ABSTRACT Boron compounds exhibit low toxicity and diverse molecular structures, rendering them effective flame‐retardant additives in polymer‐based materials through various mechanisms of action. Magnesium tetraborate (MTB) and melamine formaldehyde (MF) resin‐encapsulated MTB were used to enhance the flame‐retardant performance of polyurethane (PU). MTB was synthesized by solid‐state synthesis. MF microcapsulated MTB‐MF is prepared by in situ polymerization. The synthesized MTB‐based materials are characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). PU composites containing MTB and MTB‐MF with varying amounts were produced by reaction of isocyanate and polyether polyol. The flame‐retardant action of MTB and MTB‐MF in PU was studied using the limiting oxygen index (LOI), a mass loss calorimeter (MLC), and TGA. In addition to the thermal behaviors of the PU composites, which were characterized by TGA and TGA coupled with FTIR, the morphologies of the residues were investigated using scanning electron microscopy (SEM). Results show that 5PHR‐MTB containing a PU composite achieved a 24% LOI value. Besides, the peak heat release rate of 5PHR‐MTB containing PU composites was reduced by 8% with respect to the PHRR of neat PU. 5PHR‐MTB‐MF microcapsule (the mass ratio of MTB:MF‐1:3) achieved the maximal LOI value of 27%, and significantly decreased the peak heat release rate from 350 to 70 kW/m 2 with respect to neat PU. The present work demonstrates that MF microcapsules, prepared with high efficiency, exhibit remarkable fire‐proof performance, making them a promising multifunctional composite for use as a flame retardant in polyurethane applications.
ABSTRACT Soft polyvinyl chloride (PVC) is the dominant polymeric material for medical devices, yet its inherent susceptibility to bacterial colonization and biofilm formation during clinical use remains a critical safety risk. This work reports a novel multifunctional antifouling additive with a hyperbranched poly(ethyleneimine) ‐ poly(ε‐caprolactone) (PEI‐PCL) core. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) and/or 2‐(dimethylamino)ethyl methacrylate (DMAEMA) were grafted onto the core via atom transfer radical polymerization (ATRP), followed by quaternization yielding two cationic variants (PEI‐PCLQ, PEI‐PCLQE). Thermal and structural characterizations confirm PEGMA incorporation preserves the core's semi‐crystallinity, imparting robust anti‐adhesion to PVC composites, while quaternary ammonium functionalization induces an amorphous transition, delivering > 90% bactericidal efficiency for PVC. Notably, the dual‐functional PEI‐PCLQE exhibits remarkable synergy: it enables fine tuning of additive‐PVC compatibility while integrating anti‐adhesion and bactericidal functions. The optimized composite delivers comprehensive antifouling performance (suppressed bacterial adhesion, inhibited biofilm formation, attenuated platelet activation) and excellent hemocompatibility (hemolysis rate < 2%). This study establishes a feasible design strategy for multifunctional polymeric additives, supporting the development of high‐performance biocompatible medical PVC with tailorable surface properties and dual‐mode antifouling functions.
ABSTRACT Thermoplastic polyurethane (TPU) envelope materials used in lighter‐than‐air (LTA) vehicles are susceptible to degradation from ultraviolet radiation, ozone exposure, heat, and humidity, leading to deterioration in mechanical performance and service life. In this study, TPU‐based hybrid nanocomposites containing 3 wt.% octamethyl polyhedral oligomeric silsesquioxane (OMP‐POSS), bis (2,2,6,6‐tetramethyl‐4‐piperidyl) sebacate (HALS), and 3‐mercaptopropyl trimethoxy silane (MPTMS) were developed and optimized to improve environmental durability. The influence of HALS and MPTMS loading on thermal stability, morphology, viscoelastic behavior, and aging resistance was systematically investigated. The optimized formulation U2S0.9 exhibited the highest thermal stability, with an onset degradation temperature of 239.5°C compared to 184.4°C for the control TPU. FTIR analysis and depth profiling revealed that aging‐induced chemical modifications were primarily confined to the exposed surface, while the siloxane‐rich interfacial structure remained preserved within the bulk. Mechanical retention studies demonstrated superior aging resistance, with U4S0.9 exhibiting tensile strength retention of 133.3% and 158.3% after accelerated weathering and ozone aging, respectively. The hybrid stabilization effects of HALS, MPTMS, and OMP‐POSS effectively suppressed environmental degradation, demonstrating the potential of these hybrid nanocomposites as durable protective envelope materials for aerostat and LTA vehicle applications.
