Aug 2026· Macromolecular Symposia· 0 citations· 44 references
Abstract
This study develops an industrially applicable composite by combining polylactic acid (PLA) with chitosan (CS) for antimicrobial properties and microcrystalline cellulose (MCC) for enhanced mechanical performance. Mechanical behaviour, microstructure, and morphology were analysed using tensile tests, scanning electron microscopy (SEM), and X‐ray diffraction (XRD). Antibacterial activity was evaluated against Gram‐positive and Gram‐negative bacteria. The samples were prepared by heating thermoplastic polylactic acid (PLA) and subsequently molding them into test specimens in accordance with ASTM D638. Results showed that adding MCC increased tensile strength and modulus, with the highest values in PLA (A) containing 2% MCC and 2% CS. Higher MCC content caused agglomeration, reducing mechanical properties. SEM and XRD revealed that MCC increased crystallinity, while CS decreased it. PLA/MCC/CS composites demonstrated stronger antibacterial activity than pure PLA. The findings indicate that the composites offer both improved mechanical properties and enhanced antibacterial function, making them promising for biomedical applications. Further optimization is needed to improve interfacial adhesion and reinforcement dispersion.
This study developed polylactic acid (PLA) composites reinforced with chitosan (CS) and sugarcane bagasse‐derived fillers, including untreated sugarcane bagasse (SCB), ultrasound‐assisted‐alkaline‐treated sugarcane bagasse (UASCB), and ultrasound‐assisted‐alkaline‐acid‐treated (UAASCB). The objective was to improve the structural and functional properties of PLA composites through fiber treatment and chitosan incorporation. Fiber treatments significantly increased the cellulose content and crystallinity of SCB, with the best result reaching 71.7% cellulose and 91.36% crystallinity after 30 min of 4 wt% NaOH treatment followed by 45 min of 2 N sulfuric acid treatment. Composite characterization was carried out using FTIR, XRD, SEM, and tensile testing. In this study, pure PLA showed a tensile strength of MPa and a tensile modulus of MPa. The PLA–CS–UASCB composite showed a comparable tensile strength () MPa with a slight increase in tensile modulus () MPa. In contrast, the PLA–CS–UAASCB composite displayed lower tensile strength () MPa and tensile modulus () MPa. The PLA–CS–UASCB composite demonstrated the highest antimicrobial activity, reducing the growth of
E. coli
by 20.28% and
S. aureus
by 28.33%. This research offers a promising foundation for further development of sustainable PLA‐based biocomposites tailored for multifunctional and environmentally friendly applications.
A. Fatmawati, Athalia Beatrice Molianto, T. Pranata et al.· Applied Research· 0 citations
The increasing demand for sustainable materials has accelerated the development of biodegradable polymer composites with enhanced multifunctional performance for engineering, packaging, and biomedical applications. In this study, poly(lactic acid) (PLA)/polyhydroxyalkanoate (PHA) biocomposites reinforced with microcrystalline cellulose (MCC) and a compatibilizer were fabricated by melt blending followed by compression molding. Fourier-transform infrared spectroscopy confirmed enhanced hydrogen-bonding interactions between MCC and the PLA/PHA matrix, indicating improved interfacial compatibility. X-ray diffraction and Differential scanning calorimetry revealed that MCC acted as an significant heterogeneous nucleating agent, increasing the crystallinity from 28.6% for the neat PLA/PHA blend (S0) to 40.1% while reducing the cold crystallization temperature from 115.2 to 110.5 °C and increasing the melting enthalpy from 29.8 to 38.9 J g−1. Thermogravimetric analysis demonstrated improved thermal stability, with the maximum degradation temperature increasing from 325.1 to 343.8 °C and the residual char yield increasing from 5.6% to 16.8%. Specimen S7, containing 6 wt.% MCC and 2 wt.% compatibilizer exhibited the optimum overall performance, achieving a tensile strength of 64 MPa, Young’s modulus of 2500 MPa, impact strength of 5.8 kJ/m2, cell viability of 98%, and 88.5% weight loss after 180 days of soil burial. These findings demonstrate that interfacial engineering with MCC and compatibilizer significantly enhances the structural, thermal, mechanical, biological, and biodegradation performance of PLA/PHA biocomposites, making them promising candidates for sustainable advanced packaging and biomedical applications.
