RSC Applied Polymers最新文献

Inverse vulcanisation is a rapidly developing field of chemistry and materials science with the potential to afford low cost, green chemistry adherent, next generation polymeric materials from the industrial waste product: elemental sulfur. With tuneable properties, recyclability, as well as convenient and adaptable syntheses and processing, inverse vulcanised polymers may be used in several desirable applications, such as batteries, water purification, and advanced optical components. In the ten years since the field's conception, inverse vulcanisation has garnered growing research interest and popularity, and has even seen some recent commercial uptake. This review article is focused on supporting the growth of the inverse vulcanisation field by providing a resource for new researchers to have the most efficient possible start in the field. In that regard, this review article is designed to act as an ideal starting point for researchers looking to become invested in the field. This review first outlines the origin of inverse vulcanisation, before giving a small account of the applications of inverse vulcanisation and pointing to other useful reviews on these applications, thus making a case for research interest and providing sources of potential inspiration for new ideas. Most importantly, this review goes on to provide an effective resource for lab based researchers to establish themselves with foundational knowledge of the field, while offering a guide to practical skills in performing inverse vulcanisation. In doing so, this review offers a guide to standardising methods in inverse vulcanisation whilst also allowing new lab workers to avoid some of the pitfalls that are not obvious, and not common to other fields of chemistry. Then, this review examines methods of analysing inverse vulcanised polymers, which can be challenging, and sometimes needs careful consideration. Finally, this review looks at some mechanistic considerations of inverse vulcanisation before proposing directions for future research in the field.

The current study focuses on finding a viable and sustainable alternative to hazardous chrome-based pigments commonly used in organic anticorrosive coatings. We investigated the effectiveness of cerium and phosphate precursor modified conventional silica through a simple synthetic route. The synthesised pigment was further surface-modified with aminopropyl trimethoxy silane to improve its interaction with the epoxy binder. The resulting silane functionalised hybrid pigment-reinforced epoxy coating has a resistance of 9.91 × 10⁹ Ω cm², two and five orders of magnitude higher than those of silica–epoxy and bare epoxy coatings, respectively. Also, it shows a hydrophobic contact angle of 100°, which further enhances the barrier properties. Continuous electrochemical impedance spectroscopy (EIS) was used to examine coating performance with and without artificial defects. The results showed improved performance compared to commercial chrome-based pigments and an active protection mechanism. Our study presents a reliable, inexpensive, and healable approach using conventional silica particles to prevent steel corrosion in saline media.

This work demonstrates the application of pilot-scale surface functionalization of cellulose nanofibrils (CNFs) by aqueous grafting-through polymerization and subsequent spray drying in 3D printed poly(lactic acid) (PLA) composites. Grafted-CNF composites attain an ultimate tensile strength of 88 ± 3 MPa and a tensile modulus of elasticity of 7.8 ± 1.3 GPa in the printing direction at 20 wt% reinforcement loading. These increases, 42% and 139% over neat PLA, respectively, represent the strongest reported 3D printed CNF/PLA composite to date in the literature. The mechanisms behind these improvements are investigated by comparisons to neat PLA and unmodified spray-dried CNF/PLA controls using melt rheology, dynamic mechanical analysis, and assessment of the reinforcement dispersion. These experiments reveal that improved network formation and shear-induced alignment of the grafted CNFs facilitate the remarkable tensile properties of the printed composites.

Porous polymer materials, including polymer foams and melt-blown fibers, have nano or micro-size pores and a large specific surface area that endows them with great potential as engineered oil ad/absorption materials. This review provides an overview of the recent developments in the processing of polymer foams and melt-blown fiber-based porous polymeric materials for oil absorption properties. Detailed processing and preparation methods of polymer foams utilized in oil absorption are scrutinized, along with the recent peer-reviewed published research on the development of new polymer foams, such as nanocomposite foams and biodegradable foams. Critical reviews are also conducted on the modification methods, such as employment of surfactants, coating, plasma treatment, and chemical grafting. In addition, the recent progress in the processing of melt-blown fibers and the potential applications for oil absorption are discussed. A comparative analysis of the strengths and weaknesses of porous polymer materials between polymer foams and melt-blown fibers is presented. Lastly, the potential for developing melt-blown non-woven fibers as a viable alternative for oil absorption materials is explored.

Epoxy vitrimers are versatile thermoset polymers with good mechanical and reprocessable properties. Generally, they are prepared with complex procedures by using petroleum-based monomers. Herein, we report a one-pot catalyst-free procedure to synthesize bio-based epoxy vitrimers. Diacrylate was used to react with amine via aza-Michael addition yielding β-amino esters with reversible dynamic covalent bonds which can be strengthened by the in situ generated tertiary amine groups. Because of the ester and β-amino esters, the bio-based epoxy vitrimers can be reprocessed and readily programmed. Moreover, due to the introduced ester group from diacrylate, the produced epoxy vitrimer showed good recyclability. This study provides a feasible strategy to develop intelligent materials based on epoxy vitrimers.

