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This study introduces a novel method to enhance the antibacterial functionality of electrospun nanofibrous textiles by integrating silver nanoparticles (AgNPs) into poly (lactic acid) (PLA) fabrics through pre- and post-electrospinning techniques. AgNPs were incorporated into hydrophobic and modified hydrophilic PLA textiles via pre-solution blending and post-solution casting. A PEG-PPG-PEG tri-block copolymer was utilized to enhance hydrophilicity and water stability, while AgNPs served as antibacterial agents. Morphological analyses confirmed uniform, smooth, and beadless nanofibers with diameters between 435 and 823 nm. Energy-dispersive X-ray spectroscopy spectra and elemental analysis verified the successful incorporation of AgNPs, with higher Ag content in the post-electrospinning samples. Contact angle measurements showed an improved hydrophilicity of the modified PLA textiles, absorbing water droplets within 2 s. The X-ray crystallography patterns confirmed the amorphous structures of the PLA and PEG-PPG-PEG, with reduced crystallinity in the samples containing AgNPs. Thermal analysis indicated lower decomposition temperatures for the hydrophilic samples due to the plasticizing effects of PEG-PPG-PEG on PLA. Mechanical testing showed comparable tensile strengths but reduced elongation in the post-treated samples. The antibacterial efficacy was assessed against various bacterial strains, with post-electrospinning AgNP incorporation showing the most effective antibacterial properties. The results indicate that integrating electrospinning and nanofiber modification techniques expands the applications of PLA-based protective fabrics for disabled individuals. [ABSTRACT FROM AUTHOR]

Poly (lactic acid) PLA based biodegradable polymers and their bio composites are found to be promising as an alternative to the non-biodegradable plastics that are harmful for the environment and humans. These biodegradable and biocompatible polymers have great prospect in applications especially food packaging and bio medical. In bio medical, these have been used in drug delivery, tissue engineering, gene delivery, bone regeneration, and antibacterial biomaterials. This is due to their mechanical, physiological, and chemical properties in addition to their improved functionality, processibility, and sensitivity toward stimuli. The current review sought to highlight the main findings of research on improvements in properties of PLA and its bio composites by blending it with other polymers, adding biomaterials and the applicability of such biopolymers in food packaging and biomedical applications. Further, the advantages and disadvantages followed by challenges in PLA based bio composites and their possible solutions have also been discussed. [ABSTRACT FROM AUTHOR]

To expand the potential applications of polylactic acid (PLA), it is essential to incorporate a highly flexible polymer into the blend. Polycaprolactone (PCL) is an ideal choice due to its ductility and biodegradability. However, blending PLA with PCL resulted in weak mechanical properties. To address this issue, glycidyl methacrylate (GMA) and nano calcium carbonate (NCC) were introduced to enhance the adhesion at the interface between PLA and PCL. Scanning Electron Microscope (SEM) images provided clear visual evidence of the impact of GMA and NCC on the morphology of the blend. Both components were effective in reducing the size of the dispersed PCL phase, shrinking it to approximately half the size of the original blend. Spectroscopic analysis revealed that GMA caused a reaction between its epoxy group and the hydroxyl and carboxyl groups of PLA and PCL. This reaction led to the formation of strong peaks in the 6.5 to 7.5 range in 1H NMR, as well as peaks at 76 and 139 ppm in 13C NMR. These findings were further corroborated by FT-IR, which demonstrated that NCC, despite its surface coating, did not create any new bonds. Rheological studies further demonstrated the positive effects of GMA and NCC. Both the storage modulus (G′) and complex viscosity (η*) of the blends increased, showing improved post-processing performance. Investigation into the shear-thinning behavior of the uncompatibilized blends revealed that NCC caused a significant decrease in complex viscosity at higher frequencies, indicating the disruption of the nanoparticle network. The power-law slope was measured to be 0.62. In contrast, the blend containing the compatibilizer demonstrated a moderate decrease in viscosity, with a power-law slope of 0.36. To analyze the behavior of the PLA/PCL blends in the presence of compatibilizers and nanoparticles at intermediate frequencies, the Palirene model was utilized. The superior integrity of the compatibilized blend was effectively demonstrated by the model, which showed enhanced stress transfer and phase relaxation. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The incorporation of biopolymers and natural colorants in smart packaging has garnered significant attention in the food packaging industry. This study investigates the design and characterization of novel fibrous films incorporating betalain extract (BE) from Stenocereus thurberi in poly (lactic acid) (PLA). An electrospinning technique was developed with varying PLA concentrations (2%–12% w/v) and BE concentrations (8%–12% w/v) to create a colorimetric freshness indicator. BE was characterized by quantifying its phytochemical content and assessing its antioxidant capacity. Morphological and structural analyses included scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), polydispersity index (PI), mechanical properties, and functional characteristics such as ammonia sensitivity and total antioxidant activity. The results indicated that the incorporation of BE significantly influenced the average diameter of the nanofibers, ranging from 313 ± 74 nm to 657 ± 99 nm. SEM micrographs showed that PLA12-BE12 films exhibited smooth surfaces without bead formation. The FTIR analysis confirmed effective BE incorporation, revealing intermolecular interactions between the betalain molecules and the PLA matrix, which contributed to enhanced structural and functional stability. The mechanical properties analysis revealed that moderate BE additions (8%–10% w/v) enhanced the Young's modulus and tensile strength, while higher BE concentrations (12% w/v) disrupted the polymer network, reducing these properties. Additionally, the strain at break decreased significantly with BE incorporation, reflecting limited molecular chain mobility. Increasing BE concentration notably improved antioxidant activity, with the BE concentration of 12% (w/v), the ABTS•+, DPPH•, and FRAP radical scavenging activities at the highest values of 84.28 ± 1.59%, 29.95 ± 0.34%, and 710.57 ± 28.90 µM ET/g, respectively. Ammonia sensitivity tests demonstrated a significant halochromic transition from reddish-pink to yellow, indicating high sensitivity to low ammonia concentrations. The possible mechanism is alkaline pH induces aldimine bond hydrolysis and generates betalamic acid (yellow) and cyclo-DOPA-5-O-ß-glucoside (colorless) The fibrous films also exhibited reversible color changes and maintained good color stability over 30 days, emphasizing their potential for use in smart packaging applications for real-time freshness monitoring and food quality assessment. [ABSTRACT FROM AUTHOR]

