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Biochar, a carbon‐rich biomass material has emerged as promising reinforcement and offers versatile applications and potential benefits in various fields, especially in fused deposition modeling (FDM). This study focuses on the development and characterization of groundnut shell‐derived biocarbon (GNSC) reinforced polylactic acid (PLA) filaments for FDM. The GNSC was synthesized through pyrolysis using a tubular furnace at temperatures 700, 800, and 900°C. Synthesized carbon was characterized using Raman spectroscopy, XRD, and SEM analysis. The results showed that the synthesized carbon particles were graphitic, spherical, and nanosized with an average diameter of 40 nm. The preferred biocarbon material, GNSC800 was selected for its high carbon content (98.25%) observed through EDX analysis. Composite filaments were produced with different GNSC800 loadings of 0.25%, 0.5%, and 0.75% using solvent casting and extrusion techniques. Thermal stability was evaluated using TGA and DSC, which showed improved properties with the addition of biocarbon. The mechanical properties and electrical conductivity were enhanced with the inclusion of biocarbon. The data were also validated using ANOVA and Tukey's test. Filament with the 0.5 wt% loading showed the most favorable thermomechanical properties exhibiting a 39.8% increase in tensile strength and a 17.5% improvement in tensile modulus. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) composite serve as widely used filaments in fused deposition modeling (FDM) 3D printing. This study investigates the enhancement of PLA composite's comprehensive mechanical properties and thermal stability through the incorporation of carbon fiber (CF). The influence of FDM process parameters on the mechanical properties of PLA composite is also analyzed. Results show that adding 5 wt.% CF significantly enhances the stiffness and comprehensive mechanical properties of PLA composite. The order of printing factors affecting the tensile strength of the PLA composite product is as follows: printing layer thickness, bottom plate temperature, printing speed, and nozzle temperature. Finally, optimal tensile strength is achieved under specific conditions: 0.1 mm layer thickness, 60 °C bottom plate temperature, 40 mm/s printing speed, and 215 °C nozzle temperature. [ABSTRACT FROM AUTHOR]

Highlights The objective of this study is to improve the properties of polylactic acid (PLA), a biopolymer produced from renewable resources, without compromising its environmentally friendly “natural composite” properties. The aim was to expand the application range of PLA by making it suitable for the production of high performance composites. With this in mind, it was decided to use inorganic and environmentally friendly materials such as basalt fiber (BF) and boric acid (BA) as reinforcements. Adhesive wear and tensile tests were used to investigate the tribological and mechanical performance of the composites. Differential scanning calorimetry (DSC) and dimensional stability analysis (DSA) methods were used to investigate the thermal properties. Scanning electron microscopy analysis was also used to investigate the morphological properties of the samples. In addition, a matrix modification process using Joncryl®, an epoxy‐based chain extender chemical, was applied to enhance the interfacial interaction between the composite components and improve the composite properties by improving the dispersion of reinforcing materials. As a result of the characterization tests, it was observed that a significant improvement in the properties of the material type containing 10 wt% BF, 0.25 wt% BA and 2 wt% Joncryl® was achieved. A 19% increase in tensile strength of this type of material was observed compared with unreinforced PLA, while the sharp peak increase in the coefficient of friction (COF) curve was shifted from 20 m to 60 m. As a result, it has been presented that environmentally friendly and inorganic materials such as BF and BA can be used to produce composite materials that will serve sectors where the need and use of high performance materials is intense, especially in the automotive, aerospace and aviation sectors. The properties of PLA matrix composites were improved by the simultaneous use of BF and BA and the addition of Joncryl®. The structural properties of PLA, an environmentally friendly polymer, have been improved without compromising this characteristic. PLA matrix natural composites with performance that can be used in the automotive, aerospace and aviation sectors have been developed. [ABSTRACT FROM AUTHOR]

Increasing toughness of brittle polymer without losing modulus of elasticity and tensile strength is highly important for enlarging the range of applications. In this study, polylactic acid (PLA) modified with epoxidized linseed oil (ELO) and polypropylene-grafted maleic anhydride (PPgMA) with a good balance of toughness and rigidity was successfully prepared by melt mixing procedure. The addition of PPgMA/ELO with appropriate proportions (3:1, 5:1, and 5:5 wt %) resulted in PLA modified samples with significant ductility improvement (around 2200% of elongation at break and 1800% of tensile toughness compared to the neat PLA) with low decrease in Young modulus and tensile strength. This feature was attributed to improved interfacial interactions and the formation of crosslinked structures at the interface that also increased viscosity of the melting system and cold crystallization temperature of PLA. The scanning electron microscopy revealed the presence of small domains of modified systems. The effectiveness of reactive compatibilization among the components was also suggested by Fourier transform infrared (FTIR) spectroscopy and thermal degradation analysis. The combination of toughness, modulus of elasticity and good thermal properties make this low-cost and scalable ecofriendly material a promising candidate for use as biodegradable plastic in several fields including medical applications and packaging. [ABSTRACT FROM AUTHOR]

This study investigated the incorporation of akermanite into a polylactic acid (PLA) matrix using the solution casting method, with akermanite ratios ranging from 0.05% to 2% w/w. To facilitate even distribution of akermanite, 5 wt% triacetin was used as a plasticizer. The resultant PLA/akermanite composite films were evaluated and compared against neat PLA and plasticized PLA films in terms of color, optical, physical, mechanical, thermal and structural properties. Fourier-transform infrared spectroscopy (FT-IR) revealed structural formations attributed to the added plasticizers and akermanite in the PLA matrix. The films containing akermanite showed reduced transparency compared to neat PLA. Differential Scanning Calorimetry (DSC) results indicated an enhancement in crystallinity with the addition of akermanite to the PLA matrix, which suggests improved thermal properties. Mechanical testing showed that the inclusion of triacetin decreased the tensile strength of the PLA films from 31.01 MPa to 29.19 MPa, while the Young's modulus increased from 1.23 GPa to 1.33 GPa. The elongation at break also improved significantly, rising from 5.60% to 8.26%. These changes indicate an overall enhancement in the ductility and stiffness of the films. Additionally, the water solubility and moisture content of the composite films decreased, whereas their water absorption increased compared to neat PLA. These results suggest that the PLA/akermanite composites, with altered physical and mechanical properties, have significant potential for use as biocomposite materials in food packaging applications, offering a sustainable alternative with enhanced performance characteristics. [ABSTRACT FROM AUTHOR]

