L-lactic Acid Research Articles

Eco-friendly zinc-metal-organic framework as a nucleating agent for poly (lactic acid)

Eco-friendly poly(L-lactic acid) (PLA) can be made more versatile, and its crystallization rate is accelerated by adding Zinc-based metal-organic framework (Zn-MOF) particles. Using differential scanning calorimetry (DSC), the non-isothermal melt crystallization behavior of biodegradable PLA nucleated by 0.3 to 3 wt% of Zn-MOF was examined. The non-isothermal melt crystallization kinetics parameters were determined using a modified Avrami model and Mo approach. Zn-MOF dramatically accelerated the crystallization process, as evidenced by several non-isothermal crystallization metrics, including the crystallization half-time and crystallization rate constant. The melt crystallization temperatures of the PLA-Zn-MOF composites, with contents of 0.7 and 1 wt%, were increased by 21 °C compared to the neat PLA. Using the Friedman isoconversional kinetic method, the neat PLA and PLA-Zn-MOF composites' effective activation energy values, ∆E, were determined. The ∆E values of PLA-Zn-MOF from 0.3 to 1 wt% Zn-MOF composites were lower than that of neat PLA. Moreover, polarized optical microscopy revealed the formation of numerous small-sized PLA spherulites upon Zn-MOF addition. The results indicate that the Zn-MOF (at concentrations of 0.7 to 1.0 wt%) can be used as an efficient nucleating agent for PLA, where it increases the melt crystallization temperature, nucleation density, and crystallinity without changing the crystalline structure, while also significantly reduces the effective activation energy and the size of spherulites. Additionally, scanning electron microscopy confirms good dispersion of Zn-MOF (0.3 to 1 wt%) within the PLA matrix.

Synthesis of cerium-based flame retardant containing phosphorus and its impact on the flammability of polylactic acid

The synthesis and characterization of [Ce2(PPPA)4(OH)2]·4H2O, wherein PPPA denotes 3-(hydroxy(phenyl)phosphoryl)propanoate, were conducted. Its potential as a flame-retardant additive for poly(L-lactic acid) (PLA) in conjunction with ammonium polyphosphate (APP) was investigated. Remarkably, with just incorporation of the 1 % Ce-complex and 4 % APP, the resulting PLA composite (PLA-8) meets the V-0 standard, exhibiting an impressive limiting oxygen index (LOI) of 29.4 %. Moreover, the introduction of the Ce-complex leads to a significant extension of ignition time (TTI), a significant 24.1 % decrease in total heat release (THR) compared to pure PLA, and a notable increase in residual carbon rate from 0.3 % to 3.51 %. Although PLA-8 exhibits a minor decline of 8.7 % in tensile strength and 3.4 % in elongation at break, respectively, compared to pure PLA, there is a substantial improvement of 32.2 % in Young's modulus and 29.9 % in impact resistance. These results emphasise the potential of cerium-based phosphorus-containing flame retardants, with cerium playing a key role in enhancing the flammability characteristics of PLA. This study contributes to the development of sustainable and fire-resistant materials in polymer chemistry.

Competition between biodetoxification fungus and lactic acid bacterium in the biorefinery processing chain for production of cellulosic L-lactic acid

Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars. However, one barrier for practical application is the sustained cell viability in the consequent fermentation step to compete the fermentable sugars with fermenting strains, resulting in sugar loss and reduced target product yield. This study investigated the competitive growth property between the biodetoxification fungus Paecilomyces variotii FN89 and the L-lactic acid bacterium Pediococcus acidilactici ZY271 under varying temperature and lactic acid osmatic stress. The results show that the L-lactic acid bacterium Ped. acidilactici ZY271 showed less thermotolerance to Pae. variotii FN89 at high temperature of 45 °C to 50 °C in both synthetic medium and wheat straw hydrolysate. In the higher temperature environment, the growth of the biodetoxification strian failed to compete with the lactic acid fermentation strain and was quickly eliminated from the fermentation system. The high temperature fermentation facilitated a fast transition from the detoxification stage to the fermentation stage for higher production of L-lactic acid.