Poly (lactic acid) (PLA) membrane is fabricated through electrospinning, which effectively absorbs oil from the oil/water mixture. The prepared PLA electrospun membrane is hydrophobic with a water contact angle (WCA) of 117.2⁰. Introduction of POSS (polyhedral oligomeric silsesquioxane) particles as nanofiller into the PLA matrix, as well as a coating on the electrospun membrane, appreciably enhances the hydrophobicity and thermal stability of the nanofibrous membranes. The membranes become dense, less porous, and crystalline after heat treatment. The unannealed nanofibrous membrane with a highly porous, oleophilic surface helps to impart higher oil absorption properties than that of annealed membranes, which are 60.45 g/g and 66.03 g/g for palm oil and used engine oil respectively. The as-prepared PLA fibrous membranes can absorb oil from the oil-water interface, showing excellent recyclability and separation efficiency > 70%. [ABSTRACT FROM AUTHOR]

The widespread use of traditional petroleum‐based plastics is causing significant environmental pollution for example microplastics issues, due to its non‐biodegradability. Poly (lactic acid) (PLA) as a representative biodegradable polymer is a promising candidate to replace petroleum‐based plastics in some fields of disposable packaging materials and tableware. In this work, in order to improve the poor crystallization, mechanical and heat resistance performances of PLA, styrene–acrylonitrile‐glycidyl methacrylate (SAG) as a chain extender and octamethylenedicarboxylic dibenzoylhydrazide (ST‐NAB3) as a heterogeneous nucleating agent (HNA) were added simultaneously into PLA matrix. The chain‐extended PLA (CPLA) with branch structures had smaller crystal sizes and higher crystal density, compared with those of pure PLA. In addition, thanks to the nucleation effect of ST‐NAB3 and the development of "shish‐kebab", this tendency became more pronounced in CPLA/HNA systems. It was worth mentioning that, CPLA with the ST‐NAB3 content of 1 wt% (CPLA‐1) possessed the highest crystallinity of 43.6%. Meanwhile, CPLA‐1 had the best impact strength and heat deformation temperature of 38.9 kJ/m2 and 91.3°C respectively, which had increased by 11.3 kJ/m2 and 32.4°C contrast to pure PLA. On the whole, this study proposed a simple and effective method, which provided a new possibility for PLA modification research. [ABSTRACT FROM AUTHOR]

Composite materials are used in many engineering applications and industrial fields due to their superior properties, such as high strength, lightweight, and stiffness. These outstanding properties have made these materials an alternative to metallic materials. The vital need for new lightweight and inexpensive materials with superior strength properties has led to research on "hybridisation". Hybrid composites with more than one type of polymer in the same structure are needed to achieve a better balance of properties and to combine many desired properties in a single material. Many researchers have studied the hybrid effect and contributed to the understanding and modelling of the subject. Studies to explain the primary mechanism of the hybrid effect are limited and insufficient to explain the complex interaction. In this study, a three-dimensional printer using fused deposition modelling technique was used to produce hybrid materials, and the influence of printing parameters on the mechanical, absorptive, and morphological properties of poly (lactic acid) (PLA), Tough PLA, and PLA/Tough PLA hybrid materials were investigated. The hybrid material form exhibited superior properties when selecting specific production parameters from individual raw elements. It can be said that the mechanical properties of the PLA/Tough PLA hybrid material increased with the increase in production temperature. [ABSTRACT FROM AUTHOR]

