Progress in Organic Coatings最新文献

Poly (dimethylsiloxane) (PDMS) elastomer is one of key polymer resins for fouling release (FR) coatings, but it shows extremely poor antifouling (AF) activity in seawater since bacteria and diatoms could readily attach to surface. Modifying PDMS-based coatings via incorporating antifouling additives is effective for enhancing overall FR and AF activity. In this work, we prepared a well-defined organoalkoxysilane coating additive with quaternary ammonium and benzoisothiazolinone pendent groups, and the synthesized copolymers were covalently conjugated onto PDMS network in a one-pot reaction. AF and FR activities of the modified PDMS coatings were studied against soft fouling microorganisms. When microorganisms come into contact the coating surface, contact-active action mode works, quaternary ammonium groups could cause bacteria cell membrane disruption and microalgae photosynthesize inhibition via positive charge. Unexpectedly, a surprisingly lasting antimicrobial efficiency could be still observed in the neighboring coating, even the top-surface was completely covered with bacteria biofilm. Chemically conjugated benzoisothiazolinone could be sustainably released via side-group hydrolysis, thus, repelling and preventing the planktonic foulings from approaching the coating surface via release-active action mode. The modified PDMS coating with dual antifouling action modes could inhibit the biofilm formation at solid-liquid-air three-phase contact line, and could find valuable applications in marine transportation, water treatment and other antifouling fields.

A fluorinated monomer with crosslinkable benzocyclobutene groups has been successfully synthesized starting from bio-based paeonol through the Suzuki and Grignard reaction. Treating this monomer at high temperature forms a cross-linked resin (cured PFB), which exhibits high glass transition temperature (T_g) of 439 °C, low coefficient of thermal expansion (CTE) of 87.4 ppm/°C, low dielectric constant (D_k) of 2.62, and low dielectric loss (D_f) of 8.45 × 10^-4 at a frequency of 10 GHz. In particular, cured PFB displays low water uptake of 0.1% even immersing it in boiling water for 96 h. These results demonstrate that the fluorinated bio-based monomer is a suitable precursor for the preparation of the low-dielectric packaging materials used in the microelectronic industry. Especially, this contribution provides a new way for the conversion of bio-based paeonol into the high-performance materials.

Industries are demanding more and more for the high corrosion protection and thermal conductivity of organic coatings. However, organic coatings always have low thermal conductivity, and the effective distribution of inorganic particles within these organic coatings remains imperative for further enhancing both anti-corrosion and thermal conductivity capabilities simultaneously. Herein, a novel method is introduced for the exfoliation of reduced graphene oxide (rGO) through wet ball milling, incorporating fly ash-based zeolites. The resulting particles (A-rGO) formed two structures: rGO sheets wrapped around or partially loaded on the surface of zeolite particles. Notably, the absolute zeta potential of A-rGO measures 47.8, marking a 4.26-fold increase compared to rGO, thereby facilitating enhanced dispersion within the coating matrix. Then, benzoxazine/A-rGO based coatings are made, which formed a thermally conductive pathway and constructed an anti-corrosion barrier. The results showed that the highest thermal conductivity of the prepared coating (A-r-2) was as high as 1.561 W·m⁻¹ K⁻¹, which was 676.1 % higher than that of benzoxazine based coating, and 159.7 % higher than that of the same content of benzoxazine/rGO coating. Furthermore, the low-frequency impedance value of the A-r-2 coating reached 2.433 × 10⁹ Ω·cm² with a water contact angle as high as 129.8 ± 0.2°. The particles designed in this study provides a new system additive for fabricating highly thermally conductive composite coatings with high corrosion resistance.

2D nanofillers can effectively improve coatings' barrier and anti-corrosion properties but are less compatible with coatings and prone to agglomeration. In this paper, glucose-derived phosphorus-doped carbon dots (P-CDs) were prepared as dispersants, and functionalized α-zirconium phosphate (α-ZrP) was prepared by combining with α-ZrP through π-π interactions, which showed good dispersion and compatibility in waterborne epoxy (WEP). The corresponding modified WEP coating is prepared on Q235 substrates through the scrape coating method. The effect of fillers on the physical and chemical properties of the coating was studied by electrochemical impedance spectroscopy (EIS), neutral salt spray test, and immersion test. The results of the electrochemical test show that the |Z|_{0.01 Hz} value of the coating prepared by P-CDs@ZrP as the filler after soaking in 3.5 wt% NaCl solution for 30 d is three orders of magnitude higher than that of the WEP coating, and the corrosion resistance is greatly improved. The salt spray and soaking tests prove that the prepared P-CDs@ZrP coating has excellent barrier properties and corrosion resistance. Besides, P-CDs can also act as an effective passivation agent, which could adsorb on the surface of the Q235 substrate and form a passivation film, preventing further corrosion of the substrate. This study provides a new way to enhance the corrosion resistance of the coating.