Climate change-induced water scarcity threatens global plant life and agricultural productivity. Here, we present a novel atmospheric water harvesting (AWH) coating designed to alleviate heat and dry stress potentially. This polymer coating utilizes block copolymers carrying catechol-anchoring groups, specifically poly(dopamine methacrylamide) (PDOMA), to adhere to plant leaves. As a hydrophilic block, either poly((oligoethylene glycol) methacrylate) (POEGMA) or the thermoresponsive block poly(N-isopropylacrylamide) (PNIPAM) was used, which can adsorb water from the air during cooler periods in its hydrophilic state. As the temperature increases above the lower critical solution temperature (LCST) of PNIPAM, the polymer transitions to a hydrophobic state, releasing the captured water to the leaf surface. We synthesized PNIPAM-b-PDOMA copolymers via RAFT polymerization and confirmed their composition (IR, ¹H NMR and ¹H DOSY NMR spectroscopy) with a cloud point temperature of 33 ± 1 °C. The coatings were applied to model substrates (SiO₂, polyethylene) and corn leaves. Compared to uncoated controls, coated substrates demonstrated a substantial increase in water uptake from humid air, absorbing up to 50 wt% of the coating's weight. The coating's adherence and thermoresponsive behavior were confirmed on corn leaves through contact angle measurements, showing a shift from hydrophilic (29 ± 3°) below the LCST to hydrophobic (80 ± 2°) above the LCST, closer to the native, hydrophobic leaf (110 ± 10°). Crucially, photosynthesis induction experiments revealed that the coating did not negatively impact the plant's natural photosynthetic processes. This study establishes a promising copolymer platform for developing AWH coatings to support plants in the face of increasing drought conditions.

The precise encapsulation of polymer chains within nanometer-scale spaces or structures has sparked a dynamic research field with vast potential for technological applications. Through confinement, properties such as morphology, thermal stability, and mechanical strength can be finely tuned, offering opportunities for advanced materials and biomedical devices. Various confinement methods, including nanoparticle encapsulation, planar thin films, and cylindrical confinement, induce unique alterations in polymer behaviour, affecting their optical, electronic, and thermal properties. The remarkable expansion in the applications of confined polymers across numerous research fields underscores the need for critical discussions on future potential. Therefore, this perspective article aims to identify key challenges and opportunities in this interdisciplinary research community, with a special focus on their practical applications.

We conducted an experiment to compare the predicted outcomes with the practical results of synthesizing four-dimensional (4D) hydrogels and observing their 4D motion. We employed a computer simulator and utilized PET-RAFT and orthogonal chemistry methods. To initiate the study on 4D materials, we employed the swelling method and controlled it by utilizing visible light synthesis. To regulate the irradiation time of blue light, we employed cinnamoyl ethyl acrylate as an orthogonal system to control crosslinking density. Various physical properties were assessed using a rheometer. Our findings confirmed that the movement could be controlled by adjusting the swelling ratio of the upper and lower parts, thereby implementing a bi-layer design based on differences in crosslinking density. This study highlights the successful synthesis of hydrogels with diverse physical properties and demonstrates the potential of 4D materials through the orthogonal synthesis technique.

In mixed ionic–electronic conductive polymers, electronic conduction is optimal in tightly packed flat chains, while ionic conduction benefits from free volume accommodating large ions. To this end, polymers with high crystallinity are often excluded from structure–property studies of high-performing mixed conductors due to their unbalanced transport, which favors electronic charges over ionic ones. Herein, we investigated how mixed conduction can be achieved in ordered conjugated polymers by systematically combining interchain order with side chain engineering. We synthesized a series of isoindigo (IID)-based copolymers with varying amounts of aliphatic and hydrophilic side chains and examined the impact of interchain order on mixed conduction. Through crystallographic, spectro-electrochemical, and molecular dynamics studies, we demonstrated that systematically introducing hydrophilic side chains reduces the bulk order and long-range aggregation by increasing chain flexibility while preserving the interchain stacking distances within crystalline domains. Testing these IID polymers in transistor devices revealed that ion insertion and device transconductance strongly depend on the amount of hydrophilic side chains. We demonstrated that glycol side chains can enhance mixed conduction while maintaining interchain order. Our findings suggest that the IID system is promising for designing polymers that can accommodate ionic species without compromising the chain ordering required for electronic conduction.

An advanced multilayer thermoplastic composite, composed of Polyethylene of Raised Temperature (PERT), Polyamide 12 (PA12), and Maleic Anhydride Grafted Polyethylene (MA), has been developed for high-temperature, high-pressure applications. An adhesive layer consisting of 35–60–5 wt% PERT-PA12-MA (Blend), has been tailored to optimize adhesive strength between PERT and PA12 layers. The developed three-layer composite (Trilayer) demonstrated exceptional water vapor and CO₂ barrier properties by incorporating PERT as a water transmission retarder and PA12 as a CO₂ diffusion retarder. At 82 °C, the water vapor transmission rate and CO₂ permeability of Trilayer samples were 58%, and 31% lower than those of the Blend, respectively. The Trilayer samples exhibited an average Young's modulus that was 17% higher than that of the Blend, while the yield stress was similar to the Blend. In terms of creep resistance, the Trilayer samples showed a 29% and 40% reduction in tensile creep strain and creep rate, respectively, compared to the Blend. Additionally, the Trilayer samples achieved 48% and 39% decreases in flexural creep strain and creep rate, respectively, in the flexural creep test. The Trilayer also exhibited a 56% decrease in deformation under drop-weight impact and a 14% improved impact absorption compared to the Blend. The overall performance of the multi-layer thermoplastic composite made from PERT and PA12 constituents was significantly enhanced, aligning with the carbon footprint reduction initiative to substitute thermoset, metal, and other traditional materials.