RSC Applied Polymers最新文献

Correction for ‘Modifying bacterial cellulose dispersions with deep eutectic solvent and pectin to tune the properties of open-celled foams’ by Hareesh Iyer et al., RSC Appl. Polym., 2025, 3, 407–419, https://doi.org/10.1039/D4LP00348A.

The persistent presence of hospital-acquired bacterial infections and the growing prevalence of antibiotic-resistant bacterial strains necessitates a greater understanding of the initial adhesion of bacteria to biomaterials. While the mechanical properties of polydimethylsiloxane (PDMS) gels have been shown to influence the initial attachment of microorganisms, to date, attachment has only been assessed on gels that are 1000× larger than the microorganisms evaluated. Here, a library of nine PDMS gels were manufactured to be thin (∼10 µm), medium (∼35 µm) and thick (∼100 µm) with distinct Young's Moduli that were considered to be soft (E = ∼60 kPa), standard (E = ∼1150 kPa), and stiff (E = ∼1700 kPa). All gels were well characterized using atomic force microscopy. Next, the initial adhesion of microorganisms to the gels was assayed using two strains of Escherichia coli (K12 MG1655 and CFT073), as well as two strains of Staphylococcus aureus (SH1000 and methicillin-resistant S. aureus, i.e., MRSA), representing both well-studied and clinically relevant microorganisms. Bacterial adhesion was the greatest on the thinnest, softest PDMS gels, with S. aureus SH1000 demonstrating the greatest changes in adhesive behavior in response to gel thinness. These findings suggest that both PDMS gel stiffness and thickness are important factors when considering the initial adhesion of these Gram-negative and Gram-positive microorganisms to hydrophobic biomaterials.

Direct ink writing (DIW) is an extrusion-based form of 3D-printing that has gained popularity over the last decade. DIW uses thixotropic fluid extrusion to form a particular shape. In order to form stable structures, the rheology of the paste is important to allow for extrusion from the syringe, stability of the growing print, and prevention of unwanted seeping flow during jog moves. In this work, we use wood pulp as a bio-based filler that can provide shear thinning properties to the ink, which produces a stable ink for DIW processing. Additionally, the filler imparts improved mechanical and thermal performance compared to neat resin. The wood pulp provided the shear thinning behavior necessary for DIW printing, and pulp loadings greater than 6 wt%, provided sufficient yield stress so that the composite could self-support during printing. Nanoclay was utilized to further improve ink rheology and appearance to enable larger scale printing. Overall, this work showed successful DIW of an epoxy resin with a sustainable filler improving its stiffness and thermal properties and provides an avenue for further development of bio-based inks for DIW towards various applications.

The development of degradable elastic materials has become important to reduce waste and develop transient devices. Most degradable elastomers have issues with uncontrolled and random degradation and poor storage stability. Self-immolative polymers (SIPs) can offer stabilization and triggered depolymerization through stimuli-responsive end-caps. In this paper, we describe the crosslinking of poly(ethyl glyoxylate) (PEtG), a SIP with UV and acid labile end-caps, to create an elastic polymer network. The material withstood strains up to 100 percent before failure in our pull to break tests and was able to withstand up to 10 repeated strains of 20 percent with little change to the stress strain curve. The material was then exposed to degradation conditions where UV light triggered partial degradation and 1 molar hydrochloric acid degraded it fully. The controlled degradability and mechanical properties of this material represent a step towards sustainable transient devices.

The growing demand for eco-friendly substitutes of traditional plastics has further driven the research on compostable and biodegradable films with enhanced functionality. Epoxidized soybean oil (EPSO) was prepared through in situ peracid epoxidation and used as a nontoxic, hydrophobic plasticizer in thermoplastic starch (TPS)/poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites in this study. For better interfacial compatibility and functionality, TPS was filled with nanocrystalline cellulose (NCC) and mixed with EPSO, glycerol, maleic anhydride (MA), rice bran wax (RBW), and stearic acid (SA). The flexible films (50–80 μm) were prepared using blown film extrusion. Structural assessments verified effective soybean oil epoxidation and its homogeneous integration into the polymer matrix. Mechanical analysis indicated that EPSO-modified films, especially 20% glycerol–10% EPSO and 15% glycerol–15% EPSO, exhibited higher tensile strength (13.63 MPa), better sealability, and maintained ductility. Barrier analysis demonstrated these films have lower water vapor permeability and greater hydrophobicity (contact angle up to 108.6°). Thermal analysis (TGA, DSC and FTIR) also confirmed their higher stability and compatibility. Soil burial tests provided proof of excellent biodegradability (>75%), emphasizing the compostability of the films. In general, the synergistic contribution of EPSO and bio-reinforcements resulted in mechanically stable, hydrophobic, and biodegradable films that provide an eco-friendly substitute for single-use packaging and farming purposes.

