Bio-based hydrophobic coating modified cotton fabrics with durable flame retardancy are of high interest in the application of oil-water separation for not only avoiding the use of hazardous ...substances but also improving the fire safety during use. Herein, phytic acid@Polyurushiol‑titanium complex coated cotton fabric was developed using the facile dip-coating method involving the sequential immersion in the solution of poly(ethyleneimine), phytic acid, titanium oxide, and urushiol. The underlying coating accommodated abundance of phytic acid, which imparted excellent flame retardancy to cotton fabric, and the top coating composed of the polyurushiol‑titanium complex endowed cotton fabric with high hydrophobicity that the water contact angle (WCA) was up to 149.8°. The hydrophobicity also guaranteed effective protection of the underlying phytic acid against chemical solvents and abrasion. Besides, the hydrophobic coating allowed cotton fabric for good self-cleaning and effective oil-water separation. Therefore, the preparation of phytic acid@polyurushiol‑titanium complex coated cotton fabric offers a promising approach to construct durable biomass-coated cellulose-based fabric with multifunctionality.
Flexible polyurethane foam (FPUF) is widely used in our life, but it is inherent flammable. The demand for environmental-friendly multi-functional FPUF has been increasing rapidly in the last decade. ...In this work, a novel bio-based flame retardant coating was constructed by chemically reacting sodium alginate (OSA) and polydopamine (PDA) on the FPUF, followed by depositing nanorod-like β-FeOOH molecules through complexation reaction to form a biomimetic structure. The limiting oxygen index of the coated FPUF samples reached 25.5%. The peak heat release rate was reduced by 45.0%, and the smoke density of the coated sample was decreased by 69.1% compared to that of the control FPUF sample. It was proposed that the OSA-PDA-β-FeOOH decomposed during combustion to promote the formation of compact crosslinked char and released inert gases to dilute the combustible gases, and the β-FeOOH transferred to Fe2O3 to settled the smoke particles reducing the smoke release. Furthermore, the coating with shark skin like structure endowed FPUF antibacterial ability because of its good superoleophobicity underwater. This work provided a novel strategy to construct a biomimetic multifunctional coating on the FPUF.
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•A biobased coating was constructed on flexible polyurethane foam (FPUF).•The coating with a biomimetic structure improved the flame retardancy of FPUF.•The LOI of the coated FPUF reached 25% after washing and/or abrasion.•The coating decreased the peak smoke density of FPUF by 68.5%.•FPUF with superoleophobicity underwater showed antibacteria for cleaning application.
Bio-based coatings are becoming more relevant today due to depleting fossil resources as well as the adverse environmental impacts from the wide usage of petrochemicals in coating formulations. The ...growing interest in this research area is evident from the increasing volume of reports on the innovation of new coating binders derived from various renewable resources such as plant oil, fatty acids, cellulose, cardanol, etc. Although this is a positive development, many of the bio-based coatings are however still formulated as solvent-borne coatings, and the vapour emitted during curing of such coatings is known to be one of the major pollutants from the coating industry. To maximize the environmental benefits of bio-based coatings, it is necessary to adopt a curing mechanism or formulation which eliminates the use of organic solvents. The current review paper details the recent progress of bio-based coatings in waterborne systems, with specific focus on synthetic route and the selection of monomers derived from renewable resources used to develop such coating. The scope of this review paper includes waterborne bio-based polyurethane coatings, waterborne bio-based polyester and alkyd coatings, and waterborne bio-based epoxy coatings. Detailed discussion on the modifications adopted to induce specific properties in some of the coatings to serve as flame retardant, antimicrobial and anticorrosion coatings were elaborated as well.
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•Development of bio-based polymeric coatings in waterborne system•Renewable materials for bio-based coatings range from plant oil to natural rubber.•Ionic centres in polymeric chains improve water solubility of binders.•Properties of bio-based waterborne coating comparable to petrochemical counterpart
A novel polymer-coated nitrogen (N) fertilizer was developed using bio-based polyurethane (PU) derived from liquefied locust sawdust as the coating material. The bio-based PU was successfully coated ...on the surface of the urea fertilizer prills to form polymer-coated urea (PCU) fertilizer for controlled N release. Epoxy resin (EP) was also used to further modify the bio-based PU to synthesize the interpenetrating network (IPN), enhancing the slow-release properties of the PCU. The N release characteristics of the EP-modified PCU (EMPCU) in water were determine at 25 °C and compared to that of PCU and EP-coated urea (ECU). The results showed that the EP modification reduced the N release rate and increased the longevity of the fertilizer coated with bio-based PU. A corn growth study was conducted to further evaluate the filed application of the EMPCU. In comparison to commercial PCU and conventional urea fertilizer, EMPCU was more effective and increased the yield and total dry matter accumulation of the corn. Findings from this work indicated that bio-based PU derived from sawdust can be used as coating materials for PCU, particularly after EP modification. The resulting EMPCU was more environmentally friendly and cost-effective than conventional urea fertilizers coated by EP.
Xuan paper is outstanding representative of the precious Chinese handmade papers which is popular with traditional calligraphy and painting. However, the highly flammability of Xuan paper results in ...the latent fire risk. In this research, fire-resistant and antibacterial Chinese Xuan papers were prepared by fully bio-based chitosan (CS)/phytic acid (PA) intumescent flame retardant system. Xuan paper achieved the excellent flame retardancy with limit oxygen index value of 36.4% when it was coated with 20 BL CS/PA on pulp fibers. The vertical flame properties and cone calorimetry test of Xuan papers also revealed their flame retardancy were greatly improved. The tensile strength of Xuna paper was slightly influenced by CS/PA coating. The CS/PA coating on Xuan papers could greatly enhance their antibacterial properties. The flame retardant mechanism of coated Xuan papers was investigated. The results showed the CS/PA coating on pulp fibers could act through intumescent flame retardant action. The ink wetting property of Xuan paper won’t be influenced by CS/PA coating on the pulp fibers. This research provides research basis for fire-resistant and antibacterial Xuan papers by using the fully bio-based chitosan/phytic acid coating on pulp fibers.
