Advances in Polymer Technology最新文献

The quest for efficient and sustainable energy storage solutions has prompted exploration into advanced materials that meet stringent mechanical and thermal requirements. This study investigates graphene-reinforced thermoplastic polymers specifically polyether ether ketone (PEEK), polyethylene terephthalate glycol (PETG), and polylactic acid (PLA) fabricated through additive manufacturing techniques. Traditional materials often suffer from limitations in structural integrity, flexibility, and thermal stability, presenting challenges for their application in energy storage. This research aims to evaluate the mechanical properties of these graphene-reinforced polymers to assess their suitability for energy storage components. Using additive manufacturing, test samples were fabricated, and mechanical testing was conducted to evaluate tensile, flexural, and compression strengths. The results indicate that graphene-reinforced PEEK (G-PEEK) exhibits superior mechanical performance, with an ultimate tensile strength of 120 MPa, Young’s modulus of 1700 MPa, ultimate flexural strength of 160 MPa, and ultimate compression strength of 200 MPa, making it an ideal candidate for applications requiring high structural integrity. Graphene-reinforced PETG (G-PETG) offers a balance of strength and flexibility, with an ultimate tensile strength of 55 MPa, while graphene-reinforced PLA (G-PLA) serves as a cost-effective option, despite lower mechanical properties (ultimate tensile strength of 45 MPa).

Polyolefins such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) are among the most widely used packaging materials in the cosmetic industry. Since these materials are in direct contact with cosmetic products, various components of the products are adsorbed to the packaging material’s surface and migrate within the amorphous regions of the polyolefin. This migration process, which occurs in both virgin and post-consumer recyclate (PCR) materials, can lead to deformation of the packaging. In this study, different types of virgin and PCR pellets were examined to investigate their interaction with cosmetic products and to understand the factors influencing the migration process. The migration of cosmetic oils was observed in all pellet samples, depending on the composition of the product and environmental conditions. The process was characterized by the weight gain of the plastic pellets and further identified through nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. Additionally, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) measurements were performed to analyze the polymer structure. Components with lower molecular weight (MW), high nonpolarity, and elevated temperatures were found to accelerate the migration process. Moreover, migration occurred more slowly from oil-in-water emulsions with larger droplet sizes compared to water-in-oil systems with smaller droplets. Among the different polyolefins, PP demonstrated a higher uptake of migrating components but at a slower migration rate compared to HDPE and LDPE. When comparing virgin and recycled polyolefins, it was observed that migration was consistently slower in virgin materials than in recycled ones. The ability of oils to migrate is influenced by the molecular structure of the polymers: high density, crystallinity, and low levels of branching reduce both the migration speed (MS) and the maximum saturation, as seen in virgin HDPE. In contrast, materials like LDPE, with a less dense polymer structure, exhibited higher MSs and saturation limits. As a control, polyethylene terephthalate (PET) was used, and it showed no migration due to the polymer’s high density.

This work presents an investigation on the quality of parts manufactured using fused deposition modeling (FDM), which is influenced by a large number of different elements. Some of which are based on the materials used in the production of the part, though others are rather pertinent to the process parameters. The manufacturing process and filament formulation has also a significant impact on the cost of the final product, as well as its physical, mechanical, and thermal properties. As the result, judicious combination of parameters can effectively act toward fine-tuning FDM toward three-dimensional printing (3DP) of pieces with quality fit-for-application. In this sense, the use of design of experiments (DOEs) is often needed for the purpose. Printing process parameters, including layer height, wall thickness, temperature, printing velocity, and tool path, have been discussed, in the understanding that 3DP time increases with decreasing layer thickness, and in turn increases production time and overall cost. A specific account is given on recent developments increasingly and more thoroughly focused on recognizing the impact of the process parameters and raw materials on the final product.