The objective of this study is to enhance the dielectric properties of biocomposite films through the fabrication of biaxially oriented films (BO) and the incorporation of silver-coated microcrystalline cellulose (Ag/MCC). The silver coating was used in concentrations ranging from 0.2 to 2% using an environmentally friendly method. The dielectric constant and dielectric loss of all sample were measured in the frequency range from 103 to − 106 Hz. The sample containing 0.6% silver on microcrystalline cellulose (0.6Ag/MCC) demonstrated the highest dielectric constant, measured 64. Subsequently, biocomposite films were produced by utilizing 0.6%Ag/MCC at different ratios (1–5 phr) through a one-step cast film twin-screw extruder. The sample with the highest dielectric constant was PLA-0.6Ag/MCC4, which increased from 3 (PLA) to 37. Furthermore, biaxially oriented films were successfully prepared using a film biaxial stretching machine, achieving a thickness of 70 μm. This technique can significantly improve their dielectric properties, surpassing those of unstretched films. The improvement in dielectric properties can be attributed to the reorganization of molecular chains, promoting a more orderly arrangement and increases crystallinity. Therefore, the resultant biocomposite and biaxially oriented film demonstrate exceptional dielectric properties, rendering them suitable for dielectric applications such as capacitor dielectric films. [ABSTRACT FROM AUTHOR]

This paper reviewed the blending modification of polylactic acid (PLA) from the aspects of degradable materials, nanomaterials and polyurethane, and its applications were summarized. Finally, the future development prospect in modification of PLA was proposed. [ABSTRACT FROM AUTHOR]

PLA was melt-blended with a chain extender (CEAX8840) and a nucleating agent (ST-NAB3) by using a torque rheometer, and the microstructure, crystallization behavior, mechanical properties, and heat resistance of the modified PLA were characterized by suing scanning electron microscope, hot-plate polarizing microscope, differential scanning calorimeter, thermal deformation meter, universal testing machine, and impact tester. The results indicated that the modified PLA obtained the smallest crystal size at CEAX8840 and ST-NAB3 contents of 6 and 1 wt%, respectively; however, its crystal density was the highest. Moreover, the crystallization temperature and crystallinity degree of the modified PLA were increased to 123. 9 °C and 44. 9 %, respectively. In addition, its impact strength and thermal deformation temperature were increased to 64. 7 kJ/m² and 84. 9 °C, respectively. [ABSTRACT FROM AUTHOR]

The application of lignin as a filler for poly (lactic acid) (PLA) is limited by their poor interfacial adhesion. To address this challenge, lignin-graft-poly(lauryl methacrylate) (LG-g-PLMA) was first blended with poly (lactic acid), and then epoxidized soybean oil (ESO) was also added to prepare PLA/LG-g-PLMA/ESO composite, which was subsequently hot pressed to prepare the composite films. The effect of ESO as a plasticizer on the thermal, mechanical, and rheological properties, as well as the fracture surface morphology of the PLA/LG-g-PLMA composite films, were investigated. It was found that the compatibility and toughness of the composites were improved by the addition of ESO. The elongation at break of the composites with an ESO content of 5 phr was increased from 5.6% to 104.6%, and the tensile toughness was increased from 4.1 MJ/m3 to 44.7 MJ/m3, as compared with the PLA/LG-g-PLMA composite without ESO addition. The toughening effect of ESO on composites is generally attributed to the plasticization effect of ESO, and the interaction between the epoxy groups of ESO and the terminal carboxyl groups of PLA. Furthermore, PLA/LG-g-PLMA/ESO composite films exhibited excellent UV barrier properties and an overall migration value below the permitted limit (10 mg/dm2), indicating that the thus-prepared biocomposite films might potentially be applied to environmentally friendly food packaging. [ABSTRACT FROM AUTHOR]

PGA is currently getting great attention as a potential biodegradable polymer due to its biodegradability, high gas barrier, and high thermal stability; however, its low processability and brittleness are key factors to be overcome for various applications. The purpose of this study was to investigate the feasibility of poly(glycolic acid) (PGA) as a packaging material for a bio-based poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend with improved properties. The optimized PLA/PBAT blend composition was determined with balanced mechanical properties along with microstructural observation. The PGA was first modified with a chain extender to improve its processability, and then it was introduced to PLA/PBAT blends with various compositions via the melt processing method. The melt strength of PGA was found to be improved about 90% with the addition of 0.5 phr of chain extender, achieving better processability. The Young's modulus and tensile strength of the PLA/PBAT/mPGA blend showed no statistically significant differences, which is an interesting finding as compared to other ternary blend system. For barrier properties, the O2 and H2O permeabilities showed no statistically significant difference among ternary blends except the PLA/PBAT blend, but H2O permeability showed a decrease tendency with a value of about 27% as compared to the PLA/PBAT blend. In addition, the morphological observation was also performed to assess the structure-properties relationship in the multi-phase blends system. [ABSTRACT FROM AUTHOR]