The need for renewably sourced polymers has intensified with the worsening of global challenges such as emissions and plastic pollution. Here, we report a CO₂-based poly(cyclohexene carbonate) (PCHC) vitrimer cured with zinc stearate that directly addresses both issues. Enhanced zinc dispersion within the network enabled faster curing and reprocessing than possible with zinc acetate systems, while maintaining consistent T_g and mechanical integrity across multiple cycles. The vitrimer undergoes rapid glycolysis in ethylene glycol, valorisation into ethylene carbonate with up to 97% yield without additional catalyst. When applied to carbon fibre-reinforced polymers (CFRPs), applying this strategy enabled the development of sustainable CO₂-based CFRP that can undergo full resin valorisation and recovery of clean, damage-free fibres. Collectively, this tandem CO₂ valorisation strategy—from vitrimer synthesis to fibre-reinforced composites and subsequent chemical valorisation—establishes multiple recycling and valorisation pathways and provides a promising routte for carbon capture and utilization as well as material recycling.

Healthcare associated infections are widely reported to cost the European economy alone over £20 billion per year and cause an estimated extra 25 million hospital days considerably increasing patient morbidity and mortality. Implanted medical devices have previously been developed without the consideration of their potential to harbour pathogens at their surface, and this has resulted in many devices that suffer from bacterial biofilm colonisation and fibrotic foreign body responses that cause inflammation and inhibit wound healing. Here we report the development of a fibrous bioinstructive co-polymer mat that reduces biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus by 84% and 59% respectively compared to poly(lactic acid) fibres. The fibres also promote proliferation of fibroblast cells by 2.2-fold over 3 days compared to 1.2-fold for poly(lactic acid) samples, showing that the fibres promote a wound healing environment. Through the development of new materials for bioinstructive meshes, this work aims to develop new materials that can be used for surgical meshes that can prevent infections without the need for antimicrobials or toxic leaching compounds.

The rising popularity of fiber-reinforced polymer (FRP) composites in the aerospace, automotive, and energy industries leads to waste management difficulties. This review critically considers 3R (recycling, recovery, and reuse) options for thermoset-based FRP composites, contrasting traditional (landfilling and incineration) and developing (solvolysis, microwave-assisted recycling, and catalytic) approaches. As the thermal recycling method leads to industrial recycling, it has a detrimental effect on the fibers’ characteristics and demands high energy input. Advanced solvolysis techniques, such as Fenton-based degradation, enable effective resin decomposition under mild conditions while retaining approximately 90% of the fiber strength. This review article emphasizes the practical applications of recycled carbon fibers (rCFs) in the automotive and aerospace industries, highlighting their economic as well as environmental benefits. Lifecycle assessments show that solvolysis is the most sustainable option, reducing greenhouse gas emissions by ∼30–50% compared to landfilling. The challenges of scalability, cost, and policy alignment are highlighted, along with future possibilities in hybrid recycling and advanced applications. This study proposes an outline for conveying FRP waste to a circular economy while balancing technical feasibility and industrial sustainability.

We present a new method to obtain tertiary amine-based prodrugs with dual functionality, enabling (i) signal-triggered drug activation and (ii) covalent incorporation in polymer materials through a clickable azido-group unit on the molecular prodrug scaffold. Using nucleophilic substitution on an electron deficient azido-phenyl allyl bromide scaffold, we were able to obtain prodrugs from a variety of amine drug candidates. Subsequent drug activation was initiated by using S or N-terminal biomarker nucleophiles including amino acids, a neurotransmitter, and glutathione as chemical signals. Hydrogel scaffolds labelled with anti-cancer or antibiotic prodrugs were tested in aqueous and cellular media. Through this strategy, we achieved controlled drug release upon signal activation for in vitro cancer models with ∼100% wound closure inhibition of A549 small lung cancer cells. We anticipate that this new strategy for the development of responsive prodrug-conjugate incorporated materials will lead to further advancements in drug delivery and specialized therapeutics.

Soft actuators are at the forefront of the innovation tide in medicine, manufacturing, and aerospace because they are able to mimic the behavior of biological tissue and adapt to complex, unstructured environments. Of all the materials used, silicone-based elastomers have drawn enormous attention since they offer a superb combination of mechanical flexibility, biocompatibility, thermal stability, and long-term durability. In the past few years, there has also been a rapid pace of material evolution, additive manufacturing, and biointegration that has enhanced the performance and applications of silicone-based soft actuators. However, there is no focused and timely review compiling these advances. This review seeks to address that need by critically discussing recent advancements in advanced silicone materials, exploring new fabrication methodologies, and discussing emerging applications that range from wearable devices to implantable robotics. We also present suggestions for directions and the problems which must be addressed in order to further develop the performance and potential of silicone-based soft actuators, justifying the relevance and urgency of this effort.