ABSTRACT High‐performance dielectric materials, the utilization of inorganic waste materials as triboelectric active materials, and high output voltage under humid conditions are critical for developing efficient and environmentally friendly triboelectric nanogenerators (TENGs) for energy harvesting and self‐powered sensing applications. In this study, marble waste (MW) particles were incorporated into a polyvinyl alcohol (PVA) matrix via solution casting to develop a composite film for dielectric and triboelectric energy‐harvesting applications. Structural and morphological analyses confirmed the successful incorporation and uniform dispersion of MW particles within the PVA matrix. The PVA–MW composite exhibited improved thermal stability, reduced water absorption, and a high dielectric constant of approximately 500 at 100 Hz due to interfacial polarization. The fabricated PVA–MW TENG generated a high open‐circuit voltage of ~110 V and a current density of ~1.0 μA cm −2 , which are significantly higher than those of pristine PVA (45 V and 0.045 μA cm −2 , respectively). Furthermore, the developed device achieved a maximum output power and volumetric power density of 180 μW and 267 μW cm −3 , respectively, with a mechanical‐to‐electrical conversion efficiency of 16.3%. The developed PVA–MW TENG successfully charged various capacitors and exhibited a high output voltage of 35 V even under high relative humidity (80% RH) under the same applied vertical pressure. These findings establish marble waste as an effective dielectric filler and triboelectric active material for developing high‐performance PVA‐based composites for mechanical energy harvesting and stable output performance under humid conditions for self‐powered sensing applications.
In the present study, polymethyl methacrylate (PMMA)/nickel oxide (NiO) nanocomposites were successfully synthesized via in situ free radical polymerization, and their structural, morphological, optical, thermal, mechanical, electrical, and dielectric properties were systematically examined to assess the influence of improved interfacial compatibility and uniform nanoparticle dispersion. FTIR confirmed the characteristic PMMA functional groups and interactions between PMMA chains and NiO nanoparticles, suggesting the formation of PMMA/NiO nanocomposites. UV-Vis spectroscopy revealed the lowest optical bandgap energy and maximum refractive index at 7 wt% NiO loading. FE-SEM and HR-TEM showed uniform dispersion and nanoscale homogeneity of NiO within the polymer matrix. Contact angle measurements indicated enhanced hydrophobicity upon nanoparticle addition. TGA revealed improved thermal stability, as evidenced by a shift in degradation temperature to higher values. The nanocomposite showed higher tensile strength and Young's modulus, along with reduced elongation at break. The integration of NiO nanoparticles into PMMA increased the conductivity with increasing filler content and temperature, with the 7 wt% composite exhibiting optimal conductivity. The PMMA/7 wt% composite showed the lowest activation energy, while the dielectric constant increased by nearly five times. Overall, the 7 wt% NiO nanocomposite exhibited superior multifunctional performance, highlighting its potential for advanced polymer-based applications.