Anti/de-icing coatings to equipment surface are emergingly becoming an essential protection against ice formation and accumulation, especially when they serve in harsh environments. Herein, a novel approach for obtaining photothermal superhydrophobic anti/de-icing FCF-BP/SiO₂ coating with prominent abrasion resistance properties was presented. The fluoroalkyl silane and amino silane were polymerized at elevated temperatures and then closely combined with the resin and curing agent to obtain a film-forming polymer. This polymerization process involved the reaction of amino group on the surface of the modified fluorocarbon resin with the isocyanate group in the curing agent. Then the polypyrrole-coated basalt scales (BP) and SiO₂ NPs were employed to the modified coating system to construct a wear-resistant microscopic surface structure by the inverse infusion process (IIP). The water contact angle (CA) and the sliding angle (SA) of the tested coating was up to 155° ± 2° and 1.5° ± 0.5°, respectively, delaying the icing time to 656 s and maintaining the ice adhesion strength lower than 20 kPa after several icing-deicing cycles. It was verified that the FCF-BP/SiO₂ coating remained superhydrophobic and exhibited excellent mechanical durability even after 300 times of abrasion with sandpaper and 100 times of tape-peeling. Even at −10 °C, the frost (accumulated at −10 °C for 2 h) or ice cube (0.5 g) on the FCF-BP/SiO₂ coating could be effectively removed by 1.00 Sun within approximately 309 s and 760 s, respectively. This provides potential applications for fabricating functional anti/de-icing materials in some prospective fields including marine or aviation fields.

In regions experiencing cold weather, road icing poses significant challenges to transportation safety. Traditional anti-icing or de-icing methods, such as salt spraying, have raised environmental concerns, prompting the exploration of more sustainable alternatives. This study introduces a novel approach by developing a hydrophobic coating for road surfaces. This method involves using room-temperature vulcanized silicone rubber (RTV) and carbon nanotubes (CNTs) for the hydrophobic modification of emulsified asphalt (EA), resulting in the preparation of modified emulsified asphalt (RCEA). This method does not cause environmental pollution and makes the road surface highly hydrophobic and effective at preventing ice formation. When the dosages of RTV and CNTs are 20 wt% and 4 wt%, respectively, the contact angle of RCEA reaches 118.6°, showing a significant increase of 73.4 % compared to EA. Comparative tests have revealed that RCEA extends the freezing time of water droplets by 66.7 % at −10 °C compared to traditional emulsified asphalt (EA). Furthermore, the adhesion force of ice on the RCEA surface is 58.2 % lower than on EA, indicating significantly improved de-icing efficiency. The results of ultraviolet aging and freeze-thaw cycle tests show that RCEA maintains its hydrophobicity, evidenced by only a slight reduction in the contact angle. Additionally, water seepage coefficient tests and anti-skid performance assessments confirm that RCEA meets the requisite standards for road performance. In summary, RCEA emerges as a promising anti-icing and de-icing material for asphalt roads, offering an environmentally friendly alternative to traditional de-icing methods.

In this study, insect-based resin, i.e., shellac, was spray-coated onto molded pulp product (MPP) as a water and grease-resistant food-grade barrier coating for packaging applications. The shellac was first crosslinked by curing at 125 °C for 210 min, and DSC confirmed the formation of a thermoset material. Moreover, the Tg of shellac increased after crosslinking, showing a decrease in free volume and a reduction in molecular mobility. The shellac-coated MPP was further crosslinked and then tested for different barrier properties. FE-SEM confirmed the uniform coating of shellac over the MPP, and the crosslinking showed the removal of micro holes from the coating and increased the interfacial bonding with the MPP. The crosslinked shellac coating showed a high water barrier, as Cobb and water vapor transmission rate (WVTR) showed while providing excellent grease resistance through KIT test, mustard oil penetration, and heptane transmission rate (HTR). Further, the crosslinked shellac was also under the migration limit with all the food simulants at room and elevated temperatures, showing the safe usage of different food products at different temperatures. The coating also improved the coated MPP's tensile index and bending stiffness.

