC) when exposed to aggressive chemicals under mechanical stress. In this research, eight groups of test specimens were evaluated, with variations including coated and uncoated surfaces, and exposure to anti‐corrosion oil under controlled strain conditions. The specimens were fabricated using Sabic EXL9330 resin, subjected to tensile testing, and analyzed for surface defects using optical microscopy and Fourier transform infrared (FTIR) spectroscopy. Results showed that anti‐corrosion oil significantly exacerbates ESC, leading to considerable surface defects such as crazes and pores, particularly in uncoated specimens under strain. In contrast, silver‐coated specimens demonstrated enhanced ESCR, with a notable reduction in surface defects and only a modest decrease in ductility (approximately 9.5%) compared to the control group. FTIR analysis confirmed that chemical composition remained unchanged, reinforcing the role of ESC in the observed material degradation. This study underscores the effectiveness of silver coating in improving the resistance of polycarbonate materials to environmental stress cracking, highlighting its potential for applications where chemical exposure and mechanical stress are prevalent.Highlights Silver coating improves environmental stress crack resistance (ESCR) in polycarbonate. Anti‐corrosion oil exposure significantly exacerbates stress cracking in polycarbonate. Coated specimens show reduced surface defects and minimal loss in ductility (9.5%). Uncoated specimens exposed to oil and strain exhibit severe crazes and pores. FTIR analysis confirms no chemical degradation in tested polycarbonate samples.

Effect of the Infill Density on 3D-Printed Geometrically Graded Impact Attenuators.

Three-dimensional printing is widely becoming prevalent in various industries, including the automotive sector. As this technology advances, critical structures subjected to impact loads may also be produced using additive manufacturing. A key parameter in this technique is the infill density of the printed geometry, which directly affects mechanical properties such as strength, stiffness, and ductility. Functionally graded layouts present themselves as one of the best techniques to design effective impact attenuators. The present work combines these techniques and parameters to evaluate the behaviour of geometrically graded impact attenuators produced through additive manufacturing, with different infill densities for polylactic acid (PLA) and polycarbonate (PC) materials. The results obtained show an increase in the mechanical strength for both materials and all the infill densities when compared to reference quasi-static results.

Facile fabrication of hemicrystalline bio-based polycarbonate with superhydrophobic and high transmittance

Developing materials that combine superhydrophobic properties with high optical transmittance poses a significant challenge. In this study, hydroxyl-terminated polydimethylsiloxane (HT-PDMS) and isosorbide (ISB) were polymerized in a single step to create a covalently bonded optical polycarbonate material. By inducing the formation of micro-papillary and lotus-shaped nanoscale structures via a solvent-triggered process, we significantly enhanced the “air cushion” effect, achieving a structure scale of approximately 5–7 μm. This resulted in a water contact angle of 157° while maintaining over 90 % optical transmittance. The structures were uniformly distributed throughout the polymer matrix, leading to a 500 % increase in tensile strength at break compared to pure isosorbide polycarbonate, with a maximum strength exceeding 50 MPa. These multifunctional materials show great promise for applications in smart windows, solar panels, camera lenses, and other optoelectronic devices.

High-Quality Foaming and Weight Reduction in Microcellular-Injection-Molded Polycarbonate Using Supercritical Fluid Carbon Dioxide under Gas Counter Pressure.

Microcellular injection molding (MuCell®) using supercritical fluid (SCF) as a foaming agent to achieve weight reduction has become popular in carbon emission reduction. In the typical MuCell® process, SCF N2 is commonly used. Although SCF CO2 exhibits high solubility and can achieve a high weight reduction, controlling the foaming is not easy, and its foaming cells are usually larger and less uniform, which limits its industrial application. Our previous studies have shown that gas counter pressure (GCP) can improve the foaming quality effectively. Here, we investigated whether or not the CO2 SCF foaming quality could be improved, and weight reduction was achieved for polycarbonate (PC) material. This is quite important for the electronics industry, in which most of the housing for devices is made of PC materials. MuCell® was subjected to molding experiments using the parameters of the SCF dosage, melt temperature, mold temperature, and injection speed. The results revealed that using CO2 gas for the PC material can reduce the size of microcellular cells to 40 µm and increase the cell densities to 3.97 × 106 cells/cm3. Using GCP significantly improved the microcellular injection-molded parts by reducing the cell size to 20.9 µm (a 45.41% improvement) and increasing the cell density to 8.04 × 106 cells/cm3 (a 102.48% improvement). However, implementing GCP may slightly decrease the target weight reduction. This study reveals that microcellular injection molding of PC parts using SCF CO2 can achieve high-quality foaming and reduce the weight by about 30%.