Polyamide 11 (PA11) is a bio-based polymer with promising applications due to its excellent mechanical strength, biodegradability, and strong adhesion; however, its major drawbacks include low flame retardancy and limited thermal stability. In this study, PA11 was blended with poly(phenylene oxide) (PPO) in the presence of a compatibilizer poly(phenylene ether-graft-maleic anhydride) (PPE-g-MAH or FB), and graphene nanoplatelets (GNPs) modified with (3-aminopropyl)triethoxysilane (APTES). The silane-modified GNPs (GS) significantly improved the dispersion of graphene within the polymer matrix, leading to enhanced stress transfer efficiency and improved phase stability. The nanocomposite containing 2 wt.% GS exhibited outstanding mechanical performance compared to the neat blend, including improvements in Young's modulus, tensile strength, flexural strength, flexural modulus, and storage modulus. Notably, the nanocomposites showed a simultaneous increase in dielectric constant, a reduction in dielectric loss, and a significant enhancement in dielectric breakdown strength, reaching up to 29.2 kV/mm. In addition, the optimized material achieved a UL-94 V-2 rating, along with improved thermal stability. These results indicate that GS functions both as an effective compatibilizer and reinforcing filler, interacting strongly with the polymer matrix. This work provides a promising pathway for developing multifunctional bio-based PA11 nanocomposites with enhanced mechanical, electrical, thermal, and flame-retardant properties.
Polymethyl methacrylate (PMMA) is prone to severe electrostatic accumulation. Conventional antistatic modifications fail to balance its optical and mechanical properties. In this study, we prepared transparent antistatic coatings using an acrylic resin/isocyanate curing agent system. Two antistatic agents, a fatty alcohol ether phosphate/quaternary ammonium salt polymer composite (H1) and a quaternary ammonium salt/nonionic surfactant composite (H2), were separately added into this system to prepare the coatings. We studied how coating surface resistivity changes with antistatic agent content at three humidity levels: 40% RH, 60% RH, and 80% RH. We also ran sealed storage tests at room temperature for 1 month to check long-term stability. Test results prove both coatings can resist static electricity. H1 performs much better overall. Its large molecular structure stops migration and precipitation. Its lowest surface resistivity hits 1011 Omega. It barely responds to humidity, and its performance stays steady after long storage. In comparison, H2 is made of small molecules. These small molecules easily aggregate and move inside the coating. H2 is highly sensitive to humidity, and its antistatic ability drops sharply after storage. All coatings have light transmittance above 90%, 5B adhesion and 3H pencil hardness. Their surface wettability can be adjusted, and they resist abrasion well. These multifunctional coatings suit medical and aerospace applications. This research offers guidance for designing transparent antistatic materials.
The rapid advancement of electronic and communication technologies has led to a significant increase in electromagnetic (EM) pollution, necessitating the development of efficient electromagnetic interference (EMI) shielding materials to mitigate adverse effects on both human health and electronic systems. In this study, a series of ternary nanocomposites comprising NiFe 2 O 4 @carbon nanotubes (NFO@CNTs) was synthesized via the solvothermal method. Subsequently, NiFe 2 O 4 @CNTs were incorporated into polyvinylidene fluoride (PVDF) to fabricate PVDF/NiFe 2 O 4 @CNTs composites. The CNTs content was varied from 1 to 5 wt.% w.r.t NiFe 2 O 4 to optimize electrical conductivity and impedance matching, while tuning the synthesis temperature. X‐ray diffraction (XRD) and Raman analysis confirmed the successful formation of NiFe 2 O 4 @CNTs composites, while transmission electron microscopy (TEM) images revealed the uniform functionalization of CNTs, the anchoring of NiFe 2 O 4 nanoparticles on CNTs walls, and the formation of a 3D conductive network. Ternary composite NTC10(5) exhibited maximum EMI shielding effectiveness (SE T ) of 16.20 dB, equivalent to 97.61% attenuation, which further increased to 22 dB (> 99% attenuation) upon optimizing the processing temperature to 100°C. Additionally, electromagnetic wave (EMW) absorption performance was evaluated by introducing a metallic backing layer. The NTC7(1) sample demonstrated the highest reflection loss (RL min ) of −30 dB, corresponding to greater than 99.9% EMW absorption.