Purpose: The paper aims to fabricate shape memory composites using polylactic acid (PLA) matrix and graphite. Shape memory polymers are a promising family of materials for biomedical applications because of their favourable mechanical properties, fast reactions and good biocompatibility. For most SMPs, however, achieving controllable sequential shape change is challenging. Design/methodology/approach: In the present work, 4D printing technology is used to fabricate shape memory composites using polylactic acid (PLA) matrix and graphite. A comparative study of pure PLA and graphite's different weight % composition has been done. Findings: By carefully managing the deformation state, PLA with graphite shape memory composites produced controllable sequential deformation with an amazing shape memory effect. Surface morphology, thermal properties, melt flow index and shape recovery tests have all been carried out to assess the qualities of manufactured samples. Originality/value: This is a one-of-a-kind to fabricate shape memory composites using graphite and a PLA matrix. Thus, this research attempts to deliver the possible use of PLA/graphite composites fabricated using 4D printing in robotics and biomedical devices. [ABSTRACT FROM AUTHOR]

Different chemical treatment methods were employed to modify the surface of cotton stalk fibers, which were then utilized as fillers in composite materials. These treated fibers were incorporated into polylactic acid/polypropylene melt blends using the melt blending technique. Results indicated that increasing the surface roughness of cotton stalk fibers could enhance the overall mechanical properties of the composite materials, albeit potentially leading to poor fiber–matrix compatibility. Conversely, a smooth fiber surface was found to improve compatibility with polylactic acid, while Si-O-C silane coating increased fiber regularity and interfacial interaction with the matrix, thereby enhancing heat resistance. The mechanical properties and thermal stability of the composite materials made from alkali/silane-treated fibers exhibited the most significant improvement. Furthermore, better dispersion of fibers in the matrix and more regular fiber orientation were conducive to increasing the overall crystallinity of the composite materials. However, such fiber distribution was not favorable for enhancing impact resistance, although this drawback could be mitigated by increasing the surface roughness of the reinforcing fibers. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of poly (ethylene glycol) (PEG) on the properties of nanocomposites consisting of polylactic acid (PLA) and 3-aminopropyltriethoxysilane-modified bacterial cellulose (MBC) nanofibers. Differential scanning calorimetry (DSC) studies indicated that the presence of PEG enhanced the chain mobility of PLA during crystallization, thereby enabling the MBC to act as efficient nucleation agents. Furthermore, DSC and X-ray diffraction (XRD) analyses provided evidence for the formation of two distinct crystal structures, namely α and α,' as well as various spherulitic dimensions. Finally, the toughening of PLA was occurred by adding PEG to PLA and ternary nanocomposites. [ABSTRACT FROM AUTHOR]

This study aims to develop sustainable, renewable and biodegradable biocomposite films from environmentally friendly materials. For this purpose, completely biodegradable polymer composites were prepared by mixing polylactic acid (PLA) with a new source, quince peel (QP), by solvent casting method, and their structural, mechanical and thermal properties were examined. The tensile strengths of the composites prepared using QP in proportions varying between 5% (P5Q) and 30% (P30Q) by weight vary between 21.13 ± 0.80 and 12.01 ± 0.10 MPa, and their elongations at break vary between 11.33 ± 0.38 and 4.08 ± 1.06 %. As the QP contribution increased, the tensile strength and breaking elongation of these composites generally decreased, while the elastic modulus also increased. Among these composites, whose elastic modulus varies between 1040.00 ± 140.01 and 811.33 ± 13.31 MPa, it was determined that the elastic modulus (1040.00 ± 140.01 MPa) of the 20% QP added composite (P20Q) was higher than the others. When the thermal analysis of PLA/QP films were examined, it was observed that the glass transition temperatures (Tg) were between 58.54 and 51.45°C and the melting temperatures (Tm) were between 167.71 and 164.28°C, and these temperatures generally decreased with increasing QP doping. When the T50 values, which represent the temperature at which 50% of the composite materials decompose, were examined, it was found that the QP-added ones were higher than the pure composites. While this value was 317.96°C in pure PLA composite, T50 values varied between 327.92 and 340.80°C depending on the varying QP ratios. According to the XRD results performed to evaluate the crystalline properties of PLA composites containing quince bark, the crystallinity of pure PLA was determined as 19.5% and the crystallinity of composites containing 5, 10, 20 and 30 wt % QP additives was determined as 19.3, 18.3, 16.4 and 14.6%, respectively. [ABSTRACT FROM AUTHOR]

Plastic‐induced environmental issues could be solved using biomaterials, such as polylactic acid (PLA) film. PLA film is a costly solution suggesting the need to add less expensive starch. However, PLA and starch do not mix due to their diverging water behavior. In this study, we evaluated the impact of lecithin as a compatibilizer in varying ratio of PLA and starch film. The results show that inclusion of lecithin in PLA/starch composite leads to enhanced mechanical properties compared with the composite without lecithin. All films' thermal properties were stable but the thermograph of PLA/starch display two peaks whose distance is impacted by lecithin. In addition, morphology and functional group fingerprints revealed that the addition of lecithin improved the interfacial adhesion between the two polymers. Lecithin influenced the positioning and dispersion pattern of starch granules and distinct transmittance characteristics. The improved compatibility of PLA/starch makes the resulting films less susceptible to water penetration and dissolution. This work demonstrated the possibility of using lecithin as emulsifier between PLA and starch which could expand the application of PLA/starch film especially in packaging industries and bale net wrapping. [ABSTRACT FROM AUTHOR]

Blends of polylactic acid (PLA) with amorphous polyhydroxyalkanoate (aPHA) are less brittle than neat PLA, thus enabling their use as biodegradable packaging. This work investigated the impact of recycling on the properties of neat PLA and PLA/aPHA blends with 90 and 75 wt. % PLA. After the materials were subjected to five heat histories in a single-screw extruder, the mechanical, rheological, and thermal properties were measured. All recycled compounds with 100% PLA and 75% PLA had similar decomposition behavior, whereas the decomposition temperatures for the blends with 90% PLA decreased with each additional heat cycle. The glass transition and melting temperatures were not impacted by reprocessing, but the crystallinity increased with more heat cycles. The complex viscosity of the reprocessed PLA and PLA/aPHA blends was much lower than for the neat PLA and increasing the number of heat cycles produced smaller reductions in the complex viscosity of 100% PLA and the blend with 90% PLA; no change in complex viscosity was observed for blends with 75% PLA exposed to 2 to 5 heat cycles. The tensile properties were not affected by reprocessing, whereas the impact strength for the 75% PLA blend decreased with reprocessing. These properties suggest that users will be able to incorporate scrap into the neat resin for thermoformed packaging. [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–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 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]