Medical catheters might cause a high morbidity of catheter-associated urinary tract infections (CAUTIs) because of the bacterial adhesion onto the surface. In addition, the inherent hydrophobicity of catheter materials exacerbates mechanical friction, leading to tissue damage. Therefore, coatings with integrated antibacterial and lubricative properties are appealing approaches to mitigate these challenges. In this study, a kind of polyurethane (PU)-based coatings were developed and prepared on medical catheters, which were modified with a cationic antibacterial agent, quaternized ammonium-modified methyldiethanolamines (QMDEAs). Due to the reaction among castor oil tertiary alcohols, isocyanates and QMDEAs, a polymer cross-linked network was fabricated, in which a hydrophilic polymer, polyvinylpyrrolidone (PVP), was added to form a semi-interpenetrating network. The structures of the coatings were regulated by adjusting the lengths of alkyl chain of QMDEAs, concentrations of pre-coated solutions, ratios of QMDEA:isocyanate, and parameters of preparation process. Among the coatings we prepared, PU-C10–46 possessed the optimized performances, which reduced the dynamic friction coefficient by 91.38 % and had the antibacterial efficiency of 99.9 % with good biocompatibility. The in vivo anti-infective properties of PU-C10–46 were also demonstrated by an infected animal model. Furthermore, PU-C10–46 was produced in an industrial equipment, and the large-scaled industrial products also had the same performances. This work could provide a promising strategy to deal with the challenges of medical catheter-associated infection.

Waterborne blend, hybrid and block copolymer latexes containing hard and soft polymeric phases in different polymer particles, in the same polymer particles or in the same polymer chains are prepared in order to analyse how the coalescing aids added in order to produce continuous films at room temperature affect their final mechanical properties. The minimum film formation temperature is measured for the three latexes upon addition of Texanol and BDG coalescing aids, and the possibility of producing continuous films at room temperature with different amounts of the coalescing aids is analysed. The plasticizing effect of each coalescing aid is analysed by DSC and by measuring their partition coefficients between the water and the polymeric phases. Finally, the evolution of the mechanical properties of the films plasticized with BDG and dried for different times is related to the evolution of the coalescing aid remaining in the film after those drying periods and to the morphology of each film.

Elaborating the structure–activity relationship between hyperbranched polymer architecture and the resulting surface antifouling performance is critical for biomedical applications. In this work, a series of poly(2-methyl-2-oxazoline) (PMeOx)-based hyperbranched poly((poly(2-methyl-2-oxazoline) acrylate)-co-(S-(4-vinyl) benzyl S′-propyltrithiocarbonate))s (poly(PMeOxA-co-VBPT)s) with varying degrees of branching (DBs) were synthesized via reversible addition-fragmentation chain transfer polymerization and self-condensing vinyl polymerization (RAFT-SCVP) of poly(2-methyl-2-oxazoline) acrylate (PMeOxA) and S-(4-vinyl) benzyl S′-propyltrithiocarbonate (VBPT). The copolymers were anchored onto surfaces using a material-independent dopamine-assisted co-deposition method. We systematically investigated the hyperbranched structure effects of the copolymers concerning the surface compositions, hydration, morphology, and antifouling properties. Our results demonstrated that the hyperbranched structure provided surfaces with higher PMeOx chain density and superior antifouling properties compared to the linear counterpart. Furthermore, it was found that the antifouling efficacy of the hyperbranched PMeOx-based coatings depended on the surface PMeOx chain densities, which were determined by the DB and PMeOx content in copolymers. Specifically, the PMeOxA(3)-co-VBPT(1)/polydopamine (PDA) coating with optimized formulation displayed the highest resistance to protein, platelet, and cell adsorption (98.4–99.3 % reduction) compared to unmodified surface. Taken together, this work highlights the significant impact of hyperbranched architecture on surface anti-biofouling performances and provides valuable guidelines for manipulating surface properties in applications such as drug delivery, diagnostic, and biosensors.