Journal of Coatings Technology and Research最新文献

The increasing demand for environmentally sustainable materials has increased interest in renewable raw materials for polymer synthesis. Among these sources, waste cooking oil (WCO) has been considered a promising alternative due to its abundance, low cost and rich triglyceride content suitable for polymeric applications. This review examines the use of WCO in the synthesis of alkyd resins, highlighting significant improvements in raw material processing, resin formulation development and resulting physicochemical properties. The addition of WCO not only addresses waste disposal concerns but also offers a path toward the development of high-performance, bio-based coating materials. The effects of oil pretreatment, polyol selection and reaction parameters on resin properties are discussed in this study. Comparison with conventional alkyds shows that WCO-derived resins exhibit competitive drying behavior, mechanical stability and adhesion properties, although they have some limitations in oxidative resistance. The review also examines recent innovations aimed at improving the quality and durability of WCO-based alkyds, with the aim of positioning them as sustainable candidates in the coatings industry.

A tannic acid-polyphenylene methylene modified acrylic resin was synthesized by solution polymerization technique. The synthesis route involved reaction of tannic acid with suitable acrylic monomers to form tannic acid modified acrylic resin followed by in situ polymerization of this modified acrylic with benzyl chloride in presence of catalyst. The formation of such modified acrylic structure was confirmed by FTIR and ¹H NMR spectroscopic analysis. The novelty of this work is in the synthetic approach to incorporate tannic acid and polyphenylene methylene in acrylic resin matrix to utilize the properties of phenolic hydroxyl and π orbital system of polyphenylene methylene moiety to improve mechanical and anticorrosive properties of coating film. Polyurethane coating based on this modified acrylic resin was evaluated. It was found that the coating with 2 wt% tannic acid containing resin exhibited excellent mechanical properties like flexibility, adhesion, hardness, impact resistance along with anticorrosive performance. Such coating has potential for usage as in high-performance protective coating.

The rising demand for nutrient-efficient and environmentally sustainable fertilizers has driven innovation in advanced controlled-release fertilizers (CRFs). This review comprehensively analyzes hybrid coating systems that combine stimuli-responsive polymers and nanomaterials to enable precise and adaptive nutrient delivery. The discussion covers the underlying mechanisms of nutrient diffusion, polymer degradation, and stimuli-triggered release, supported by insights from laboratory evaluations and modeling approaches. Nanomaterials contribute enhanced barrier strength, structural stability, and sustained release, whereas smart polymers provide environmental responsiveness, enabling synchronization between nutrient release and plant uptake. When integrated, these components yield hybrid coatings with improved mechanical integrity, prolonged release duration, and reduced nutrient loss through leaching and volatilization. The review also evaluates recent progress in synthesis strategies, coating architectures, and field performance, while addressing biodegradability, safety, and regulatory challenges. Finally, it identifies key research gaps and future directions for developing next-generation, eco-efficient CRFs that align with sustainable and precision agriculture goals.

Recently, the environmental impact of oil spills has intensified the quest for efficient and sustainable methods for oil/water separation. To address this pressing environmental challenge, superwettable surfaces are being studied intensively. Superwettability is a property where the substrate surface exhibits extreme wetting properties, i.e., superhydrophobic or superhydrophilic, achieved by modifying the surface with micro/nano-hierarchical roughness and surface chemistry. Superhydrophobic surfaces, characterized by their extraordinary water-repellent properties, and superhydrophilic surfaces, with excellent oil-repellent behavior, can revolutionize the oil/water separation techniques. This inherent water-repellent or oil-repellent nature makes superwettable surfaces particularly adept at selectively repelling water while attracting and capturing oil-based substances or vice versa. This paper offers an in-depth evaluation of the current landscape of superwettable materials for oil/water separation. Despite the reported data displaying promising results, further intensive research is required to overcome the ethical, environmental, and durability constraints of nanotechnology intervention.

The complex drug and fertilizer release processes may take much work to understand and fully predict. Many empirical, semiempirical, and mathematical models have been developed to address the issue. Among the well-known models are Higuchi, power law, Hixson–Crowell, and Baker and Lonsdale. The primary factors influencing the release process include the release environment and the interaction between the active ingredients of medications and fertilizers, as described by Fick’s first law. Thus, choosing the best model is essential to accomplishing efficient drug release. Furthermore, it is crucial to comprehend the release processes, including osmotic pumping, erosion, diffusion through polymers, and diffusion via water-filled pores. Selecting the appropriate release mechanism is also necessary as it may help preserve the environment and save significant money. By thoroughly examining these models and mechanisms, it is possible to optimize active ingredient delivery, reduce expenses, and minimize pollution. This article explores drug and fertilizer release models and mechanisms to help achieve these goals.

In this review study, we look at how nanomaterials can prevent biofouling in marine antifouling coatings, which have a significant influence on maritime vessels and structures. Nanomaterials with wide surfaces, improved reactivity, and mechanical robustness are excellent resources for creating innovative antifouling approaches. The study assesses a variety of new formulations, including metal oxide nanoparticles, carbon-based nanomaterials, polymeric nanocomposites, hybrid nanomaterials, and bioinspired designs, all of which are effective and durable against fouling. Furthermore, the processes behind nanomaterials' antifouling activity are discussed, as are the prospective uses of nanomaterial-based antifouling coatings, as well as the accompanying restrictions and challenges. Finally, the article outlines forthcoming research avenues, including the creation of multifunctional coatings and the utilization of sustainable, nonharmful nanomaterials. Through the fusion of state-of-the-art nanotechnology with pragmatic implementations, this review evidences the capacity of nanomaterial-based antifouling coatings to transform the maritime sector by offering more effective, economically feasible, and environmentally friendly solutions.