A binary blend of polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT), along with algae in their respective composites, were successfully produced using a melt extrusion process. The produced in-house coupling agent was used to enhance interfacial adhesion and algae dispersion. The influence of algae content incorporated into the compatibilized binary blend was thoroughly investigated, focusing on the bio-composites morphology, mechanical, and thermal properties. The addition of PLA-g-MA to the binary blend led to notable improvements in the storage modulus, mechanical strength, and thermal properties of the binary blend. Subsequently, the introduction of algae into the compatibilized binary blend further augmented the storage modulus, with an optimum algae concentration of 10 wt%. However, higher algae content led to decreased tensile strength, elongation at break, and impact resilience. The optimal balance of these properties was achieved at an optimal loading of 5-10 wt% of algae into the compatibilized binary blend. The thermal stability of the bio-composites was notably impacted by algae concentration, with the 10 wt% algae bio-composite exhibiting increased thermal stability. Increasing algae content correlated with decreased bio-composite crystallinity. These findings underscore the potential of optimized biobased algae composites for achieving desired mechanical and thermal properties, contributing to the development of sustainable and eco-friendly polymer biocomposites. [ABSTRACT FROM AUTHOR]

This study focuses on examining the influence of bast fibers on the flammability and thermal properties of the polylactide matrix (PLA). For this purpose, Urtica dioica and Vitis vinifera fibers were subjected to two types of modifications: mercerization in NaOH solution (M1 route) and encapsulation in an organic PLA solution (M2 route). In a further step, PLA composites containing 5, 10, and 15 wt% of unmodified and chemically treated fibers were obtained. The results of the tests show that only biocomposites containing mercerized fibers had a nearly 20% reduced flammability compared to that of PLA. Moreover, the biofiller obtained in this way belongs to the group of flame retardants that generate char residue during combustion, which was also confirmed by TGA tests. The M2 modification route allowed to achieve higher mass viscosity than the addition of unmodified and M1-modified fibers. The reason is that fibers additionally encapsulated in a polymer layer impede the mobility of the chain segments. The inferior homogenization of the M2-modified fibers in the PLA matrix translated into a longer combustion time and only a 15% reduction in flammability. [ABSTRACT FROM AUTHOR]

Polyethylene glycol (PEG), polypropylene glycol (PPG), and poly(ethylene glycol‐co‐propylene glycol) (PEPG) of number average molar masses (Mn) of 6–20 kDa are used as macroinitiators in the ring‐opening polymerization (ROP) of l‐lactide to synthesize high molar mass (50 kDa < MnCopo < 120 kDa) PLLA‐b‐polyether‐b‐PLLA linear triblock and starblock copolymers. At the studied block lengths, PEG and PEPG blocks exhibit miscibility with the PLLA blocks in the amorphous domains leading to a plasticization effect. As the PEG or PEPG block content is increased to 18 %wt, the Tg (Tg ≈ 24 °C) and the elastic modulus (E ≈ 500 MPa) are reduced, while the elongation at break (εb ≈ 280%) and crystallization rate are increased. At the same time, small angle oscillatory shear (SAOS) rheometric measurements show that the plasticized copolymers have a reduced melt viscosity. In contrast, SAOS and DSC measurements of the PPG‐containing block copolymers reveal phase separation of the PPG and PLA blocks leading to microstructures in the melt. Tensile tests show that the phase‐separated PPG‐containing block copolymers are more ductile than PLA homopolymers, but more brittle than the PEG‐ or PEPG‐plasticized block copolymers. [ABSTRACT FROM AUTHOR]

Non‐solvent induced phase separation (NIPS) method was employed to fabricate biodegradable poly(lactic acid) (PLA) nanocomposite membranes. Morphological studies using scanning electron microscopy revealed that all the membranes prepared display asymmetric structures comprising finger‐like macropores. The incorporation of modified polyhedral oligomeric silsesquioxane (POSS) particles into the PLA matrix resulted in enhanced crystallinity, mechanical, and thermal properties. Annealing of the membranes was performed to explore the influence of temperature on the morphology and properties. After annealing, membranes become more thin and compact, and drastic enhancement in crystallinity is also observed. Consequently, Young's modulus experiences a significant improvement. The reduction in oil absorption capacity after annealing can be attributed to the higher level of crystallinity, reduced porosity, and smaller pore diameter observed in the annealed membranes. Additionally, the unannealed PLA nanocomposite membranes demonstrated exceptional oil absorption capacity, reaching approximately 88%. It is foreseeable that these PLA/POSS nanocomposite membranes possess the potential to be utilized as effective tools for oil–water separation, offering the advantage of mitigating secondary pollution. [ABSTRACT FROM AUTHOR]

This research proposes a novel cooling system to minimize the external rotor type of electric motor temperature by installing fan blades (wafters) on the inner housing of the electric motor. Fan blades (wafters) are made by printing using 3D printer technology and using polylactic acid (PLA) as the material. Wafters are then installed on an in-wheel motor with a power of 1500 W, having 48 poles and 52 slots. The study included thermal simulation and experimental techniques to ascertain how fan blades (wafters) affected the electric motor's thermal properties. The motor rotated at 500 rpm during the experimental test with no load condition. The temperature of the electric motor is known using an infrared thermal imager. Using Ansys Motor-CAD 15.1 software, thermal modeling employs the lumped circuit model approach. Thermal simulation results show almost the same results as the experimental test results. Applying wafters on the in-wheel motor housing significantly reduces the winding temperature by 3.047 °C or experiences a temperature reduction of 4.34%. Using wafters in the in-wheel motor housing also speeds up the stable state temperature of the electric motor by 9 min compared to in-wheel motors without wafters. [ABSTRACT FROM AUTHOR]

Most of the polymers made from fossil fuels end up as waste material and this environment-damaging situation has revealed the need to take some precautions such as the use of eco-friendly, biodegradable materials obtained from renewable sources as an alternative. Biopolymers are being evaluated as alternatives to traditional polymers especially in the automotive industry due to their better-understood properties such as mechanical and physical behavior through the studies conducted. On the other hand, when the literature studies are evaluated, it can be seen that the production of foam materials, which are focused on lightness and carbon dioxide (CO2) emission limitations that are important and essential for the automotive sector, is an area that is also researched and studied for biopolymers. Several studies are carried out with both physical and chemical foaming agents on this subject in recent years. In this study, it is aimed to develop light, environmentally friendly, high-performance polylactic acid (PLA) based polymeric composite foams that can be used in the automotive industry by using twin screw extruder and compression molding methods. For this purpose, polyamide 6 (PA6) and polypropylene (PP) polymers were used with PLA and by adding 1 wt.%, 1.5 wt.% and 2 wt.% chemical blowing agents to the polymer mixtures, the physical, thermal, mechanical, morphological properties and changes in these properties were investigated. The most suitable chemical blowing agent ratio was found to be 1.5 wt.% for PLA/PP and PLA/PA6 mixtures. [ABSTRACT FROM AUTHOR]

