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Poly(lactic acid) (PLA) is a biosourced green plastic derived from natural sources that can replace polyolefins in many applications; however, it is seldom recycled. PLA is a prime candidate for chemical recycling by depolymerization, which produces valuable commodity chemicals and/or fresh monomer for new production, compared to mechanical/thermal reprocessing which produces lesser-quality resin. A scalable, low-cost depolymerization process could render PLA the premier choice for designed-to-be-recycled products in a future circular plastics economy. Here, we report a novel process for depolymerization of PLA under mild conditions using alcoholysis with ionic liquid catalysts in the presence of dimethyl (or diethyl) carbonate as a green solvent, along with critical technoeconomic analysis of the potential impact of this process. The effects of catalyst structures, the solvent system, and PLA resin type on conversion and yield were studied. The reaction kinetics were statistically analyzed with experimental and modeling data, suggesting a fast first-order reaction in PLA degradation. Predictive modeling results based on empirical data further guide the design of scenarios and potential for practical application.

Biofoam products have attracted considerable attention lately because there is a growing demand for green/sustainable products. To this end, various biobased foams have either been developed or are currently in development, e.g., bio-based polyurethanes (PUs), polylactic acid (PLA), starch, and polyhydroxyalkanotates (PHAs). Indeed, significant progress has been made; however, challenges still persist, for example, biobased foam products have poor processability, inferior compatibility, thermal and strength properties. In this review, we focus on five biofoam products: namely bio-based PUs, PLA, starch, PHAs, and cellulose biofoam products, along with their properties and performance, as well as their manufacturing processes. Further efforts are still needed to unlock the full potential of these bio-based products and meet the goal of complementing and gradually replacing some of their fossil-based counterparts. Finally, the challenges, as well as arising opportunities of future research directions are discussed.

Polylactic acid (PLA) is a biodegradable and bio-based aliphatic polyester. It has received extensive attention due to its great environmental and economic value. As a biodegradable material, Polylactic acid (PLA) has poor impact toughness, resulting in a limitation of application. Blending PLA with polybutylene adipate terephthalate (PBAT) can significantly enhance its toughness. PLA/PBAT composite films, as a biodegradable material, is widely used due to its advantages of abundant raw materials, low cost, and environmental friendliness. This article outlines the different preparation methods and current research status of PLA/PBAT composite membranes. The modification technologies of composite membranes, including inorganic fillers, chain expansion and compatibilization, crosslinking agent modification, starch modification, and synergistic modification are summarized. Finally, the application and development prospect of PLA/PBAT composite films in food packaging is introduced, which provide theoretical references and new ideas for future research on PLA/PBAT films in food packaging.

Rationale: Plastic mulch film manages weed growth and moisture loss on the surface of cropping beds. The chemical components of such plastics include polymer(s), additives and non‐intentionally added substances (NIASs). The unknown chemical nature and behaviours of these constituents require investigation due to their potential to add to the anthropogenic chemical burden in the agrifood system. Methods: Solvent extracts of a commercial 15% polylactic acid (PLA)/85% poly(butylene adipate‐co‐terephthalate) mulch film were investigated using gas chromatography–mass spectrometry (GC–MS) with electron ionisation to characterise the additive and NIAS components. The obscurity of some of the NIASs meant their identification was not readily achieved through routine MS library comparisons. As such, the identification of several polymer‐derived compounds required interpretation of the MS data and re‐application of the derived fragmentation patterns with reference to the wider literature. Unknowns were confirmed using commercially available compounds. Results: Unknown NIASs were identified as cyclic oligoesters comprised of the monomeric building blocks of the polymer system. Cyclic structures derived from the monomers of polybutylene adipate (PBA) and polybutylene terephthalate (PBT) fragmented through a primary pathway involving 1,5‐ and 1,3‐H transfers at ester linkages. Characteristic ions at m/z 111, 129, 183 and 201 for PBA‐derived cyclic oligoesters and m/z 104, 132, 149 and 221 for PBT‐derived cyclic oligoesters were assigned in the mass spectra of unknowns. Cyclic oligoesters containing sebacate moieties were also identified, indicating the presence of polybutylene sebacate as an unexpected component of the mulch. Conclusions: Systematic analyses of the sort reported here are valuable for providing alternative approaches for the identification of plastic‐related chemicals. Open publication of MS spectral data is required to build a greater understanding of the mulch film chemical components contributing to the environmental chemical load introduced to agroecosystems. [ABSTRACT FROM AUTHOR]

A simple and inactive structure is able to transform into a complex and active one via four-dimensional (4D) printing. Controlling bending deformation, activation time, and temperature is crucial in 4D printing. This study aimed to comprehensively evaluate and analyze the effect of different process parameters on the bending deformation of polylactic acid (PLA) shape-morphing produced by material extrusion additive manufacturing. These parameters included layup, layer thickness, printing speed, nozzle temperature, nozzle diameter, and bed temperature. Since the bending deformation is significantly affected by the specimen wall, this study has focused, for the first time, on the simultaneous influence of process parameters and presence of a wall on the deformation. Furthermore, the study examined the influence of printing parameters on activation time and activation temperature. The results indicated that increasing the pre-strain stored in the parts led to a decrease in activation time and activation temperature. Subsequently, the Taguchi design of experiment method was used to optimize the most influential parameters on the bending deformation. The difference between the optimal predicted and the experimental deformations was less than 2%. Layer thickness, layup, nozzle temperature, and printing speed were recognized as the most effective parameters for controlling deformation, respectively. [ABSTRACT FROM AUTHOR]