Sustainable poly(lactic acid) (PLA)/propylparaben (PPB) composite based films were fabricated via solution casting approach. The assessment of PLA/PPB composite films in terms of active food packaging characteristics like thermal, mechanical, UV–Vis, oxygen barrier, anti-bacterial as well as anti-oxidant effect is carried out. The PLA/PPB-5 composite film resulted in three-fold (23%) increase of elongation-at-break while maintaining a tensile strength (42 MPa) in comparison with PLA film. Consequently, the PLA/PPB-5 composite film displayed a 70% UV–B blockage and reduced the oxygen transmission rate by 52% as compared to PLA film. Further, the PLA/PPB-5 composite film exhibited significant improvement (52%) in the radical scavenging activity which can be really helpful to keep the food products fresh for longer periods. The PLA/PPB filler showed good antibacterial activity against food-borne bacteria [Staphylococcus aureus and Escherichia coli]. The fabricated PLA/PPB composite films have shown desirable active food packaging characteristics and therefore may be suitable for food packaging applications. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

This article introduces a catalyst, (N, N-dimethyl-octadecylamine, DMSA), into the blend of poly(lactic acid)(PLA) and ethylene-butyl acrylate-glycidyl methacrylate graft copolymer (EBA-GMA), to improve the impact toughness of the PLA/EBA-GMA (70/30) blend system through the promotion of in-situ reaction between PLA and EBA-GMA. The influence of DMSA content on the mechanical properties of the blend system was investigated. The results show that the impact strength of the PLA/EBA-GMA (70/30) blend without DMSA is only 10. 9 kJ/m² . When the content of DMSA is 0. 5%, the impact strength of the PLA/ EBA-GMA (70/30) blend reaches as high as 63. 1 kJ/m² . Structural and morphological characterizations indicate that the addition of a small amount of DMSA effectively promotes the reactivity between epoxy groups on EBA-GMA and terminal groups of PLA, thereby enhancing the impact toughness of the PLA/EBA-GMA blend. [ABSTRACT FROM AUTHOR]

In this work, we improved the compatibility between layered double hydroxide and poly (lactic acid) (PLA) by organically modified Ni-Zn-Al-layered double hydroxides (T@5S-LDHs) through intercalation and amidation. The structural changes of T@5S-LDHs before and after modification were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and static contact angle. PLA/T@5S-LDHs nanocomposites films were prepared by blown molding process. The addition of T@5S-LDHs was found to further improve the crystallization ability of PLA through polarizing microscopy analysis. The molecular dynamics simulations showed that the interaction force increased from 279.9 to − 863.6 kcal/mol, which indicated that T@5S-LDHs had strong compatibility with PLA. In the natural degradation behavior, the molecular weights of PLA and PLA/T@5S-LDHs nanocomposites films decreased from 95,542 to 97,569 g/mol to 71,174 and 82,438 g/mol before and after natural degradation, respectively. The relevant degradation index R.M.I increased from 1.1200 to 1.0665 to 1.3424 and 1.1835 between the 28 and 56 days of degradation, respectively. Meanwhile, the carbonyl index of the both films decreased from 3.744 to 3.200 to 2.393 and 2.827 before and after degradation, respectively, which demonstrated that T@5S-LDHs effectively mitigated the degradation behavior of PLA and could prolong the service lifetime of PLA films to some extent. [ABSTRACT FROM AUTHOR]

The main goal of this study is to investigate the impact of aramid nanofiber (ANF) on enhancing various properties of poly(lactic acid) (PLA), including thermal stability, crystallization rates, melt-rheological behavior, and mechanical properties. To achieve this, ANF fillers were produced using a modified deprotonation process from commercial aramid fibers, and a masterbatch (PLA/ANF = 90/10 by wt%) was prepared through solution blending and drying. The masterbatch was then combined with neat PLA through meltblending to create a range of PLA nanocomposites containing 1-10 wt% ANF loadings. Microscopic and spectroscopic analyses confirmed the uniform dispersion and intermolecular interaction of ANFs within the PLA matrix, respectively. As a result, the nanocomposites exhibited a slight increase in glass transition temperature with higher ANF loading, while the cold-crystallization temperature decreased due to ANFs acting as nucleating agents during PLA crystallization. Isothermal crystallization analysis confirmed accelerated meltcrystallization rates in nanocomposites with greater ANF content. The introduction of ANFs enhanced the thermal degradation temperature of the PLA matrix and the 700°C residue of the nanocomposites, attributed to ANFs' barrier and flame retardant effects on PLA. Moreover, the nanocomposites with higher ANF loading demonstrated superior tensile strength, strain at break, toughness, and impact strength owing to the effective bonding interactions at the interfaces between the PLA matrix and the ANF fillers. Highlights • ANF-reinforced PLA nanocomposites are prepared by masterbatch meltcompounding. • Uniform dispersion of ANFs in PLA is attained via effective interfacial bonding. • ANFs boost the melt-crystallization of the PLA matrix. • ANFs enhance the thermal stability of the PLA matrix. • Tensile strength and toughness of PLA are improved with higher ANF content. [ABSTRACT FROM AUTHOR]