I n this study, polypropylene (PP) was blended with polylactic acid (PLA) to enhance PP's mechanical properties, such as tensile strength and modulus, and to encourage the adoption of eco-friendly, renewable resource based material in polymer production. Even though PLA's biodegradability cannot be fully utilized in PP/PLA blends, but PLA can still improve PP's mechanical properties and provide an alternative resource for biobased raw materials. To meet the requirement, PP and PLA were blended in a 70:30 ratios with a compatibilizer and nanosilica at different loading levels by melt-blending. Blends of PP and PLA materials were processed without any problems, since both materials have melting points in the range of 170°C. Despite this, the properties of polymer blends are limited by the immiscibility between these neat polymers. To solve this problem, compatibilizers like polypropylene-graftedmaleic anhydride (PP-g-MA) were added to blends to improve their compatibility. Nanosilica was also added to this compatibilizer to study the system's compatibility and modify the hydrophobicity of PLA. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), tensile strength, and field emission scanning electron microscopy (FESEM) were used to analyze the polymer blend. Results indicate that compatibilizers play a significant role in improving tensile properties, thermal stability, and blend dispersion in the system, mainly in 5 parts compatibilizer-based systems. Composition with 5 parts compatibilizer increases tensile strength of 70/30 blend from 19.7 to 27 MPa, while elongation increases from 2.2 to 3.6 %. Additionally, a composition with 0.7 parts of nanosilica increases the modulus from 1488 to 1732 MPa when compared to the 70/30 blend. [ABSTRACT FROM AUTHOR]

In this work, the functional polylactic acid (PLA) was synthesized using epoxy chain extender (ADR) as a chain extender agent through melt blending method. The effects of ADR content on the molecular structure, thermal properties, and tensile properties of the functional PLA were investigated. Meanwhile, the hydrolytic behavior of the PLA/ADR materials at different hydrolysis temperatures was explored. It was found that ADR effectively regulated the molecular structure of PLA in the molten state and significantly increased the relative molecular weight, storage modulus, and complex viscosity of PLA. In addition, the Cole‐Cole diagram results suggested the branched structure of PLA chain expansion systems. Based on mechanical property tests, it was noted that the addition of ADR made the molecular chain form a micro‐crosslinked structure. Additionally, the mass loss rate of PLA/1.6ADR (the dosage of ADR was 1.6 wt%) was 14.75% after 14 weeks of hydrolysis under hydrolysis conditions at 58°C, while that of pure PLA was 25.89%. Moreover, the functional PLA/ADR materials exhibited significantly slower decrease rates in molecular weight, melting temperature, and tensile strength, and still maintained intact morphology after 14 weeks of hydrolysis compared to pure PLA. Therefore, the molecular structure of PLA is effectively regulated by ADR, which greatly enhances the hydrolysis resistance and further promotes the range of application of PLA. [ABSTRACT FROM AUTHOR]

The composites of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/calcium carbonate (PLA/PBAT/CaCO3) with nano-sized, micro-sized calcium carbonate particles, and both were prepared by using a twin-screw extruder. The effect of the CaCO3 particles on the structure and properties of the composites were investigated comparatively by using DSC, SEM, XRD, FTIR, and TGA technologies and tensile testing. The interaction between nano-sized CaCO3 particles and the PLA/PBAT matrix in PLA/PBAT/CaCO3 composites retarded PLA crystallization, while 5 portions of micro-sized CaCO3 particles were beneficial to PLA crystallization, and 10 portions of micro-sized CaCO3 particles were unfavorable to PLA crystallization, which is attributed to the role of nucleation and cross-linking in blocking the movement of PLA molecular chains. The study of non-isothermal crystallization kinetics showed that the Jeziorny method indicated that the PLA phase crystallization dimension was slightly higher in this composite, and the Mo method showed that the PLA phase in this composite had a similar crystallization mechanism as that in the composite containing 5 parts of micro-sized CaCO3 particles. Nano-sized, micro-sized CaCO3 particles and both did not change the lattice parameters of PLA crystals in PLA/PBAT/CaCO3 composites, but reduced the thermal stability of the composites. SEM micrographs showed that nano-sized CaCO3 made PBAT dispersed in PLA in the form of grains, while micro-sized CaCO3 made PBAT dispersed in PLA in the form of flakes. This study promoted the application of calcium carbonate in biodegradable plastics. [ABSTRACT FROM AUTHOR]

Prototype development nowadays can rarely be imagined without 3D printing. In the fast‐moving electronics industry, 3D printing is a good way to react quickly to changing developments, for example, when it comes to heat sinks made of thermally conductive material. 3D printing of thermally conducting plastics, which are also electrically insulating, is an ideal candidate for the rapid generation of heat sink. Nevertheless, 3D printing also shows some drawbacks in regard to properties of the printed parts, as porosities or layer adhesion, emerging from layer deposition in the process. Therefore, the aim of this work was to investigate the influence of the orientation of fillers on the thermal conductivity of filled polylactic acid (PLA). PLA was filled with amounts of 15–45 wt.% of boron nitride and aluminum granules and printed into heat sinks in two different orientations to investigate this influence on the thermal conductivity. The printed heat sinks were then placed on a heated aluminum block and the thermal transport was examined with an infrared camera. It could be shown that especially with platelet‐shaped fillers such as boron nitride, the orientation of these in the test specimen has a large influence on the thermal conductivity. Highlights: 3D printing of thermally conductive heat sinksThermal characterization of 3D printed heat sinksComputer tomography scans of heat sinks to evaluate the porosity [ABSTRACT FROM AUTHOR]

