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Reducing the fire risk of epoxy coatings has been a significant focus in the research of thermosetting resin materials. Various carbon nitride/polyaniline/metal oxide hybrids (CNPMOs) were synthesized using in‐situ oxidative polymerization and modified adsorption methods. Combustion analysis results indicated that CNPMOs effectively reduced the heat release of epoxy coatings during combustion. The epoxy coatings containing various CNPMOs (EFe, EY, and ETi) exhibited excellent smoke suppression and toxicity reduction properties. Furthermore, in comparison to the pure sample (E0) and reference sample (E1), the epoxy coatings EFe, EY, and ETi demonstrated improved thermal stability. In water resistance tests, the water absorption rates of EFe, EY, and ETi were significantly lower than that of E0. The CNPMOs enhanced the hydrophobicity of the epoxy coating to better protect the substrate in humid environments. [ABSTRACT FROM AUTHOR]

Plant protein‐based adhesives are gaining traction owing to their low cost and eco‐friendliness. However, achieving flame retardancy and long‐term water resistance in them under room‐temperature curing conditions remains a challenge due to the hydrophilicity and low reactivity of plant proteins. Herein, a novel adhesive synthesized from soybean meal (SM), activated sodium alginate (aSA), nano‐hydroxyapatite (nHA), and polyamidoamine‐epichlorohydrin (PAE) resin addresses this challenge. aSA as a reactive bio‐based cross‐linker formed covalent cross‐linking structures with SM matrix at room temperature, while the nHA‐induced biomineralization and PAE‐constructed supramolecular cross‐linking promote water drainage from the adhesive, preventing water erosion of the adhesive structure. The developed adhesive shows versatility across multiple substrates, with its wet shear strength on wood reaching 0.76 MPa, surpassing that of the commercial aldehyde‐based adhesive. The adhesive is effective over a wide temperature range from room temperature to 150 °C due to the reactivity of the PAE resin above 60 °C. Moreover, it exhibits excellent flame retardancy (limiting oxygen index of 31.2%) owing to its dense structure and the abundance of N‐containing and P‐containing components. This work is expected to break the monopoly of petroleum‐based adhesives in the realm of room‐temperature adhesives. [ABSTRACT FROM AUTHOR]

Magnesium sulphoaluminate (MSA) cement has good bonding properties and is suitable as an inorganic adhesive for repairing materials in civil engineering. However, there are still some problems with its use, such as its insufficient 1 day (d) strength and poor volumetric stability. This paper aims to investigate the influences of metakaolin (MK) on the physical and mechanical properties of magnesium sulphoaluminate (MSA) cement. The hydration products and microstructures of typical MSA cement samples were also analysed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the addition of metakaolin reduces the fluidity and shortens the setting time of the MSA cement. The initial setting time and final setting time shortened maximally by 15–27 min and 25–48 min, respectively, with the addition of 10–30% metakaolin. Moreover, the compressive strength and flexural strength of the MSA cement improved significantly with the addition of 10–30% metakaolin at a curing age of 1 d. Compared with the compressive and flexural strengths of the control sample at 1 d, the compressive strengths of the modified samples showed obvious increases of 98%, 101%, and 109%, and the flexural strengths increased by 39%, 31%, and 26%, respectively, although they decreased slightly when the curing ages were 7 d, 14 d, and 28 d. The addition of 10% metakaolin improved the water resistance of the MSA cement immersed in water for 7 d and resulted in even higher water resistance at 28 d. The addition of 10–30% metakaolin improved the volumetric stability of the MSA cement with increasing dosages before 28 d of ageing. XRD and SEM-EDS analyses showed that the metakaolin accelerated the early hydration reaction and optimised the phase composition of the MSA cement. The results indicate that the addition of 10–20% metakaolin improved the strength after 1 d of ageing, water resistance, and volumetric stability of the MSA cement, providing theoretical support for the application of MAS cement as an inorganic bonding agent for repairing materials. [ABSTRACT FROM AUTHOR]