In this study, pure polyurethane (PU) and poly (lactic) acid-silver nanoparticle (PLA-Ag NP) bicomponent nanofibers were successfully obtained alternately by using in the core or shell with coaxial electrospinning. The effects of displacements in the core and shell of fibers on the characterization, antibacterial, and cytotoxicity properties of whole bicomponent fibers were examined in detail. Using PLA-Ag NPs in the core, produced bicomponent mats that were thinner whereas locating PLA-Ag NPs to the shell, obtained bicomponent nanofibers that were more hydrophobic. TEM and FTIR analysis proved that PLA-Ag NPs and pure PU are obtained as a bicomponent structure without mixing with each other. When pure PU was used in the core, bicomponent mats showed high elasticity and strength. As the Ag NPs ratio in the core has increased, the viability of the mouse fibroblast cell line (L929) also has increased. The bicomponent nanofiber with 10% Ag NP in its core has supported cell growth and has shown a high antibacterial effect against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. This study reported that prepared mats could be used as an antibacterial wound dressing, especially for dry wounds, if renewed every 24 hours. [ABSTRACT FROM AUTHOR]

The enhancement of the mechanical and thermal characteristics of 3D printed polylactic acid (PLA) composites reinforced by coir fiber powder (CFP) has been investigated by varying the weight percentage (wt%) of the reinforcement and annealing process. CFP/PLA composite filaments with CFP compositions of 0.1, 0.3, and 0.5 wt% were fabricated. These filaments were used to print CFP/PLA test specimens. The specimens were annealed at 90°C for 120 min in a hot air oven followed by cooling at room temperature. Mechanical, morphological, crystalline, and thermal characterizations were conducted on these specimens. The tensile and flexural strength of neat PLA were observed as 49.7 and 82.4 MPa which decreased by 6.4% and 8.13% respectively for printed composite specimens with 0.5 wt% CFP as reinforcement material. On the other hand, the annealed CFP/PLA composite specimen, with 0.1 wt% CFP as a reinforcement material, demonstrated higher tensile and flexural strength. Specifically, it exhibited a maximum tensile strength of 56.4 MPa and a maximum flexural strength of 92.9 MPa, which are 13.5% and 12.7% higher, respectively, than neat PLA. These strengths are 15.5% and 16.7% higher, respectively, than those of the unannealed CFP/PLA composite specimen with the same wt% of CFP reinforcement. The annealing process increased the crystallinity of composites by enhancing the crystallinity index (63%) and crystalline size (6.7 nm). The high thermal stability of composites (with a glass transition temperature of 256°C) makes them suitable for applications in food and medical packaging. Highlights: Enhancement of thermo‐mechanical characteristics of 3D printed bio‐composites.Annealing process improved mechanical features of 3D printed bio‐composites.Annealed composite with 0.1 wt% as reinforcement demonstrated better properties.SEM and XRD studies confirmed failure mechanisms and crystalline structure.Thermal and mechanical assets favor its utilization in food wrapping applications. [ABSTRACT FROM AUTHOR]

To develop and evaluate a low-cost three-dimensional (3D)-printed video laryngoscope (VL VET) for use with a commercial borescope. Instrument development and pilot study. A total of six adult male Beagle dogs. The VL VET consisted of a laryngoscope handle and a Miller-type blade, and a detachable camera holder that attached to various locations along the blade. The laryngoscope and camera holder were 3D-printed using black polylactic acid filament. Dogs were premedicated with intravenous (IV) medetomidine (15 μg kg−1) and anesthesia induced with IV alfaxalone (1.5 mg kg−1). The VL VET , combined with a borescope, was used for laryngeal visualization and intubation. Performance was evaluated by comparing direct and video-assisted views in sternal recumbency. The borescope camera was sequentially positioned at 2, 4, 6, 8 and 10 cm from the blade tip (distance LARYNX-CAM), which was placed on the epiglottis during intubation or laryngoscopy. At the 10 cm distance LARYNX-CAM , laryngeal visualization was sequentially scored at inter-incisor gaps of 10, 8, 6, 4 and 2 cm. Laryngeal visualization scores (0–3 range, with 0 = obstructed and 3 = unobstructed views) were statistically analyzed using the Friedman's test. Under direct visualization, the 2 cm distance LARYNX-CAM had a significantly lower score compared with all other distance LARYNX-CAM (all p = 0.014) because the view was obstructed by the camera holder and borescope camera. With both direct and camera-assisted views, visualization scores were higher at inter-incisor gaps ≥ 4 cm compared with 2 cm (all p < 0.05). During laryngoscopy and intubation, the VL VET and borescope facilitated both direct and video laryngoscopy at distance LARYNX-CAM in Beagle dogs when inter-incisor gaps were ≥ 4 cm. [ABSTRACT FROM AUTHOR]

Thymus daenensis Celak. (T. daenensis) essential oil (TDO) was encapsulated into beta-cyclodextrin (β-CD) by co-precipitation method and incorporated into polylactic acid (PLA) films along with silver nanoparticles (AgNPs) to generate the active PLA film for extending the ground beef shelf life at 4 °C. Scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FTIR) confirmed the proper dispersion of AgNPs, TDO, and β-CD/TDO throughout the PLA films. Different physical properties were observed in the active PLA films, so that the addition of β-CD/TDO in the films increased the thickness and decreased the tensile strength (TS) and elongation at break compared to TDO films. The color of the AgNP films was lightly darker than the others. The microbial evaluation of the packaged ground beef samples with active PLA films indicated that accompanying AgNPs with β-CD/TDO and TDO could synergistically inhibit total viable bacteria counts, psychrotrophic bacteria counts, and Enterobacteriaceae counts during the sample's storage for 12 days. This effectiveness was also observed in controlling changes in pH and total volatile basic nitrogen (TVB-N) in the samples. Considering the efficient entrapment of TDO in β-CD, the shelf life of samples was significantly extended, due to sustained and long-lasting release of the essential oil compounds, compared to the net TDO films. Based on the results, it can be concluded that β-CD/TDO+AgNP film can be a promising approach to extend the shelf life of ground beef. [ABSTRACT FROM AUTHOR]