Nowadays, biodegradable polymers have gained more attention due to environmental concerns and several inherent properties. However, poor mechanical and thermal properties limit their use for various applications. The nanocomposite is one of the techniques to improve its mechanical and thermal properties. Hence, this technique may be employed to improve its desired properties. This work reports the synthesis and characterization of biodegradable polylactic acid (PLA) nanocomposites. PLA was synthesized by the ring-opening polymerization of lactic acid, magnesium phosphate (MgP), and calcium phosphate (CaP) nanoparticles were added into the PLA matrix. The nanocomposites were prepared by ultrasonic vibration-assisted melt mixing and vacuum casting techniques. The prepared PLA nanocomposites were further characterized to determine their tensile strength and thermal conductivity. The experiments were designed by employing the central composites design to study the effect of MgP and CaP nanoparticle concentration on the mechanical and thermal properties of PLA nanocomposites. The result indicates that the highest tensile strength was achieved for 10 wt% CaP and 2.35 wt% concentration whereas maximum thermal conductivity of PLA nanocomposites was obtained for 20 wt% CaP and 2.35 wt% concentration. [ABSTRACT FROM AUTHOR]

The material extrusion 3D printing process known as fused deposition modeling (FDM) has recently gained relevance in the additive manufacturing industry for large-scale part production. However, improving the real-time monitoring of the process in terms of its mechanical properties remains important to extend the lifespan of numerous critical applications. To enhance the monitoring of mechanical properties during printing, it is necessary to understand the relationship between temperature profiles and ultimate tensile strength (UTS). This study uses a cyber–physical production system (CPPS) to analyze the impact of four key thermal parameters on the tensile properties of polylactic acid (PLA). Layer thickness, printing speed, and extrusion temperature are the most influential factors, while bed temperature has less impact. The Taguchi L-9 array and the full factorial design of experiments were implemented along with the deposited line's local fused temperature profile analysis. Furthermore, correlations between temperature profiles with the bonding strength during layer adhesion and part solidification can be stated. The results showed that layer thickness is the most important factor, followed by printing speed and extrusion temperature, with very close influence between each other. The lowest impact is attributed to bed temperature. In the experiments, the UTS values varied from 46.38 MPa to 56.19 MPa. This represents an increase in the UTS of around 17% from the same material and printing design conditions but different temperature profiles. Additionally, it was possible to observe that the influence of the parameter variations was not linear in terms of the UTS value or temperature profiles. For example, the increase in the UTS at the 0.6 mm layer thickness was around four times greater than the increase at 0.4 mm. Finally, even when it was found that an increase in the layer temperature led to an increase in the value of the UTS, for some of the parameters, it could be observed that it was not the main factor that caused the UTS to increase. From the monitoring conditions analyzed, it was concluded that the material requires an optimal thermal transition between deposition, adhesion, and layer solidification in order to result in part components with good mechanical properties. A tracking or monitoring system, such as the one designed, can serve as a potential tool for reducing the anisotropy in part production in 3D printing systems. [ABSTRACT FROM AUTHOR]

In this study, the combined effect of algae loading and in‐house produced coupling agent on thermal and mechanical properties of polylactic acid (PLA) prepared by melt compounding were investigated. The PLA‐grafted with maleic anhydride (MA) (PLA‐g‐MA) was used as a coupling agent to improve the interfacial adhesion between PLA and algae. The extent of grafting level was confirmed with FTIR and direct titration method. The results demonstrated the dependence of thermal stability and tensile properties on the grafting level of MA, and also on the concentrations of algae. Thus, it could be deduced that combination of algae at low concentrations (5 and 10 wt%) and PLA‐g‐MA with high grafting level can significantly improve the thermal stability of PLA. High grafting level of MA, showed increase in thermal stability of PLA. On the other hand, at high grafting level, there was an improvement in tensile modulus of PLA. The morphological analysis indicated better adhesion between algae and PLA, in composites containing PLA‐g‐MA with high grafting level. Overall, PLA/algae composites with improved interfacial adhesion and thermal stability were successfully prepared, in the presence of PLA‐g‐MA with high grafting level. [ABSTRACT FROM AUTHOR]

This study investigates the effects of thermal treatment and silver nanoparticles on the mechanical and thermal properties of additively manufactured wood/polylactic acid (PLA) specimens. The 5 and 10 wt% additions of the wood flour into the PLA matrix are done in the twin screw extruder. The test specimens are produced from the filaments with a diameter of 1.75 mm using 3D printer. The mechanical properties of the 3D‐printed wood/PLA specimens are affected by the wood flour content, thermal treatment of wood, and silver nanoparticles. The 3D‐printed neat PLA specimens have better mechanical properties than the wood flour‐filled PLA specimens. The bending strength of the specimens enhances with increasing wood flour content while the tensile strength decreases. The increases in the mechanical properties reveal that the thermal treatment of the wood improves the compatibility between wood and PLA matrix, which hereby improves the interfacial adhesion. The addition of the silver nanoparticles positively affects the mechanical properties and it is more compatible with thermally modified wood particles as compared to the untreated wood particles. [ABSTRACT FROM AUTHOR]

This study explores the impact of different levels of halloysite nanotubes (HNT) and d-isomer on the non-isothermal crystallization behavior of the polylactic acid (PLA). The processing conditions, thermal flow, molecular orientation and the presence of nanofillers can affect the crystallinity and properties of PLA. In this work, PLA-based nanocomposite filaments were produced and their crystallization kinetics was studied. The data obtained through experiments, using differential scanning calorimetry at various cooling rates, were analyzed employing the Jeziorny and Mo models. And the activation energy of crystallization was determined by the Friedman method. The results showed that the growth of PLA crystals is three-dimensional, the HNT can accelerate the crystallization process, and crystallization occurs at higher temperatures in the presence of flow. The activation energy increased with addiction of more HNT in the nanocomposite. The study also found that the d-isomer has a more significant influence on the crystallization of PLA than HNT, which can inhibit crystal formation in some cases. These findings provide insights into the factors that can influence the properties of PLA nanocomposites and how they can be optimized. [ABSTRACT FROM AUTHOR]

Contemporary researchers are directing attention towards enhancing the structural integrity of biodegradable matrices, such as polylactic acid (PLA), through the incorporation of plant fibers. The utilization of novel fibers is becoming more prevalent to achieve the specific demands of composite applications, particularly in the automotive and packaging fields. Woven fabrics are commonly favored for reinforcing composites due to their elevated specific strength and dimensional stability. In pursuit of this context, we have developed a unique woven fabric using 100% okra fiber and utilized it in the production of PLA biocomposites. This approach was made due to the unexplored potential of okra woven fabric in the field of composite manufacturing. To optimize the performance of the composites, three distinct weight proportions of okra woven fabric (OWF) were chosen, including 20%, 30%, and 40%. The obtained composites were mechanically, morphologically, and thermally characterized. The manufactured composite's maximum tensile and thermal property was attained by adding 20% OWF to the PLA. Scanning electron microscopy analysis revealed that 20% OWF composite possessed superior fiber‐matrix adhesion, improving all properties' efficacy. The overall findings reveal that the OWF/PLA composites are promising as a green material for applications in the automotive and packaging industries. Highlights: A novel class of composite has been created using 100% okra woven fabric.The composite with 20% fabric content showed the best mechanical properties.Thermal properties of composites are also optimized using 20% fabric content.SEM confirms the strong fiber‐matrix bonding of 20% OWF/PLA composites.The composites are suitable for automotive and packaging applications. [ABSTRACT FROM AUTHOR]