The low toughness and high softening temperature of bismaleimide (BMI) resin limit its application in the field of electronic packaging. Herein, a series of flexible BMI resins with maleic anhydride terminated were synthesized via the imide reaction between dianhydrides and bio‐based 8,8′‐(4‐hexyl‐6‐octylcyclohexane‐1,3‐diyl)bis(octane‐1‐amine) (HOBOA). The degree of polymerization of these BMI resins was controlled to 1, 3, and 5 by adjusting the molar ratio of dianhydrides to HOBOA. These BMI resins show a low softening temperature below 100°C. These BMI resins were cured by the thermal procedure as follows: 145°C/2 h, 185°C/2 h, 225°C/2 h, and 275°C/2 h. The thermal decomposition temperature of cured resins is above 395°C. The tensile testing results demonstrated that cured resins exhibit a high elongation at break of around 60%. The dielectric constant of the cured resins is between 2.72 and 3.09 at room temperature. The water absorption rate of cured resins is less than 0.7% after being soaked in water for 30 days. After the cured resins were soaked separately in acid and alkali, the tensile strength retention rate reaches more than 90%. Additionally, the lap shear strength of cured resins coated on 7075 aluminum alloy exceeds 7.0 MPa. [ABSTRACT FROM AUTHOR]

This study explores the potential of graphene oxide (GO) as an additive in waterborne polyurethane (WPU) resins to create eco-friendly coatings with enhanced anticorrosive properties. Traditionally, WPU's hydrophilic nature has limited its use in corrosion-resistant coatings. We investigate the impact of incorporating various GO concentrations (0.01, 0.1, and 1.3 wt%) and functionalizing GO with ethylenediamine (EDA) on the development of anticorrosive coatings for carbon steel. It was observed, by potentiodynamic polarization analysis in a 3.5% NaCl solution, that the low GO content in the WPU matrix significantly improved anticorrosion properties, with the 0.01 wt% GO-EDA formulation showing exceptional performance, high Ecorr (−117.82 mV), low icorr (3.70 × 10−9 A cm−2), and an inhibition corrosion efficiency (η) of 99.60%. Raman imaging mappings revealed that excessive GO content led to agglomeration, creating pathways for corrosive species. In UV/condensation tests, the 0.01 wt% GO-EDA coating exhibited the most promising results, with minimal corrosion products compared to pristine WPU. The large lateral dimensions of GO sheets and the cross-linking facilitated by EDA enhanced the interfacial properties and dispersion within the WPU matrix, resulting in superior barrier properties and anticorrosion performance. This advancement underscores the potential of GO-based coatings for environmentally friendly corrosion protection. [ABSTRACT FROM AUTHOR]

Petroleum-based food packaging causes environmental problems such as waste accumulation and microplastic generation. In this work, biobased films from stable polyelectrolyte complex suspensions (PECs) of xylan and chitosan (70 Xyl/30 Ch wt% mass ratio), at different concentrations of citric acid (CA) (0, 2.5, 5, 7.5 wt%), were prepared and characterized. Films were treated at two temperatures (135 °C, 155 °C) and times (30 min, 60 min) to promote covalent crosslinking. Esterification and amidation reactions were confirmed by Fourier Transform Infrared Spectroscopy and Confocal Raman Microscopy. Water resistance and dry and wet stress–strain results were markedly increased by thermal treatment, mainly at 155 °C. The presence of 5 wt% CA tended to increase dry and wet stress–strain values further, up to 88 MPa—10% (155 °C for 60 min), and 5.6 MPa—40% (155 °C for 30 min), respectively. The UV-blocking performance of the films was improved by all treatments, as was thermal stability (up to Tonset: 230 °C). Contact angle values were between 73 and 84°, indicating partly wettable surfaces. Thus, thermal treatment at low CA concentrations represents a good alternative for improving the performance of Xyl/Ch films. [ABSTRACT FROM AUTHOR]

