Bioplastics, derived from renewable biomass sources, are emerging as sustainable alternatives to conventional petrochemical plastics. Their global production capacity is projected to reach 5.73 million tons by 2029. However, a significant challenge remains in simultaneously achieving mechanical robustness, high-temperature resistance, and processability that are comparable to traditional plastics. While designing stimuli-responsive supramolecular networks can enhance mechanical performance, bioplastics often lag behind their petrochemical counterparts in shaping and manufacturing behaviors.
Inspired by the need to overcome these limitations, the groups led by Prof. Dawei Zhao from Shenyang University of Chemical Technology, Prof. Haipeng Yu from Northeast Forestry University, and Prof. Lisha Sun from Shengjing Hospital of China Medical University developed an innovative strategy. They introduced thermally stimulated polyethylene glycol (PEG) molecules to optimize the supramolecular assembly of cellulose and polyvinyl alcohol (PVA). This approach successfully mediated the reconstruction of a denser and more resilient supramolecular network, resulting in a novel cellulose-based supramolecular plastic, termed Cel-T plastic (Figure 1). The developed Cel-T plastic exhibits an impressive combination of properties, including high mechanical strength, excellent thermal stability from -40 to 135°C, and versatile 3D shapeability, all while being biodegradable and recyclable.
The microscopic mechanism of performance enhancement of Cel-T plastic was revealed through molecular dynamics simulation (MD). Heat treatment, while maintaining the stability of the Cel-PVA supramolecular network, induces the expansion movement of PEG molecular chains within the system, significantly enhancing the molecular entanglement and hydrogen bond interaction between cellulose and PVA. This thermal stimulus-induced directional densification of microstructure is the key to achieving a coordinated improvement in the mechanical strength and toughness of materials, and endows them with excellent load-bearing capacity and multi-process formability. It provides a theoretical basis and structural foundation for designing high-performance bio-based plastics at the molecular level (Figure 2).
Solid-state nuclear magnetic resonance (
1H SNMR) and Fourier Transform infrared spectroscopy (FTIR) confirmed that the introduction of the heat-responsive molecule PEG significantly enhanced the hydrogen bond interaction between cellulose and PVA, driving the supramolecular network to rearrange towards a denser and ordered structure. X-ray diffraction (XRD) and Raman spectroscopy further indicated that PEG effectively induced the recrystallization behavior of PVA molecular chains, enhancing the uniformity and compactness of the material's microstructure. Wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) analyses clearly presented the structural division of labor among the three components. Cellulose serves as a rigid molecular skeleton to provide mechanical support, PVA acts as a configurational reconstruction phase to endow structural tunability, and PEG serves as molecular cross-linking and stimulus-responsive unit to enable dynamic regulation. The three elements work together to construct a strong, dense, and oriented multi-level supramolecular configuration, providing a clear structural origin for the excellent mechanical properties, thermal stability and multiple formability of Cel-T plastic. The design principle of the three-component cooperative assembly was clarified at the molecular level, providing a referenceable supramolecular engineering strategy for the development of high-performance bio-based plastics (Figure 3).
Cel-T plastic demonstrates significant advantages in mechanical properties. Compared with commercial plastics such as polylactic acid (PLA), polymethyl methacrylate (PMMA), acrylonitrile-butadiene-styrene (ABS), and polyethylene terephthalate (PET), Cel-T plastic combines the synergies of high strength, high rigidity, and high toughness. Under the action of stable tensile stress, Cel-T plastic shows structural integrity and plastic deformation behavior. Its tensile strength reaches 63.86 MPa and the elastic modulus is as high as 3.3 GPa. The performance indicators are comprehensively superior to the above-mentioned comparison materials. Its dense and ordered supramolecular reorganization structure endows the material with excellent stress dispersion and energy absorption capabilities, thereby achieving outstanding mechanical bending resistance, impact resistance and puncture resistance. Specifically, the flexural strength of Cel-T plastic reaches 108.6 MPa and the flexural modulus is 4.9 GPa. These results indicate that Cel-T plastic maintains high rigidity while also having excellent toughness, demonstrating great potential as an alternative to high-performance engineering plastics (see Figure 4).
Cel-T plastic designed through supramolecular networks not only possesses outstanding mechanical properties and processability, but also has excellent resistance to high and low temperatures. Dynamic mechanical analysis (DMA) shows that from -40 ℃ to 135 ℃, the energy storage modulus, loss modulus and loss tangent curve of Cel-T plastic are smooth, indicating that its supramolecular structure can remain stable within a wide temperature range without deformation or softening. After long-term exposure to -40 ℃ and 135 ℃, Cel-T plastic still maintains its mechanical toughness and flexibility, while comparison materials such as PLA, PMMA, ABS and PET show embrittlement or softening deformation (see Figure 5).
Cel-T plastic also demonstrates attractive closed-loop recyclability and natural degradability. Its fragments can be recycled by dissolving in the recovered ionic liquid ([Bmim]Cl) and reprocessing, and the tensile strength retention rate of the recycled plastic exceeds 85%. Cel-T plastic can be completely biodegraded in natural soil within 55 days, while PET, PA66, PMMA, ABS and even PLA plastics show almost no change during the same period. Cel-T plastic also has good biocompatibility. After co-culture with human fibroblasts, the cell survival rate exceeds 98.5%, providing a guarantee for its application in medical and food fields. Preliminary economic feasibility analysis shows that its production cost is approximately $3,066 per ton, and it has market potential to compete with petrochemical plastics (Figure 6).
A meaningful and scalable supramolecular mediation strategy was presented, utilizing thermally stimulated PEG molecules to optimize the assembly of cellulose and PVA. This resulted in a bioplastic with a reinforced supramolecular architecture, overcoming the traditional trade-off between mechanical robustness, thermal stability, and shapeability. The resulting Cel-T plastic exhibits a unique combination of high strength, impact resistance, wide-temperature-range stability, versatile processability, complete biodegradability, and good recyclability. This study highlights the immense potential of supramolecular design in developing advanced functional materials from renewable resources, offering a promising path to mitigate petrochemical plastic pollution.
“Biodegradable, Thermally Stable, and Programmable Cellulosic Bioplastics Enabled by Supramolecular Stimulated Mediation" was supported by the National Key Research and Development Program of China (Grant No. 2023YFD-2200504), the National Natural Science Foundation of China (Grant Nos. 32371823 and 32330072), and the Liaoning Province Xingliao Talents Leading Talent Program (Grant No. XLYC2402043). Prof. Dawei Zhao from Shenyang University of Chemical Technology, Prof. Haipeng Yu from Northeast Forestry University, and Prof. Lisha Sun from Shengjing Hospital of China Medical University served as the paper's corresponding authors.
The complete study is accessible via DOI:10.34133/research.1098