Among all technologies applied in three-dimensional printing (3DP), fused deposition modeling (FDM) is the most developing one because it is capable of producing parts with geometrically complex figures. Despite its wide applications, there are some drawbacks to its extension, for instance, weak mechanical characteristics and low dimensional accuracy. In this paper, the influence of four FDM process parameters (layer height, printing speed, infill density, and the number of top and bottom layers) on four criteria (impact strength, dimensional accuracy, consumed raw material, and production time) of polylactic acid (PLA) parts is studied. Unlike previous research, this research not only optimizes the properties of produced parts but also minimizes production costs. First, each criterion is analyzed singly; then, in an investigation, all criteria are combined and optimized simultaneously. In other words, a comprehensive decision is made considering both products' qualities and the production costs. The applied methodology for multi-criterion decision-making in this research is also usable in other fields of industry. With the help of this methodology, the best selection of process parameters' levels is attainable. According to the results, layer height = 0.3 mm, number of top and bottom layers = 2, infill density = 60% and print speed = 45.28 mm/s are the best choice while considering all four criteria. Layer height is found the most effective parameter. An increase in layer height leads to a stronger part with a shorter production time but a heavier one with less dimensional accuracy. [ABSTRACT FROM AUTHOR]

Fused deposition modelling (FDM) is a popular additive manufacturing method involving the deposition of a molten filament along a specific path. In this paper, the microstructure and properties of the filament and the printed part are compared to understand the microstructure and property evolution during the printing process. Two commonly used materials Poly-lactic acid (PLA) and carbon fiber-reinforced PLA (CF + PLA) are used for the study. A thorough experimental campaign is undertaken to compare different properties including elastic properties (modulus, ultimate tensile strength, strain to failure), fiber length distribution, fiber orientation distribution, X-ray diffraction (XRD) analysis, and multiscale characterization of damage/mode of failure. The addition of CF reinforcement led to an increase in Young's modulus and a reduction of the tensile strength for both the filament as well as printed coupons. There is extensive microstructural change during the printing process with major fiber breakage and increased misalignment. In general, Young's modulus of the printed part is significantly lower than the filament whereas the strength depends on the printing orientation. Both the filament and printed part display complex modes of failure at multiple length scales. The damage modes for the filament and corresponding printed part are different with a strong dependence on the raster orientation for the latter. XRD confirms somewhat different amorphous behavior for the filament and printed part. [ABSTRACT FROM AUTHOR]

The escalating significance of 3D printing in various industries is underscored by its ability to rapidly and cost-effectively produce distinctive parts. Among the 3D printing methods, fused filament fabrication (FFF) has emerged as a highly productive and cost-effective approach. While extensive efforts have been made to enhance the qualities of FFF products, challenges persist in material availability and quality compared to traditional methods. This study provides a meticulous overview of the FFF process, delving into various 3D printing processes, polymers, and polymer composites. Despite documented efforts to augment mechanical, thermal, and electrical properties, material constraints remain a focal point. Our analysis extends to various PLA/biocomposites, shedding light on achieved improvements and potential applications. Looking forward, the future trend in FFF technology suggests a paradigm shift towards enhanced material diversity and performance. Anticipated applications span beyond traditional use cases, encompassing sustainable manufacturing, medical devices, and eco-friendly construction materials. This comprehensive review not only consolidates the current state of FFF and PLA-biocomposites but also anticipates future trends and potential applications. This research enhances the current knowledge of additive manufacturing and sets a standard for assessing developments in FFF technology by comparing them to previous works. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) film composites filled with two clays, Raw Kaolin (KAO), an inorganic structure, and Leonardite (LEO), an organic structure, as well as KAO/LEO mixtures, were prepared via solvent casting method. The main aim of this research was to investigate both the individual and the synergetic effects of LEO and KAO; they are incorporated together into a PLA matrix. The influence of these fillers content on the morphological and structural characteristics of the composites was investigated by the DSC, TGA, FT-IR, SEM, XRD, color, haze, and opacity analysis. According to the TGA analysis, significant decreases in Tmax2 were observed with the addition of LEO in PLA. It is also seen in films with KAO/LEO that support this result. Utilizing the solvent casting method, two melting points were formed in PLA films. The P0 film has lower Tg, Tcc, and Tm1 values than other films. However, there were small changes in Tg and Tm2 values in all films. Up to 7.5% amount of LEO and KAO, the mechanical properties of the films improved. The 3L film exhibited the best mechanical properties. The filler materials used were mostly homogeneously distributed, according to the SEM analysis, and as the amount increased, agglomerations were observed in the fillings on the surface. The addition of LEO and KAO changed the surface color, visual appearance, and opacity significantly. The haze values of films are near 100. These film composites have been shown to improve many properties of the P0 film. [ABSTRACT FROM AUTHOR]