In this study, the curing and thermal degradation kinetics of epoxidized soybean oil (ESO) were investigated using L-aspartic acid (AA) and DL-malic acid (MA)-two bio-derived dicarboxylic acids-as curing agents, in the presence of aluminium triflate (AT) as catalyst (0.5 and 1 wt%). Reactions were monitored by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and coupled TGA-FTIR techniques, and data were evaluated by model-free and model-fitting kinetic approaches to elucidate cure behavior, degradation mechanisms, and volatile decomposition products. Both ESO/AA and ESO/MA systems exhibited comparable total curing enthalpies, with AA formulations showing consistently higher activation energies, attributed to the zwitterionic nature of the amino acid. Despite the higher energetic demand, ESO/AA compositions demonstrated superior thermal stability, with onset degradation temperatures above 200 degrees C and degradation activation energies (Ea) exceeding 700 kJ & centerdot;mol-1. Model fitting revealed a multi-step degradation mechanism, best described by Avrami-Erofeev (An) and & Scaron;est & aacute;k-Berggren (SB) models, indicating nucleation-dominated behavior with secondary surface contraction. TGA-FTIR analysis confirmed water, carbon dioxide, and carbon monoxide as primary gaseous products. These findings highlight the strong potential of amino acid-cured ESO systems as thermally robust, non-toxic, and renewable alternatives to conventional epoxy resins in applications such as adhesives and composites.
Water solubility of poly(vinyl alcohol) (PVA) advantageously prevents the formation of harmful micro- and nano-plastics, but it currently lacks practical viability due to its poor water resistance. In this study, PVA films were reinforced with acid-treated palm kernel shell biochar to enhance their water resistance and wet strength. Incorporation of the treated biochar resulted in significant improvements in mechanical strength, reduced swelling, and higher gel content upon immersion in water, indicating enhanced network stability. At 5 wt% biochar loading, the films exhibited a significant drop in the swelling ratio, decreasing from 296.2% (neat PVA) to 133.1%, while gel content of the corresponding films increased from 76.5% to 93.0%. The most significant mechanical reinforcement occurred at a 3 wt% loading, which yielded a 25.9% increase in tensile strength. Furthermore, the benefits of biochar incorporation were highly evident in wet strength analyses where the samples were subjected to tensile test right after 24 and 48 h of water immersion. The PVA/biochar films maintained a tensile strength of at least five times greater than that of the neat PVA film. By valorizing a renewable waste material to enhance polymer performance, this approach demonstrates a strategic pathway toward practical yet environmentally friendly plastics.
Traditional sorption materials suffer from several significant drawbacks, including low sorption capacity, poor effectiveness in removing heavy oils, limited efficiency in oil-water separation, and inadequate flame-retardant properties during oil spill incidents. In this study, an environmentally benign and multifunctional composite sponge with enhanced flame-retardant properties was developed by modifying a polydimethylsiloxane (PDMS) sponge fabricated via a low-cost and simple sugar molding method. Boric acid (BA) and borax (BX), both halogen-free and low-toxicity boron-based compounds, were incorporated at different ratios to improve the thermal stability of the sponge, with a 1:1 BA/BX composition showing the most favorable performance. Subsequently, a dispersion containing candle soot (CS), a waste-derived carbonaceous material, was impregnated into the sponge to increase surface roughness and hydrophobicity. The resulting PDMS@BA(1)/BX1@CS sponge demonstrated improved self-cleaning behavior against common contaminants, with a static contact angle of approximately similar to 139 degrees, along with high oil-water separation efficiency. The modified sponges showed sorption capacities ranging from 6.5 to 11.3 g/g for various oils and organic solvents. Moreover, the PDMS@BA1/BX1@CS sponge extinguished the ignited flame within 12 s after adsorbing the flammable solvent. These results reveal that the developed sponge has great potential for applications such as oil-water separation, rapid fire extinguishing, and self-cleaning.