Enhancing tendon-bone integration and healing with advanced multi-layer nanofiber-reinforced 3D scaffolds for acellular tendon complexes

Advancements in tissue engineering are crucial for successfully healing tendon-bone connections, especially in situations like anterior cruciate ligament (ACL) restoration. This study presents a new and innovative three-dimensional scaffold, reinforced with nanofibers, that is specifically intended for acellular tendon complexes. The scaffold consists of a distinct layered arrangement comprising an acellular tendon core, a middle layer of polyurethane/type I collagen (PU/Col I) yarn, and an outside layer of poly (L-lactic acid)/bioactive glass (PLLA/BG) nanofiber membrane. Every layer is designed to fulfill specific yet harmonious purposes. The acellular tendon core is a solid structural base and a favorable environment for tendon cell functions, resulting in considerable tensile strength. The central PU/Col I yarn layer is vital in promoting the tendinogenic differentiation of stem cells derived from tendons and increasing the expression of critical tendinogenic factors. The external PLLA/BG nanofiber membrane fosters the process of bone marrow mesenchymal stem cells differentiating into bone cells and enhances the expression of markers associated with bone formation. Our scaffold's biocompatibility and multi-functional design were confirmed through extensive in vivo evaluations, such as histological staining and biomechanical analyses. These assessments combined showed notable enhancements in ACL repair and healing. This study emphasizes the promise of multi-layered nanofiber scaffolds in orthopedic tissue engineering and also introduces new possibilities for the creation of improved materials for regenerating the tendon-bone interface.

Rejuvenation of the dorsal hand by injectable poly-D, L-lactic acid: A pilot study.

Rejuvenation of the dorsal hand by injectable poly-D, L-lactic acid: A pilot study.

Effective improvement methods for striae distensae: A novel approach utilizing laser-induced micro-jet injectors with poly-d,l-lactic acid.

Striae distensae (SD), or stretch marks, result from rapid stretching of the skin due to various factors. Conventional treatments often yield unsatisfactory results, leading to the exploration of alternative methods. Laser-induced microjet technology offers a promising approach for drug delivery to target areas. This study investigates the efficacy of using a microjet injector with poly-d,l-lactic acid for treating SD. Four female participants with SD were treated with poly-d,l-lactic acid solution using a microjet injector over five sessions. Patients were assessed based on severity scales before and after treatment. Topical anesthetics were applied to minimize discomfort. Injection techniques were optimized to reduce side effects such as bleeding and pain. All patients showed significant improvement in SD appearance after 5-7 treatments. Assessment scales indicated positive outcomes both immediately after treatment and at the 32-week follow-up. Minimal side effects, primarily petechiae, were observed. Laser-induced microjet technology offers several advantages, including rapid drug delivery and mechanotransduction effects, promoting skin regeneration. Poly-d,l-lactic acid injections demonstrated effectiveness in treating SD, particularly when delivered via microjet injectors. Patients expressed high satisfaction due to the procedure's minimal invasiveness and quick recovery. Utilizing a needleless microjet injector with poly-d,l-lactic acid shows promise as a treatment for SD, typically requiring 5-7 sessions for optimal results. Mild petechiae may occur as a common side effect. This approach offers an effective and minimally invasive alternative for addressing this common cosmetic concern.

Microfluidic Assembly of Degradable, Stereocomplexed Hydrogel Microparticles.

Hydrogel microparticles (HMPs) have been investigated widely for their use in tissue engineering and drug delivery applications. However, translation of these highly tunable systems has been hindered by covalent cross-linking methods within microparticles. Stereocomplexation, a stereospecific form of physical cross-linking, provides a robust yet degradable alternative for creating translationally relevant HMPs. Herein, 4-arm polyethylene glycol (PEG) stars were used as macromolecular initiators from which oligomeric poly(l-lactic acid) (PLLA) was polymerized with a degree of polymerization (DPn) of 20 on each arm. Similarly, complementary propargyl-containing ABA cross-linkers with enantiomeric poly(d-lactic acid) (PDLA) segments (DPn = 20) on each arm. Droplets of these gel precursors were formed via a microfluidic organic-in-oil-in-water system where microparticles self-assembled via stereocomplexation and were stabilized after precipitation in deionized water. By varying the flow rate of the dispersed phase, well-defined microparticles with diameters of 33.7 ± 0.5, 62.4 ± 0.6, and 105.7 ± 0.8 μm were fabricated. Gelation due to stereocomplexation was confirmed via wide-angle X-ray scattering in which HMPs exhibited the signature diffraction pattern of stereocomplexed PLA at 2θ = 12.2, 21.2, 24.2°. Differential scanning calorimetry also confirmed stereocomplexation by the appearance of a crystallization exotherm (Tc = 37 °C) and a high-temperature endotherm (Tm = 159 °C) that does not appear in the homocrystallization of PLLA or the hydrogel precursors. Additionally, the propargyl handle present on the cross-linker allows for pre- or post-assembly thiol-yne "click" functionalization as demonstrated by the addition of thiol-containing fluorophores to the HMPs.