8/20 µs lightning pulse current generators (LPCG) used in testing surge arresters require a laborious production process that needs a high budget. An easily repairable, portable, and affordable test system with a maximum energy of 2.9 kJ and a voltage level of 24 kV that can alter its parameter values was described in this work. Simulation and experimental studies were carried out to investigate the effects of the resistor and coil elements in the Pulse Current Generator (PCG) circuit on the amplitude, front, and tail time of the pulse current. Most components of the experimental system were created using 3D printing technology with polylactic acid (PLA) material. The production costs were significantly reduced, according to equivalent pulse generators. Tests at different pulse currents and voltage levels were performed with the experimental system. Power capacitors may often fail due to overvoltage, switching, and partial discharge reasons. The high voltage (HV) power capacitors used in the pulse generator introduced in the study were obtained with the help of low voltage capacitor stacks. As a result, a less expensive, high-capacity capacitor system that is easily and quickly repairable in case of failure was achieved. [ABSTRACT FROM AUTHOR]

In this paper, flame retardant composites were prepared by incorporating three flame retardants (FRs), including triphenyl phosphate (TPP), polysiloxane (PSQ) and phosphite functionalized polysiloxane (PPSQ), respectively into a polylactic acid (s/PLLA) matrix. The results indicated that the ultimate oxygen index increased from 20.6% (s/PLLA) to 22.5% (s/PLLA/TPP), 21.1% (s/PLLA/PSQ), and 23.3% (s/PLLA/PPSQ). The composites exhibited a decrease in peak heat release rate (pHRR) and prolonged peak time according to the cone calorimetry analysis. s/PLLA/PPSQ possessed the highest residual carbon content and the densest char residue with finest and smallest pores, indicating excellent flame-retardant performance. The crystallization behavior analysis revealed that the three FRs resulted in an increased crystallization rate and crystallinity. Notably, the crystallinity of s/PLLA/PPSQ increased from 25.8% in s/PLLA to 37.3%. Additionally, PSQ and PPSQ effectively enhanced the mechanical properties of composite materials. Compared to s/PLLA, the tensile strength of s/PLLA/PSQ and s/PLLA/PPSQ increased by 11.5% and 31.3% respectively, and storage modulus increased by 50.0% and 14.6%. This research demonstrated that among the three additives, PPSQ can effectively provide both flame retardancy and mechanical properties to the s/PLLA matrix, resulting in the composite with the best comprehensive performance. [ABSTRACT FROM AUTHOR]

This study investigates the development of polylactic acid (PLA) by incorporating thermochromic black pigments (TCB) at varying concentrations of 0, 0.5, 1, 2 and 3 wt% through the process of melt blending. The color transition and reversion behaviors of the resulting specimens were examined at different temperatures (−10, 10, 30, 35 and 50 °C) using colorimetric analysis. Additionally, mechanical properties, thermal characteristic and thermal stability were assessed through tensile testing, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The study revealed that an increase in TCB concentrations led to a reduction in lightness (L*). Higher pigment content enhanced thermochromic properties, resulting in more pronounced color changes. The total color difference (ΔE) remained reproducible over five cycles of heating and freezing, and this reproducibility persisted after thermal aging. Tensile strength and elongation at break exhibited improvement with increasing pigment content. Glass transition temperature (Tg) and melting temperature (Tm) of the thermochromic samples showed minimal reduction compared to that of neat PLA, which is 64.2 °C. Crystallinity degree (Xc) increased slightly by 0.2–0.92 %. The thermal stability of the PLA matrix was only marginally affected by the presence of thermochromic pigments. [ABSTRACT FROM AUTHOR]

This document is a contents list for the New Journal of Chemistry, providing a summary of papers published in 2024. The journal covers a wide range of topics in the chemical sciences, including selenium compounds as antiviral agents, guanidinium-terminated gold nanoparticles for protein delivery, and the synthesis of macroporous nanocarbon for sodium ion batteries. The journal aims to connect the global chemistry community and reinvest profits into the field. Additionally, the document includes an expression of concern and a correction for previous articles. [Extracted from the article]

The preparation of alanine from waste polylactic acid (PLA) is not only an effective way to recycle waste plastics, but also of great significance to develop a green, clean and efficient amino acid production process. In this work, we studied the synthesis of alanine by amination of PLA with ammonia solution over different types of supported bimetallic catalysts without external hydrogen. It was found that the bimetallic catalyst consisting of Ru and a non-precious metal Co supported on TiO2 (Ru–Co/TiO2) was efficient for the reaction. The selectivity of alanine and turnover frequency (TOF) were 65.2% and 1.5 h−1, respectively. The synergistic effect existing between Ru and Co in the catalyst was crucial for the catalytic performance, and the content of precious metal Ru in the catalyst was lower. This was the first attempt to introduce a non-precious metal component into the catalyst for the amination of polylactic acid to alanine through thermocatalysis. [ABSTRACT FROM AUTHOR]

Natural vitamin E was extracted from crude palm oil and palm fatty acid distillate, both of which were converted into biodiesel before the extraction process. To enhance the stability of vitamin E, the study investigated the formation of inclusion complexes between vitamin E and β-cyclodextrin and hydroxypropyl-β-cyclodextrin. The results demonstrated improved thermal and light stabilities, prolonging the shelf life at room temperature while maintaining the antioxidant activity of vitamin E. Furthermore, the study successfully applied these complexes to poly(lactic acid) (PLA) fabrics, a biodegradable natural polymer, without altering their appearance. These findings underscore the potential of utilizing natural vitamin E from CPO and PFAD sources in the form of inclusion complexes for textile applications. [ABSTRACT FROM AUTHOR]

