Aliphatic polycarbonate modified poly(ethylene furandicarboxylate) materials with improved ductility, toughness and high CO2 barrier performance

Plastics of the Future? An Interdisciplinary Review on Biobased and Biodegradable Polymers: Progress in Chemistry, Societal Views, and Environmental Implications

Global demand to reduce polymer waste and microplastics pollution has increased in recent years, prompting further research, development, and wider use of biodegradable and biobased polymers (BBPs). BBPs have emerged as promising alternatives to conventional plastics, with the potential to mitigate the environmental burdens of persistent plastic waste. We provide an updated perspective on their impact, five years after our last article, featuring several recent advances, particularly in exploring broader variety of feedstock, applying novel chemical modifications, and developing new functionalities. Life-cycle assessments reveal that environmental performance of BBPs depends on several factors including feedstock selection, production efficiency, and end-of-life management. Furthermore, the introduction of BBPs in several everyday life products has also influenced consumer perception, market dynamics, and regulatory frameworks. Although offering environmental advantages in specific applications, BBPs also raise concerns regarding their biodegradability under varying environmental conditions, potential microplastic generation, and soil health impacts. We highlight the need for a circular approach considering the entire polymer life cycle, from feedstock sourcing, modification and use, to end-of-life options. Interdisciplinary research, collaborative initiatives, and informed policymaking are crucial to unlocking the full potential of BBPs and exploiting their contribution to create a circular economy and more sustainable future.

Flexible and Recyclable Bio-Based Polyester Composite Films with Outstanding Mechanical and Gas Barrier Properties Using Leaf-Shaped CNT@BNNS Covalent Heterojunction

With the depletion of petroleum resources, the development of sustainable alternatives for plastic substitutes has grown in importance. It is urgently desirable yet challenging to design high-performance polyesters with extensive mechanical and prominent gas barrier properties. This work uses bio-based PBF polyester as a matrix, "leaf-shaped" carbon nanotube@boron nitride nano-sheet (CNT@BNNS) covalent hetero-junctions as functional fillers, to fabricate CNT@BNNS/PBF (denoted as CBNP) composite films through an "in-situ polymerizing and hot-pressing" strategy. The covalent CNT "stem" suppresses the re-stacking of BNNS "leaf", endowing hetero-structured CNT@BNNS illustrates superior stress transfer and physical barrier effect. The covalently hetero structure and high orientation degree of CNT@BNNS greatly improve the comprehensive performance of the CBNP composites, including excellent mechanical (strength of 76 MPa, modulus of 2.3 GPa, toughness of 85 MJ m-3, elongation at break of 193%) and gas barrier (O2 of 0.015 barrer, and H2O of 1.1 × 10-14 g cm cm-2 s-1 Pa-1) properties that are much higher than for pure PBF or other-type polyesters, and most engineering plastics. Moreover, the CBNP composites also boast easy recyclability, overcoming the tradeoff between high performance and easy recycling of traditional plastics, which makes the polyester composite competitive as a plastic substitute.

High ion barrier hydrogel with excellent toughness achieved by directional structures

Owing to their nontoxicity, environmental friendliness, and high biocompatibility, physically cross-linked hydrogels have become popular research materials; however, their high water content and high free volume, along with the weak bonding interactions inherent to ordinary physically cross-linked hydrogels, limit their application in fields such as flexible devices, packaging materials, and substance transport regulation. Here, a structural barrier approach based on directional freezing-assisted salting out was proposed, and the directional structure significantly enhanced the barrier performance of the hydrogel. When the direction of substance diffusion was perpendicular to the pore channel structure of the directional freezing-PVA hydrogel (DFPVA), the Cl- transmission rate was 57.2% for the uniform freezing-PVA hydrogel (UFPVA). By adjusting the concentration of the salting-out solution and the salting-out time, the crystallinity and crystal domain size of the hydrogel could be further changed, optimizing and regulating the barrier performance of the hydrogel, with the best Cl- unit permeability being 36.02 mg mm per cm2 per day. Additionally, DFPVA had excellent mechanical properties (stress of 6.47 ± 1.04 MPa, strain of 625.85 ± 61.58%, toughness of 25.77 ± 3.72 MPa). Due to the barrier and mechanical properties of the direct structure, DFPVA is suitable as a drug carrier for slow drug release in vitro.

3D-printing of biomass furan-based polyesters with robust mechanical performance and shape memory property

3D-printing provides a feasible technique for realizing new materials into structural and intelligent parts. In this work, biomass furan-based polyesters poly (ethylene furanoate) (PEF), poly (trimethylene furanoate) (PTF), and poly (butylene furanoate) (PBF) were successfully synthesized in a 5 L reactor through the melt polycondensation process and fabricated into 3D-printing feedstocks. It was demonstrated that the three furan-based polyesters were additively-manufactured into complicated structures. Besides, the mechanical and thermal properties of furan-based polyesters could be tailored by the chain length of diol monomer. The mechanical performance of 3D-printed PEF, PTF and PBF were characterized and compared with commercial filaments. The tensile strength of PEF and PTF could reach 74.6 and 63.8 MPa respectively, which exhibited superior tensile property to poly(ether-ether-ketone) (PEEK), polyamide (PA) and polylactic acid (PLA). Meanwhile, the compression results demonstrated that the PEF and PTF possessed comparable energy absorption capacity with PEEK and PLA respectively, which indicated excellent mechanical properties of furan-based polyesters. It was interesting to find that the 3D-printed structures including solid cube, bionic flower and lattice structures were employed to prove that the PTF possessed excellent shape memory properties. Therefore, the proposed biomass furan-based polymers would offer more freedom in the field of 3D-printing.