Organ chips with integrated multifunctional sensors enable continuous metabolic monitoring at controlled oxygen levels

Despite remarkable advances in Organ-on-a-chip (Organ Chip) microfluidic culture technology, recreating tissue-relevant physiological conditions, such as the region-specific oxygen concentrations, remains a formidable technical challenge, and analysis of tissue functions is commonly carried out using one analytical technique at a time. Here, we describe two-channel Organ Chip microfluidic devices fabricated from polydimethylsiloxane and gas impermeable polycarbonate materials that are integrated with multiple sensors, mounted on a printed circuit board and operated using a commercially available Organ Chip culture instrument. The novelty of this system is that it enables the recreation of physiologically relevant tissue-tissue interfaces and oxygen tension as well as non-invasive continuous measurement of transepithelial electrical resistance, oxygen concentration and pH, combined with simultaneous analysis of cellular metabolic activity (ATP/ADP ratio), cell morphology, and tissue phenotype. We demonstrate the reliable and reproducible functionality of this system in living human Gut and Liver Chip cultures. Changes in tissue barrier function and oxygen tension along with their functional and metabolic responses to chemical stimuli (e.g., calcium chelation, oligomycin) were continuously and noninvasively monitored on-chip for up to 23 days. A physiologically relevant microaerobic microenvironment that supports co-culture of human intestinal cells with living Lactococcus lactis bacteria also was demonstrated in the Gut Chip. The integration of multi-functional sensors into Organ Chips provides a robust and scalable platform for the simultaneous, continuous, and non-invasive monitoring of multiple physiological functions that can significantly enhance the comprehensive and reliable evaluation of engineered tissues in Organ Chip models in basic research, preclinical modeling, and drug development.

Compatibilizing and foaming of PC/PMMA composites with nano‐cellular structures in the presence of transesterification catalyst

AbstractCompatibility 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.

Failure analysis of thermoplastic composites subject to galvanic corrosion in hybrid metal–composite joints

The damage sustained by carbon fibre reinforced polymers due to the effect of galvanic corrosion induced by coupling between carbon fibres and a metallic material in a hybrid joint is investigated. Composite laminates with two fibre architectures and two thermoplastic matrices (polycarbonate and polyamide 6) are coupled to a metallic fastener and exposed to salted fog conditions. Both the effects of the salted fog environment and the coupled effect of the environmental and the galvanic corrosion are analysed. The analysis is centred in, firstly, characterising the functional properties of the hybrid joint, secondly characterising the laminate properties and finally characterising the chemical degradation of the matrix. The results show a degradation of properties for the polycarbonate material, in terms of bearing performance and interlaminar shear strength as well as presenting obvious changes in the thermal characterisation. The polyamide composites remain largely unaffected and only minor changes in the surface appearance are noteworthy.

A new effective phenomenological constitutive model for semi‐crystalline and amorphous polymers

AbstractA 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.

Hydrophobic micro-crosslinked sulfonated polystyrene flame retardant for simultaneous fire safety, transparency and high performance of polycarbonate

Sulfonate is considered to be the best flame retardant, which can endow polycarbonate (PC) excellent flame retardancy with low addition. Unfortunately, the water absorption and solubility of sulfonate will increase the cost of transportation and storage. In addition, sulfonate flame retardant is easy to migrate and precipitate from PC composites resulting in a negative impact on the sustainable use of PC materials. To ameliorate this issue, a sulfonate flame retardant (CSPS) with unparalleled hydrophobicity and thermal stability was synthesized through the incorporation of sodium p-styrene sulfonate as the main chain of crosslinked polystyrene. The PC/CSPS composites could pass UL 94 test V-0 rating with 0.3 wt.% CSPS addition, and the LOI is increased from 24.5 % to 31.4 %. Simultaneously, the PC/CSPS composites preserve their initial transparency. Moreover, the combustion test results indicated that the peak of heat release rate (PHRR) and the peak of smoke production rate (PSPR) of PC/CSPS-0.3 composites decreased by 40 % and 41 % respectively, and the time to reach PHRR and PSPR increased by 35.8 % and 56.5 % respectively. These results were attributed to the catalytic char formation and gas phase limitation of CSPS, which made PC composites with higher fire safety. Importantly, the PC/CSPS-0.3 composites can maintain tensile strength similar to that of PC. This research proposes a simplified and efficient methodology for fabricating PC composites with outstanding water resistance, flame retardancy, transparency, and mechanical fortitude, which is of considerable importance for the application of PC composites in emerging fields.

