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•The cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives with water-repellency and self-healing properties were synthesized by RAFT-assisted Pickering ...emulsion polymerization.•The cellulose nanocrystals modified with the amphiphilic and photo-responsive triblock copolymer were used as Pickering stabilizers.•The influence of pH value on Pickering emulsion and emulsion polymerization was investigated in detail.•The self-healing behavior was achieved by the photo-reversibility of coumarin groups.
Polymeric coatings are easy to be damaged by harsh environment condition, which causes cracks and loss of function. Inspired by the natural self-healing phenomenon, we successfully synthesized dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives by RAFT-assisted Pickering emulsion polymerization. The amphiphilic and photo-responsive copolymer, PDMAEMA-b-PGMA-b-P(HFBA-co-VBMC) was synthesized by RAFT process, followed by characterization using FT-IR, SEC, 1H NMR and UV–vis. The cellulose nanocrystals were modified by the copolymer, which were confirmed via XPS, UV–vis and so on. Besides, the droplet size of Pickering emulsion gradually increased and the creaming layer gradually decreased as the pH value increased. The TEM result showed that the modified cellulose nanocrystals were effectively anchored on the outside of latex particles. The size of the spherical-like latex particles increased and the stability of latex particles was worse with increasing pH value. Finally, the finished fabric had excellent water resistance due to the combination of micro- or nanoscale hierarchical structure and low surface energy. Moreover, the latex film exhibited excellent repeatability of self-healing ability. The fabric coating achieved the intrinsic and superficial dual-functional self-healing performance by the reversible 2 + 2 cycloaddition of coumarin groups. This strategy provides a powerful guide for preparing the high-performance waterborne fluorinated polyacrylate coating.
•Nano ZnO reduced flow time of waterborne polyacrylate coating and increased pH.•Nano ZnO decreased elongation of waterborne polyacrylate coating.•Nano TiO2 and ZnO caused chemical changes in coating ...after accelerated exposure.•Nano TiO2 and ZnO increased colour stability of waterborne polyacrylate coating.
The rapid development of nanotechnology allowed implementation of metal oxide nanoparticles in coatings and protection of coatings without significant influence on transparency. To avoid negative impact on coating properties it is important that nanoparticles are uniformly dispersed and that the emulsion of nanoparticles is compatible with the components in coating. In this article the effect of TiO2 and ZnO nanoparticles on properties of polyacrylate waterborne coating and on stability of coating films exposed to outdoor conditions are studied. The results of this research show that ZnO nanoparticles reduce flow time of waterborne polyacrylate coating and increase pH. Furthermore, TiO2 and ZnO nanoparticles increase colour stability of waterborne polyacrylate coating. Moreover TiO2 nanoparticles have a great impact on increase of Tg, and ZnO nanoparticles on decrease of elongation and thereby on increase of brittleness of waterborne polyacrylate coating.
Different modifiers are often added to coatings to impart a variety of special functions to the coating materials. Due to the interactions between their different properties, this can result in a ...decline in system stability and complex formulations, with the properties offsetting each other and the emergence of new film disadvantages. Modifiers characterized by multiple advantageous properties can be used to address these problems. In this study, O-carboxymethyl chitosan was used as the cross-linking and antibacterial agent for room-temperature self-crosslinked polyacrylate coatings, resulting in coatings with excellent mechanical properties and antibacterial characteristics, which were then successfully applied to wood coatings. The results revealed that with an increase in O-carboxymethyl chitosan content from 0 wt% to 10 wt%, the cross-linking density of the coating increased from 281.41 to 690.11 mol/m3, the tensile strength increased from 9.82 to 20.17 MPa, the elastic modulus increased from 51.05 to 343.83 MPa, the fracture work increased from 28.86 to 33.03 MJ/m3, the pencil hardness of the coating increased from 3 to 4H, and the width of the Staphylococcus aureus bacteriostatic ring increased from 1.02 to 11.12 mm. The waterborne polyacrylate coatings with excellent mechanical properties and antibacterial properties prepared using O-carboxymethyl chitosan as the cross-linking and antibacterial agent could potentially be used in various fields for the fabrication of materials used in the medicinal industry, wood coatings, and leather coatings.
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•The biomacromolecule O-carboxymethyl chitosan (OCMC) was used as the cross-linking and antibacterial agent.•Multiple effects using a single agent were achieved.•A waterborne polyacrylate coating with excellent mechanical properties and antibacterial properties was prepared.
The incorporation of metal ions into polyacrylate coating shows great potential in enhancing the performances of polyacrylate coatings, as well as providing additional functionalities. Herein, we ...developed a new type of water-soluble polyacrylic acid-Zn(II) composite (PAA-Zn) via the coordination of Zn2+ ions and carboxyl groups of PAA, which showed an extremely high stability in water in a wide range of pH (2–11). It was also facilely applied in polyacrylate latex (PL) as bifunctional additive to prepare high mechanical property, abrasion durable and antibacterial active coating. The PAA, acted as dispersing carrier of Zn2+ ions, and thus promoted uniform dispersion of Zn2+ ions in PL, while buffered the coordination between Zn2+ ions and PL. The as-prepared PL/PAA-Zn coating exhibited significantly improved tensile strength (11.45 MPa) and tear strength (21.01 kN/m) by 120% and 50% compared with those of pristine PL coating. Notably, abrasion durability was considerably enhanced in PL/PAA-Zn coating, showing the decreased mass loss by 36% when subjected to 2000 times of intensive abrasion with sandpaper (320 mesh) under 44 kPa. In addition, the PL/PAA-Zn coatings showed appreciable antibacterial activity against Gram-positive and Gram-negative bacteria. This work demonstrated a promising strategy for the uniform dispersion of metal ions in polyacrylate coatings for enhancing comprehensive properties.