For polyacrylate latex pressure-sensitive adhesives (PSAs), high peel strength is of crucial significance. It is not only a key factor for ensuring the long-lasting and effective adhesive force of polyacrylate latex PSAs but also can significantly expand their application scope in many vital fields, such as packaging, electronics, and medical high-performance composite materials. High peel strength can guarantee that the products maintain stable and reliable adhesive performance under complex and variable environmental conditions. However, at present, the peel strength capacity of polyacrylate latex PSAs is conspicuously insufficient, making it difficult to fully meet the urgent market demand for high peel strength, and severely restricting their application in many cutting-edge fields. Therefore, based on previous experimental studies, and deeply inspired by the adhesion mechanism of natural marine mussels, in this study, a traditional polyacrylate latex PSA was ingeniously graft-modified with 3,4-dihydroxybenzaldehyde (DHBA) through the method of monomer-starved seeded semi-continuous emulsion polymerization, successfully synthesizing novel high-peel-strength polyacrylate latex pressure-sensitive adhesives (HPSAs) with outstanding strong adhesion properties, and the influence of DHBA content on the properties of the HPSAs was comprehensively studied. The research results indicated that the properties of the modified HPSAs were comprehensively enhanced. Regarding the water resistance of the adhesive film, the minimum water absorption rate was 4.33%. In terms of the heat resistance of the adhesive tape, it could withstand heat at 90 °C for 1 h without leaving residue upon tape peeling. Notably, the adhesive properties were significantly improved, and when the DHBA content reached 4.0%, the loop tack and 180° peel strength of HPSA4 significantly increased to 5.75 N and 825.4 gf/25 mm, respectively, which were 2.5 times and 2 times those of the unmodified PSA, respectively. Such superior adhesive performance of HPSAs, on the one hand, should be attributed to the introduction of the bonding functional monomer DHBA with a rich polyphenol structure; on the other hand, the acetal structure formed by the grafting reaction of DHBA with the PSA effectively enhanced the spatial network and crosslink density of the HPSAs. In summary, in this study, the natural biological adhesion phenomenon was ingeniously utilized to increase the peel strength of pressure-sensitive adhesives, providing a highly forward-looking and feasible direct strategy for the development of environmentally friendly polyacrylate latex pressure-sensitive adhesives. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is a solid waste generated by phosphate fertilizer industries that is currently used in concrete materials. However, adding PG to concrete usually results in reducing its water resistance and corrosion resistance. This paper presents a new method of applying PG to concrete to improve its water resistance. In this paper, a green superhydrophobic PG (SPG) coating was prepared using modified PG as a hydrophobic medium and cement as the bonding material. The contact angle between the superhydrophobic phosphogypsum coating (SPG coating) and water was 156°, and the coating reached a superhydrophobic state with good self-cleaning ability. Even when sandpaper was used to polish the coating, the water contact angle of the coating was still greater than 150°, indicating that the coating had good wear resistance. In addition, the results of water absorption and electrochemical experiments indicated that mortar coated with SPG had better water resistance and corrosion resistance than ordinary mortar. The SPG coatings with water resistance, wear resistance, and self-cleaning properties have potential applications in building exterior walls. [ABSTRACT FROM AUTHOR]

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Most traditional adhesives applied in the wood industry are synthetic resins obtained from petroleum. However, the production of these resins raises substantial environmental issues because of formaldehyde release, which leads to detrimental impacts on both human health and the environment. In contrast, bio-based adhesives offer an eco-friendly option that is created by renewable biomass resources. These adhesives can effectively overcome the above problems. Hence, it is crucial to pay more attention to bio-based adhesives. However, the inherent characteristics of the raw materials used in the production of bio-based adhesives result in a number of limitations, including weak bond strength, poor water resistance, and susceptibility to mildew, which restrict their further applications. Most researchers have used physical and chemical methods to modify bio-based adhesives in order to improve their overall performance. The defects of bio-based adhesives, including their limited bond strength, inadequate resistance to water, and vulnerability to mildew, are summarized in this paper, and the investigation of potential modification methods on bio-based adhesives is reviewed. Moreover, we encourage the widespread use of bio-based adhesives in various fields to promote sustainable development due to their eco-friendly characters. [ABSTRACT FROM AUTHOR]