Material Damping Estimation within Low-, Medium- and High-Frequency Ranges

When considering the dynamic response of mechanical systems, material damping is a main factor to account for. It largely affects phenomena at different time scales, from the transient response of the system, to its modal response, up to the acoustic wave propagation within the bulk and at the contact interfaces. Nevertheless, despite the key role of the material damping in the mechanical response, its estimation within a wide frequency range is still a challenge, when considering the existing technics. Moreover, the material damping varies largely with respect to frequency and the actual approaches for its estimation are limited within restricted frequency ranges. An approach for estimating the material damping within the overall frequency range does not exist in the literature. This paper proposes an approach where structural and acoustic technics are combined with an energy statistical approach, for identifying the trend of material damping within a larger frequency range. The approach is here applied to polycarbonate (PC) material. The results highlighted that the material damping in the low–medium frequency range (1[Formula: see text]Hz-several kHz) fits with the Rayleigh damping model. On the other hand, the damping in the higher frequency range (106 Hz) showed a stabilization with the increase of the frequency.

Effects of photodegradation performance with PLA‐containing samples on double injection molding

AbstractThe influence of different overlay layers (ABS, PC, and PLA) is investigated on the photodegradation behavior of poly(lactic acid) (PLA)‐containing samples in double injection molding, and PLA/PLA samples serve as the control group. In terms of microstructure, an analysis is conducted on the chemical structure, thermal performance, crystallinity, and molecular weight of the base layer of samples. The carbonyl index and molecular weight of the base layer of PLA/PLA samples decrease rapidly, and the trend of crystallinity change is also fast. Among them, the number of molecular chain scissions decreases to 0.61, and the crystallinity increases to a maximum of 17.93%, which indicates that the photodegradation degree of the base layer of PLA/PLA samples is greater than that of the other two samples. The microscopic surface morphology change of the base layer of three PLA‐containing samples is analyzed. The base layer of PLA/PLA samples becomes rougher after 600 h of UV degradation. Meanwhile, compared with other PLA‐containing samples, the percentage of tensile strength loss of PLA/PLA samples is higher, decreasing by 16.64%. In summary, using acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) materials as overlay layers for double injection molding can mitigate the photodegradation of the base layer of PLA‐containing samples in double injection molding.

Design of New Bis(1,2,3-triazol-1-yl)methane-Based Nitrogen Ligands: Synthesis and Coordination Chemistry.

The reaction between bis(1,2,3-triazol-1-yl)methane derivatives and nBuLi and various aldehydes, yielded novel neutral ligand precursors incorporating alcohol functional groups. The resulting compounds exhibited distinct characteristics depending on the steric hindrance of the aldehyde employed. In instances where aromatic aldehydes were utilized, functionalization occurred at the methine group bridging both triazole rings. Conversely, the use of pivalic aldehyde prompted functionalization at the C5 position of the triazole ring. These compounds were subsequently employed as ligand precursors in the synthesis of organometallic aluminum and zinc complexes, yielding dinuclear complexes with high efficiency. The structural elucidation of all compounds was accomplished through spectroscopic methods and validated by X-ray crystallography. Preliminary catalytic investigations into the coupling reaction of cyclohexene oxide and CO2 revealed that aluminum and zinc complexes catalyzed the selective formation of polyether and polycarbonate materials, respectively.

Self‐healing polymers for aviation applications and their impact on circular economy

