Search Results (194)

Lignin is a promising bio-based filler for poly(butylene adipate-co-terephthalate) (PBAT), yet its true contribution to biodegradation remains unclear—most studies rely on weight loss alone, neglecting CO₂ mineralization and lignin’s antibacterial activity. Here, lignin/PBAT composites with 1 wt% (LP-1) and 3 wt% (LP-2) lignin are assessed under composting conditions using both weight loss and mineralization rate. Lignin exhibits a dual role: it promotes hydrolytic weight loss (18.3% and 28.6% for LP-1 and LP-2 at 40 days), but significantly inhibits ultimate mineralization (one-year mineralization: 65.71% for pure PBAT vs. 48.74% and 29.53% for LP-1 and LP-2). A negative initial mineralization rate suggests transient antibacterial activity from released phenolic compounds. Lignin increases crystallization temperature (48.4 → 92.6 °C) and T_g (−28.5 → 49.1 °C), with 1% loading largely preserving mechanical properties. These findings demonstrate that weight loss alone is insufficient to assess degradation; mineralization must be included. Appropriate lignin loading enables balanced performance and degradation controllability, offering new insights into lifecycle assessment of green composites. Full article

Polylactic acid (PLA) is one of the most promising bio-based and biodegradable polymers, yet its inherent brittleness limits its application in flexible film products. This study compares three mixing strategies, applied as four sample series, to improve the mechanical performance of PLA-based binary blends: (1) single-pass melt blending with poly(butylene adipate-co-terephthalate) (PBAT) or poly(butylene succinate) (PBS) at 10, 20, and 30 wt%; (2) addition of poly(ethylene glycol) (PEG 4000 or PEG 20000) as a plasticizer/compatibilizer at 1, 3, and 5 wt%; (3) double melt processing of PLA/PBAT and PLA/PBS blends. Thin films were characterised by tensile testing, differential scanning calorimetry (DSC), FTIR, SEM and contact angle measurements. Double processing emerged as the most effective approach, yielding elongation at break values up to approximately 137% for 70PLA/30PBAT blends, compared to 16.9% for the equivalent single-processed samples. Relative to the single-processed controls, double processing raised elongation at break by approximately 712% for 70PLA/30PBAT and 1201% for 70PLA/30PBS, and by 98% (80PLA/20PBAT), 175% (80PLA/20PBS) and 278% (90PLA/10PBAT); the latter three increases were statistically significant (p < 0.05). By contrast, PEG addition changed maximum stress by at most about 18% and never raised elongation at maximum stress above 6%. Two-way ANOVA confirmed that blend ratio was a significant factor for maximum stress (p < 0.001) whereas PEG molecular weight was not (p > 0.10). PEG addition produced moderate improvements in tensile stress, but did not replicate the ductility enhancement observed after reprocessing. DSC data confirmed a decrease in the glass transition temperature (Tg) and altered crystallisation behaviour in double-processed samples, consistent with improved interfacial compatibility. Contact angle results showed broadly similar surface wettability across all series, pointing to processing history, rather than surface chemistry, as the key variable governing final mechanical behaviour in these blends. Full article

The extensive use of common petroleum-based plastics in food packaging has raised serious environmental concerns, accelerating the search for biodegradable and functional alternatives. In this study, poly(butylene adipate-co-terephthalate)/curcumin (PBAT/Cur) bioactive composite films with colorimetric sensing properties were successfully prepared via solution casting. A systematic characterization was conducted on the structural, morphological, barrier, antioxidant, antibacterial, and colorimetric properties of the films. The optimal PBAT/Cur1% films exhibited potent antioxidant activity (DPPH scavenging up to 95.6%) and moderate antibacterial activity against E. coli and S. aureus. Additionally, curcumin incorporation not only increased the water contact angle of the PBAT/Cur1% films, indicating enhanced surface hydrophobicity, but also concurrently improved the barrier properties, as evidenced by a reduced water vapor permeability (WVP of 14.58 g·mm/m²·day·kPa) and a lower oxygen transmission rate (OTR of 7.533 × 10⁻³ cm³/m²·day·Pa) compared to the neat PBAT films. Notably, the films displayed a distinct and rapid color change from yellow to reddish-brown upon exposure to ammonia vapor, suggesting their promise for on-package visual freshness indication. These findings highlight PBAT/Cur composite films as a sustainable option for active and intelligent food packaging, with combined antioxidant, antibacterial, and colorimetric properties, making them promising for packaging protein-rich foods (e.g., meat and seafood). Full article