Spatiotemporal modulation of immune microenvironment via composite hydrogel brakes for diabetic wound healing

Uncontrolled programmed polarization of macrophages plays an important role in chronic diabetic wound healing. Therefore, correcting programmed macrophage polarization while inducing new tissue remodelling through materials and preventing scar formation is desirable. Herein, a composite hydrogel brake that enables spatiotemporal regulation of the immune microenvironment was constructed to promote skin tissue regeneration. The system was based on thiolated hyaluronic acid to reshape the programmed polarization of macrophages, methacrylate gelatin as a mechanical support, and poly (L-lactic acid) nanoparticles loaded with TGF-β receptor antagonists to inhibit scar formation. Notably, the composite hydrogel acts as a double brake: in the early stage, self-induced M2-type polarization is achieved with the help of thiols; the TNF and NLRP signalling pathways are downregulated; and the immune microenvironment is regulated. During tissue remodeling, the long-term biological effect of TGF-β secretion by M2-type macrophages is interrupted by the slow release of antagonists, which inhibits excessive collagen deposition and prevents scar formation. The dual effect of restraint on reprogramming macrophage polarization and inhibiting scar formation was further confirmed in a diabetic rat skin defect model. Therefore, based on the immunological mechanism, a composite hydrogel brake was specifically designed to regulate the immune microenvironment, induce new tissue remodelling, and provide a promising clinical strategy for treating chronic diabetic wounds.

Choline chloride-L-lactic acid mixtures as solvents for extraction of Coumarin from cinnamon-containing foods

The determination of coumarin in generally available cinnamon-containing foods such as biscuits, cereals is important to ensure that the populations consuming these foods more frequently are not exposed to higher levels and are not at risk. This study describes the development of an analytical method for determination of coumarin in foods containing cinnamon. Solid-liquid phase extraction with conventional stirring-assisted and ultrasound-assisted extraction (UAE) procedures were used to prepare sample extracts for liquid chromatography analysis. The green solvent, a mixture of choline chloride:L-lactic acid (1:4, mol/mol)/water (50:50 v/v), as a deep eutectic solvent-like mixture, was selected as an extraction solvent. The extraction conditions were optimized by using the design of the experiment strategy obtaining parameters, temperature 47 °C, time 36 min, solvent volume 4 mL, sample amount 0.8 g, stirring speed 20 rpm for rotary stirring-assisted extraction procedure, and temperature 30 °C, time 5 min, solvent volume 3.5 mL, sample amount 0.8 g for UAE. High-performance liquid chromatography separation with a total analysis time of 12 min was performed with a stationary phase of octadecyl type and a gradient of mobile phase of methanol-1 % acetic acid. The methods were successfully validated to show the detection limit of 0.13 μg.mL−1, the linearity range of 0.4–50 µg.mL−1 (R2 = 0.999), recovery values more than 80 %, and the RSDs of less than 7 %. Rotary stirring-assisted extraction showed moderately higher recovery values than UAE, while lower RSD % was observed for UAE.

