Dual-function ChCl:MEA deep eutectic solvent for plasticization and compatibilization of starch–lignin blends: enhanced mechanical and thermal properties
Jul 2026· Journal of polymer engineering· 0 citations· 42 references
Abstract
Abstract Starch–lignin (CS–Lig) blends commonly suffer from low ductility and poor interfacial compatibility, which limit their performance and processability. In this study, a choline chloride:monoethanolamine (ChCl:MEA, 1:3 molar ratio) deep eutectic solvent (DES) was investigated as a single dual-function additive for simultaneous plasticization of the starch-rich matrix and compatibilization of the starch–lignin interface, using glycerol as the reference plasticizer. Relative to glycerol, the DES system reduced mixing torque, melt temperature, and processing energy, indicating easier melt processing. It also produced a stronger depression of the glass-transition temperature, decreasing T g to 48.4 °C at the highest DES loading, and markedly increased elongation at break to 192.47 %. In addition, DES-plasticized blends showed a more homogeneous morphology, fewer interfacial defects, and higher onset thermal stability than the glycerol-plasticized counterpart (196.08 °C vs. 166.88 °C for the representative 2.0-part formulations). Overall, these results demonstrate that ChCl:MEA acts not only as an efficient plasticizer for the starch-rich matrix but also as an effective compatibilizer for the starch–lignin interface, providing a practical route to more processable and performance-balanced CS–Lig biocomposites.
Developing sustainable, high-performance hydrocolloid packaging remains challenging because polysaccharide films are typically brittle and provide limited barrier protection. Here, we present a synergistic strategy combining distiller's grains prolamin (DGSP) and deep eutectic solvents (DES) to tailor the structure and performance of chitosan (CS) films. CS/DGSP composites were first optimized for protein incorporation, and subsequently plasticized with three choline chloride-based DES (ChCl-glycerol, ChCl-xylitol, and ChCl-urea) at 0.5-2 wt%. Among the ratios tested, a CS/DGSP mass ratio of 2:1 was selected primarily for its superior barrier performance, with favorable film-forming stability and optical properties. DES plasticization, particularly 0.5 wt% ChCl-urea, further enhanced extensibility, UV shielding, and thermal stability, most notably increasing elongation at break to 70.93%, approximately 14-fold higher than that of the non-plasticized control. Structural characterizations indicated that DES-mediated multipoint hydrogen bonding partially replaced polymer-polymer interactions, enabling dual regulation of chain mobility and network densification. This flexible yet compact network suppressed water permeation while maintaining integrity and homogeneity. Strawberry preservation tests confirmed the superior ability of the optimized film to retard moisture loss, shrinkage, and microbial spoilage without compromising sensory quality. These findings provide a DES-assisted protein-polysaccharide design strategy that enables high-value DGSP utilization and offers mechanistic insights into structure-property relationships for sustainable packaging.
Lin Deng, Haoyang Sun, Xiaomeng Li et al.· Food Research International· 0 citations
This study developed hybrid poly(lactic acid) (PLA)/thermoplastic starch (TPS) biocomposites reinforced with spent coffee grounds (AK, 0–30 wt%) and compatibilized with maleic anhydride (MA, 5 wt%). The composites were characterized using Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile testing, melt flow rate (MFR), water absorption, and soil‐burial biodegradability. Increasing AK content improved stiffness and biodegradation because of its lignocellulosic structure; however, excessive filler loading caused agglomeration and reduced ductility. MA enhanced interfacial compatibility, filler dispersion, stress transfer, and moisture resistance at low to moderate AK contents. The AK 10% + MA formulation showed the most balanced performance, achieving a tensile strength of 29.86 MPa, low water absorption, favorable melt flow behavior, and 28.03% weight loss after 3 months of soil burial. These results clarify the role of AK and MA in controlling the processing–structure–property–biodegradation relationship of PLA/TPS composites and support the use of spent coffee grounds as sustainable fillers for biodegradable bioplastics.
E. Ardelia, S. S. Kusumah, R. C. Nissa et al.· Journal of Applied Polymer S...· 1 citation
This study prepared high‐performance PBAT/starch composite films using biodegradable PBAT, starch, and a ternary deep eutectic solvent (DES) composed of glycerol/choline chloride/citric acid. The films were fabricated via in situ plasticization of starch with DES, melt blending, and film blowing. With 1.13 parts citric acid, 10.13 parts total DES, and 20% starch, the composite film achieved a longitudinal tensile strength of 19.63 MPa and elongation of 449%, and a transverse tensile strength of 20.75 MPa and elongation of 500%. Compared to the traditional glycerol‐plasticized system (8.43/8.77 MPa), strength increased by over 130%; compared to the binary DES system (15.07/15.45 MPa), strength further increased by over 30%. The composite film also showed good thermal stability within the processing range (150°C–160°C), and the water contact angle was significantly improved, demonstrating high strength, toughness, enhanced hydrophobicity, and good thermal stability. The ternary DES effectively disrupts the crystalline structure of starch for efficient plasticization, and the citric acid it contains may trigger interfacial esterification crosslinking between starch and PBAT, thereby enhancing two‐phase compatibility and stress transfer efficiency. This developed film has application potential in biodegradable packaging, disposable products, and environmentally friendly daily‐use films.
