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Polylactic acid (PLA) is the prevailing raw material for fused deposition modeling (FDM) 3D printing filaments, offering benefits such as a low printing temperature, minimal shrinkage, and biodegradability. However, this material has challenges such as poor toughness, low heat deflection temperature, susceptibility to moisture‐induced thermal degradation, and high costs. This study addressed these concerns by incorporating natural bamboo fiber (BF) into PLA, elevating heat the deflection temperature and lowering the material costs. Additionally, a synthesized branched structure compatibilizer, in the form of epoxidized soybean oil‐branched cardanol ether (ESOn‐ECD), enhanced the toughness of PLA, the bonding strength between PLA and the BF surface, and the flowability of high‐fiber composites during processing and printing. The mechanical, thermal, and rheological properties were assessed, demonstrating the promising processing performance of PLA/BF/ESO3‐ECD. The fully biobased composite exhibits strength, toughness, good processability, excellent 3D printability, and durability, implying substantial potential in FDM 3D filament production. Highlights: Bio‐based PLA/bamboo fiber/ESO3‐ECD FDM 3D printing filaments were developed.The excellent nucleation ability of the bamboo fibers enhances the crystallization rate and crystallinity of PLA.The epoxy values and branching degree of ESOn‐ECD are crucial for its effective modification. [ABSTRACT FROM AUTHOR]

Plasticizers are widely used in poly(vinyl chloride) (PVC), polylactic acid (PLA), thermoplastic starch (TPS), and other modified powder materials to enhance the flowability, flexibility, and processability of macromolecules. Because of the reprotoxicity of phthalates in animals and humans, certain phthalates have recently been banned in the United States and Europe. Biobased plasticizers from green biomass–derived renewable resources with low toxicity are expected to be a substitute for phthalates. Among a variety of newly developed biobased monomers, cardanol, and isosorbide are the two most promising materials because of their unique structural features. This review summarizes the research progress of cardanol‐ and isosorbide‐based plasticizers with synergistic effects of plasticization, thermal stabilization, and anti‐migration. By summarizing and analyzing the relationship between molecular structure of plasticizer and plasticizing performance, this review can provide theoretical guidance for future research on the design of isosorbide‐ and cardanol‐based plasticizers. Highlights: Biobased plasticizers with low toxicity are expected to replace certain phthalates.The plasticizing effect of single biobased plasticizer is not good.Biobased plasticizer with synergistic effects is required.There exists the trade‐off effect between the molecular weight and the compatibility.Epoxidized isosorbide ester can be used as a heat stabilizer. [ABSTRACT FROM AUTHOR]

The application of bamboo fibers (BFs) as a reinforcing filler in polylactic acid (PLA) is hindered by their poor compatibility owing to the intrinsic hydrophilia of BFs and the hydrophobicity of PLA. To solve this issue, cardanol (CD) and epoxidized cardanol glycidyl ether (ECGE) were used as compatibilizers to strengthen and toughen PLA/BF bio‐composites, to the best of our knowledge, preparing PLA/BF/CD and PLA/BF/ECGE bio‐composites. The impact strengths of the synthesized bio‐composites increased from 7.75 to 23.75 and 7.75 to 23.95 kJ/m2, respectively, compared with that of a PLA/BF composite without compatibilizer. The investigation of the mechanical properties, crystallization, fractured surface morphology, and solvent stress‐cracking resistance properties revealed that the toughening mechanism of the PLA/BF/CD bio‐composites are mainly based on the plasticization of CD, which results in high impact toughness but low tensile strength. Moreover, the modification with ECGE improves the impact and tensile strengths of the bio‐composite owing to the following factors: (1) the epoxy groups of ECGE generate strong interactions with the BF surface and PLA to form an enhanced interfacial structure; (2) when present at high concentrations, chain extension reaction between ECGE and PLA to increase the molecular chain entanglement of PLA; and (3) upon curing and crosslinking, ECGE forms an entangled network structure that toughens the matrix. [ABSTRACT FROM AUTHOR]

