Xipo Zhao

Although polylactic acid (PLA) possesses excellent eco-friendliness and biocompatibility, its inferior oxygen-barrier properties have restricted its widespread application in the food packaging field. Traditional techniques, such as physical blending or multilayer compositing with high-barrier polymers, often encounter challenges including poor uniformity, weak interfacial bonding, and complex processing requirement. To address these drawbacks, this work proposes a green, low-cost and high-efficiency processing strategy of cellulose nanocrystal (CNC) coatings to achieve a significant enhancement in the oxygen-barrier performance of PLA films. By employing UV-induced in-situ crosslinking of aldehyde/thiol-modified CNC with the flexible poly(ethylene glycol) diacrylate (PEGDA), a CNC-cys-PEGDA crosslinking coating was successfully constructed onto the PLA surface, exhibiting high oxygen-barrier properties, strong adhesion, and excellent flexibility. The results indicate that the modified coating reduced the oxygen transmission rate (OTR) of the PLA film from 393.33 to 39.25 cm3/(m2·24 h·0.1 MPa), while maintaining flexibility and improved interfacial adhesion by 70.58% compared to the pure CNC coating. Furthermore, strawberry packaging tests demonstrated that the CNC-cys-PEGDA/PLA composite film effectively delayed spoilage and exhibited superior preservation effects compared with pure PLA films. This work provides new insights and technical support for enhancing the comprehensive performance of PLA film in the practical applications of food packaging industry.

Poly(lactic acid) (PLA)/nano‐hydroxyapatite (nHAP) composites show broad potential for biomedical applications; however, poor interfacial compatibility between the two phases remains a key bottleneck limiting their performance. In this work, PLA prepared via melt polycondensation using l ‐lactic acid as the feedstock was employed as the matrix. Epoxy‐functionalized nano‐hydroxyapatite (cnHAP) was obtained through surface modification of nHAP, and PLA/cnHAP composites with different mass ratios were fabricated by melt blending. XPS results indicate an epoxy grafting degree of 17.46% for cnHAP, which effectively suppresses particle agglomeration. The PLA/cnHAP composites achieved an impact strength of 710 J/m ² , representing a 68.65% increase relative to neat PLA. Mechanistic analysis suggests that the covalently bonded interface promotes efficient stress transfer across the phases, induces pronounced plastic deformation of the matrix, and dissipates impact energy synergistically via crack deflection and matrix yielding. In addition, the thermal stability and thermal properties of the composites are also improved synergistically, providing insights for interfacial engineering design of PLA‐based composites.

Cellulose nanocrystals (CNC) tend to form irreversible hard aggregates during drying and melt processing, severely limiting their nanodispersion in polylactic acid (PLA). Herein, a hexadecyl etherification strategy is proposed to induce a loosely packed “soft agglomeration” structure via steric hindrance and hydrogen-bond weakening. The modified CNC forms free-flowing powders with an average particle size of ~9.5 μm after conventional oven drying. During melt processing, the thermal motion of grafted alkyl chains drives CNC mobility, enabling nanoscale redispersion. With the addition of 3 wt.% C16-CNC, the crystallinity of PLA increases from 12.9% to 23%, the storage modulus improves by 71%, and the thermal deformation at 70 ℃decreases from 42% to 4%. This strategy provides a simple and scalable route for producing redispersible CNC powders for sustainable composite materials.

Biodegradable PLA- b -PA4 copolymers were synthesized via thiol-ene click chemistry. The synergistic effect of block components facilitates the fabrication of stable electrospun fibers with tunable morphology and mechanical properties.

Polylactic acid (PLA)/plant fiber composites have attracted increasing interest as sustainable alternatives to petroleum‐based plastics due to their renewability, biodegradability, and environmental compatibility. However, the inherent polarity mismatch between hydrophilic plant fibers and the hydrophobic PLA matrix often results in weak interfacial adhesion, poor compatibility, and fiber agglomeration. This review provides an overview of recent developments in PLA composites reinforced with bast fibers (hemp, flax, ramie), bamboo fibers, and wood fibers. Particular attention is given to interfacial modification strategies—including alkali treatment, silane coupling, acetylation, aerogel, and bio‐inspired coatings—and their effects on interfacial bonding, mechanical strength, moisture resistance, UV stability, and flame retardancy. Studies have demonstrated that optimizing processing parameters such as fiber content (20–50 wt%), treatment concentration, reaction temperature, and melt‐blending conditions significantly improves interfacial compatibility and stress transfer efficiency. Recent research also highlights that synergistic modification approaches, such as combined alkali–silane treatment and nano‐filler incorporation, can effectively enhance mechanical performance while maintaining biodegradability. Overall, interfacial engineering and process optimization are identified as the key pathways to achieving high‐performance and eco‐sustainable PLA/plant fiber composites, paving the way for their broader application in packaging, automotive, and biomedical fields.

This study employed a two‐step approach involving melt polycondensation and chain extension to synthesize high‐molecular‐weight PLA. Initially, the mechanism of ring‐forming side reactions during polycondensation was systematically investigated using MALDI‐TOF‐MS. The results demonstrated that the SnCl ₂ /TSA composite catalyst effectively suppressed the formation of cyclic oligomers, and the optimal reaction conditions were determined as 180°C for 8 h. Based on these findings, HDI was chosen as an efficient chain extender. By optimizing both the molecular weight of PLA during polycondensation and the HDI content, chain‐extended PLA with a molecular weight of 1.48 × 10 ⁵ g/mol was successfully obtained. The results showed that the chain‐extended product exhibited excellent overall performance. Its tensile strength (75.5 MPa) was comparable to that of commercial PLA 4032D (75.3 MPa), while its elongation at break (12.21%) slightly exceeded that of the commercial sample (11.1%). This work provides a novel strategy for the industrial production of high‐performance PLA.

Amylose content was 57.26%. Electrospinning preparation of enzymatic hydrolysis starch micronano fiber. Fiber diameter in 200–500 nm.