Liang Tang, Jingfeng Huang, Xiangying Chen et al.· Journal of Applied Polymer S...· 0 citations
Cellulose, hemicelluloses, and lignin in wood cell walls form a biological macromolecular network whose organization and intermolecular interactions determine the compressibility and moisture stability of densified wood. This study presents a deep eutectic solvent (DES)-retention strategy that enables in situ plasticization and modification of this network during densification. The retained DES lowered the softening temperature from 100 to 55 °C, promoted the viscoelastic deformation of cell-wall polymers, and substantially relieved internal stress during compression. The resulting densified wood reached a density of 1.01 g cm-3, a modulus of rupture (MOR) of 197.04 ± 9.88 MPa, a modulus of elasticity (MOE) of 10.17 ± 0.71 GPa, and a Shore D hardness of 91, while exhibiting only 1.5% set recovery after soaking-boiling-drying cycles. Multiscale characterization indicated that DES pretreatment induced matrix depolymerization and cellulose swelling/disordering, whereas hot pressing promoted cellulose realignment and lignin recondensation, thereby stabilizing the compressed structure. The resulting material also showed improved resistance to fungal decay and mold growth, as well as improved flame-exposure behavior. A cradle-to-gate life cycle assessment further indicated lower environmental impacts than steel under the evaluated conditions. These results demonstrate that retaining DES to regulate cell-wall macromolecules provides an effective route to high-strength densified wood with negligible set recovery.
Yangyang Ran, Jiamin Wang, Wang Wang et al.· International Journal of Bio...· 0 citations
Deep eutectic solvents (DESs) are widely applied in lignocellulosic biomass pretreatment for their green, reusable, and lignin-selective merits. However, lignin accumulation during DES cycling significantly increases solvent viscosity and reduces pretreatment efficiency, severely limiting its sustainable application. To address this bottleneck, we innovatively combined recycled lactic acid/zinc chloride (LA/ZnCl2) DES with acrylic acid (AA), leveraging the synergistic effect of lignin and metal ions to drive free radical polymerization. This strategy enables a simple and efficient preparation for lignin eutectic gels with excellent mechanical properties and low-temperature resistance. The optimized gels (with 3 wt% lignin) exhibited high tensile stress (1.2 MPa), elongation at break (580%), multi-surface adhesion (32 kPa), and maintained a stable electrical conductivity of 1.1 mS cm-1 even at -18 °C. At room temperature, the assembled flexible sensors possessed a fast response speed (160 ms), linear deformation response, and robust electrical stability (<5% signal decay over 700 cycles of 100% deformation). This study pioneered the coupling of DES pretreatment and eutectic gel preparation, facilitating full utilization of lignocellulose and DES components to advance DES-based lignocellulose fractionation, valorization, and the entire biorefinery industry.
Leixin Huang, Enqing Zhu, Ziliang Dai et al.· Bioresource Technology· 0 citations
Poly(lactic acid)/poly(butylene succinate) blends, which are composed of biodegradable aliphatic polyesters, are promising candidates for sustainable polymer applications. However, their poor interfacial compatibility limits the simultaneous improvement of strength and ductility. This study aimed to regulate the interfacial structure and mechanical response of 70PLA/30PBS blends through reactive compatibilization with a multifunctional epoxy chain extender and reactive plasticization with epoxidized soybean oil. The blends were prepared by reactive melt extrusion and characterized by mechanical testing, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. The results showed that 5 phr epoxy chain extender refined the dispersed phase and improved interfacial adhesion, giving a tensile strength of 76.89 MPa and an elongation at break of 261%. Further addition of 2 phr epoxidized soybean oil increased the elongation at break to 292% while maintaining a tensile strength of 65.06 MPa. The combined results suggest that the epoxy chain extender mainly provides reactive interfacial anchoring and structural support, whereas epoxidized soybean oil improves chain mobility and plastic energy dissipation. By distinguishing the effects of chain extender content, epoxidized soybean oil content, and premixing sequence within a fixed 70PLA/30PBS formulation platform, this work clarifies how reactive interfacial anchoring, reactive plasticization, and reaction‐distribution control jointly regulate crystallization behavior, interfacial morphology, and the strength–ductility balance of PLA/PBS blends.
Jinsong Ou, Qinling Wang, Zhiqin Jin et al.· Polymer Engineering & Sc...· 0 citations