The current study focuses on the development of innovative bio‐based filaments using new natural lignocellulosic particles obtained from the bark of the Morinda citrifolia L. plant as reinforcement. Polylactic acid (PLA 4043D) filaments with a diameter of 1.75 mm were produced by varying the volume fraction of M. citrifolia bark particles (MCBP) in three compositions (i.e., 0%, 3%, and 6%). These filaments were then used to print test specimens, which underwent quasi‐static mechanical tests (i.e., tensile and flexural; thermal characterization, thermo‐mechanical tests, and visco‐elastic analysis). The experimental findings demonstrated a remarkable improvement in the tensile strength (i.e., +15%) when the PLA was reinforced with 6% in volume of lignocellulosic particles. Additionally, 3% MCBP and 6% MCBP composites showed substantial increases in flexural strength and modulus (i.e., +25% and +34%), respectively; in comparison to the neat matrix. Moreover, the 3D‐printed composites exhibited significant enhancements in storage modulus, glass transition temperature, and structural stability at elevated temperatures. Hence, this work highlights the potential of the developed bio‐based filaments as feedstock filament material, enabling the production of various customized lightweight products in the automotive and sports industries like cycling helmets, protective guards, knee guards, etc. Highlights: Innovative bio‐based filaments are developed for FDM 3D printing.Morinda citrifolia bark particles (MCBPs) reduce warping risk in PLA printing.The hot crystallization enthalpy of PLA increases with the addition of MCBP.6% MCBP‐PLA exhibits the best mechanical performances.MCBP reinforcement reduces the thermal expansion of PLA. [ABSTRACT FROM AUTHOR]

The morphological transformation of expanded vermiculite (VC) during injection molding with brittle PLA and ductile PP polymers along with its positive and negative contribution to mechanical response is investigated. Polymer/VC mixtures with 30 wt. % VC are prepared by thermokinetic high shear mixing at 4000 rpm without any ex‐situ exfoliation agents or compatibilizers. Obtained composite mixtures are then injection molded onto three‐point bending and tensile test specimens. Performed mechanical tests suggested a significant increase in tensile (110%) and flexural modulus (112%) of PP30VC samples. Presented fractographic and morphological investigations suggested that the root cause of measured improved tensile (36%) and bending strength (26%) of PP is the fibrillation of VC associated with PP/VC interactions under high shear. A similarly increasing trend for tensile (147%) and bending modulus (137%) was observed for PLA30VC samples. Contrary to PP30VC, a decreasing pattern was present in the case of tensile (−40%) and bending strength (−13%) of PLA30VC. The root cause for such reduction is determined to be (i) in situ exfoliation of VC inside PLA matrix and transformation of VC into micrometer‐sized platelets; (ii) evaporation of trapped water/crystalline water in the interlayer region of VC which caused in situ degradation of PLA during manufacturing. Highlights: Vermiculite‐loaded PP and PLA composites are produced at high shear.Composites have superior modulus compared to neat polymers.Fibrillation of platelet vermiculite is observed in only the PP matrix. [ABSTRACT FROM AUTHOR]

The use of three‐dimensional (3D) printing technology for producing continuous fiber‐reinforced composites has given us the freedom to fabricate individual designs and lightweight composite structures with improved specific strength, modulus, and fatigue resistance. In this direction, utilizing in‐nozzle impregnation, 3D‐printed continuous cotton fiber (CCoF) reinforced poly lactic acid (PLA) bio‐composites have been fabricated, and the influence of varying layer widths (i.e., 0.5, 0.6, 0.7, and 0.8 mm) on the mechanical performance of the CCoF‐PLA composites was investigated. Results revealed that 3D printing of PLA/CCoF at 0.5 mm layer width enhanced the tensile and flexural strength by 1.2 times and 3.1 times compared with 3D printed neat PLA specimens. The relationships between layering width—microstructural characteristics—mechanical properties of PLA/CCoF composite were quantitatively analyzed based on experimental results. Highlights: CCoF‐reinforced PLA composites fabricated through a 3D printing routine.CCoF/PLA samples were fabricated at different layer widths (0.5, 0.6, 0.7, and 0.8 mm).Better mechanical performance is achieved at 0.5 mm layer width.σy and UTS of composites enhanced by 1.19 times and 1.87 times, respectively.Ef of composites printed at 0.5 mm layer width enhanced by two times. [ABSTRACT FROM AUTHOR]

The demand for robust yet lightweight materials has exponentially increased in several engineering applications. Additive manufacturing and 3D printing technology have the ability to meet this demand at a fraction of the cost compared with traditional manufacturing techniques. By using the fused deposition modeling (FDM) or fused filament fabrication (FFF) technique, objects can be 3D-printed with complex designs and patterns using cost-effective, biodegradable, and sustainable thermoplastic polymer filaments such as polylactic acid (PLA). This study aims to provide results to guide users in selecting the optimal printing and testing parameters for additively manufactured/3D-printed components. This study was designed using the Taguchi method and grey relational analysis. Compressive test results on nine similarly patterned samples suggest that cuboid gyroid-structured samples perform the best under compression and retain more mechanical strength than the other tested triply periodic minimal surface (TPMS) structures. A printing speed of 40 mm/s, relative density of 60%, and cell size of 3.17 mm were the best choice of input parameters within the tested ranges to provide the optimal performance of a sample that experiences greater force or energy to compress until failure. The ninth experiment on the above-mentioned conditions improved the yield strength by 16.9%, the compression modulus by 34.8%, and energy absorption by 29.5% when compared with the second-best performance, which was obtained in the third experiment. [ABSTRACT FROM AUTHOR]