Due to the fine particle sizes and interparticle porous structures, polyvinyl chloride (PVC) paste resin produced by microsuspension polymerization is favorable for forming plastisol. However, it requires high processing temperatures or large amounts of external plasticizers to achieve sufficient plasticization, which causes high energy consumption or the risk of plasticizers' migration. In this work, a hybrid plasticization strategy was demonstrated by introducing butyl acrylate (BA) as an internal plasticizing comonomer into PVC paste resin prepared by microsuspension polymerization. A series of poly(vinyl chloride-butyl acrylate) (PVC-BA) copolymer paste resins with controlled BA contents were synthesized, and the effects of BA incorporation on chemical structure, particle morphology, thermal property, plasticization behavior, and rheological performance were systematically examined. It could be found that BA copolymerization resulted in not only the reduction in glass transition temperature from 77.8 degrees C of PVC paste resin to 71.6 degrees C of the copolymer, but also an increased specific surface area of 40 m2/g. These two structure features had a positive synergistic effect on the practical processing. Plastisol with an efficient plasticizer uptake was achieved at low fusion temperature of 140 degrees C. The modified plastisol exhibited enhanced rheological stability across a broad processing range of 100 degrees C-150 degrees C. Furthermore, PVC foams prepared from the copolymer paste resins displayed refined cellular structures and enhanced mechanical performance, including high ductility and improved elastic recovery. As a result, this work provides an effective strategy for developing high-value PVC products by microsuspension polymerization, and demonstrates its application in producing energy-efficient, high-performance PVC foam.
Protein fouling severely limits the performance of poly(vinylidene fluoride) (PVDF) membranes due to their intrinsic hydrophobicity, which promotes fouling adsorption and pore blockage, leading to rapid flux decline. Herein, we report a facile, environmentally friendly surface modification strategy to enhance the hydrophilicity and antifouling performance of PVDF microfiltration membranes using polydopamine (PDA) and glucosamine. A conformal PDA interlayer was first deposited on the membrane surface, followed by glucosamine grafting to form a durable PDA/glucosamine composite coating. Atomic force microscopy (AFM) revealed an increase in surface roughness from 83.7 nm for unmodified PVDF to 96.5and 98.3 nm for PDA- and PDA/glucosamine-modified membranes, respectively. Filtration experiments using pure water and bovine serum albumin (BSA) solutions demonstrated that glucosamine grafting significantly improved membrane permeability and fouling resistance compared to unmodified and PDA-only modified membranes, achieving a maximum pure water flux of 1423 L/m2 h and a BSA flux of 1194 L/m2 & centerdot;h. Furthermore, PDA-based coatings substantially reduced BSA adsorption compared to unmodified membranes and maintained high permeability and antifouling performance over multiple filtration cycles, particularly for PDA/glucosamine-modified membranes, confirming robust coating stability. Density functional theory (DFT) simulations revealed strong interactions between dopamine and glucosamine, including hydrogen bonding and covalent bonding, which facilitate the formation of durable surface coatings on PVDF membranes and corroborate the observed experimental performance. This environmentally benign and scalable modification strategy offers an effective route to mitigate membrane fouling and enhance the long-term performance of polymeric membranes for sustainable water treatment applications.
Poly(vinyl chloride) has been a key polymeric material since its commercial production in 1931, demonstrating versatility across numerous industries due to its compatibility with various additives. PVC's inherent properties, flame retardance, durability, and recyclability make it ideal for building and construction, which accounts for a significant portion of its consumption in Europe. This paper reviews the thermal degradation, decomposition, and combustion behavior of plasticized PVC, focusing mainly on classical stabilization systems and novel nanostructured additives such as polyhedral oligomeric silsesquioxane (POSS), which offer promising advances in improving PVC's thermal stability and fire performance. The review highlights how these aspects, mainly when addressed with innovative additives, could shape the future of PVC compounds in high-performance applications, especially in the cable industry, where fire performance and regulatory compliance are increasingly important.