In this study, quaternary ammonium salts (QAS) with different alkyl chain lengths (C12 and C18) were incorporated into starch/poly(butylene adipate-co-terephthalate) (PBAT) matrices with ethylenediaminetetraacetic acid (EDTA) to prepare blown films. The film with the combination of QAS and EDTA (D18D12E) achieved antibacterial rates of ≥99% against both Staphylococcus aureus and Escherichia coli, while maintaining cytocompatibility with HepG2 cells (viability ≥ 70%) and preliminary tobacco-growth compatibility. Compared with the control, the D18D12E film showed lower tensile strength (7.60 MPa) and higher oxygen (22.42 × 10⁻¹³ cm³·cm·cm⁻²·s⁻¹·Pa⁻¹) and carbon dioxide permeability coefficients (22.10 × 10⁻¹³ cm³·cm·cm⁻²·s⁻¹·Pa⁻¹). Its elongation at break (805.80%) and water vapor permeability (4.03 × 10⁻¹¹ g·m·m⁻²·s⁻¹·Pa⁻¹) remained statistically comparable to those of the control. Furthermore, the D18D12E films delayed the visible deterioration of Chinese steamed bread and strawberries during 4 and 8 days of storage, respectively. These findings show that EDTA-assisted reduction in QAS loading can maintain antibacterial activity, but the associated mechanical and gas-barrier trade-offs require further formulation optimization. Full article

This study investigated the effects of fully biodegradable poly(butylene adipate-co-terephthalate) (PBAT) mulch films with different thicknesses on soil hydrothermal conditions, soil fertility indicators, soil enzyme activities, and peanut growth and yield in a three-year field experiment. Three PBAT thicknesses (0.006, 0.008, and 0.010 mm) were compared with 0.010 mm polyethylene (PE) mulch and a bare soil control (CK). The effects of PBAT mulch films with different thicknesses on peanut yield, agronomic traits, photosynthetic characteristics, soil fertility indicators, and soil enzyme activities were systematically evaluated. PBAT008 showed the most favorable overall balance among the tested treatments. Compared with PE, PBAT008 significantly increased pod yield by 6.87–13.69% and 100-pod weight by 10.36–18.94%, whereas PE tended to reduce pod yield by 5.55–5.95% relative to CK. PBAT008 also promoted biomass accumulation and increased photosynthetic pigment content. Although PE showed the strongest water-retention capacity, PBAT008 maintained moderate soil moisture and suitable soil temperatures during pod formation. PBAT treatments improved soil organic matter, dissolved organic carbon, available phosphorus, and soil enzyme activities more effectively than PE. Path analysis identified available phosphorus, stem weight, and soil temperature as the strongest positive drivers of pod yield. Overall, PBAT008 enhanced peanut yield by achieving a coordinated improvement in soil hydrothermal conditions, soil fertility, and crop physiological performance, suggesting that an appropriate PBAT mulch thickness may provide an agronomically viable biodegradable alternative to PE mulch in peanut production. Full article