Current research on materials engineering focuses mainly on bio-based materials. One of the most frequently studied materials in this group is polylactide (PLA), which is a polymer derived from starch. PLA does not have a negative impact on the natural environment and additionally, it possesses properties comparable to those of industrial polymers. The aim of the work was to investigate the potential of organosilicon compounds as modifiers of the mechanical and rheological properties of PLA, as well as to develop a new method for conducting mechanical property tests through innovative high-throughput technologies. Precise dosing methods were utilized to create PLA/silicone polymer blends with varying mass contents, allowing for continuous characterization of the produced blends. To automate bending tests and achieve comprehensive characterization of the blends, a self-created workstation setup has been used. The tensile properties of selected blend compositions were tested, and their ability to withstand dynamic loads was studied. The blends were characterized through various methods, including rheological (MFI), X-ray (XRD), spectroscopic (FTIR), and thermal properties analysis (TG, DSC, HDT), and they were evaluated using microscopic methods (MO, SEM) to examine their structures. [ABSTRACT FROM AUTHOR]

Biodegradable polylactic acid (PLA) has been widely used in fused deposition modeling (FDM) 3D printing. In order to improve its comprehensive properties in 3D printing, in this study, 0-40% content of polybutylene adipate terephthalate(PBAT) was selected to be blended with PLA in a twin-screw extruder; the resulting pellets were drawn into a homogeneous filament; then, PBAT/PLA samples were prepared by FDM 3D printing, and the effects of the dosage of PBAT on the mechanical properties, thermal behavior, surface wettability and melt flowability of the samples were investigated. The results showed that all the samples could be printed smoothly, and the ductility was slightly improved by the increase in the PBAT dosage; the thermal stability of PLA was enhanced by blending with PBAT, and the crystallinity increased monotonically with the increase in PBAT. After blending with PBAT, the surfaces of the samples were more hydrophilic and flowable. The important conclusion achieved in this work was that the PBAT/PLA blends, especially those containing 30%PBAT, showed great potential to replace petroleum-based plastics and are suitable for use in FDM 3D printing technologies for different applications. [ABSTRACT FROM AUTHOR]

Nowadays, increased food safety and decreased food waste are two of the major global interests. Self-healable active packaging materials are an attractive option to achieve such targets. This property is critical for the hygiene and the consumption appropriateness of the food. Polylactic acid is a very promising polymeric matrix that potentially could replace the widely used low-density polyethylene due to its biobased origin and its easy biodegradable nature. The main drawback of this polymeric matrix is its brittle, fragile nature. On the other hand, tetraethyl citrate is a biobased approved food additive which became an attractive option as a plasticizer for industries seeking alternative materials to replace the traditional petrochemically derived compounds. A novel biobased film exhibiting self-healing behavior suitable for food-active packaging was developed during this study. Polylactic acid's brittleness was reduced drastically by incorporating tetraethyl citrate, and a random cut on the original self-repairing film was fully healed after 120 s. The optimum concentration of tetraethyl citrate in the polylactic acid was around 15% v/w with a water/oxygen barrier close to the relevant of polylactic acid and low migration. According to the EC50 parameter, the antioxidant activity was 300% higher than the relevant of pure polylactic acid, while according to the thiobarbituric acid and heme iron parameters, the film resisted lipid oxidation and deterioration. Finally, the total viable count parameter indicates the strong antimicrobial activity of this sample. [ABSTRACT FROM AUTHOR]

The increased use of plastics in industrial and agricultural applications has led to high levels of pollution worldwide and is a significant challenge. To address this plastic pollution, conventional methods such as landfills and incineration are used, leading to further challenges such as the generation of greenhouse gas emissions. Therefore, increasing interest has been directed to identifying alternative methods to dispose of plastic waste from agriculture. The novelty of the current research arose from the lack of critical reviews on how 3-Dimensional (3D) printing was adopted for recycling plastics, its application in the production of agricultural plastics, and its specific benefits, disadvantages, and limitations in recycling plastics. The review paper offers novel insights regarding the application of 3D printing methods including Fused Particle Fabrication (FPF), Hot Melt Extrusion (HME), and Fused Deposition Modelling (FDM) to make filaments from plastics. However, the methods were adopted in local recycling setups where only small quantities of the raw materials were considered. Data was collected using a systematic review involving 39 studies. Findings showed that the application of the 3D printing methods led to the generation of agricultural plastics such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), and High-Density Polyethylene (HDPE), which were found to have properties comparable to those of virgin plastic, suggesting the viability of 3D printing in managing plastic pollution. However, limitations were also associated with the 3D printing methods; 3D-printed plastics deteriorated rapidly under Ultraviolet (UV) light and are non-biodegradable, posing further risks of plastic pollution. However, UV stabilization helps reduce plastic deterioration, thus increasing longevity and reducing disposal. Future directions emphasize identifying methods to reduce the deterioration of 3D-printed agricultural plastics and increasing their longevity in addition to UV stability. [ABSTRACT FROM AUTHOR]

