RSC Applied Polymers最新文献

Elastane fibers, renowned for their balanced strength, elasticity, and comfort, are a prevalent component in blended fabrics. However, their strong adhesion within core-spun yarns and resistance to chemical dissolution pose significant challenges for separation and recycling. The lack of a universal single-solvent strategy across blend types limits the scalability of selective dissolution recycling. Here, we propose an alternative approach using a dissolvable chitosan (CS) finishing layer applied to elastane fibers, which can be selectively removed at end-of-life to enable separation from sheath fibers. We implemented a continuous dip-coating process and demonstrated its feasibility at pilot scale using a roll-to-roll setup. By tuning solution viscosity, we achieved uniform, conformal coatings on neat elastane. A 4 wt% CS solution in 0.5 N HCl yielded a 5–10 μm-thick coating that forms strong non-covalent interactions with the elastane core without compromising the elastic modulus or energy dissipation under cyclic strain. The CS layer can be redissolved under mild acidic conditions, preserving the chemical integrity of the recovered elastane. This proof-of-concept highlights CS dip-coating as a promising finishing strategy for scalable elastane recovery from diverse fiber blends via selective dissolution.

The solvent-free photopolymerization of a eutectic mixture consisting of a quaternary ammonium methacrylate salt, urea, and functional co-monomer to yield polymeric eutectogels with unique properties and function is reported. Herein, we prepare eutectic solvents based on urea as a hydrogen bond donor, [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) as a hydrogen bond acceptor, and 2-hydroxyethyl methacrylate (HEMA) as a comonomer to modulate physical properties, such as viscosity and hydrophilicity. METAC was used as the isolated salt, rather than as aqueous solution, to directly prepare water-free eutectic solvents with control over the final composition. These viscous, room-temperature stable liquids possess tunable glass transition temperatures and shear-dependent viscosity. Their direct photopolymerization, either via ultraviolet or visible-light-mediated methods and in the presence of crosslinker, gives rise to polyelectrolyte eutectogels with very high and tunable swelling capacity in aqueous media. The viscous nature of the eutectic mixture enables rapid photopolymerization kinetics compared to the equivalent process in water, with close to seven-fold increase in polymerization. Their cationic nature gives the gels inherent antimicrobial properties, as shown through their deactivation of S. aureus bacterial cells. Variation of the crosslinker concentration enables eutectic resins to be formed that show potential for direct ink writing (DIW) photopolymerization methods, highlighting the versatility of these materials.

This work presents a wearable temperature sensor fabricated by inkjet printing using poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) ink, with a top layer of extrusion-printed silver ink serving as electrodes, on both glass and cotton-based fabric substrates. PEDOT:PSS, a widely used conductive polymer, was selected due to its affordability, conductivity, and biocompatibility. The sensors demonstrated excellent humidity resistance with enhanced conductivity, making them ideal for wearable technology applications. The glass-based benchmark sensor exhibited a resistance change of approximately 30% across a temperature range of 23 to 40 °C, with sensitivity exceeding 1.7% per °C. In comparison, the fabric-based sensor, designed for wearable applications, showed a 20% decrease in resistance with sensitivity greater than 0.65% per °C. This represents a notable enhancement compared to values reported in the literature. Both sensors exhibited a strong linear relationship between temperature and resistance, with coefficients of determination (R²) of 0.995 and 0.779 for the glass and fabric sensors, respectively. These results highlight the potential of fabric-integrated sensors for wearable applications, offering reliable performance and temperature sensitivity comparable to those of traditional glass-based sensors.

The surface patterning of polymers is an important approach to enhancing material properties for a large variety of applications. Due to the formation of irreversible crosslinks however, thermoset polymers tend to be challenging to pattern. In this paper we present a novel method of patterning a commonly used thermoset polymer, polydimethylsiloxane (PDMS), through controlled photothermal curing. We show that by incorporating 0.05% carbon black by weight into PDMS and moving a continuous wave-based laser engraver over the surface in a snake pattern, we can photothermally generate micron-scale surface features, and that these patterns can be controlled through laser parameters. Finally, we show that the photothermally patterned PDMS surfaces undergo changes in the optical properties as a result of patterning.

Wound healing is a multifaceted physiological process, often hindered by persistent inflammation, homeostatic imbalance, and impaired tissue regeneration. Traditional therapies frequently fall short in addressing these challenges, underscoring the need for advanced therapeutic strategies. In this study, we designed a novel nanodrug delivery system based on poly(ρ-coumaric acid) (PCA), a bioactive polymer derived from natural sources, known for its anti-inflammatory and antioxidant properties. The PCA nanoparticles (NPs) were engineered to encapsulate ibuprofen (IBP), a non-steroidal anti-inflammatory drug, and subsequently integrated with hyaluronic acid (HA) to enhance wound site adhesion and create a moist regenerative microenvironment. This multifunctional platform (PCA@IBP NPs/HA) could synergistically achieve sustained drug release and leverage the intrinsic bioactivity of its components. In vitro assays demonstrated that the system effectively promoted cell migration and angiogenesis due to the combined anti-inflammatory effects. In vivo studies using an acute wound model confirmed accelerated wound closure, superior re-epithelialization, and collagen deposition. This work provided a novel strategy that synergistically integrated traditional herbal bioactive with nanotechnology, offering a promising platform for the development of next-generation wound-healing therapeutics.