This study investigates the use of Posidonia oceanica (PO) leaves, derived from coastal banquette residues, as a filler in PBSA, aiming to valorise a natural biomass typically treated as waste within a circular materials approach, while reducing production costs and enhancing seawater biodegradation of the polymer matrix. Composites containing 5 and 10 wt.% of PO, with and without micro-talc, were prepared via extrusion and injection molding. Materials were characterized morphologically, chemically, thermally, and mechanically, while biodegradation was assessed in a controlled seawater environment. Thermal analyses confirm that both PO and micro-talc do not compromise PBSA thermal stability, with degradation temperatures remaining at approximately 403 degrees C. Calorimetric results highlighted an increment of crystallization temperature and the appearance of a secondary melting peak at similar to 79 degrees C, while the main PBSA melting peak remains at similar to 85 degrees C and overall crystallinity degree is unchanged. Chemical and morphological analyses reveal no chemical interactions and confirm homogeneous filler dispersion with good interfacial adhesion. Mechanical testing shows a moderate stiffening and embrittling effect with the addition of PO, with elastic modulus increasing from 0.32 to 0.51 GPa and elongation at break decreasing from 450% to 325%, while impact toughness is markedly reduced at high filler loadings. Seawater exposure demonstrates accelerated biodegradation for Posidonia-filled composites, showing a similar to 20% mass loss after 4 months and rapid mechanical deterioration. The incorporation of PO fillers constitutes an effective approach to modulate and accelerate degradation under marine conditions.
Developing flame-retardant epoxy resin (EP) with high performance has drawn extensive attention recently due to the growing public concern for fire safety. However, the simultaneous enhancement of flame retardancy and toughness without the sacrifice of mechanical strength and thermal stability is still a challenge for EP. Herein, a novel kind of imidazole-based reactive flame retardant MD containing P/N/Si was synthesized and applied into EP. The results demonstrated that due to the presence of P/N/Si multiple flame-retardant elements, incorporating 4 wt% MD could make EP/MD pass UL-94 V-0 grade and have a limiting oxygen index (LOI) of 29.7%. Meanwhile, compared with pure EP, the peak heat release rate (PHRR), total heat release rate (THR), peak smoke production rate (PSPR), and total smoke production (TSP) of EP composite containing 4 wt% MD exhibited an obvious reduction of 41.5%, 11.4%, 24.2%, and 12.9%, respectively. Moreover, thanks to the high reactivity of imidazole groups, the MD could participate in the cross-linking reactions of EP and form strong interfacial interaction between the matrix and flame retardant. Therefore, the mechanical strength and toughness as well as the glass transition temperature of EP/MD composites could be simultaneously and greatly enhanced (tensile strength +30%, flexural strength +35%, impact strength +22%, and T g + 7 degrees C). This work provided a feasible methodology for the fabrication of highly efficient flame-retardant EP with prominent mechanical and thermal properties.
Pharmaceutical blister packaging, composed of complex multilayer materials such as polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and aluminum, poses significant recycling challenges due to its intricate structure. This study investigates the feasibility of a dissolution-based recycling process to recover high-purity PVC from pharmaceutical composite packaging. Using specific solvents, PVC was selectively dissolved, enabling the separation of undissolved PVDC and aluminum layers. The process was successfully scaled from laboratory to small-technical scale, achieving a recovery yield of 47% for recycled PVC (rPVC). Comprehensive material characterization, including FTIR and gel permeation chromatography, confirmed the chemical integrity of the recovered PVC, with minimal residual solvent content and no significant degradation. Recycled PVC was incorporated into pharmaceutical film recipes at a 30 phr content, demonstrating comparable mechanical and thermal properties to virgin PVC films. Thermoforming trials further validated the suitability of rPVC-containing films for blister production, with reliable sealing and leak-proof performance. While slight yellowing was observed in rPVC films, this effect is deemed manageable through coloring or enhanced cleaning processes. The study highlights the potential of dissolution-based recycling as a sustainable solution for pharmaceutical blister packaging, offering a pathway to circular use of PVC in the industry. Future work will focus on scaling the process to pilot plant operations and evaluating its economic and environmental viability.