The application of bamboo fibers (BFs) to reinforce the impact strength of polylactic acid (PLA) is attractive because of its low cost and high specific strength. However, the main disadvantages of PLA/BF composites are their low compatibility and poor interfacial adhesion caused by different surface energies. In this work, a bio‐based compatibilizer is used to modify PLA/BF composites with a BF content up to 30 wt%. First, sebacic acid (SA) and epoxidized soybean oil (ESO) are reacted to obtain ESO‐SA oligomers with different branching and crosslinking structures. Next, ESO‐SA is incorporated into a PLA/BF composite through dynamic vulcanization, and fully bio‐based PLA/BF/ESO‐SA ternary composites are prepared. Compared to the PLA/BF composite without ESO‐SA addition, the impact strength of PLA/BF/16ESO‐SA12 increases from 5.8 to 14.55 KJ/m2. The toughening mechanism results confirm that the chemical structure of ESO‐SA is the key indicator of the toughening efficiency. [ABSTRACT FROM AUTHOR]

In this work, lignin was used as a heterogeneous nucleating agent to increase polylactic acid (PLA) crystallinity. To enhance the gas barrier performance of PLA/LG composite films, two graft copolymers, polylactide‐graft‐glycidyl methacrylate (PLA‐g‐GMA) and polylactide‐graft‐poly (ethylene glycol) methyl ether methacrylate (PLA‐g‐PEGMA) were successfully synthesized and separately used as compatibilizers to modify PLA/LG composite properties such as interfacial adhesion, crystallinity, and mechanical properties. Since crystallites can act as obstacles to gas diffusion, the higher the crystallinity of the polymer matrix, the better gas barrier performance of the composite film will be. The crystallinity and crystalline structure of the PLA matrix was demonstrated by wide‐angle X‐ray diffraction and differential scanning calorimetry results. Since LG particles can act as efficient heterogeneous crystal nucleating agents, a roughly 50% reduction in oxygen permeability (PO2) was obtained by adding 1 phr LG to the PLA matrix (PLA/1LG). Following addition of 10 phr PLA‐g‐GMA to the PLA/LG composite, PLA/PLA‐g‐GMA/LG composite films showed lower gas barrier properties than PLA/LG composites without added compatibilizer. Moreover, the interfacial adhesion of PLA/LG composites was significantly improved after addition of PLA‐g‐GMA. Therefore, PLA/PLA‐g‐GMA/3LG showed the highest tensile strength, 33% higher than that of neat PLA. Following addition of 10 phr PLA‐g‐PEGMA to the PLA/LG composite, the long liner side chains of PLA‐g‐PEGMA were able to act as nucleating agents for PLA to promote the crystallization of PLA. Accordingly, PLA/PLA‐g‐PEGMA/3LG with 3 phr LG showed a roughly 86% reduction in PO2 when compared with neat PLA film. [ABSTRACT FROM AUTHOR]

Polymer/clay composites are an innovative class of materials. In this study, we present a facile method for the preparation of biodegradable and robust PLA/organomodified montmorillonite (OMMT) composite films with excellent gas barrier performance. When the design of PLA/OMMT composite films, in addition to making OMMT have good intercalation effect in the matrix, the compatibility of intercalating polymer and matrix should also be considered. In this work, two polymers with high gas barrier properties, namely poly(vinyl alcohol) (PVA) and ethylene vinyl alcohol copolymer (EVOH), were selected to intercalate OMMT. The morphology and microstructures of the prepared PLA/PVA/OMMT and PLA/EVOH/OMMT composites were characterized by the X-ray diffraction measurement, scanning electron microscopy, and differential scanning calorimetry. It was shown that the good dispersibility of PVA in the PLA matrix, rather than the intercalation effect, was responsible for the improved gas barrier and mechanical properties of PLA/PVA/OMMT composite. The elongation at break increases from 4.5% to 22.7% when 1 wt % PVA is added to PLA/OMMT. Moreover, gas barrier of PLA/PVA1/OMMT measured as O2 permeability is 52.8% higher than that of neat PLA. This work provides a route to intercalate OMMT interlayer with high gas barrier polymers and thus can be a useful reference to fabricate PLA/OMMT composites with improved gas barrier and mechanical properties. A comparison of oxygen permeabilities with existing commercial packaging films indicates that the biodegradable PLA/PVA/OMMT may serve as a viable substitute for packaging film applications. [ABSTRACT FROM AUTHOR]