The obtained results confirm the potential of PLA-based composites modified with hydroxyapatite and gentamicin as functional biodegradable materials for implant applications in regions with moderate mechanical loading, combining mechanical support, bioactivity, and local antimicrobial protection.
A. Khrustaleva, A. Yedrissov, D. Khrustalev et al.· Medicine and ecology· 0 citations
The development of polymer composites with antibacterial functionality and improved mechanical performance has attracted increasing attention for applications requiring both structural integrity and microbial resistance. In this study, poly(lactic acid) (PLA) composites containing silver nitrate (AgNO₃; 1, 3, and 5 wt%) were fabricated by stereolithography (SLA) and characterized. SEM and EDX analyses confirmed the presence of silver within the PLA matrix, with relatively uniform distribution at lower contents and localized heterogeneities at higher loadings. FTIR results indicated that the chemical structure of PLA was largely preserved after AgNO₃ incorporation, with minor spectral shifts suggesting possible interactions with silver-containing species. TGA revealed a slight increase in the onset degradation temperature, from 315 °C for neat PLA to 321 °C for the composite containing 5 wt% AgNO₃. Mechanical testing showed improvements in both tensile and flexural properties with increasing AgNO₃ content, with tensile strength rising from 39.6 MPa to 55 MPa and flexural strength from 45.4 MPa to 76.7 MPa. Antibacterial tests demonstrated clear inhibition against Escherichia coli and Staphylococcus aureus, with stronger activity observed at higher AgNO₃ contents.
Mustafa Eren Taşkıngül, F. N. Parın, Can Ekinci· Journal of Innovative Engine...· 0 citations
This study investigates the development of sustainable polymer composites using cornstalk (CS) fibers as reinforcement in a polylactic acid/poly(butylene succinate) (PLA/PBS) matrix plasticized with a dual system of polyethylene glycol (PEG) and triacetin (TA). The effects of CS fiber size (≤75 µm and >75 µm) and plasticizer content (5, 7.5, and 10 wt%) on thermal, mechanical, and morphological properties were systematically evaluated. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed no significant differences in thermal behavior across fiber sizes. Dual plasticization effectively increased the melt flow index (MFI) and enhanced processability, but at the expense of overall mechanical properties. Scanning electron microscopy (SEM) confirmed adequate dispersion and interfacial adhesion without chemical bonding, as supported by Fourier-transform infrared spectroscopy (FTIR). The results reveal that all CS-reinforced PLA/PBS composites exhibit low thermal conductivity, comparable to conventional gypsum board, demonstrating the potential for developing agro-waste-based polymer composites suitable for thermal insulation applications in architecture.
Athip Chanthaluck, T. Waroonkun, S. Kamthai· Chiang Mai Journal of Scienc...· 0 citations
OBJECTIVES
This study aimed to evaluate bio-based, biodegradable polylactic acid (PLA) as a sustainable material for clear aligners by comparing its physicochemical, mechanical, and biological properties with commercial aligner materials (Essix Ace, Essix C+, Zendura FLX, and Zendura).
METHODS
PLA and commercial materials, both neat and aged in artificial saliva for up to 14 days, were examined as sheets. Thermal properties were measured using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical and optical properties were evaluated using a universal testing machine (UTM) and UV-visible spectrophotometry. Degradation behavior was assessed via weight and average molar mass changes, and surface morphology via scanning electron microscopy (SEM). Cytotoxicity was tested using human gingival fibroblasts with an MTT assay.
RESULTS
PLA showed a glass transition temperature of 55.4 °C, melting temperature of 152.1°C, and degradation onset temperature of 362.9 °C, comparable to commercial aligner materials. Its tensile strength and yield stress were similar to those of commercial materials, indicating adequate strength. However, PLA exhibited lower elongation at break and higher Young's modulus, reflecting higher brittleness and stiffness. Aging caused negligible water absorption, minimal weight loss, and minor thermal property change. Mechanical properties remained stable upon aging. Aged PLA was transparent when wet but became hazy when dry, which occurs reversibly. Extracts from PLA were non-cytotoxic, maintaining 90% cell viability in average.
SIGNIFICANCE
PLA demonstrated properties comparable to commercial aligner materials, with the exception of increased stiffness and brittleness. Its stability during aging and favorable biocompatibility supports its potential as a sustainable alternative for clear aligner applications.
Mayuri Parappullil Vellayappan, Sean Johnson, Taylor Stewart et al.· Dental Materials· 0 citations