The development of fully biodegradable poly(3-hydroxybutyrate) (PHB)-based materials with improved mechanical performance remains a major challenge due to the limited ductility and processability of this highly crystalline polymer. Blending and plasticisation are viable strategies to enhance PHB toughness; however, the interactions governing polymer–plasticiser compatibility and their impact on structure–property relationships remain not fully understood. In this work, the compatibility and plasticisation mechanisms of two citrate-based plasticisers, tributyl citrate (TBC) and acetyl tributyl citrate (ATBC), were systematically investigated in biodegradable blends based on PHB, polylactic acid (PLA), and poly(butylene adipate-co-terephthalate) (PBAT). Polymer–plasticiser affinity was evaluated through Hansen Solubility Parameters and interaction radius, which indicated good compatibility of PHB with both plasticisers and a stronger affinity for ATBC. Differential scanning calorimetry showed that citrate plasticisers reduced the glass transition temperature, modified crystallisation kinetics, and altered the crystalline morphology of the blends. Dynamic mechanical analysis confirmed the reduction in the glass transition temperature of PHB–PLA systems, which is in agreement with the DSC results. Migration experiments showed equilibrium after approximately 72 h, with PHB–PLA blends exhibiting better plasticiser retention than PHB–PBAT systems. TBC consistently showed higher migration than ATBC, in line with its lower molecular weight and higher volatility. Mechanical testing demonstrated that plasticisation efficiency strongly depended on blend composition: TBC was more effective in enhancing ductility in PHB–PLA blends, whereas ATBC performed better in PHB–PBAT systems. It was also highlighted that the plasticisers had a remarkable ability to substantially increase the ductility of the blends compared with their unplasticised counterparts, as reflected by the pronounced decrease in stiffness and the marked increase in elongation at break. SEM analysis of tensile fracture surfaces evidenced a brittle failure mode for PHB–PLA blends, whereas PHB–PBAT systems exhibited a ductile fracture mode with fibrillar features and clear signs of phase separation. Finally, thermogravimetric analysis showed no appreciable thermal degradation within the processing temperature window used for mixing and hot pressing, confirming the thermal stability of the materials under the selected conditions. These findings establish clear correlations between thermodynamic compatibility, migration behaviour, thermal properties, fracture mechanisms, and mechanical performance, providing useful guidelines for the design of citrate-plasticised PHB-based biodegradable materials. Full article

Microplastics (MPs) and pesticides increasingly co-occur in agricultural ecosystems, where they may jointly affect plant physiology and plant–microorganism interactions. This study investigated the individual and combined effects of biodegradable poly(butylene adipate-co-terephthalate) (PBAT), the herbicide metolachlor (MET), and the beneficial fungus Trichoderma harzianum KKP 534 on wheat (Triticum aestivum). Plant growth, physiological responses, chlorophyll content, cell membrane damage, antioxidant enzyme activities and selected metabolomic and lipidomic biomarkers were evaluated. High PBAT concentrations negatively affected wheat growth by reducing root and shoot length and increasing oxidative stress, as evidenced by elevated TBARS levels, increased antioxidant enzyme activities (POD, GST, CAT, and SOD), and enhanced membrane damage. Metabolomic and lipidomic analyses further revealed stress-associated changes in amino acid metabolism and membrane lipid remodelling. PBAT also adsorbed MET and 2,4-di-tert-butylphenol (DTBP), potentially altering their bioavailability and environmental behaviour. Although T. harzianum KKP 534 promoted plant growth and enhanced antioxidant responses under control conditions, these beneficial effects were attenuated in the presence of PBAT MP. The results suggest that biodegradable microplastics may influence plant–microbe interactions and modify pesticide dynamics under controlled conditions, highlighting the need for further studies in soil-based systems. Full article