Polymeric blends are employed in the production of filaments for additive manufacturing to balance mechanical and processability properties. The mechanical and thermal properties of polymeric filaments made of poly (lactic acid) (PLA), polyhydroxyalkanoates (PHA), and its blend (PLA–PHA) are investigated herein and correlated to their measured structural and physicochemical properties. PLA exhibits the highest stiffness and tensile strength, but lower toughness. The mechanical properties of the PLA–PHA blend were similar to those of PLA, but with a significantly higher toughness. Despite the lower mechanical properties of neat PHA, incorporating a small amount (12 wt.%) of PHA into PLA significantly enhances toughness (approximately 50%) compared to pure PLA. The synergistic effect is attributed to the spherulitic morphology of blended PHA in PLA, promoting interactions between the amorphous regions of both polymers. Thermal stability is notably improved in the PLA–PHA blend, as determined by thermogravimetric analysis. The blend also exhibits lower cold crystallization and glass transition temperatures as compared to PLA, which is beneficial for additive manufacturing. Following additive manufacturing, X-ray photoelectron spectroscopic showed that the three filaments present an increase in C–C and C=O bonds associated with the loss of C–O bonds. The thermal process induces a slight increase in crystallinity in PHA due to chain reorganization. The study provides insights into the thermal and structural changes occurring during the melting process of additive manufacturing. [ABSTRACT FROM AUTHOR]

Biodegradable composite films comprising of poly(butylene adipate-co-terephthalate) (PBAT), polylactic acid (PLA), and tetrapod-zinc oxide (T-ZnO) whisker were prepared by a melt-extrusion and blow molding process. The effect of the incorporation of the T-ZnO whisker (1 to 7 wt.%) in the PBAT/PLA blend film was studied systematically. The composite films with an optimal T-ZnO whisker concentration of 3 wt.% exhibited the highest mechanical (tensile strength ~32 MPa), rheological (complex viscosity~1200 Pa.s at 1 rad/s angular frequency), and gas barrier (oxygen permeability~20 cc/m2·day) properties, whereas the composite films with 7 wt.% T-ZnO whiskers exhibited the highest antibacterial properties. The developed composite films can find potential application as antibacterial food packaging materials. [ABSTRACT FROM AUTHOR]

Plastic containers, commonly produced from non-biodegradable petroleum-based plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET), raise significant environmental concerns due to their persistence. The disposal of agricultural waste, specifically rice straw (RS), through burning, further compounds these environmental issues. In response, this study explores the integration of polylactic acid (PLA), a biodegradable material, with RS using a twin-screw extruder and injection process, resulting in the creation of a biodegradable packaging material. The inclusion of RS led to a decrease in the melt flow rate, thermal stability, and tensile strength, while concurrently enhancing the hydrophilic properties of the composite polymers. Additionally, the incorporation of maleic anhydride (MA) contributed to a reduction in the water absorption rate. The optimized formulation underwent migration testing and met the standards for food packaging products. Furthermore, no MA migration was detected from the composite. This approach not only provides a practical solution for the disposal of RS, but also serves as an environmentally-friendly alternative to conventional synthetic plastic waste. [ABSTRACT FROM AUTHOR]

Additive manufacturing, with its fast development and application of polymeric materials, led to the wide utilization of polylactic acid (PLA) materials. As a biodegradable and biocompatible aliphatic polyester, produced from renewable sources, PLA is widely used in different sectors, from industry to medicine and science. The aim of this research is to determine the differences between two forms of the PLA material, i.e., fused deposition modeling (FDM) printed filament and digital light processing (DLP) printed resin, followed by aging due to environmental and hygiene maintenance conditions for a period of two months. Specimens underwent 3D scanning, tensile testing, and Fourier transform infrared (FTIR) spectrometry to obtain insights into the material changes that occurred. Two-way Analysis of Variance (ANOVA) statistical analysis was subsequently carried out to determine the statistical significance of the determined changes. Significant impairment can be observed in the dimensional accuracies between both materials, whether they are non-aged or aged. The mechanical properties fluctuated for aged FDM specimens: 15% for ultimate tensile stress, 15% for elongation at yield, and 12% for elastic modulus. Regarding the DLP aged specimens, the UTS decreased by 61%, elongation at yield by around 61%, and elastic modulus by 62%. According to the FTIR spectral analysis, the PLA materials degraded, especially in the case of resin specimens. Aging also showed a significant influence on the elastic modulus, ultimate tensile stress, elongation at yield, elongation at break, and toughness of both materials, which was statistically shown by means of a two-way ANOVA test. The data collected in this research give a better understanding of the underlying aging mechanism of PLA materials. [ABSTRACT FROM AUTHOR]

Polymeric materials, renowned for their lightweight attributes and design adaptability, play a pivotal role in augmenting fuel efficiency and cost-effectiveness in railway vehicle development. The tailored formulation of compounds, specifically designed for additive manufacturing, holds significant promise in expanding the use of these materials. This study centers on poly(lactic acid) (PLA), a natural-based biodegradable polymeric material incorporating diverse halogen-free flame retardants (FRs). Our investigation scrutinizes the printability and fire performance of these formulations, aligning with the European railway standard EN 45545-2. The findings underscore that FR in the condensed phase, including ammonium polyphosphate (APP), expandable graphite (EG), and intumescent systems, exhibit superior fire performance. Notably, FR-inducing hydrolytic degradation, such as aluminum hydroxide (ATH) or EG, reduces polymer molecular weight, significantly impacting PLA's mechanical performance. Achieving a delicate balance between fire resistance and mechanical properties, formulations with APP as the flame retardant emerge as optimal. This research contributes to understanding the fire performance and printability of 3D-printed PLA compounds, offering vital insights for the rail industry's adoption of polymeric materials. [ABSTRACT FROM AUTHOR]