The Nucleated Poly(L-lactic acid): The Role of a Phenylacetic Hydrazide Derivative

The melt-crystallization, cold-crystallization, melting behaviors, thermal stability, and optical properties of poly(L-lactic acid) (PLLA) nucleated by a phenylacetic hydrazide derivative (DAPH) were investigated. The melt-crystallization confirmed DAPH’s heterogeneous nucleation role in improving PLLA’s poor crystallization capability, concurrently DAPH loading, cooling rate and final melting temperature were three key factors affecting PLLA’s melt-crystallization behaviors. The results from cold-crystallization indicated that the addition of DAPH could accelerate PLLA’s cold-crystallization via cold-crystallization peak’s shift toward the lower temperature side as DAPH loading increased. Through analysis of PLLA/DAPH’s multiple melting behaviors after melt-crystallization, it was found that DAPH loading, the previous melt-crystallization and heating rate determined PLLA/DAPH’s melting processes after melt-crystallization; and PLLA/DAPH’s melting processes after isothermal crystallization depended on the previous crystallization temperature. A drop in thermal decomposition temperature for 5 wt.% mass loss suggested that pure PLLA has better thermal stability compared with PLLA/DAPH. Additionally, the introduction of DAPH could not improve PLLA’s transparency, in contrast, the haze of PLLA was increased greatly owing to the existence of DAPH.

Development of high barrier poly(l-actic acid)/chitosan/graphene oxide flexible films for meat packaging by layer-by-layer

An new high-barrier packaging films for meat preservation were obtained by depositing graphene oxide (GO) layer-by-layer (LbL) on poly(l-lactic acid)(PLLA)-poly (butylene itaconate) (PBI) copolymers (PLBI) with chitosan (CS) as bonding layer in this study. The 1H NMR results revealed that PLBI copolymer was successful synthesized. The introduction of PBI reduced the Tg and crystallization capacity of PLLA film, which made the copolymer films exhibit extremely high flexibility (up to 186.1% elongation at break). The film also exhibited high hydrophilicity, which was favorable for the effective attachment of CS. With CS as an intermediate layer, the FTIR and SEM results showed that the GO was evenly distributed onto the PLBI film surface due to the electrostatic interaction. The oxygen, water vapor and UV light barrier properties of PLBI/CS/(GO-CS)x films were improved and increased with the GO-CS layers. The PLBI/CS/(GO-CS)10 films, with extremely low oxygen permeability coefficients about 0.4 × 10−8 cm3 m/m2·h·Pa, delayed the increase in weight loss, hardness, pH, TVB-N, TBARS, and total viable counts of chilled meat during storage. It also decreased the discoloration, and loss of springness and cohesiveness of chilled meat caused by long-term refrigeration. The LbL films even showed better freshness-keeping effect than commercial PA/PE films due to its superior barrier and certain antibacterial properties, suggesting great potential application in fresh meat preservation.

Application of poly(L-lactic acid)-based films for equilibrium modified atmosphere packaging of “Kyoho” grapes and its favorable protection for anthocyanins

Grapes were packaged by different Poly (L-lactic acid)-based packaging films (PLTL-PLEL) and stored at 5 °C for 35 days to investigate the effects of equilibrium modified atmosphere packaging on the quality of “Kyoho” grapes during storage. Changes in physiochemical quality, antioxidant content and senescence of grapes were studied. Furthermore, UPLC-Q-TOF-MS/MS was used to observe and identify key factors influencing the variation of grape anthocyanins under different atmosphere conditions. Alterations in gas components and enzyme activities significantly impacted anthocyanin levels, highlighting oxygen concentration as the primary influence on total anthocyanin levels. The PLTL-PLEL50 packaging resulted in an approximate 5.7% lower weight loss and increased soluble solids by approximately 14.4%, vitamin C, total phenols and flavonoids reaching 60.2 mg/100 g, 8.4 mg/100 g and 7.2 mg/100 g, respectively. This packaging also preserved higher anthocyanin levels, with malvidin-3-glucoside and peonidin-3-glucoside at 0.55 μg/mL and 1.62 μg/mL, respectively, on the 35th day of storage.

Strength and toughness of semicrystalline polymer fibers: Influence of molecular chain entanglement

The mechanical properties of oriented semicrystalline polymers fibers are mainly determined by the semicrystalline morphology in which lamellar crystals and disordered amorphous layers are in staggered arrangement. As a stress transmission channel, amorphous entanglement network can affect the strength and toughness of fiber together with crystalline phase. In this study, the relationship between mechanical properties and amorphous entanglement of oriented poly (l-lactic acid) fibers was clarified by studying the cyclic loading characteristics. Based on the Haward-Thakray model of semi-crystalline polymers, the energy contributions of the crystalline phase and the amorphous phase are separated. During the deformation of oriented fiber, the crystal will be broken under the action of tight entanglement network, and the entanglement network can transfer stress well without failure under the action of straight chain. Therefore, although the crystalline phase and the amorphous phase jointly bear the strength, the toughness and fracture behavior mainly affected by the entangled network of the amorphous phase.