•Fire-resistant and antibacterial Xuan paper was prepared by fully bio-based coating.•Xuan paper achieved a LOI value of 36.4% when it was coated by 20 BLs CS/PA.•CS/PA coating on pulp fibers greatly enhance the antibacterial property of Xuan paper.
The interest in environmentally friendly coatings is rising to substitute for the oil-derived materials in the coating industry. In the present study, natural tannic acid (TA) is investigated as an ...additive to an epoxidized soybean oil-based (ESO) coating. TA solutions in propylene carbonate at two different concentrations were prepared and added to an ESO matrix with different weight ratios. The UV-curing process of the coatings was deeply assessed through real-time Fourier Transform Infrared (FTIR) spectroscopy and Differential Scanning photo Calorimetry (photo-DCS). A significant increase in high epoxy group conversion, around 90 %, was achieved thanks to the activated monomer mechanism, which involves the TA polyphenols. This mechanism accelerated the photocrosslinking process, but reduced the coatings' crosslinking density, as demonstrated by the dynamic thermal mechanical analysis. The hardness of coatings containing the TA additive decreased, while the hydrophobicity of the surface coatings remained unchanged after the TA incorporation. Lastly, the adhesion of the UV-cured coating was evaluated on low-carbon steel substrates. An outstanding enhancement in adhesion property was provided by the TA additive, whose phenols not only participate in the photocrosslinking reaction but also coordinate iron on the steel surface. Moreover, the influence of two different steel surface pre-treatments, the pickling and plasma processes, on the coatings' adhesion strength was studied.
Textiles with efficient moisture management provide a comfortable microenvironment for human body. However, little attention has been paid to sweat-induced bacterial growth alongside. In this study, ...chitooligosaccharide (COS) was used to modify lysozyme (Lyz-COS) to obtain more excellent antibacterial activity. Lyz-COS could undergo an amyloid-like aggregation by reducing its disulfide bond and hydrogen bond triggered by thiourea dioxide (TD). The Phase-Transited Lyz-COS (PTL-COS) coating increases the hydrophilicity and antibacterial properties of wool fabrics, which can withstand 50 washing cycles and 100 rubbing cycles. In addition, two methods are proposed to customize Janus wool fabrics as desired. Method 1: The PTL-COS film was prepared first, and then the film was transferred to one side of the wool fabric. Method 2: Simply spray the PTL-COS solution on one side of the wool fabric. These two processes are simple to operate and can be customized on demand, enabling single transport of sweat and inhibiting sweat-induced bacterial growth. This work underlines the significance of chitooligosaccharide-modified PTL coatings for functionalization of textile surfaces and provides new insights into the development of more adaptable and smarter textiles and clothing.
•COS modified lysozyme to improve the antibacterial and hydrophilic properties of PTL-COS coating.•New process for preparing Janus wool fabrics using PTL-COS bio-based coating is proposed.•The PTL-COS coating can customize functional textiles with different properties as required.•The PTL-COS coating optimally couples durable antibacterial and moisture management properties.•The Janus wool fabrics still maintain excellent water vapor transmission rate and breathability
In this work, the use of potato fruit juice (PFJ) in combination with poly(3-hydroxybutyrate) (PHB) was explored as a biobased barrier coating on paperboard. A two-layer and three-layer solution were ...explored. In the two-layer structure, the PFJ layer was rod-coated on pigment-coated paperboard, followed by extrusion coating of PHB on top. In the three-layered coating, paperboard without pigment coating was extrusion-coated with PHB, followed by rod coating of PFJ, and finally, extrusion-coated with PHB. The specific water vapour transmission rate was reduced by approximately 95 % and 90 % for the two- and three-layer coatings, respectively, relative to the uncoated paperboard. Besides contributing to barrier properties, the PFJ increased the bonding strength between the PHB and the paperboard. Although the three-layer coated paperboards showed better oxygen barrier properties than the two-layered coatings, the oxygen permeability was still high. Three-layer coatings exhibited moderate peeling strength, and better creasing and grease barrier properties compared to two-layered coated paperboards.
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Mineral oil saturated hydrocarbons (MOSHs) are commonly found in food packaging printing inks. They can migrate into packaged food, posing risks to human health.
In this study, a bio-based coating ...using sugarcane fibre (SF), anionic starch (AS), nanofibrated cellulose (NFC), and chitosan (CTS) is developed and applied to the internal surface of a food packaging white cardboard. The coating is investigated for its efficiency in reducing MOSH migration into dry food simulants (Porapak). The MOSH adsorption capacity of coated white cardboard is 4.6 and 14 times greater than those of uncoated and polythene (PE)-coated versions, respectively. Hence, the surface of SF-AS-NFC-CTS coating functions as a sponge and protective screen, adsorbing and hindering significant amounts of MOSH and subsequently slowing and reducing the migration of MOSH to food.
Meanwhile, the basic properties, such as mechanical properties, air permeability (barrier property to MOSH), oil resistance, thermal stability, and antibacterial efficacy, of the coated cardboard for food packaging are all improved. Therefore, this study can offer a promising solution to food contamination concerns for food packaging.
•SF-AS-NFC-CTS coating improves the gas barrier properties of white cardboard.•SF-AS-NFC-CTS coating enhances the antibacterial performance of the cardboard.•SF-AS-NFC-CTS exhibits excellent adsorption and slow discharge effect on MOSH.•SF-AS-NFC-CTS coating improved gas–oil barrier characteristics.