Today, the use of biodegradable polymers has become widespread in a wide range of industries. This research scrutinized the physical, mechanical, and rheological properties of poly (lactic acid)/poly (ethylene oxide)/carbon nanotube (PLA/PEO/CNTs) blend nanocomposites, as a good candidate for usage in the packaging industry. PEO and CNTs were added at various concentrations to improve the flexibility, toughness, gas permeability, thermal stability, and mechanical properties of PLA via solution blending. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Field Emission Scanning Electron Microscope (FESEM), water contact angle (WCA), rheometric mechanical spectrometer (RMS) test, gas permeability, and tensile characterization were performed to characterize the properties of the prepared blends and nanocomposites. The experimental results revealed that the addition of 25 wt% PEO to the PLA matrix made a partially miscible blend with a droplet‐matrix morphology. PEO at this concentration increased the elongation at break (from 2.2% to 18%) while reducing the modulus (from 25 to 6 MPa). Also, the experimental results indicated that the miscibility of PLA and PEO was enhanced by the addition of 1 wt% CNTs to the prepared blend, associated with diminished entropy of mixing in the LCST phase diagram. Theoretical calculations predicted that the CNTs would be localized in the PLA phase which increased the total crystallinity of the sample by 28%, considerably reducing the amount of gas permeation into the nanocomposite. In addition, the introduction of the CNTs to the blend increased the elongation at break and tensile strength by 13% compared to pure PLA and lowered the rate of thermal degradation effectively. Also, the final results showed that the COOH‐CNTs located in the PEO phase caused a decline in the crystallinity and an increase in the gas permeability of the prepared nanocomposite. Highlights: Improvement of physical properties of PLA by blending with PEO and CNTs.A deep investigation on rheological behavior of the prepared nanocomposite.Increasing the crystallinity degree of PLA/PEO blend by adding CNTs.Improvement of the miscibility between PLA and PEO in the presence of CNTs.Controlling the CNTs localization by surface modification. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Poly (lactic acid), PLA, a commercially available thermoplastic derived from plant sugars, finds increasing applications in consumer products, disposable packaging, textiles, etc. However, the widespread applications of this bioplastic are limited by its brittleness. This preliminary study inspired a structural analogy with the structure of triglycerides with arms having the nature of PLA itself. Biobased tri-armed toughening additives were synthesized with two oligo (lactic acid) arm lengths. Bio-based resins, or bioresins, are derived from renewable resources such as vegetables. The oligomeric bioresins were characterized by Fourier transform infrared (FTIR) and Nuclear Magnetic Resonance (1 H-NMR and 13 C-NMR) spectroscopies. Easy-to-use green chemistry metrics and simplified life-cycle assessment, i.e., EcoScale and GREEN MOTION scales, were also considered to provide an opening insight into the efficiency and greenness of the processes used to prepare the bioresins. The modifying bioresins (with dosages of 10 and 20 wt%) were blended with PLA to prepare the modified films. Crystallization, mechanical, and thermal properties of the films were evaluated by XRD, tensile experiments, DSC, and TGA apparatuses. The results showed that adding the modifiers improved the flexibility and mechanical properties of the PLA films. The migration and the water vapor permeability tests revealed that the modified films exhibited good resistance against the modifier migration. Overall, this preliminary study indicated a promising modification of the bioplastic PLA using entirely biobased oligomers of its own nature that could be implemented by cost-effective, simple, and clean methods. The modified PLAs might be considered candidates for packaging and additive manufacturing applications. [ABSTRACT FROM AUTHOR]