Blending with ductile polycaprolactone (PCL) is one of the common toughening methods for polylactic acid (PLA). However, it seems inevitable to experience a trade‐off in mechanical strength and thermal stability of PLA. Therefore, this study aimed to improve the mechanical and thermal properties of PLA/PCL blends by adding different contents of talc (0–10 wt%) and conducting annealing treatments. Interestingly, the maximum tensile strength (52.04 MPa), elongation at break (83.51%), and impact strength (6.05 kJ/m2) were achieved by incorporating 2.5 wt% talc into the blends without annealing. Meanwhile, the addition of just 1 wt% talc shortened the semi‐crystallization time of PLA to one‐third of the neat PLA at 100°C. Particularly, after annealing treatment, the crystallinity of PLA increased to 32.1%, and the Vicat softening temperature reached as high as 133.3°C with 2.5 wt% talc. Importantly, the increase in crystallinity did not compromise the toughness of PLA composites but significantly enhanced the impact strength to 8.91 kJ/m2. This study provides an updated understanding of the relationship between toughness and crystallinity in PLA composites. Highlights: Thermo‐resistance of polylactic acid (PLA) composite increases to 133.3°C.Talc aids nucleation and promotes PLA crystallization.Increased crystallinity and high toughness are simultaneously realized.Adding 1 wt% talc reduced PLA semi‐crystallization time by one‐third.Crystal transformation and sea‐islands structure are vital for reinforcements. [ABSTRACT FROM AUTHOR]

In order to improve the comprehensive properties of polylactic acid (PLA) and broaden the application field of PLA composites, reduced oxidized graphene (rGO) grafted caprolactone (CL) was prepared as a nanofiller, and rGO-PCL/PLA composites material were prepared by solution blending. The chemical structure, micromorphology and dispersibility of rGO-PCL were studied. The effects of rGO-PCL mass fraction on the microstructure, mechanical properties, thermal properties and hydrophilic angle of the composite were discussed. The results show that the rGO-PCL nanofiller demonstrated excellent dispersibility in the blend solution. Compared with pure PLA, when the mass fraction of rGO-PCL reaches 1%, it could be uniformly dispersed in the PLA matrix, and has excellent hydrophilicity. The tensile strength and the elongation at break increase by 19% and 180%, respectively. The thermal stability and crystallinity are significantly improved. The rGO-PCL/PLA composite holds promising potential for applications in textile fibers, 3D printing materials, packaging materials and other fields. [ABSTRACT FROM AUTHOR]

The energy-conserving performance of a building, normally realized by a variety of insulation materials, needs to be carefully considered, from the design to construction operations. Traditional mineral or chemically synthesized insulation materials are facing severer environment or health challenges. Hence, this work aims at developing an alternative thermal insulation material from wood. Two species, balsa and Paulownia, were chosen for their naturally low densities. Lignin and hemicellulose components were removed to create a "foamed" structure with more air induced. Polylactic acid (PLA) was applied to cover the delignified wood samples to further improve the hydrophobicity. The microstructure, physical properties, thermal conductivity and insulation properties of the treated wood samples were assessed. After lignin and hemicellulose removal, the original porous micro skeleton of balsa and Paulownia wood was retained, along with an increased porosity to 96.6% and 94%, respectively. Meanwhile, the thermal conductivity was successfully decreased by 22% to 0.053 W/(m·K) for balsa wood and by 27% to 0.067 W/(m·K) for Paulownia wood. PLA-covering treatment further enhanced the water resistance of the delignified wood samples without an evident change in the thermal conductivity. The above findings demonstrated the feasibility of applying delignified wood as a potential insulation material in modern construction operations, which may help set up a new pathway for a low-carbon and energy-saving construction industry. [ABSTRACT FROM AUTHOR]

The industry desires to create robust, resilient, thermally stable, and environmentally friendly composites. In this study, we created a poly (lactic acid) (PLA) composite via a straightforward method. The Ti3C2TX was surface‐coated with polydopamine (PDA) via a bioinspired approach and was then reinforced in the PLA using melt blending. The PDA layer adorned on the Ti3C2TX provided several functional groups for the MXene nanosheets and strengthened the PLA‐MXene interaction by hydrogen bonding. The well‐dispersed PDA@Ti3C2TX in the PLA improved mechanical, thermal, and tribological properties. For PLA/PDA@Ti3C2TX‐1, the tensile strength and elongation at the break of the nano‐composite were 9.03% and 25.5% higher than pure PLA, respectively. The flexural strength and modulus were increased by 49.5% over pure PLA, reaching 148.8 and 6702 MPa, respectively. The nanocomposite toughness increased by up to 53.3%. The nanocomposites had 3.8% and 49.08% lower friction coefficient and specific wear rate, respectively, than pure PLA. The addition of Ti3C2TX and PDA@Ti3C2TX increased the thermal stability of PLA at lower temperatures and promoted carbonization. PLA/PDA@Ti3C2TX‐1 showed the maximum char yield of 10 wt.% at 800°C, proving the highest thermal barrier effect due to MXene exfoliation during PDA and increased PLA dispersion state. [ABSTRACT FROM AUTHOR]

In this paper, the research findings about the impact of polydopamine and tannic acid coatings on specific thermal properties of polylactide are discussed. The influence of deposited coatings on the resistance to oxidation, heat resistance, and the temperatures of phase transitions was determined. Therefore, the oxidation induction temperature, thermogravimetry, and differential scanning calorimetry studies were carried out. To gain a deeper understanding of the findings, mass measurements for the samples before and after the deposition process were conducted, as well as scanning electron microscopy studies. Studies have shown that the application of coatings can improve the resistance of polylactide against oxidative and thermal degradation. However, these coatings have minimal impact on the intensity and temperature of phase transformations. The polylactide showed increased thermal resistance when coated with polydopamine, whereas tannic acid coating was found to be more effective in increasing oxidation resistance. The differences observed were likely caused by variations in the structure of the coatings applied, impacting the level of oxygen diffusion and heat transfer within the material. [ABSTRACT FROM AUTHOR]