AbstractPolymers have swiftly replaced conventional metallic materials in aviation due to their lightweight and easy processability. Usages of polymers are presently mostly limited to non‐critical components. Flight safety is paramount in aviation and overrides all other factors. The aviation industry is averse to the usage of polymeric materials in critical component applications owing to the nature of failure being catastrophic. The review has covered various polymeric component failures and their root cause reasons. To overcome the inherent weakness in polymers currently used, a strategy to mimic nature is being explored by researchers. Self‐healing polymers can overtake metals if coupled with safe fail technology. Such materials have additional advantages in terms of enhanced longevity and ultimate life cycle. This review critically analyzed various factors driving research and development of self‐healing material for aviation applications. Various extrinsic and intrinsic self‐healing materials have been reviewed in the present work. Composites with an extrinsic self‐healing mechanism possess good healability and strength and can potentially replace current materials. Further, candidate polymeric materials with intrinsic self‐healing capability for the aviation field are extensively reviewed. Various aviation‐grade polymers like epoxy, Poly(methyl methacrylate), polycarbonate, and elastomeric materials with possible chemistries of intrinsic healing like Diel‐Alder reaction, Shape memory assisted self‐healing and covalently adaptable networks have been critically examined. Authors believe that extrinsic self‐healing technology is mature enough for use in the secondary structure of aircraft. At the same time, present technologies of intrinsic materials are not mature enough for flight safety reasons in aircraft; however, they are candidate materials for UAVs. Fast‐growing aviation field, coupled with the entry of UAVs, calls for environmentally sustainable material support. Therefore, this review explores materials within the sphere of high mechanical properties coupled with a low environmental impact.

Solvent-Promoted Catalyst-Free Recycling of Waste Polyester and Polycarbonate Materials.

Polymeric materials are indispensable in our daily lives. However, the generation of vast amounts of waste polymers poses significant environmental and ecological challenges. Instead of resorting to landfilling or incineration, strategies for polymer recycling offer a promising approach to mitigate environmental pollution. Pioneering studies have demonstrated the alcoholysis of waste polyesters and polycarbonates; however, these processes typically require the use of catalysts. Moreover, the development of strategies for catalyst removal and recycling is crucial, particularly in some industrial applications. In contrast, we present a catalyst-free method for the alcoholysis of common polyester and polycarbonate materials into small organic molecules. Certain polar organic solvents exhibit remarkable efficiency in polymer degradation under catalyst-free conditions. Employing these polar solvents, both polymer resins and commercially available products could be effectively degraded via alcoholysis. Our design contributes a straightforward route for recycling waste polymeric materials.

Thermo-environmental performance of polycarbonate materials as a glazing substitute in hot climates

ABSTRACT Buildings consume substantial energy, primarily for cooling and heating, resulting in equivalent CO2 emissions. Proper building envelope design in hot climates is crucial for reducing heat transmission, especially in transparent glazed-dominated envelopes with low thermal insulation compared to opaque walls. Compared to conventional glass, this study investigates the impact resistance, thermal performance, and environmental impact of polycarbonate (PC) sheets used as exterior glazing for windows and skylights. The study conducted literature reviews, Solar Heat Gain Coefficient (SHGC) measurements, and energy simulations of PC alternatives using a hotel in Madinah. Findings indicate that all PC alternatives' thermal and environmental performance performed better than ordinary glass, reducing total energy consumption and greenhouse gas (GHG) emissions. Single glazing decreased energy from 1% to 15%, double glazing from 1% to 19%, and triple glazing from 1% to 20% as window glazing. Skylight glazing also lowered overall energy use and gas emissions, with single glazing reducing 2% to 28%, double glazing 3% to 42%, and triple glazing 4% to 49%. Furthermore, the 25mm 9 wall X-Structure PC sheet performed best for windows and skylights in all glazing systems (single, double, and triple). The PC sheets' thickness and section composition affect thermal and environmental performance.

Comparative Analysis of Different Injection Molding Process Parameters through Injection Molding Flow Simulation for Various Gate Locations

This study deals with part quality concerning gate location on the part for injection molding. Through injection molding filling simulations, basic parameters such as injection pressure, bulk and surface temperature, shear rate, solidification, shrinkage, air entrapment, weld lines and others were analysed. The simulation was conducted on a fan blade model with Polycarbonate material. Polycarbonate is a commonly used polymer in the industry and is famous for its rigidity, strength-to-weight ratio and reliability in critical system. Simulation is done at six possible gate locations labelled A1 through A6. Injection molding filling simulations was performed to evaluate the performance of each gate location. Among the considered gate locations, gate A4 exhibited a considerably high pressure drop, while gate A5 exhibited a comparatively uniform pressure drop across the mould cavity, also gate A5 showed consistent and smooth filling along with uniform cooling implying less chance of defects. Gate A4 and A5 exhibit uniform distribution across the cavity in shear rate analysis. Gate locations A2, A3, A4, and A5 exhibited controlled solidification, indicating consistent part quality. However, Gate A6 exhibited problems with volume shrinkage, which requires process optimization. Gate A6 exhibited a significant reduction in air entrapment as compared to other gate locations.