In this work, modified saponite (SAP‐g‐PS) was prepared by Pickering emulsion polymerization, and the optimum synthesis conditions of SAP‐g‐PS were investigated. Furthermore, SAP‐g‐PS was used as a reinforcing filler for poly (lactic acid) (PLA) and the mechanical properties results revealed that the elongation at break increased by 81.51% compared to pure PLA when SAP‐g‐PS was added up to 0.5 wt%. Scanning electron microscopy analysis showed that the fracture of PLA based nanocomposite films was ductile. The thermal analysis results showed that the maximum thermal decomposition temperature was increased from 352.19°C (PLA0, pure PLA film) to 361.63°C (PLA3, 0.5 wt% SAP‐g‐PS), and the crystallinity was increased from 18.2% (PLA0) to 31.3% (PLA3) at the traction ratio of 14. The stretch‐induced crystallization behavior of PLA based nanocomposites films was investigated under the conditions of the optimum blow molding process, and it was found that the elongation at break of PLA0 films increased from 25.8% to 37.4% and that of PLA3 was increased from 81.4% to 135.5% with the increase of the traction ratio, the crystallinity of both films showed an increasing trend, which indicated that the presence of the tensile flow field improved the orientation of the PLA, and increased its crystallization and mechanical properties. The thermo‐oxidative aging kinetics of PLA based nanocomposites films with different additions of SAP‐g‐PS were investigated by thermo‐oxidative aging experiments, and the lifetime of the films were predicted by the Arrhenius equation, which showed that the addition of SAP‐g‐PS effectively improved the lifetime of PLA based nanocomposites films. [ABSTRACT FROM AUTHOR]

Biodegradable poly (lactic acid) (PLA) as a great substitute for petroleum-based plastics was widely used to reduce environmental pollution resulted by greenhouse gas emissions. However, the practical application range of PLA was limited due to the inherently poor crystallization, mechanical and heat resistance properties. In this context, a heterogeneous nucleating agent (HNA) was incorporated into PLA matrix to address the problems mentioned above. The effects of HNA on the crystallization kinetics of PLA were explored by Avrami method. Isothermal and nonisothermal crystallization kinetics of PLA/HNA systems containing various HNA contents (0–0.75 wt.%) proved that HNA could generate the heterogeneous nucleation of PLA matrix and effectively improve its crystallization rates. The t1/2 of PLA/HNA-0.75 composite decreased to 2.35 min compared with 34.12 min for pure PLA at isothermal temperature of 135 °C. The crystallinity of PLA/HNA-0.75 composite was enhanced by 42.1% in contrast with pure PLA. The "shish-kebab" structure of PLA/HNA composites containing various HNA contents (0.25–0.75 wt.%) was observed by polarized optical microscope as the concentration of HNA exceeded 0.375 wt.%. PLA/HNA-0.75 composite possessed the highest unnotched izod impact strength (33.6 kJ/m2), notched izod impact strength (4.3 kJ/m2) and heat deformation temperature (73.2 °C). In general, a feasible method was proposed for preparation of PLA with excellent mechanical and heat resistance properties through this work. [ABSTRACT FROM AUTHOR]

Biodegradable materials based on poly (lactic acid) (PLA) and a phenolic free modified rosin resin were obtained and studied to control the biodegradability under composting conditions of the materials. The resin was blended in concentrations of 1, 3, 5, 10, and 15 parts per hundred (phr) of base polymer using industrial plastic processing techniques. Additionally, to study the effect of the resin on the compatibility of the PLA, the physical performance, water absorption, mechanical behavior, thermal stability, and microstructure of the materials were assessed. The resin incorporation decreased the resistance to thermal degradation of the resultant material, and the composting disintegration rate was slowed down with the increasing content of the resin. The water diffusion was delayed, and the diffusion and corrected diffusion coefficients decreased with the rising content of UP. The mechanical properties tend to decrease while a saturation effect was observed for contents higher than 3 phr of resin. The optimal amount of resin that can be added to achieve good interaction with PLA matrix, complete miscibility, and good material cohesion is 3 phr. [ABSTRACT FROM AUTHOR]

In this paper, ammonium polyphosphate (APP) and casein (CSN) were added to poly (lactic acid) (PLA) to improve flame retardancy and maintain biodegradability. The flame retardancy, mechanical, and thermal properties of PLA/APP/CSN composites were evaluated, and the optimum ratio of APP and CSN was determined. The results showed that with the addition of 9 wt% flame retardant (APP:CSN=5:4), the limiting oxygen index (LOI) of the PLA/APP/CSN composite reached 28.3%, and passed the UL‐94 V‐0 rating at 3 mm, char residue increased at 800°C and smoke emission was also significantly reduced compared to addition of APP without the addition of CSN. Besides that, the cone calorimeter result showed that the peak heat release rate and total heat release of the PLA/APP/CSN‐5 composite were 18.2% and 13.3%, respectively, lower than those of pure PLA. The addition of flame retardants inevitably led to a reduction in tensile and flex strength values, but the impact strength was improved. [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]