Aerogel fibers, known for their lightweight and exceptional thermal insulation properties, provide an ideal material solution for fabricating triboelectric nanogenerators (TENGs) for self‐powered wearable electronics in extreme environments, such as firefighting gear. However, current aerogel fibers face limitations due to their poor mechanical properties and lack of performance stability under harsh conditions. Herein, a facile strategy for preparing silica/aramid nanofiber (ANF) composite aerogel fibers with interpenetrated dual networks and a silica‐dominant component (≈64 wt.%) is demonstrated; the unique structure and composition endow the composite aerogel fibers with high tensile strength (3.4 MPa), low thermal conductivity (0.033 W (m·K)−1), a large specific surface area (587 m2 g−1), and outstanding fire resistance at 95% porosity, combining the best properties of both ANF and silica aerogel. Moreover, the composite aerogel fibers exhibit excellent mechanical flexibility at extremely low temperatures (−196 °C) and maintain structural integrity even when exposed to flame for up to 5 min. Leveraging these exceptional properties, composite aerogel fiber‐based TENGs show high electrical output performance before and after combustion (>94% retention). The fabrication strategy offers promising opportunities for modulating the properties and functionalities of aerogel fibers on demand, holding great potential for future applications in wearable smart protective fabrics for extreme environments. [ABSTRACT FROM AUTHOR]

Aliovalent substitution reduces the oxygen vacancy formation energy and generates more oxygen vacancies to facilitate the catalytic reaction. [Display omitted] Developing cost-effective monolith catalyst with superior low-temperature activity is critical for oxidative efficacious removal of industrial volatile organic compounds (VOCs). However, the complexity of the industrial flue gas conditions demands the need for high moisture tolerance, which is challenging. Herein, CoMn–Metal Organic Framework (CoMn–MOF) was in situ grown on Ni foam (NiF) at room temperature to synthesize the cost-effective monolith catalyst. The optimized catalyst, Co1Mn1/NiF, exhibited excellent performance in toluene oxidation (T 90 = 239 °C) due to the substitution of manganese into the cobalt lattice. This substitution weakened the Co–O bond strength, creating more oxygen vacancies and increasing the active oxygen species content. Additionally, experimentally and computationally evidence revealed that the mutual inhibiting effect of three typical aromatic hydrocarbons (benzene, toluene and m–xylene) over the Co1Mn1/NiF catalyst was attributed to the competitive adsorption occurring on the active site. Furthermore, the Co1Mn1/NiF catalyst also presents outstanding water resistance, particularly at a concentration of 3 vol%, where the activity is even enhanced. This was attributed to the lower water adsorption and dissociation energy derived from the interaction between the bimetals. Results demonstrate that the dissociation of water vapor enables more reactive oxygen species to participate in the reaction which reduces the formation of intermediates and facilitates the reaction. This investigation provides new insights into the preparation of oxygen vacancy–rich monolith catalysts with high water resistance for practical applications. [ABSTRACT FROM AUTHOR]

Environmentally friendly materials have attracted much more attention in agricultural plastic film, instead of traditional petroleum-based materials. Among them, some challenges also remain in the traditional polyvinyl alcohol (PVA) in the field of film, such as low mechanical strength, water resistance, and UV isolation. The film performance and properties can be improved for the better use value of biomass resources. In this study, the raw materials were selected as PVA, Lignin, and WBPU (waterborne polyurethane). Among them, the WBPU was used as the filler to liquefy the lignin, in order to prepare the lignin-liquefied substance L(D). The lignin-based WBPU/PVA blend film was successfully prepared by solution pouring. The single-factor experiment was carried out to compare the addition amount of L(D) and WBPU. A systematic investigation was then implemented to explore the effects of the types and the content of additives on the properties of the blend film, such as tensile strength, elongation at break, light transmittance, opacity, thickness, water absorption, and water solubility. FTIR (Fourier transform infrared spectroscopy) and SEM (scanning electron microscopy) were used to analyze the microstructure and chemical composition of the films. The transmittance and absorbance of the films were identified by UV-VIS spectrophotometer. The size and shape of the grain were characterized by XRD (phase analysis of X-ray diffraction). The mechanical properties of the film were evaluated by a universal material testing machine. The thickness of the film was measured to calculate the opacity using a thickness-measuring instrument. The results show that both L(D) and WBPU were fully mixed with the PVA, where the addition of L(D) improved the tensile strength and elongation at the break of the film. The composite film with 15%L(D) shared the best mechanical properties, while the addition of WBPU only exhibited low mechanical properties. However, the addition enhanced the UV resistance of the film. Furthermore, 8:2L(D)/WBPU/PVA blend film behaved with a transmittance of 1.57% at the UV region of 400mm, indicating a stronger performance to prevent the ultraviolet light, compared with the pure PVA film in the transmittance of 81.44% under the UV region. The water absorption and solubility of the blended film with L(D) were improved, compared with the pure PVA film. Specifically, the water absorption was reduced from 532% to 362%, and the water solubility was also reduced from 42% to 35%, indicating better waterproof. The water absorption and water solubility of the blended film were further improved after adding WBPU. The water absorption of 5:5L(D)/WBPU/PVA blend film was even reduced to 170% with the increase of WBPU content, and the water solubility was also reduced to 18%. Therefore, the water resistance and UV resistance of the blended film can be further improved under different L(D)/WBPU mass ratios. The blended film can be prepared with a high application potential in the plastic film. The findings can provide a strong reference in the food and pharmaceutical packaging fields. [ABSTRACT FROM AUTHOR]