Effect of Glass Transition Temperature on Enhanced Dielectric Breakdown Strength and Lifetime of Multilayer Polymer Films.

High temperature, high energy density, and low loss dielectric films are promising candidates for miniaturized capacitors in electric vehicles and high-speed trains. However, single-component polymers could not achieve these desired properties simultaneously. Polymer multilayer films (MLFs), which combine a high dielectric constant polymer [e.g., poly(vinylidene fluoride) (PVDF)] and a high breakdown/low loss polymer [e.g., polycarbonate (PC)] in a unique layered structure, have the potential achieve them at the same time. In this work, the effects of PC glass transition temperature (Tg) on the dielectric insulation properties (breakdown strength and lifetime) were investigated at high temperatures of 100-150 °C. Three PC materials had Tg values of 145 (PC1), 165 (PC2), and 185 °C (PC3), respectively. It is observed that MLF-PC3 with the highest Tg of PC exhibited the highest Weibull direct/alternating current (DC/AC) breakdown strength and the longest DC/AC lifetime, whereas MLF-PC1 with the lowest Tg showed the lowest Weibull DC/AC breakdown strength and the shortest DC/AC lifetime. A high-temperature high-volage leakage current study revealed that MLF-PC3 exhibited the lowest bulk conductivity at all temperatures under different electric fields. The knowledge obtained from this study will help us design better MLFs with high performance for next-generation miniaturized capacitors.

The Effect of Ultraviolet Radiation on Mechanical Properties of Fused Deposition Modeling 3D Printed Materials

This study investigates the influence of ultraviolet (UV) radiation on the mechanical properties of Fused Deposition Modeling (FDM) 3D printed materials, specifically polycarbonate (PC) and polylactic acid (PLA) specimens. The research involves conducting experiments on five test specimens of each material exposed to UV radiation and comparing their mechanical properties to those of five control specimens that remain unexposed. The results reveal a significant mean difference between the mechanical properties of the control and UV-exposed materials. UV radiation caused a decrease in tensile strength for the PC material, while the PLA material exhibited an increase in tensile strength. The impact of UV radiation on PLA was more substantial compared to PC. Flexural strength testing showed an enhancement in strength for the UV-treated materials, with UV treatment having a greater influence on the flexural strength of PLA compared to PC. The mechanical properties of PLA were more significantly impacted by UV radiation than those of PC. The study findings suggest that PC and PLA materials exhibit different responses to UV exposure, which may have implications for their practical applications. Further research is needed to fully understand the underlying mechanisms governing these divergent responses and to optimize the performance of each material under UV radiation.

Hexaphenoxy cyclotriphosphazene/boron nitride high-efficiency charring system enhancing the flame retardancy and thermal conductivity of polycarbonate

Polycarbonate (PC), as an engineering plastic, has excellent mechanical properties and electrical insulation properties. Nevertheless, with the rapid spread of 5 G applications, there is an increasing demand for functional PC materials with both thermal conductivity and flame retardant properties. In this study, the flame retardant thermal conductivity composite system of boron nitride (BN) and hexaphenoxy cyclotriphosphazene (HPCP) was constructed to study the simultaneous improvement of the flame retardant and thermal conductivity of PC. The results reveal that the inclusion of HPCP and BN in PC can significantly enhance its flame retardancy. This enhancement is evidenced by prolonged ignition time, reduced heat release rate and decreased total smoke production. In particular, 20BN/3HPCP/PC composite shows the best flame retardant effect. Through the investigation of flame retardant mechanisms, it has been found that the network structure formed by the BN sheets with phosphorus-containing products of HPCP decomposition can effectively filter and adsorb pyrolysis debris and increase the residence time of burning fragments in the pyrolysis zone promoting the pyrolysis products further fully burned to reduce the smoke caused by incomplete combustion. The phosphoric acid substances after the decomposing of HPCP can promote PC matrix to dehydration and carbonization to form the phosphorus-containing residues, which adheres on the BN network structure to form hardness char layers in the condensed phase to play an excellent role in blocking heat and combustible flue gas, which has a positive effect on reducing heat release rate and improving flame suppression. In terms of improving thermal conductivity, the infrared thermal imaging experiment further confirmed that BN sheets can increase the thermal conductivity of PC composites by more than 4 times, and the layer and layer stacks structure of BN sheets can endow an efficient thermal conductivity path for PC matrix to improve the thermal conductivity. Therefore, this study is meaningful practical exploration for developing the PC composites with excellent thermal conductivity and flame retardancy.