Acrylonitrile-butadiene-styrene (ABS) cantilever beams were reinforced with carbon black (CB) at 0-2 wt% and fabricated by mechanical extrusion (MEX)-based additive manufacturing to improve vibration damping without compromising strength. Free-decay responses were processed with three complementary estimators-logarithmic decrement (time domain), half-power bandwidth (frequency domain), and an envelope-fit that provides an analytic standard error-and the per-run damping ratios were fused by precision (inverse-variance) weighting to obtain a single with 68% confidence intervals. Composition-level results show a clear optimum at 0.3 wt% CB, where the fused damping ratio increased from 5.81 & times; 10-3 (pure ABS) to 7.75 & times; 10-3 (approximate to+33%), while the ultimate tensile strength rose from 9.83 to 18.12 MPa (approximate to+84%). At 1 wt%, the damping remained elevated but strength decreased; at 2 wt% both metrics declined, consistent with agglomeration observed in scanning electron microscope images. A strength-damping Pareto view highlights 0.3 wt% as a practical composition window for balanced performance in MEX ABS/CB parts. The workflow-multi-estimator analysis with uncertainty-aware fusion-provides reproducible damping estimates from short free-decay records and can be applied to other printed polymers and fillers.
A novel epoxidized cashew nut phenol derivative plasticizer (ECAE) was successfully designed and synthesized as a green, bio-based alternative to conventional phthalate plasticizers. Cashew nut phenol was chemically modified via a two-step reaction sequence involving esterification followed by epoxidation, yielding a multifunctional plasticizer that incorporated flexible long-chain alkyl groups, ester functionalities, and epoxy groups. When blended with PVC, ECAE exhibited superior performance: a glass transition temperature of 28.10 degrees C, elongation at break reaching 702.12% at 50 phr loading, and antibacterial activity with a 15 mm inhibition zone against Staphylococcus aureus. It also demonstrated excellent stability, with only 0.3% migration after 240 h in distilled water at 25 degrees C. Quantum chemical calculations elucidated the plasticization mechanism, revealing how the combination of spatial effects from long-chain alkyl groups and anchoring effects from polar functional groups modulates PVC chain segment dynamics. This bio-based plasticizer represents a significant advance in sustainable polymer technology, meeting environmental requirements while maintaining high performance. It holds potential for applications in food packaging and medical device manufacturing, where material performance and safety are paramount.
There has been an increasing demand for carbon allotropes-based composites in 3D printing. Thus, synthesis of carbon allotrope-polymer composite filaments is important for achieving consistent extrusion and reliable fabrication by fused filament fabrication (FFF). In this work, a solvent blending approach was used to prepare polylactic acid-based composite filaments with graphite concentration varying up to 40 wt.%. A binary solvent consisting of dichloromethane and chloroform facilitates effective dispersion of graphite, while polyethylene glycol improved filament flexibility and printability. The extruded filament was evaluated for dimensional deviation, revealing reduced die swell with increase in filler loading. The thermal stability, crystallinity, and microstructural homogeneity of fabricated composite filaments were also investigated. Mechanical and thermomechanical analyses were further performed on 3D printed specimens to assess stiffness, strength, and viscoelastic behavior. Percolation threshold was reached at 20 wt.% graphite doping and is found to give optimal mechanical properties. An increase in graphite concentrations increased the thermal as well as the electrical conductivity. The results demonstrated that solvent blending enables effective incorporation of higher graphite concentrations while maintaining adequate processability and structural integrity for additive manufacturing applications in the domain of 4D printing of structures, polymeric sensors, and energy storage.