We would like to take this opportunity to thank all RSC Applied Polymers reviewers for helping to preserve quality and integrity in chemical science literature. We would also like to highlight the Outstanding Reviewers for RSC Applied Polymers in 2024.

Designing and controlling the molecular characteristics of polymeric feedstocks is crucial for creating robust structures via the powder bed fusion (PBF) process. To explore the impact of a powder's molecular weight on printed part structure and properties, thermally induced phase separation was employed to produce spherical, appropriately sized polypropylene (PP) powders formed from individual unimodal molecular weights and molecular weight blends. More precisely, these powders are composed of 12 000 Daltons PP (12k), 250 000 Daltons PP (250k), or 340 000 Daltons PP (340k), as well as their blends (50/50 wt% of 12k/250k, 12k/340k, 250k/340k, and 33/33/33 wt% of 12k/250k/340k). Analysis of the printed parts from these powders shows that the blended molecular weight (M_w) samples exhibit lower void space and higher crystallinity than the unimodal M_w counterparts. More importantly, dynamic mechanical analysis of the printed parts shows a substantial increase in storage modulus for blended molecular weight samples compared to unimodal M_w counterparts. This significant enhancement in the mechanical property of the blended molecular weight samples is due to improved coalescence dynamics driven by the powders’ decreased melt viscosity. Improved coalescence reduces the void space in the printed parts, thereby improving mechanical performance. These results, therefore, provide a molecular-level understanding of the mechanism by which low M_w additives improve PBF processability, presenting avenues to augment the macroscopic properties of the printed parts. Additionally, the powder design approach presented in this work is cost-effective and offers a simple strategy to enhance the final part properties across various materials in additive manufacturing.

There is a range of diseases related to the insufficient lubrication of tissue surfaces. Typically, this occurs as a consequence of the reduced or incomplete production of the macromolecular key components of the respective biolubricant. Thus, developing substitute macromolecules to mitigate friction (and pain resulting thereof) in poorly lubricated joints, on the eyes, or in the oral cavity is an important task in the field of biomaterials science. To date, commercially available biomacromolecules such as hyaluronic acid (HA) and porcine gastric mucin (PGM) have mostly been in the focus of biolubrication research. However, their ability to reduce friction and surface damage generation is limited, which calls for novel approaches. Here, we create chemical modifications of commercial PGM by conjugating different catechol-like molecules (Levodopa (L-Dopa), 3,4,5-trihydroxybenzamide (THBA), or tannic acid (TA)) to the glycoprotein. Whereas solutions comprising unmodified PGMs exhibit poor lubricity, the conjugates show significantly improved surface adhesion and lubrication properties, with the TA–PGM conjugate performing the best. This particular conjugate also mitigates wear formation on PDMS and articular cartilage surfaces equally well as lab-purified porcine gastric mucin and, on hydrophilic surfaces, provides lubricity that even outperforms that of solutions comprising chemically intact, in-lab purified mucins. Our findings pave the way towards the production of a highly versatile biolubricant that can have a broad range of biomedical applications: as a biocompatible viscosupplement in osteoarthritic joints, as a lubricant additive after knee or hip implant surgery, as a component for artificial tear fluids, or for the treatment of xerostomia.

Membrane technology offers a compelling approach for separating hydrofluorocarbon (HFC) refrigerant mixtures, primarily due to lower energy demands and lower capital investment compared to traditional separation techniques. Herein, we report the development of fluorinated poly(ionic liquid)-ionic liquid composite membranes, combining the advantageous properties of both polymers and ionic liquids (ILs), for HFC gas separation. Two vinyl imidazolium-based fluorinated ionic liquid (FIL) monomers were synthesized, along with two FILs containing complementary cations and anions, which were incorporated as “free” liquid. Free-standing, IL-containing membranes were prepared by photopolymerization of the FIL-based monomer and a crosslinker in the presence of free IL. As a complementary study, membranes were also prepared from a methacrylate-based non-fluorinated imidazolium IL monomer with 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₆C₁im][Tf₂N]) as free IL. The extent of crosslinking and the relationship between membrane composition and thermal properties are reported. Pure-gas permeability of commonly used HFC gases, specifically HFC-32 (difluoromethane) and HFC-125 (pentafluoroethane), were evaluated. For all membranes, HFC-32 had higher permeability than HFC-125. Finally, we demonstrate the use of digital light processing (DLP) additive manufacturing to print the membranes, presenting a promising avenue for the rapid fabrication of bespoke membranes for difficult separations.

This review critically examines the potential of chitin nanowhiskers (ChNWs) as high-performance reinforcement materials for the plastics industry, with a specific emphasis on their impact on composite properties. It provides a structured overview of established ChNW preparation techniques—acid hydrolysis, oxidation, mechanical disintegration, and green solvent processing—and discusses advanced fabrication strategies for producing ChNW-reinforced composites of both natural (e.g., cellulose, chitosan, starch, hyaluronan) and synthetic (e.g., polyvinyl alcohol, poly(α-cyanoacrylate), polyaniline, polyethylene terephthalate, polypropylene) types. Key performance enhancements include increased mechanical strength, tensile strength, Young's modulus, thermal stability, and water resistance. These enhancements make ChNW-based composites suitable for real-world applications in aerospace, biomedical devices, packaging, and construction. Unlike previous reviews that emphasize only processing methods, this work identifies and highlights structure–property relationships as a central theme, bridging nanoscale morphology with macroscopic functionality.