Acute or chronic rotator cuff tears are major causes of shoulder dysfunction, motivating the development of scaffolds with tailored thickness and mechanics for supraspinatus tendon regeneration. This study aimed to investigate the effect of bilayer poly(butylene adipate-co-terephthalate) (PBAT) scaffold thickness on the tenogenic differentiation of rat adipose mesenchymal stem cells (r-AdMSCs) and supraspinatus tendon regeneration. Aligned fibers with a diameter of approximately 476 nm were deposited onto randomly oriented layers at different times (4 h; 4S, 6 h; 6S, 8 h; 8S), and scaffolds with increasing thicknesses from 441 µm (4S) to 1132 µm (8S) were produced. Mechanical testing showed comparable tensile strength for 4S and 6S (≈1.9–2.0 MPa) and modulus (5.5–7.3 MPa), while 8S exhibited markedly reduced stiffness (0.5 MPa) and hyper elastic deformation. Mechanical performance across degradation conditions remained strongly thickness-dependent: thinner scaffolds retained integrity and strengthened, with modulus increases during hydrolytic and enzymatic degradation, whereas thicker matrices showed limited remodeling and instability. Rat-AdMSCs’ were cultured on the scaffolds for 21 days. Cell-free and cell-laden mechanical responses further reflected thickness effects: cell-free samples stiffened due to media-induced passive matrix tightening, whereas cell-laden scaffolds showed extracellular matrix (ECM)-driven reinforcement, most prominently in 4S, which reached 2.1 MPa tensile strength with improved elasticity and balanced deformation. The 4S scaffold exhibited the highest tensile strength and significantly increased collagen-1 (col1), tenomodulin (tnmd) and scleraxis (scx) expression compared with the other groups. In conclusion, among all groups, 4S scaffolds demonstrated the most favorable mechanical and biological performance, suggesting that scaffold thickness plays a critical role in regulating tendon regeneration and will become even more suitable when matured in bioreactors. Full article

Biopolymers (BPs), obtained from urban and agricultural wastes, are known as active principles to manufacture ready-for-use finished products in several sectors of the agriculture and chemical industries. These findings prospect a biowaste-based refinery producing chemical specialities to replace products derived from fossil feedstock. The present paper reports new materials containing BPs. Composite granules containing Poly(Butylene Adipate-Co-Terephthalate (PBAT) as a matrix and BPs as fillers are manufactured by twin-screw extrusion. The granules are used to make single-layer PBAT-BP mulch films by single-screw extrusion and three-layer Starch-PBAT-BP films by blown co-extrusion. The films are tested for mechanical properties, and for structural stability and effects in the in vitro cress germination and the in-field horticulture. The results show that both the films’ effects on plant performance and the films’ structural degradation are regulated by the BP and polymeric matrix release kinetics in the operational germination medium or the field soil, and in turn, that the kinetics depend on the mulch film structural features. The horticulture trials prove that the three-layer mulch films have adequate mechanical strength (25 MPa maximum tensile strength and 520% elongation at break) and about 6 months lifespan to maintain and/or improve the soil protection and crop production (17 t/ha) over the plant seasonal cycle. These findings widen the range of renewable chemical specialities potentially producible by the envisioned biowaste-based refinery. Full article

Multilayer packaging—engineered by integrating complementary materials such as plastics, paper, and aluminum—has become a cornerstone technology for enhancing shelf life, minimizing spoilage, and reinforcing the mechanical integrity of packaging formats including films, pouches, and bottles. In this study, a laminate was developed by thermally bonding polylactic acid (PLA) with a poly(butylene adipate-co-terephthalate) (PBAT)/thermoplastic starch (TPS) matrix embedded with silver nanoparticles (Ag-NPs) at 0–3 wt.%. The resulting structures were systematically evaluated for their barrier performance, physicochemical characteristics, and antimicrobial functionality. Fourier-transform infrared (FTIR) spectroscopy confirmed the absence of chemical interactions between Ag-NPs and the polymer matrix, indicating physical dispersion rather than chemical bonding. However, at higher loading (3 wt.%), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) revealed notable nanoparticle aggregation. Functionally, the multilayer films demonstrated markedly improved water vapor barrier properties compared to single-layer PBAT/TPS films. Migration studies showed that silver release increased with nanoparticle concentration and was significantly enhanced under acidic conditions relative to distilled water. Importantly, Ag-NP-incorporated laminates exhibited pronounced antibacterial activity against Staphylococcus aureus. Collectively, these findings highlight the potential of Ag-NP-enriched, starch-based multilayer laminates as next-generation active packaging systems that combine with effective microbial control. Full article