Poly (lactic acid) (PLA) is a promising green substitute for conventional petroleum-based plastics in a variety of applications. However, the wide application of PLA is still limited by its disadvantages, such as slow crystallization rate, inadequate gas barrier, thermal degradation, etc. In this study, lignin (1, 3, 5 PHR) was incorporated into PLA to improve the thermal, mechanical, and barrier properties of PLA. Two low-viscosity epoxy resins, ethylene glycol diglycidyl ether (EGDE) and poly (ethylene glycol) diglycidyl ether (PEGDE), were used as compatibilizers to enhance the performance of the composites. The addition of lignin improved the onset degradation temperature of PLA by up to 15 °C, increased PLA crystallinity, improved PLA tensile strength by approximately 15%, and improved PLA oxygen barrier by up to 58.3%. The addition of EGDE and PEGDE both decreased the glass transition, crystallization, and melting temperatures of the PLA/lignin composites, suggesting their compatabilizing and plasticizing effects, which contributed to improved oxygen barrier properties of the PLA/lignin composites. The developed PLA/lignin composites with improved thermal, mechanical, and gas barrier properties can potentially be used for green packaging applications. [ABSTRACT FROM AUTHOR]

Curcumin (CUR) nanomicelles were developed by solvent-evaporation method using Poly (lactic acid) (PLA) for the first time with Pluronic F127 (PF127) to produce CUR@PLA@PF127 nanomicelles. The X-ray diffraction (XRD) spectra confirmed the encapsulation of CUR into the produced nanomicelles (CUR@PLA@PF127). Fourier transform infrared spectroscopy (FTIR) analysis showed the interactions of CUR with PLA and PF127. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis showed the formation of spherical shape of CUR@PLA@PF127 with a diameter around 130–160 nm. To investigate the anticancer effect of the encapsulated CUR, the activity of CUR@PLA@PF127 nanomicelles, free CUR and blank nanomicelles (PLA@PF127) were assayed against two cell lines in-vitro, human breast adenocarcinoma cells (MCF-7) and human breast skin fibroblast cells. The cytotoxicity assay of CUR@PLA@PF127 nanomicelles, revealed an IC50 value of 159.7 ± 1.36 µg/mL for MCF-7 cells which is much lower than that observed for free CUR. This result suggests that CUR@PLA@PF127 nanomicelles increased CUR potency due to improving its water solubility, resulting in longer release profile, and increasing antiproliferative effect on breast cancer cells (MCF-7). We anticipate that CUR@PLA@PF127 in drug delivery, improving drugs design and that the developed nanomicelles will be regarded one of the most promising nanocarriers for the treatment of breast cancer, and opening the door to future applications in cancer therapies. [ABSTRACT FROM AUTHOR]

A novel poly (lactic acid) (PLA) composite with excellent mechanical properties, toughness, thermal stability, and water resistance was developed using a reactive melt-blending technique. PLA was melt mixed with epoxy resin (EPOXY) and bamboo pulp (PULP) to improve its reaction and mechanical properties. FTIR analysis confirmed the successful reaction of the PLA/EPOXY/PULP composites; the epoxy groups of EPOXY reacted with the –COOH groups of PLA and the –OH groups of PULP. The PLA/EPOXY/PULP5 composite showed a high tensile strength (67 MPa) and high toughness of 762 folding cycles, whereas the highest tensile strength was 77 MPa in the PLA/EPOXY5/PULP20 sample. SEM images presented a gap between the PLA and PULP; gap size decreased with the addition of EPOXY. The Tg of the PLA decreased with the EPOXY plasticizer effect, whereas the Tm did not significantly change. PULP induced crystallinity and increased Vicat softening of the PLA/PULP and PLA/EPOXY/PULP composites. The EPOXY reaction of the PLA/PULP composites improved their tensile properties, toughness, thermal stability, and water resistance. [ABSTRACT FROM AUTHOR]

This study's primary objective was to observe the growth of marigold seedlings in biodegradable planting bags made from polylactic acid (PLA), natural rubber (NR), and rice straw (RS) film, as well as the biodegradation of the bags during planting. The flexible PLA/NR/RS film was produced using a PLA/NR blend ratio of 70:30 percent by weight (wt%) as a matrix and filled with RS at 3, 5, and 10 wt%. All PLA/NR/RS biocomposite films were produced via an extrusion casting method. To examine the growth efficiency of marigold seedlings in biodegradable planting bags, marigold seedlings were transferred into PLA/NR/RS biocomposite bags. After being planted for 90 days, the stalk diameter and dry mass of the marigold seedlings grown in the PLA/NR/RS biocomposite bags tended to increase with increasing RS content. The biodegradability of all PLA/NR/RS biocomposite bags was measured by how much weight each bag lost after marigold seedlings were planted in it. The amount of rice straw in PLA/NR/RS biocomposite bags was found to affect how much weight they lost. Maximum weight loss was observed when the film contained 10 wt% RS fiber, which corresponded to the lowest PLA molecular weight assessed by gel permeation chromatography (GPC). [ABSTRACT FROM AUTHOR]