The growing prevalence of disposable toilet seat covers in public restrooms stems from concerns about personal hygiene, given the direct contact between the seat and various users' skin. To enable these disposable cover sheets to be flushed down the toilet instead of being discarded in the trash, they must possess specific properties. These include rapid water absorption for quick disintegration, strength to endure user movement or moisture on the toilet seat surface, and a comfortable texture. To address these challenges, the study investigated the disintegration characteristics of flushable cover sheets prepared under different refining conditions. Alkyl ketene dimer (AKD) was also employed to enhance water resistance, while an organic antibacterial agent was used to impart antimicrobial properties. The findings revealed that adding 0.2% AKD and 1% organic antibacterial agent to pulp stock with a freeness of about 650 mL CSF was suitable for manufacturing disposable cover sheets with disintegration characteristics like toilet tissue paper. [ABSTRACT FROM AUTHOR]

The bio‐based hydrophilic monoglycerol succinate was synthesized and reacted with bio‐based raw materials including polyols, pentamethylene diisocyanate, 1,4‐butanediol, to prepare the waterborne polyurethane acrylate (Bio‐WPUA) emulsions with high bio‐based content. The effect of bio‐based polyol categories including poly(trimethylene ether glycol), poly(tetrahydrofuran), and castor oil on the properties of Bio‐WPUA and its films were studied. The structure, thermal stability, crystallinity, contact angle, and mechanical properties of Bio‐WPUA film were characterized with fourier infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X‐ray diffraction, contact angle analyzer, and mechanical tensile testing. It was found that Bio‐WPUA film containing poly(trimethylene ether glycol) as the soft‐segmented display good tensile stress, thermal stability, and water resistance with 1.38% of the water absorption rate, while Bio‐WPUA containing castor oil polyol as the soft‐segmented had good tensile strain and low‐temperature film‐forming properties with excellent film properties. The bio‐carbon content of Bio‐WPUA was high up to 40% according to ASTM D6866‐22, and possesses good physical mechanical and chemical resistance performance. The results provide theoretical guidance for the synthesis of polyurethane emulsions with bio‐based materials instead of petroleum‐based materials. [ABSTRACT FROM AUTHOR]

Nowadays, formaldehyde-based adhesives are heavily used in the production of WBP, which is the primary source of indoor formaldehyde pollution and severely affects people's health, work and living quality. In recent years, soy protein adhesives have attracted extensive attention in the field of wood adhesives because of their advantages such as non-toxic, biodegradable, low cost and convenient processing. However, compared with the widely used commercial formaldehyde-based adhesives such as phenolic resin and urea-formaldehyde resin, soy protein-based adhesives have some shortcomings in low bonding strength, poor water resistance and poor mildew resistance. In view of the above problems, it is commonly used to functionalize soy protein adhesives by physical and chemical means such as cross-linking modification, mixed modification, structure modification, hydrolase modification and filling modification. The different methods of functional modification of soy protein adhesive were reviewed, the problems of different modification methods were summarized, and the future development of soy protein adhesive was prospected. [ABSTRACT FROM AUTHOR]