The growing demand for sustainable food packaging has intensified interest in biodegradable materials that can reduce environmental impact while preserving food quality. Among these materials, biodegradable polyester–starch composite films functionalized with phenolic compounds have gained attention as promising active packaging systems. They combine the melt processability and structural stability of polyesters, such as poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate) (PBS), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with the renewability and biodegradability of starch and the antioxidant, antimicrobial, and UV-protective functions of phenolics, such as ferulic acid, quercetin, tea polyphenols, and anthocyanins. This review discusses recent advances in the selection of biodegradable polyesters, starch and thermoplastic starch blending, phenolic incorporation strategies, and their effects on compatibility, morphology, mechanical strength, barrier properties, optical behavior, release, and active packaging functionality. The characteristics and functionality of these films are governed not only by the individual components but also by phase morphology, interfacial interactions, phenolic location, processing conditions, and release control. Key challenges include polyester–starch incompatibility, TPS moisture sensitivity, phenolic stability during melt processing, migration safety, controlled release, and industrial scale-up. Collectively, biodegradable polyester–starch films functionalized with phenolic compounds represent a promising route for developing next-generation sustainable active packaging and may contribute to circular economy approaches. Full article

Improving the interfacial compatibility between cellulose and poly(butylene adipate-co-terephthalate) (PBAT) is critical for enhancing the performance of PBAT-based composites. Here, microcrystalline cellulose (MCC) was homogeneously silanized at the molecular chain level using t-hexyldimethylchlorosilane (TDMS-Cl) as the modifier, yielding t-hexyldimethylsilylated cellulose (TDMS-Cell). TDMS-Cell/PBAT composite films were then prepared by solution blending and casting in tetrahydrofuran (THF). Structural characterizations confirmed the successful grafting of TDMS-Cl onto cellulose chains, resulting in TDMS-Cell with a degree of substitution of approximately 2. Microstructural observations combined with thermal analysis revealed that TDMS-Cell exerted a dual effect on the crystallization behavior of PBAT: it acted as a heterogeneous nucleating agent that increased the crystallization temperature, while the pronounced steric hindrance simultaneously suppressed crystal growth. Mechanical testing showed that simultaneous strengthening and toughening were achieved at an optimal TDMS-Cell loading of 3–5 wt%. Specifically, the tensile strength increased from ~16 MPa for neat PBAT to 21 MPa (31.25% improvement), and the elongation at break increased from ~700% to 964% (37.7% improvement). In addition, the incorporation of an appropriate amount of TDMS-Cell effectively enhanced the surface hydrophobicity of the composite films. At higher filler loading, however, solvent evaporation-induced phase separation led to self-aggregation of TDMS-Cell, which in turn deteriorated both the mechanical properties and surface hydrophobicity of the composites. Overall, this work systematically elucidates the structure–property relationships of silanized cellulose/PBAT composites in a homogeneous solution system, providing a rational basis for interfacial design and property optimization of PBAT/biomass-based composite materials. The prepared TDMS-Cell/PBAT composite films with balanced mechanical strength, tunable crystallization behavior, and improved surface hydrophobicity exhibit great potential for practical applications in high-performance flexible packaging materials, functional film substrates, lightweight composite structural components, and tunable hydrophobicity coating substrates. Full article