The processability and practical applications of poly (butylene adipate-co-terephthalate) (PBAT) /poly (lactic acid) (PLA) blends are limited due to their lower miscibility. To investigate the miscibility of various PBAT/PLA composite ratios and the mechanism of miscibility between them, PBAT/PLA blends with different ratios were prepared using the melt mixing method. A combination of multi-scale simulations and experiments were employed to investigate the miscibility of the composites. Molecular dynamics simulations analyzed PBAT/PLA mixtures that are incompatible and showed the molecular basis of their incompatibility through the radial distribution function (RDF). The degree of miscibility of different ratios of PBAT/PLA composites was described using the Flory–Huggins interaction parameter, indicating that the 50/50 PBAT/PLA blend has the worst miscibility. Mesoscopic dynamics described the mesoscopic morphology of PBAT and PLA blends visually. The results obtained from the simulations were consistent with scanning electron microscope (SEM) and differential scanning calorimeter (DSC) experiments, indicating the simulations' reliability. This work provides a molecular perspective on the mechanism of thermodynamic insolubility of PBAT and PLA, which can inspire future PBAT/PLA hybrid modifications. [ABSTRACT FROM AUTHOR]

Abstract As an emerging science, tissue engineering and regenerative medicine focus on developing materials to replace, restore or improve organs or tissues and enhancing the cellular capacity to proliferate, migrate and differentiate into different cell types and specific tissues. Renewable resources have been used to develop new materials, resulting in attempts to produce various environmentally friendly biomaterials. Poly (lactic acid) (PLA) is a biopolymer known to be biodegradable and it is produced from the fermentation of carbohydrates. PLA can be combined with other polymers to produce new biomaterials with suitable physicochemical properties for tissue engineering applications. Here, the advances in modified PLA as tissue engineering materials are discussed in light of its drawbacks, such as biological inertness, low cell adhesion, and low degradation rate, and the efforts conducted to address these challenges toward the design of new enhanced alternative biomaterials.

The improvement of the crystallization of poly(lactic acid) (PLA) is one of the key areas to allow PLA to perform better at higher temperature and load bearing. Due to its slow crystallization rate, either organic or inorganic nucleating agents (NAs) can be used to improve the crystallization rate of PLA. In the case of organic NAs, aromatic sulfonate salt and bisamide compounds are promising ones because they can control better clarity. The aim of this work was to study the crystallization behavior of PLA using as-synthesized dimethyl 5-sulfoisophthalate sodium salt (SSIPA) as a nucleating agent in comparison with the commercial sulfonate salt (LAK-301). Two grades of PLA (PLA L105 and PLA 3251D) were used in this study. PLA samples were prepared by internal mixer and compression molding. All samples were investigated by DSC and POM. The results from DSC showed that after introducing the nucleating agents into PLA, the crystallinity in all samples was improved. The highest crystallinity at 57.48% was obtained from PLA L105/SSIPA1.0. Isothermal crystallization kinetics showed the improvement in overall crystallization rate of PLA with nucleating agents. The lowest half time crystallization obtained was 1.19 min for PLA L105/SSIPA1.0 at 135 °C. The results from POM indicated the substantial increase of the nucleus density and smaller spherulite size upon adding nucleating agents.

In this work, blends based on poly (lactic acid) (PLA)/acrylonitrile-butadiene-styrene (ABS) compatibilized with maleic anhydride-grafted (SEBS-g-MA) were prepared in a co-rotational twin-screw extruder by varying the concentrations of the compatibilizing agent. The influence of the compatibilizing agent on the morphology, mechanical, thermal, thermomechanical, and rheological properties of the prepared materials was analyzed. The effect of annealing on the properties of the blends was also investigated using injection-molded samples. The X-ray diffraction (XRD) results proved that the increments in crystallinity were an effect of annealing in the PLA/ABS/SEBS-g-MA blends, resonating at higher heat deflection temperatures (HDTs). The impact strength of the PLA/ABS blends compatibilized with 10 wt% SEBS-g-MA was significantly increased when compared to the PLA/ABS blends. However, the hardness and elastic modulus of the blends decreased when compared to neat PLA. The refined morphology shown in the scanning electron microscopy (SEM) analyses corroborated the improved impact strength promoted by SEBS-g-MA. The torque rheometer degradation study also supported the increased compatibility between SEBS-g-MA, PLA, and ABS. The TGA results show that the PLA/ABS and PLA/ABS/SEBS-g-MA blends are more thermally stable than the neat PLA polymer at higher temperatures. The results showed that the ideal composition is the heat-treated PLA/ABS/SEBS-g-MA (60/30/10 wt%), given the high impact strength and HDT results. The results of this work in terms of mechanical improvement with the use of compatibilizers and annealing suggest that the PLA/ABS/SEBS-g-MA system can be used in the production of 3D-printing filaments. [ABSTRACT FROM AUTHOR]

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