Graphene oxide(GO)/polylactic acid (PLA) nanocomposite, prepared using a solvent-free melt mixing processing, is investigated as a potential oxygen barrier packaging film in this work. In order to disperse GO homogeneously in PLA matrix, hydrophobic silane coupling agent, i.e., γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH560), is used to modify the graphene oxide sheets. The modified GO is able to be well bonded to the PLA due to the formation of covalent bonds between the epoxy groups of KH560 and the carboxyl and hydroxyl terminal groups of PLA. Furthermore, the thermal stability of GO is enhanced due to the long alkyl side chain of KH560, which could also increase the crystallinity of PLA. As a result, the crystallinity of PLA is significantly improved because of the linear KH560 chains, which can act as nucleating agents to improve the crystallization. The KH560-GO helps to reduce the O2 permeability of KH560-GO/PLA composite films via a dual-action mechanism: (1) providing physical barrier due to their native barrier properties, and (2) by resulting in higher degree of crystallinity. The as-prepared KH560-GO0.75/PLA is able to exhibit ca. 33% and ca. 13% decrease in the PO2 than the neat PLA and GO0.75/PLA film, respectively. Finally, the mechanical properties and impact fractured surfaces indicate that the increase in the tensile strength and elongation at break value of KH560-GO/PLA are due to the strong interfacial adhesion and the strong bonding between the epoxy group of KH560-GO and hydroxyl and carboxyl acid terminal groups of PLA matrix. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), a biodegradable polymer with low flexibility, is commonly plasticized with small molecules like tributyl citrate (TBC) for film production. However, these plasticizers, which lack chemical bonds or strong intermolecular interactions with the matrix, tend to migrate to the film surface over time. Their inclusion often compromises material strength for flexibility, increasing elongation at break but reducing tensile strength. In this research, by combining citric acid with n-butanol (B) and poly(ethylene glycol) diglycidyl ether (E), we synthesized three plasticizers, namely TE 3 , TE 2 B 1 , and TE 1 B 2 , to enhance the flexibility of PLA. TE 2 B 1 and TE 1 B 2 are equipped with butyl ester groups that offer effective plasticizing effects. Additionally, the incorporation of long-chain alkyl featuring epoxy groups can boost the interaction with PLA. The results showed that the epoxy groups of the long-chain alkyl plasticizers can improve the elongation at break without compromising tensile strength significantly. The migration of plasticizer from PLA matrix can be reduced by strong interactions like chemical bonds, entanglements, and hydrogen bonding with PLA. TE 1 B 2 demonstrated the best plasticizing effect. Adding 15 portions of TE1B2 and TBC separately increased PLA's elongation at break to 304 % and 242 %, with tensile strengths of 36.1 MPa and 22.3 MPa, respectively. • TE 2 B 1 and TE 1 B 2 are equipped with butyl ester groups that offer effective plasticizing effects. • The incorporation of long-chain alkyl featuring epoxy groups can boost the interaction with PLA. • The epoxy groups in long-chain alkyl plasticizers enhance elongation at break without reducing tensile strength. • The plasticizer migration from PLA could be reduced due to strong interactions. [ABSTRACT FROM AUTHOR]

• How the addition of an ADR chain extender affected the weathering resistance of the PBAT/PLA composite films. • Influence of Chimassorb 2020 and Irganox 1010 light stabilizers on the PBAT/PLA film service life. • Better weathering improvement was observed when Chimassorb2020 was added. Biodegradable poly (butylene adipate‑co‑terephthalate)/polylactic acid (PBAT/PLA) films were prepared by melt blending and blowing technology under the presence of a chain extender and two different light stabilizers. A comparison of the infrared spectra of the film with and without these additives before and after the weathering tests showed that the addition of chain extender and light stabilizer improved the polymer weathering resistance significantly. Without PLA, PBAT underwent serious chain scissions and crosslinking during the weathering. PBAT/PLA film chain scissions were weakened as the PLA content increased. After 200 h of the weathering, the machine direction (MD) tensile strength as well as MD and transverse direction (TD) elongation at break of both PBAT and PBAT/PLA films decreased, while their TD tensile strength changed only slightly. The film with the 85:15 PBAT:PLA ratio containing 1.5 phr of chain extender showed much better flexibility without any changes to its tensile strength. The addition of 0.6 phr of light stabilizer (Chimassorb2020 or Irganox 1010) to this blend showed significantly improved weathering resistance. Better weathering improvement was observed when Chimassorb2020 was added. The tensile strength of PBAT/PLA/ADR/ Chimassorb2020 sample in the machine and transverse directions decreased by 8.4 and 28%, respectively, after 200 h of weathering. [ABSTRACT FROM AUTHOR]