Robust Superhydrophobic Films Based on an Eco-Friendly Poly(l-lactic acid)/Cellulose Composite with Controllable Water Adhesion.

Poly(l-lactic acid) (PLLA) featuring desirable biodegradability and biocompatibility has been recognized as one of the promising eco-friendly biomaterials. However, low crystallization and poor mechanical and chemical performances dramatically hamper its practical application. In this work, we report that functionalized cellulose/PLLA composite superhydrophobic stereocomplex films with controllable water adhesion and protein adsorption can be fabricated by a facile approach for the first time. First, cellulose is surface-modified by means of two silanization modification methods. Then, superhydrophobic cellulose/PLLA composite films are prepared through a solvent-evaporation-induced phase separation method. The two cellulose/PLLA composite films exhibit extreme water repellency but tunable water adhesion from sticky to slippery. The protein adsorption capacity of the cellulose/PLLA composite films can also be regulated. In addition, the stereocomplexation of the composite film provides excellent mechanical properties with an elongation at break of 22.36%, which is 237.8% higher than that of a pure PLLA film, which is more suitable for biomaterials. Furthermore, good biodegradability of the PLLA composite films in nature enables the bio-based composites as alternative materials to replace conventional petroleum-based polymers. The superhydrophobic films have also been demonstrated for many applications, including slippery surfaces, liquid transportation without loss, and antifouling.

Amino acids-based deep eutectic solvents as additives for improved enantioseparation in capillary electrophoresis.

In this study, several amino acids deep eutectic solvents were prepared using L-valine and L-leucine as hydrogen bond acceptors, and L-lactic acid and glycerol as hydrogen bond donors. These amino acids' deep eutectic solvents were first used as buffer additives to construct several synergistic systems along with maltodextrin in capillary electrophoresis for the enantioseparations of four racemic drugs. Compared with single maltodextrin system, the separations of model drugs in the synergistic systems were significantly improved. Some key parameters affecting chiral separation such as maltodextrin concentration, deep eutectic solvent concentration, buffer pH, and applied voltage were optimized. In order to further understand the specific mechanism of the amino acids deep eutectic solvents in improving chiral separation, we first calculated the binding constants of maltodextrin with enantiomers using the capillary electrophoresis method in the two separation modes, respectively. We also used molecular simulation to calculate the binding free energy of maltodextrin with enantiomers. It is the first time that amino acids deep eutectic solvents were used for enantioseparation in capillary electrophoresis, which will greatly promote the development of deep eutectic solvents in the field of chiral separation.

PLLA scaffolds functionalized with ketoprofen via rotary jet spinning for biomedical applications

Biopolymer-based biomaterials, such as poly (l-lactic acid) (PLLA), have long been recognized as scaffolds for drug delivery applications due to their advantages, including biodegradability and biocompatibility. Ketoprofen (KET) is a non-steroidal anti-inflammatory drug known for its analgesic properties. Despite its potential, more research is needed on the effective production of scaffolds functionalized with KET for biomedical applications. This study, therefore, aimed to develop PLLA-based carriers to transport KET obtained using Rotary Jet Spinning (RJS) and evaluate the influence of KET at different concentrations. RJS allowed PLLA-KET scaffold production with high productivity and uniform fiber morphology. KET particles dispersed in the PLLA fibers were observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the presence of KET in the PLLA and that the crystalline structure of PLLA remained unchanged with the incorporation of KET, ensuring the material's structural integrity. Likewise, the thermogravimetric analysis showed the presence of KET affected the thermal stability of PLLA. Cell viability and confocal microscopy with preosteoblast cells demonstrated that PLLA-KET fibers maintained cell viability over time, indicating their compatibility with cell cultures, and revealed cell adhesion and distribution in the fibers varied with KET concentration. These results have significant implications, highlighting the potential use of PLLA-KET carriers in practical biomedical applications, such as drug delivery systems, bone implant devices, and dental applications, thereby advancing the field of biomaterials.