•Water-soluble PAA-Zn was prepared via the coordination of Zn2+ ions and COOH of PAA.•PAA-Zn showed an extremely high stability in water in a wide range of pH (2–11).•PAA acted as carrier and promoted the uniform dispersion of Zn2+ ions in PL.•PL/PAA-Zn coating possessed enhanced comprehensive properties.
Polyacrylate coating has been used for modifying Polyethylene terephthalate (PET) film to improve its oxygen barrier performance. However, comprehensive study on the oxygen barrier of polyacrylate ...coating is still underway. In this work, a series of polyacrylate coatings with different functional monomers such as maleic acid (MA), acrylic acid (AA), 2-hydroxyethyl acrylate (2-HEA), and 2-butene-1, 4-diol (1, 4-BED) were prepared by using Desmodur L75 (L75) and Erisys Ga240 (Ga240) as a curing agent. The polyacrylate coatings were characterized by Fourier Transform Infrared (FT-IR) spectrometer. The oxygen permeability (Po
2
) of the coatings was measured by Gas Permeability Tester. The results reveal that anhydride moiety produced by dehydration of carboxylic acid is the key structure for enhancing the oxygen barrier property of the polyacrylate coating. Moreover, when the anhydride coexists with other cross-linking structures, the oxygen barrier performance of the resulting coatings was not further enhanced. Compared with the pristine PET substrate, the anhydride-containing polyacrylate-coated PET film has reduced Po
2
by 68%. This work provides a facile strategy for improving the oxygen barrier performance of PET film by coating amorphous polyacrylate.
Roasting is a crucial and essential step to produce quality coffee. However, it could lead to the formation of toxic and suspected carcinogenic or procancerogenic compounds, such as polycyclic ...aromatic hydrocarbons. In this work, a simple and easily automatable green procedure based on solid-phase microextraction coupled with gas chromatography for the analysis of acenaphthene, anthracene, benzoghiperylene, benzoapyrene, chrysene, fluoranthene, fluorene, naphthalene, and pyrene, in dark roasted and decaffeinated commercial coffees, was developed. The method was optimized for the determination of the analytes both in solid samples, such as ground coffee or coffee grounds, and liquids, such as espresso coffee, using a polyacrylate-coated fused silica fiber (85 μm) by direct immersion. The performance of the analytical method, developed in terms of sensitivity, reproducibility, and recoveries, proved to be suitable for the applications. Among the 9 polycyclic aromatic hydrocarbons investigated in the selected coffees, chrysene and pyrene were the most representative congeners with values ranging from undetectable to 95.6 ± 11 ng/g for chrysene and from undetectable to 404.7 ± 42.0 ng/g for pyrene. Benzoapyrene was detected in two samples of dark roasted coffee which therefore had the highest toxicity/carcinogenicity in terms of toxic equivalent. The estimated limit of detection for benzoapyrene in ground coffee and coffee grounds was 9.0 ng/g. About 30% of the PAHs were transferred to the infusion while the remaining part was retained by the coffee grounds.
Nano-TiO
2 is modified by a method, by which nano-TiO
2 first reacts with silane coupling agent WD-70 with double bond group which subsequently copolymerizes with methyl methacrylate and butyl ...acrylate to produce a thin polymer shell on the nanoparticles. The modified nanoparticles have stable organophilicity. They are applied to polyacrylate coating and performances of the coating are measured by different methods. The modification of nano-TiO
2 particles can improve their dispersibility in coating, enhance hardness of coating and reduce water absorption and permeability of polyacrylate coating. The mechanism has been analyzed in this paper.
► We use of a novel polar sorptive phase for extraction of carvedilol using SBSE method. ► We examine an ionic liquid on the desorption step of SBSE for the first time. ► Adding ionic liquid ...increases extraction efficiency and eliminate memory effect. ► The high speed and simple treatment of proposed method are main advantages. ► The obtained detection limit is in the range of therapeutic level of carvedilol.
This article presents a method employing stir bar coated with a film of poly (methyl methacrylate/ethyleneglycol dimethacrylate) (PA-EG) and polydimethylsiloxane (PDMS) in combination with liquid desorption (LD) using ionic liquid, followed by high performance liquid chromatography (HPLC) equipped with ultraviolet (UV) detection for the determination of carvedilol in human serum samples. Stir bar sorptive extraction (SBSE) variables, such as desorption and extraction time and temperature, desorption solvent and pH of the matrix were optimized, in order to achieve suitable analytical sensitivity in a short period of time. Also, the concentration effect of 1-methyl-3-octylimidazolium tetrafluoroborate OmimBF4 ionic liquid on the efficiency of LD was investigated. A comparison between PA-EG/SBSE and PDMS/SBSE was made by calculating the experimental recovery and partition coefficient (K), where PA-EG phase demonstrated to be an excellent alternative for the enrichment of the carvedilol from serum samples. The effect of OmimBF4 on carryover was studied and no carryover was observed. Under optimized experimental conditions, the analytical performance showed excellent linear dynamic range, with correlation coefficients higher than 0.999 and limits of detection and quantification of 0.3 and 1.0ngmL−1, respectively. Intra- and inter-day recovery ranged from 94 to 103% and the coefficients of variations were less than 3.2%. The proposed method was shown to be simple, highly sensitive and suitable for the measurement of trace concentration levels of carvedilol in biological fluid media.