Rare earth (RE)-doped CaS phosphors have been widely used as light-emitting components in various fields. Nevertheless, the application of nanosized CaS particles is still significantly limited by their poor water resistance and weak luminescence. Herein, a lattice-matching strategy is developed by growing an inert shell of cubic NaYF4 phase on the CaS luminescent core. Due to their similarity in crystal structure, a uniform core–shell heterostructure (CaS:Ce3+@NaYF4) can be obtained, which effectively protects the CaS:Ce3+ core from degradation in aqueous environment and enhances its luminescence intensity. As a proof of concept, a label-free aptasensor is further constructed by combining core–shell CaS:Ce3+@NaYF4 and Au nanoparticles (AuNPs) for the ultrasensitive detection of kanamycin antibiotics. Based on the efficient FRET process, the detection linear range of kanamycin spans from 100 to 1000 nM with a detection limit of 7.8 nM. Besides, the aptasensor shows excellent selectivity towards kanamycin antibiotics, and has been successfully applied to the detection of kanamycin spiked in tap water and milk samples, demonstrating its high potential for sensing applications. [ABSTRACT FROM AUTHOR]

Introduction. Creation of waste-free technologies for production of low-energy building materials and products involving recycling of secondary raw materials is one of the priority areas of economic development in most countries. In this regard, the urgent task is to develop competitive binders based on phosphogypsum with the addition of hydrated lime by designing rational compositions of phosphogypsum-lime compositions hardening by mixed type.Materials and methods. Waste phosphogypsum from Titanium Investments LLC, Armyansk, was used as a secondary sulfate-containing raw material. Hydrated lime for research was obtained by slaking lump lime produced in shaft furnaces of the lime workshop of Crimean Soda Plant JSC, Krasnoperekopsk. Analysis of the mineralogical composition of phosphogypsum and artificial stone based on it was carried out using synchronous TG-DTA/DSC thermal analysis on an STA 8000 analyzer (Perkin Elmer). The dispersed composition of phosphogypsum and hydrated lime was determined by laser diffraction using a Partica LA-960 laser particle size analyzer (Horiba). The determination of the mechanical characteristics of the prototypes was carried out on the basis of the MCC8 control console (Controls).Results. The results of the development of compositions based on phosphogypsum-lime compositions showed that after forced carbonization of these compositions for 180 minutes in an air-gas environment with a 50 % CO2 concentration, it is possible to obtain a water-resistant stone material (Kr 0.78–0.8) with strength at compression 28–32 MPa, average density 1,750–1,780 kg/m3 and water absorption by mass and volume of 11–15 and 19–26 %, respectively.Conclusions. Probably, additional optimization of the conditions of obtaining samples (pressure, water content of the mixture, introduction of filler), the regime of forced carbonate hardening (hardening time, CO2 concentration) will further improve the studied properties of the resulting stone material. The obtained experimental data suggest that, based on the proposed binder, it is possible to produce a certain range of small-piece wall products, taking into account additional scientific research in this area.

[Display omitted] Biogenic, sustainable two-dimensional architectures, such as films and nanopapers, have garnered considerable interest because of their low carbon footprint, biodegradability, advanced optical/mechanical characteristics, and diverse potential applications. Here, bio-based nanopapers with tailored characteristics were engineered by the electrostatic complexation of oppositely charged colloidal phosphorylated cellulose nanofibers (P-CNFs) and deacetylated chitin nanocrystals (ChNCs). The electrostatic interaction between anionic P-CNFs and cationic ChNCs enhanced the stretchability and water stability of the nanopapers. Correspondingly, they exhibited a wet tensile strength of 17.7 MPa after 24 h of water immersion. Furthermore, the nanopapers exhibited good thermal stability and excellent self-extinguishing behavior, triggered by both phosphorous and nitrogen. These features make the nanopapers sustainable and promising structures for application in advanced fields, such as optoelectronics. [ABSTRACT FROM AUTHOR]