Biocomposites based on polylactic acid (PLA), tall wheatgrass (TWG), and hemp (H) were made by injection molding. The article discusses the impact of the agrofiller content on the composite properties, including thermal (DSC, DMA, and TG) and mechanical characteristics (tensile modulus, tensile strength, and impact strength). Generally, the introduction of a plant filler into the polylactide matrix reduced the thermal resistance of the resulting composites. Plant fillers influenced primarily the cold crystallization process, probably due to their nucleating properties. The addition of fillers to the PLA matrix resulted in an increased storage modulus across all tested temperatures compared to pure PLA. In the case of a composite with 50% of plant fillers, it was almost 118%. The mechanical properties of the tested composites depended significantly on the amount of plant filler used. It was observed that adding 50% of plant filler to PLA led to a twofold increase in tensile modulus and a decrease in tensile strength and impact strength by an average of 23 and 70%, respectively. It was determined that composites incorporating tall wheatgrass (TWG) particles exhibited a slightly elevated tensile modulus while showcasing a marginally reduced strength and impact resistance in comparison to composites containing hemp (H) components. [ABSTRACT FROM AUTHOR]

Beer bagasse is a residue waste produced in great amounts; nevertheless, it is still underestimated in the industry. The aim of this paper is to develop an innovative and efficient methodology to recycle the beer bagasse by producing Poly-lactic acid(PLA)-based bio-composites, in the forms of pellets and filaments, to be used in additive manufacturing processes. To assess the suitability of beer bagasse for extrusion-based 3D printing techniques, it was, firstly, physically and chemically characterized. Then, it was added in combination with different kinds of plasticizers to PLA to make bio-composites, analyzing their thermal and physical properties. The results prove the great potential of bagasse, evidencing its printability. Both composites' pellets and filaments were used in two different 3D printing machines and the mechanical properties of the 3D-printed models were evaluated as a function of the composition and the kind of technology used. All the used plasticizers improved processability and the polymer–bagasse interface. Compared to neat PLA, no changes in thermal properties were detected, but a lowering of the mechanical properties of the 3D-printed composites compared to the neat polymers was observed. Finally, a comparison between the efficiency of the two 3D printing techniques to be used with the bio-based composites was performed. [ABSTRACT FROM AUTHOR]

The synergistic effects of thermoplastic poly(ether-ester) elastomer (TPEE) and bentonite nanoclay on mechanical, morphological, thermal, and dynamic mechanical properties of recycled poly(ethylene terephthalate) (R-PET) were investigated. The efficiency of TPEE as impact modifier for the R-PET was evidenced by a significant increase in the impact strength and elongation at break with increasing TPEE contents (from 10 to 30 wt%), while the tensile strength and Young's modulus exhibited an opposite trend. The 70/30 (wt%/wt%) R-PET/TPEE blend was selected as an optimum formulation for further blending with a very low loading of bentonite (1−5 parts per hundred of resin, phr) using the same processing techniques (extruding and injection molding). X-ray diffraction and transmission electron microscopy revealed that the 1 phr bentonite nanocomposite exhibited an exfoliated structure with the highest improvement in the mechanical properties compared with other nanocomposites and the unfilled blend. Meanwhile, the nanocomposites with 2, 3, and 5 phr bentonite formed tactoid or agglomerated bentonite morphology. Differential scanning calorimetry, thermogravimetric and dynamic mechanical analyses demonstrated a noticeable increase in the crystallization temperature, a comparable thermal stability, and a slight increase in the glass transition temperature, respectively, of all nanocomposites when compared with those of the neat R-PET. Graphical Abstract [ABSTRACT FROM AUTHOR]

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The main objective of this work is to evaluate the mechanical and thermal strength of a recently developed composite made of Cissus quadrangularis fiber coupled with Polylacticacid (PLA) in comparison to other natural fibers. This study investigated three different fiber and PLA compositions—20%, 30%, and 40%, respectively used to produce a composite. In contrast, another composite with the same volume percentage was created using calcium hydroxide Ca(OH)2 to coat the fibers in order to alter their microcrystalline structure and enhance their mechanical properties. The composite was created using an injection molding procedure. Tests were performed to assess the improved properties. According to a preliminary study, the mechanical characteristics of PLA combined with treated Cissus quadrangularis fiber are increased when compared to PLA coupled with untreated Cissus quadrangularis fiber and neat PLA. Calcium hydroxide acted as a binding agent in fiber to enhance stress transmission in the matrix, increasing tensile and flexural modulus as well as toughness elongation. Further DSC analysis showed that the inclusion of the preceding components increased the glass transition temperature and melting temperature. The temperature at the beginning of deflection has risen as a result of showing how increasing HDT, fiber–matrix adhesion, and fiber content are related. The morphological analysis was performed on both untreated and chemical-treated fiber composites by using an optical microscope to see the interaction with the fiber matrix. [ABSTRACT FROM AUTHOR]

Polysilsesquioxanes are extensively studied as durable and anti-adherent coatings for medical devices due to their superhydrophobic properties. However, their particular influence on the thermo-mechanical properties and biocompatibility of poly(lactic acid) (PLA)-based materials obtained by melt compounding is scarce. Herein, a facile and promising method to improve the performances of PLA for biomedical applications via the incorporation of different mass proportions of POSS nanoparticles with allyl-heptaisobutyl (AH-POSS) substituent through a melt-blending technique is proposed. The thermal, morpho-structural, mechanical properties at room (RT) and body temperatures (BT), and in vitro biocompatibility of the developed PLA/AH-POSS nanohybrids were investigated. AH-POSS nanoparticles were found to have simultaneous nucleation and plasticizing effects on the PLA nanohybrids, inducing enhanced thermal resistance and easy control of crystallinity while preserving PLA's biocompatibility. An interesting effect of AH-POSS on the mechanical properties of PLA at body temperature was observed. These results indicate the considerable potential of the PLA/AH-POSS nanohybrids obtained by melt compounding in the fabrication of biomedical devices. [ABSTRACT FROM AUTHOR]

This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding PBS increased the tensile properties while the % elongation at break was significantly decreased. [ABSTRACT FROM AUTHOR]