This review investigates the recent advancements aimed at optimizing the mechanical performance of three-dimensional (3D)-printed polymer matrix composites (PMCs), motivated by the need to overcome the inherent limitations of additive manufacturing (AM) in achieving desired mechanical properties. The study focuses on two primary areas: (1) microstructural refinements through strategic control of parameters such as reinforcement type, size, orientation, and interfacial properties and (2) processing enhancements involving the modification of build parameters, material formulations, and posttreatments. The review systematically analyzes the interdependencies between microstructure-property relationships and processing-performance characteristics. Key findings include an improvement of up to 50% in strength and toughness through optimized microstructure and printing techniques, which are compared with results from other studies that reported a maximum of 30%–40% improvement under similar conditions. The review also highlights the successful application of these approaches in various case studies, demonstrating their potential to substantially enhance the dimensional control and functional properties of 3D-printed PMCs, making them suitable for diverse applications ranging from aerospace components to flexible sensors. Despite these advancements, challenges such as performance consistency, part quality, and scalability remain, emphasizing the need for continued research to fully exploit the potential of 3D-printed PMCs.

With the increasing incidence of bird damage affecting the reliability of transmission lines, addressing bird pest control has become an important task for the operation and maintenance of transmission lines. A viable solution involves the application of spray-coated polyurea elastomer composite materials to insulate exposed conductive points and weakly insulated connection parts of transmission line towers. To improve the comprehensive performance of polyurea elastomers, in this study, a polyurea curing system was modified by incorporating aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), and (boron nitride) BN nanoparticles. An orthogonal experiment was designed to investigate the influence of different fillers on the comprehensive performance of polyurea elastomers. These nanoparticles partially filled the defects inherent in the polyurea and BN microparticles, improving the alternating current (AC) breakdown strength of these elastomers. Compared with filler-free polyurea elastomers, optimal performance of the polyurea elastomers was achieved when using 5 wt% Al₂O₃, 0.4 wt% SiO₂, and 5 wt% BN, resulting in a 15.75% increase in the AC breakdown strength and a 10.00% enhancement in the thermal conductivity.

Polymethyl methacrylate (PMMA) has garnered significant attention in the field of dentistry due to its wide applications. This paper proposes the incorporation of the nystatin coated copper oxide (CuO) particles having desirable conductivity and antifungal properties, as a filler in the PMMA denture to address their low thermal conductivity, low impact strength, low fatigue resistance, and microbial adhesion. The prepared nystatin coated CuO particles were characterized with several analytical techniques. The nystatin coated CuO particles were mixed in different ratios (0%, 1%, 2%, and 4%) in PMMA corresponding to groups C, E1, E2, and E3, respectively. The prepared samples of composite PMMA with nystatin coated CuO were evaluated to determine their transverse strength, impact strength, Vickers hardness (HV), and thermal conductivity. Furthermore, antifungal properties of CuO particles, nystatin coated CuO particles, and their acrylic composites were evaluated against Candida albicans. Scanning electron microscopy (SEM) analysis confirmed the particles’ spherical and irregular shapes. The particle sizes range from nano to micron level. Fourier-transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the coating of nystatin on CuO. X-ray diffraction (XRD) analysis showed the diffraction patterns and planes of CuO monoclinic shape structure. The composite prepared to have higher values of HV (19.53 ± 0.65, 20.16 ± 0.37, and 21.11 ± 0.75, respectively) as compared to the control. The impact strength values were measured high at 14.12 ± 5.55 kJ/m² for 2% containing nystatin coated CuO acrylic resins compared to control and other groups. The conductivity increased linearly with the addition of CuO particles. The addition of CuO particles causes a reduction in flexural strength as compared to the control group. As the concentration of nystatin coated CuO (1%, 2%, and 4%) in acrylic samples increased, the antifungal properties were improved. Thus, the incorporation of optimized concentrations of nystatin coated CuO particles in acrylic resin resulted in the improved mechanical, thermal, and antifungal properties.

Poly(N-isopropylacrylamide) (PNIPAM) is a versatile polymer known for its phase transition properties, exhibiting a lower critical solution temperature (LCST) of approximately 32°C. Below this temperature, PNIPAM is hydrophilic, while above it, the polymer becomes hydrophobic, making it ideal for thermosensitive drug delivery systems (DDSs). In tissue engineering, PNIPAM provides a biocompatible, nontoxic and stimuli-responsive surface for cell culture. Its nontoxic nature ensures safety in medical applications. PNIPAM enhances biosensing diagnostics through its affinity for biomolecules, improving accuracy. Widely used in hydrogels, smart textiles, soft robotics and various medical applications, PNIPAM adapts to environmental changes. Its straightforward synthesis allows for the creation of diverse copolymers and composites, applicable in selective reactions and conjugations with fluorescent tags or chemical modifications. PNIPAM’s versatility extends to pH-responsive alternatives, broadening its application spectrum. Practical examples include phase separation in water treatment and cleaning processes. This discussion explores PNIPAM’s biomedical and drug delivery applications, particularly in cancer treatment, photothermal therapy (PTT) and photodynamic therapy (PDT), gene delivery and medical imaging. Additionally, it highlights PNIPAM’s noncancerous applications, such as small interfering RNA (siRNA) targeting of oncogenes and detailed imaging of deep and tumour tissues.