Identification of the Microbiota in Coconut Water, Kefir, Coconut Water Kefir and Coconut Water Kefir-Fermented Sourdough Using Culture-Dependent Techniques and Illumina-MiSeq Sequencing.

The principal objective of this study was to isolate and identify the microorganisms present in commercial kefir grains, a novel kefir-fermented coconut water (CWK) and a novel coconut water kefir-fermented sourdough using phenotypic identification and Sanger sequencing and examine the microbial diversity of CWK and CWK-fermented sourdough throughout the fermentation process using the MiSeq Illumina sequencing method. The phenotypic characterisation based on morphology identified ten isolates of LAB, five AAB and seven yeasts from kefir (K), CWK and CWK-fermented sourdough (CWKS). The results confirm the presence of the LAB species Limosilactobacillus fermentum, Lactobacillus. plantarum, L. fusant, L. reuteri and L. kunkeei; the AAB species Acetobacter aceti, A. lovaniensis and A. pasteurianus; and the yeast species Candida kefyr, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, C. guilliermondii and C. colliculosa. To the best of our knowledge, the identification of Rhodotorula from kefir is being reported for the first time. This study provides important insights into the relative abundances of the microorganisms in CWKS. A decrease in pH and an increase in the titratable acidity for CWK- and CWK-fermented sourdough corresponded to the increase in D- and L-lactic acid production after 96 h of fermentation. Significant reductions in the pHs of CWK and CWKS were observed between 48 and 96 h of fermentation, indicating that the kefir microorganisms were able to sustain highly acidic environments. There was also increased production of L-lactic acid with fermentation, which was almost twice that of D-lactic acid in CWK.

Argon nonthermal plasma etching of poly(L-lactic acid) films: Tunning the local surface degradation and hydrolytic degradation rate

Plasma technology is widely used in the industry for the surface modification of polymeric materials, improving the adhesion of paints in polymeric packaging and cellular adhesion on polymers' surfaces without using hazardous chemicals. Plasma etching is a fast way to modify polymers, creating new nanostructure surfaces and adding chemical groups for new applications like antimicrobial surfaces. Poly(L-lactic acid) (PLLA) is a biodegradable polymer with exciting properties for biomedical, tissue engineering, food packaging, and other applications. In many cases, these products must undergo plasma surface treatments to meet the technical requirements of their function. Herein, we evaluated the effects of surface modification of PLLA using Argon nonthermal plasma etching. The results from Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Excited Photoelectron Spectroscopy (XPS), and Matrix-assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-ToF-MS) show that increasing the plasma exposure time causes an enhancement in bulk and local surface degradation, crystallization kinetics and susceptibility to hydrolytic degradation for PLLA. Atomic Force Microscopy (AFM) show that the PLLA films present the highest surface roughness after 60 s of plasma etching times. Our findings suggest that plasma etching can be a suitable tool to adjust the polymer degradation rate to design intracorporeal devices with controlled degradation kinetics.

The impact of plasticisers on crystal nucleation, growth and melting in linear polymers

Plasticisers are often added to crystallising polymers to improve their processability. Despite many experimental studies, very few modelling studies have been performed to provide fundamental understanding of the impact of plasticisers on polymer cyrstallisation kinetics and thermodynamics. In this work, molecular dynamics simulations are used to study crystallisation in a model linear polymer with plasticiser. We first demonstrate that the plasticiser lowers the amorphous phase glass transition, with the extent of the effect increasing with plasticiser concentration, due to increased polymer mobility. Using a model filler surface to induce crystallisation, we find that the plasticiser also reduces crystallisation and melting temperatures. Furthermore, we find that the plasticiser is expelled from the crystals during growth so that its concentration in the amorphous matrix increases with degree of crystallisation. This has a pronounced consequence for crystal melting, and we find a broad temperature range where the crystal is in equilibrium with the amorphous phase, which we rationalise in terms of free energy changes. This has potentially important consequences for the processing of linear polymers such as polyhydroxybutyrate (PHB), poly(l-lactic acid) (PLLA) and polyvinyl alcohol (PVA), by providing the opportunity for processing the polymer in a semicrystalline rather than fully amorphous state.

High performance poly(L-lactic acid)-based film by one-step synthesis of poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) for efficient preservation of yogurt storage

Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 °C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.