Polylactic-acid–starch-based polymer composite (PLA/TPS) has good thermal stability for biocomposites. However, the physical and mechanical properties of PLA/TPS do not meet the standards. It needed additives to enhance its physical and mechanical properties. The aim was to improve the physical and mechanical properties of PLA/thermoplastic starch using sucrose. In addition, this study evaluated the enhancement of thermal properties of PLA/thermoplastic starch using sucrose. This study used sucrose as an additive to enhance the PLA/TPS composite. The addition of sucrose inhibits the degradation of biocomposites. This means that thermal stability increases. The thermal stability increased because the degree of crystallinity increased with the addition of sucrose, which was also proven in the XRD result. The addition of sucrose caused the morphology of the biocomposite to have pores. The FESEM results showed that biocomposites with the addition of sucrose had pores and gaps. These gaps result from low adhesion between polymers, causing a decrease in the mechanical and physical properties of the sample. Based on the FTIR spectra, biocomposite PLA/TPS blends with the addition of sucrose still have many hydroxyl groups that will lead to attracting other molecules or ions, such as oxygen or water. This phenomenon affects the physical and mechanical properties of materials. The physical and mechanical properties increased with sucrose addition. The best composite was prepared using 3% sucrose. This is because sucrose has a crystalline structure that affects the properties of biocomposites. However, the addition of 3% sucrose was not as effective as that of neat PLA. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is one of the most widely used materials for fused deposition modeling (FDM) 3D printing. It is a biodegradable thermoplastic polyester, derived from natural resources such as corn starch or sugarcane, with low environmental impact and good mechanical properties. One important feature of PLA is that its properties can be modulated by the inclusion of nanofillers. In this work, we investigate the influence of SiC and ZnO doping of PLA on the triboelectric performance of PLA-based tribogenerators. Our results show that the triboelectric signal in ZnO-doped PLA composites increases as the concentration of ZnO in PLA increases, with an enhancement in the output power of 741% when the ZnO concentration in PLA is 3 wt%. SiC-doped PLA behaves in a different manner. Initially the triboelectric signal increases, reaching a peak value with enhanced output power by 284% compared to undoped PLA, when the concentration of SiC in PLA is 1.5 wt%. As the concentration increases to 3 wt%, the triboelectric signal reduces significantly and is comparable to or less than that of the undoped PLA. Our results are consistent with recent data for PVDF doped with silicon carbide nanoparticles and are attributed to the reduction in the contact area between the triboelectric surfaces. [ABSTRACT FROM AUTHOR]

The research presented in this article focuses on the use of inorganic–organic material, based on titanium dioxide and lignin, as a filler for polylactide (PLA) biocomposites. To date, no research has been conducted to understand the impact of hybrid fillers consisting of TiO2 and lignin on the supermolecular structure and crystallization abilities of polylactide. Polymer composites containing 1, 3 or 5 wt.% of hybrid filler or TiO2 were assessed in terms of their structure, morphology, and thermal properties. Mechanical properties, including tensile testing, bending, impact strength, and hardness, were discussed. The hybrid filler is characterized by a very good electrokinetic stability at pH greater than 3–4. The addition of all fillers led to a small decrease in the glass transition temperature but, most importantly, the addition of 1% of the hybrid filler to the PLA matrix increased the degree of crystallinity of the material by up to 20%. Microscopic studies revealed differences in the crystallization behavior and nucleation ability of fillers. The use of hybrid filler resulted in higher nucleation density and shorter induction time than in unfilled PLA or PLA with only TiO2. The introduction of small amounts of hybrid filler also affected the mechanical properties of the composites, causing an increase in bending strength and hardness. This information may be useful from a technological process standpoint and may also help to increase the range of applicability of biobased materials. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) has attracted increasing interest as a sustainable plastic because it can be degraded into CO2 and H2O in nature. However, this process is sluggish, and even worse, it is a CO2‐emitting and carbon resource waste process. Therefore, it is highly urgent to develop a novel strategy for recycling post‐consumer PLA to achieve a circular plastic economy. Herein, we report a one‐pot photoreforming route for the efficient and selective amination of PLA waste into value‐added alanine using CoP/CdS catalysts under mild conditions. Results show the alanine production rate can reach up to 2.4 mmol gcat−1 h−1, with a high selectivity (>75 %) and excellent stability. Time‐resolved transient absorption spectra (TAS) reveal that CoP can rapidly extract photogenerated electrons from CdS to accelerate proton reduction, favoring hole‐dominated PLA oxidation to coproduce alanine. This study offers an appealing way for upcycling PLA waste and creates new opportunities for green synthesis of amino acids. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a bioresorbable and biodegradable polymer extensively used in various biomedical and engineering applications. In this study, we investigated the mass loss and thermal properties of PLA-multi-walled carbon nanotube (MWCNT) composites under simulated physiological conditions. The composites were prepared by melting PLA with 0.1, 0.5, 1.0, and 5.0 wt% MWCNTs using an ultrasonic agitator, and FTIR analysis confirmed composite formation. Subsequently, the composites were subjected to hydrolysis under simulated physiological conditions (pH 7.4 and 37 °C) for up to 60 days. The results revealed that the mass loss of the composites decreased with increasing MWCNT content, suggesting that the presence of MWCNTs decelerated the hydrolysis process. On day 58, the mass loss of pure PLA was 12.5%, decreasing to 8.34% with 0.1% MWCNT, 5.94% with 0.5% MWCNT, 4.59% with 1% MWCNT, and 3.54% with 5.0% MWCNT. This study offers valuable insights into the behavior of PLA-MWCNT composites under physiologically simulated conditions, facilitating the development of new polymer composites with enhanced thermal stability and degradation resistance for biomedical applications. [ABSTRACT FROM AUTHOR]