Plastic pollution from packaging waste is driving the development of biodegradable composites for sustainable packaging. In this work, poly(butylene adipate-co-terephthalate)/poly(3-hydroxybutyrate) (PBAT/PHBH) blends (50/50 wt.%) were reinforced with agro-industrial waste fillers—spent coffee grounds (SCG), brewer’s spent grain (BSG), and cellulose powder (CP)—at 1–15 wt.% loading. The effects of these fillers on tensile properties, impact strength, and thermal stability were examined and supported by scanning electron microscopy (SEM) of fracture surfaces and thermogravimetric analysis (TGA). The neat PBAT/PHBH blend exhibited balanced stiffness and ductility. Low BSG loadings (≤5 wt.%) produced the greatest toughening, with impact strength increasing by ~92% and elongation at break significantly improving over the neat blend. SEM analysis indicated crack deflection and particle pull-out as dominant energy-dissipation mechanisms at low BSG loading. At higher BSG loading (15 wt.%), particle clustering and larger voids acted as stress concentrators, reducing impact performance. SCG improved ductility at low loading (1 wt.%), whereas increasing SCG content led to progressive reductions in tensile strength and elongation due to increased debonding and microvoid formation. In contrast, CP exhibited minimal reinforcement efficiency within the investigated range (1–5 wt.%). Overall, filler addition generally reduced tensile strength and, in several cases, tensile modulus, reflecting limited interfacial compatibility between the hydrophilic lignocellulosic fillers and the hydrophobic polyester matrix. TGA indicated a modest improvement in thermal stability at higher BSG loadings, reflected by shifts in T_5% and T_max1 (PHBH) toward higher temperatures. Overall, this study demonstrates that upcycled coffee and beer waste fillers can impart specific toughness benefits to biodegradable PBAT/PHBH blends, but interfacial incompatibility currently limits their reinforcement efficiency. The findings highlight the potential and challenges of these biocomposites for sustainable packaging applications and suggest that interface engineering (e.g., compatibilizers) will be key to unlocking optimal performance. Full article

This study investigates the effects of organic salts, including sodium citrate (SC), calcium citrate (CC), and calcium lactate (CL), on the structure–property–function relationships of thermoplastic starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) films for active packaging applications. TPS incorporated with organic salts was prepared via twin-screw extrusion, blended with PBAT, and further processed into blown films. The films were systematically characterized using ¹H NMR, FTIR, and SEM, together with optical, mechanical, water vapor permeability, and antimicrobial evaluations against Staphylococcus aureus. The results revealed that SC primarily modulated hydrogen-bonding interactions within the starch matrix, resulting in improved structural homogeneity, balanced mechanical properties, and the highest antimicrobial activity among all formulations. In contrast, CL and CC promoted ionic crosslinking through Ca²⁺–starch interactions, leading to increased stiffness and Young’s modulus but reduced polymer chain mobility and limited release of active species, particularly in CC-containing systems. These differences in molecular interactions were consistent with variations in film microstructure, where SC-containing films exhibited more uniform morphologies, while calcium-based systems showed denser but less permeable structures. Furthermore, films containing SC and CL at appropriate concentrations achieved a favorable balance between transparency, water vapor barrier properties, and antimicrobial performance. Overall, this study provides new mechanistic insights into how monovalent and divalent organic salts govern intermolecular interactions, microstructure, and functional performance in TPS/PBAT systems. The findings highlight the critical role of additive type and concentration in designing biodegradable active packaging materials with tunable mechanical, barrier, and antimicrobial properties. Full article

We investigated the synthesis and characterization of biodegradable films composed of poly (lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT), with lignin as a natural additive and dicumyl peroxide (DCP) as a compatibilizer. The PLA/PBAT ratio of 70:30 was optimized and the DCP was incorporated at different concentrations to enhance interfacial adhesion. The effects of lignin addition (0.005–0.02%) on the mechanical, thermal, and biodegradation properties were evaluated using SEM, FTIR, XRD, and TGA analyses. The optimal formulation had improved tensile strength, elongation at break, and thermal stability, with the highest degradation rate of 44.22% after 90 days of soil burial. Life cycle assessment using SimaPro software (SimaPro 9.1.1.1) and ReCiPe 2016 Midpoint indicated that the film containing 0.005% lignin had the lowest environmental impact. The primary environmental concerns were marine and freshwater ecotoxicity, associated with solvent use. Based on the results, incorporating small amounts of lignin enhanced the biodegradability and reduced the environmental footprint of the PLA/PBAT films, highlighting their potential for sustainable packaging applications. Full article