This research aimed to prepare nonwovens from polylactic acid and polybutylene succinate using the melt-blown process while varying the melt-blown process parameters, including air pressure (0.2 and 0.4 MPa) and die-to-collector distance (15, 30, and 45 cm). Increasing the air pressure and die-to-collector distance resulted in the production of smaller fibers. Simultaneously, the tensile strength was dependent on the polymer, air pressure, and die-to-collector distance used, and the percentage elongation at the break tended to increase with an increasing die-to-collector distance. Regarding thermal properties, the PBS nonwovens exhibited an increased level of crystallinity when the die-to-collector distance was raised, consistent with the degree of crystallinity obtained from X-ray diffraction analysis. Polylactic acid could be successfully processed into nonwovens under all six investigated conditions, whereas nonwoven polybutylene succinate could not be formed at a die-to-collector distance of 15 cm. However, both polymers demonstrated the feasibility of being processed into nonwovens using the melt-blown technique, showing potential for applications in the textile industry. [ABSTRACT FROM AUTHOR]

In this study, we utilized a hybridization approach for two different fibers to overcome the drawbacks of single-fiber-reinforced PLA composites. Coir fiber and bamboo leaf fiber were used as reinforcing natural fibers as their properties complement one another. Additionally, we combined thermal annealing with hybridization techniques to further improve the overall properties of the composites. The results showed that the hybridization of BF: CF with a ratio of 1:2 gave PLA-based hybrid composites optimal mechanical and thermal properties. Furthermore, the improvement in the thermal stability of hybrid composites, attributable to an increase in crystallinity, was a result of thermal annealing. The improvement in HDT in annealed 1BF:2CF hybrid composite was about 13.76% higher than that of the neat PLA. Annealing of the composites led to increased crystallinity, which was confirmed using differential scanning calorimetry (DSC). The synergistic effect of hybridization and annealing, leading to the improvement in the thermal properties, opened up the possibilities for the use of PLA-based composites. In this study, we demonstrated that a combined technique can be utilized as a strategy for improving the properties of 100% biocomposites and help overcome some limitations of the use of PLA in many applications. [ABSTRACT FROM AUTHOR]

Starch is an essential biopolymer in biofuel production and a sizing agent in the paper and textile industries. However, native starch is unsuitable for most applications due to brittleness, inferior mechanical and thermal properties, and poor processability. In this regard, a series of modified starch‐based biopolymer composites were prepared by extrusion to produce composites with enhanced properties for enlarged applications. Unlike other studies, the developed thermoplastic starch (TPS) in this work was produced by gelatinizing starch with glycerol and poly(butylene succinate) (PBS) to induce both plasticization and compatibilization. The resultant TPS was blended with diverse organoclays and polylactide (PLA) via a twin‐screw extruder to obtain TPS/PLA/organoclay composites. The ensuing composites were studied for thermal and morphology properties using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results showed that the organoclay loading highly influenced the mechanical and thermal properties of the TPS/PLA composites by enhancing the thermal stability and stiffness of the blends. More importantly, incorporating a small amount of organoclay into PLA enhanced its compatibility with TPS, as depicted in morphological studies. The enhanced crystallization and compatibilization of the blends resulted in enhanced mechanical properties of eco‐friendly composite materials for sustainable packaging applications. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of castor oil plant (Ricinus communis) as filler in rotomolded parts using polyethylene (PE) and polylactic acid (PLA) as polymer matrixes. The vegetable shredded material was used in 5 and 10% weight following a dry blending procedure and then rotomolded to obtain cube test parts. This material was characterized to determine its chemical composition, thermal stability, and structure. The NaOH-treated material shows reduced hemicellulose content and higher thermal stability. Obtained composite materials were characterized in terms of mechanical (tensile, flexural, and impact) and thermal properties, morphology, and bio-disintegration behavior. The use of Ricinus as filler in rotomolded PE composite decreases, in general terms, mechanical properties of neat PE, while no significant changes in thermal or bio-disintegration properties are found. On the contrary, PLA composites show higher tensile strength and similar Young's modulus than the matrix, although with reduced flexural and impact properties. Alkali-treated Ricinus material produces parts with higher porosity and thus, lower mechanical properties than composites with untreated material. Finally, the incorporation of this vegetal material modifies to a great extent the thermal properties of the PLA matrix. The bio-disintegration rate increases due to the use of fibers, probably because of the higher moisture absorption of composites. [ABSTRACT FROM AUTHOR]

Although petroleum-based polymers require a long process to decompose in nature, they still have a wide range of uses. However, due to many important reasons such as the environmental pollution problem caused by these polymers, there is an increasing interest in biodegradable polymers. Poly(lactic acid) (PLA) is a biopolymer with comparable performance to conventional polymers. However, due to its poor tribological, mechanical and thermal properties, the usage area of PLA cannot expand and its use is limited to short-term material applications. In this study, it was aimed to contribute to the expansion of the usage area of PLA by improving its poor properties. For this purpose, efficiency of graphene nanoplatelet (GnP) and/or Joncryl® addition to carbon fiber (CF) reinforced PLA matrix composites to improve the composite performance by means of improved interface interaction fiber and matrix was investigated. Within this scope, effects the separately and/or simultaneously addition of CF, GnP and Joncryl® to PLA on properties were investigated by tensile test, adhesive wear test, DSC, TGA and SEM analyses. All results revealed that the composite composition prepared by simultaneously addition of 10, 0.5 and 2 wt.% CF, GnP and Joncryl®, respectively, to pure PLA performed the best in all tests and analyses. [ABSTRACT FROM AUTHOR]

The use of polylactic acid‐based composites as self‐fixing materials is a promising technology for various applications due to the shape memory effect of polylactide. In this study, hexagonal boron nitride (h‐BN) was mixed with polylactic acid (PLA) with concentrations of 0, 0.5, 1, 2, 5, and 10 wt% for subsequent film casting. The morphology, mechanical and thermal characteristics of the composite were investigated. With a high percentage of filler content, a decrease in thermal conductivity was observed. The recovery strain decreased with increasing the filler content. The amount of h‐BN had a mixed effect on the recovery stress of the composite. Thus, PLA/h‐BN composites represent a new research idea to study the influence of a heat‐conducting filler on a shape memory effect in polylactic acid. Highlights: Correlation between crystallinity, thermal and shape memory properties was describedDecrease in thermal conductivity was observed with the large percentage of fillingThe composite with 2 wt% of h‐BN exhibits optimal characteristics of SMERecovery strain decreased with the rise of filler contentAmount of h‐BN had a non‐trivial effect on the recovery stress of composite [ABSTRACT FROM AUTHOR]