To improve the deteriorated performance caused by CO₂ release during the curing process of traditional moisture-crosslinked polyurethane or polyurea and poor flame retardancy, this work realized an effective in situ crosslinking technique triggered by moisture for poly(urethane-urea) with intrinsic flame retardancy, through the incorporation of trimethoxysilane and phosphorus groups via a continuous two-stage process. Moisture-triggered crosslinking reaction of trimethoxysilane groups resulted in the establishment of a robust Si─O─Si network, as confirmed by Fourier transform infrared spectroscopy (FTIR) test. The structure transformation considerably enhanced the material’s strength, with the stress at break increasing from 1.0 to 3.2 MPa and modulus from 32.9 to 46.9 MPa. The flame retardant properties of PUUS1 (poly(urethane-urea) sample) were investigated through limiting oxygen index (LOI) and cone calorimeter (CCT) analysis, demonstrating satisfactory flame resistance, as evidenced by high LOI value of 29%, high char yield of 46.2%, and controlled smoke production. Combining thermogravimetric analysis-infrared spectrometry (TG-IR), X-ray photoelectron spectroscopy (XPS), and flame retardant performance, it is speculated that the generation of phosphorus-free radical scavengers in gas phase from diethyl bis(2-hydroxyethyl) aminomethyl phosphonate (DBHAP), coupled with the barrier effects of charred layer and distinctive Si─O─Si framework in condensed phase inhibited combustion and toxic gas emission. The results highlight the successful synthesis of a moisture-crosslinkable poly(urethane-urea) with intrinsic flame retardancy, promising for applications necessitating moisture-crosslinkable materials with superior flame resistance.

This article explores the multifaceted potential of pullulan-based films across food-packaging, pharmaceutical, biomedical, and cosmetic applications. In food-packaging, pullulan films serve as transparent, flexible, and high-oxygen barrier materials, effectively preserving the freshness and quality of a wide range of fruits and vegetables. Edible pullulan films extend the shelf life and enhance food safety, while active pullulan films inhibit microbial growth and oxidation, thus supports food preservation. In the pharmaceutical industry, pullulan-based films offer promising solutions for oral drug delivery, providing biodegradable and rapid disintegration for enhanced solubility and bioavailability of drugs. Additionally, due to their mechanical strength, biocompatibility, and antimicrobial properties, pullulan films demonstrate potential in wound dressings and tissue engineering applications. Furthermore, pullulan’s utility extends to the cosmetic industry, where it is used widely in various ingredients in skincare products, cosmetics, and personal care items. Its moisturizing, stabilizing, and film-forming properties make pullulan an attractive component in the industry. Future research directions should focus on cost-effective production methods and expanding industrial applications to further enhance their effectiveness and versatility. This in-depth analysis highlights the significant potential of pullulan-based films across multiple industries and underscores the importance of continued research and development efforts to fully unlock their diverse applications and benefits.

Chicken eggshells (ESs) consist of 96%–97% calcium carbonate, while about 3%–4% consists of organic substances, mainly in the form of protein-based membranes and occluded organic matter. Recently, ESs have been studied as a filler in polymer composite materials, which represents an innovative solution to address ES valorization. In this study, thermal and chemical treatments were investigated for membrane removal since the membrane may alter various properties when the ES fillers are added to the composite material. A nanoindentation method was used to measure changes in the ES mechanical properties. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier-transform infrared (FT-IR) spectroscopy were used to characterize the ES membrane removal through chemical treatment. The results showed that even at a heating temperature of 100°C, the ES mechanical properties were negatively affected, while a low concentration of bleach solution (25% bleach solution and 10 min of holding time) was able to remove the membrane without reducing the ES mechanical properties. The chemical treatment method offers a means for ES membrane removal while conserving the quality of the mineral fraction (calcite; CaCO₃).