Waterborne polyurethane (WPU) coatings exhibit poor water resistance and are highly permeable to corrosive media. Consequently, they may inevitably sustain damage during prolonged use, which significantly compromises their corrosion resistance. In this study, we synthesized a self-healing waterborne siloxane-modified polyurethane (WPU-Si). To develop a PU composite coating exhibiting both exceptional hydrophobicity and corrosion resistance, modified montmorillonite nanosheets and halloysite nanotubes encapsulated with 8-hydroxyquinoline were prepared. Compared to pristine WPU, WPU-Si demonstrated remarkable mechanical property enhancements, with tensile strength increasing by 293% (from 4.6 MPa to 18.1 MPa) and elongation at break enhancing by 44.5% (from 445% to 643%).The water contact angles increased from 71.04° (WPU) to 82.39° (WPU-Si), indicating enhanced hydrophobicity. All coatings demonstrated complete self-healing (100% recovery efficiency) following 12-h thermal treatment at 50 °C. The MMT-HNT/WPU-Si coating showed outstanding corrosion resistance, with 97.35% protection efficiency, due to the shielding effect of the modified montmorillonite sheets and the smart active protection provided by the release of 8-hydroxyquinoline from halloysite nanotubes. The charge transfer resistance was 3.25 × 10⁷Ω cm² after 30-min in 3.5 wt% NaCl solution, maintaining 6.92 × 10⁵Ω cm² after 30 days. This work provides constructive guidance for creating a low-cost self-healing smart PU composite coating with long-term corrosion resistance.

Steels with four different galvanizing coatings (zinc, zinc–aluminum–magnesium, zinc–iron, and zinc–aluminum) were coated with an acrylic thin organic coating and a solventborne polyurethane topcoat, followed by mechanical and water condensation testing. All the coatings passed the standardized mechanical testing (T-bend and impact resistance) and water condensation testing on flat panels (100% RH, 40°C for 1500 h). However, a combined deformation (T-bend at 0 T) and water condensation test (100% RH, 60°C for 48 h) showed differences between the samples. Below the seemingly intact organic coating, zinc and zinc–aluminum coatings showed thinning during deformation, and good early-stage resistance to humidity-induced metal oxidization. Zinc–aluminum–magnesium coating was more brittle, exposing steel, and initiating the galvanic protection process, which, because of Al and Mg content, was less pronounced than for the zinc–iron coating. Ion beam milling combined with high-resolution SEM-EDS provides an unparalleled technique to assess the early-stage degradation mechanisms and facilitates tailoring of more resistant coating systems.

Barrier coatings play a crucial role in cellulose-based food packaging by preventing the ingress of oxygen, moisture, oils, and greases, thus preserving food quality. This research explored sustainable and cost-effective alternatives for these coatings, utilizing a mix of lamellar and spherical inorganic fillers like kaolin clay, calcium carbonate, and fumed silica in an aqueous polyvinyl alcohol solution with a glyoxal crosslinker. The coatings were assessed for oxygen transmission rate (OTR), water vapor transmission rate (WVTR), and oil resistance (KIT rating), alongside characterization techniques such as Fourier transform infrared (FTIR) spectroscopy, Brookfield viscometry, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). The XRD diffractogram was utilized to determine the orientation index and relate it to the barrier properties. The SEM analysis revealed the coating’s compactness and cracks, indicating tortuosity based on different filler combinations. Results showed excellent barrier properties with OTR = 5.6 cc/m²/day and WVTR = 5.01 g/m²/day for a 70:30 combination of K2/S1, alongside a KIT value of 11-12. These sustainable coatings, showcasing such impressive performance metrics, could be considered a viable option for commercial packaging applications.

Graphical abstract

Metal/polymer coatings have low infrared emissivity and thus can enhance the infrared stealth capability of defense equipment. However, the metal/polymer coatings are susceptible to mechanical failure when subjected to mechanical action and environmental change. Therefore, Al/epoxy resin composite coating with additives of phthalate (DBP) plasticizer and silane coupling agent KH560 was proposed in the present work to achieve simultaneous low infrared emissivity and improved mechanical properties. The influences of Al powder and functional additives on the infrared emissivity and mechanical properties were thoroughly investigated through manufacturing experiments and properties characterization. It was found that increasing the mass fraction of Al powder can significantly reduce the infrared emissivity but also degrade the mechanical properties. Furthermore, both DBP and KH560 were proved to be able to effectively improve the flexibility and impact strength of the coating while retaining the low emissivity. The polymer coating, fabricated with 40 wt% Al powder and additives of 7 wt% DBP and 7 wt% KH560, exhibited a low approximate emissivity of 0.264 and enhanced mechanical properties, including a flexibility of 2 mm, hardness of 3H, and impact strength of 50 kg·cm.