为开发具有较强耐水性的环保可再生胶黏剂，以环氧大豆油（ESO）为原料，选用顺丁烯二酸酐(MA)为固化剂，乙酰丙酮锌〔Zn(acac)2〕为催化剂，制备ESO木材胶黏剂，同时制备了杨木胶合板，考察了MA添加量对胶黏剂性能的影响，通过DSC分析优化了催化剂添加量，对胶黏剂进行了红外光谱和TG/DTG分析，并利用正交实验对热压工艺进行了优化。结果表明：当MA添加量为27%时胶黏剂性能达到最佳；催化剂的最优添加量为3%；通过红外光谱和TG/DTG分析证明ESO与MA发生了交联固化反应；最佳热压工艺为热压温度150 ℃、热压时间10 min、热压压力2 MPa、涂胶量320 g/m2，在此条件下湿态胶合强度为1.613 MPa，符合国家规定的普通胶合板Ⅱ类板要求（≥0.70 MPa）。该胶黏剂制备方法具有简单、高效、环保等优势,是实现ESO在木材产品生产中可持续应用的一种很有前景的策略,具有很大的工业应用潜力。In order to develop environmentally friendly and renewable adhesives with excellent water resistance, with epoxy soybean oil (ESO) as raw material, maleic anhydride (MA) as curing agent and zinc acetylacetonate (Zn(acac)2) as catalyst, ESO wood adhesive and poplar plywood were prepared. The effect of MA dosage on the performence of adhesive was studied. The catalyst dosage was optimized by DSC analysis, and the adhesive was analyzed by infrared spectroscopy and TG/DTG. Then, the hot-pressing process was optimized by orthogonal experiment. The results showed that the best adhesive performance was achieved at 27% of MA dosage. The optimal dosage of catalyst was 3%. Infrared spectroscopy and TG/DTG analysis proved that ESO underwent crosslinking and curing reaction with MA. The optimal hot-pressing process conditions were obtained as follows: hot-pressing temperature 150 ℃, hot-pressing time 10 min, hot-pressing pressure 2 MPa, and glue spread 320 g/m2. Under these conditions, the wet bonding strength was 1.613 MPa, which was in line with the national requirement of Class Ⅱ ordinary plywood（≥0.70 MPa）. The preparation method of adhesive has advantages such as simplicity, efficiency and environmental friendliness, and it is a promising strategy for achieving sustainable application of ESO in wood product production, with great industrial application potential.

Abstract This article is aimed at discussing the combined effect of mineral admixture and servicing temperature, especially in cold environment, on the properties of magnesium phosphate repair mortar (MPM). The influence mechanism of fly ash content on the microstructure and performance of MPM were firstly investigated, and then the evolution rules in properties of fly ash modified MPM cured at − 20 °C, 0 °C, 20 °C and 40 °C were further revealed. The results show that the incorporation of fly ash has no significant effect on the setting time and fluidity of MPM. When MPM is modified with 10 wt% and 15 wt% fly ash, its mechanical properties, adhesive strength, water resistance, and volume stability are effectively improved. Fly ash reduces the crystallinity and continuity of struvite enriched in hardened MPM, and its particles are embedded among struvite and unreacted MgO. The compressive strength of MPM-10 cured for various ages increases with the elevating of curing temperature, while the flexural strength, interfacial bonding strength, strength retention and linear shrinkage exhibits the opposite laws. When cured at 0 °C and − 20 °C, MPM-10 still has good early strength, water resistance and interfacial bonding properties, which indicates that MPM-10 provides with an ability of emergency repair of cracked components served in cold environments.

Corn straw-based board has great potential for the protection of forest resources, waste recycling, and sustainable economic development. However, corn stalk-based board has poor mechanical properties due to its short fiber length and poor water resistance because of the presence of numerous hydrophilic hydroxyl functional groups in its structure. Natural mycelium originating from waste Pleurotus ostreatus substrate is a hydrophobic bio-adhesive. In the present study, formaldehyde-free corn stalk/P. ostreatus substrate bio-composites were prepared using the hot-pressing technique without the addition of any chemical adhesive. The mechanical properties and water resistance of the prepared bio-composites were excellent. The highest internal bonding strength (IBS) of 2.16 MPa and the minimum thickness swelling (TS) of 18.3% were observed, which are beyond the national standards for particleboard in China. These bio-composites were prepared using a simple, green, and convenient manufacturing method to promote their popularization and application. The method may, therefore, be used as a novel technical measure to resolve the problem of overuse of forestry resources and waste disposal.

Traditional polybenzoxazine thermosets cannot be reprocessed or recycled due to the permanent crosslinked networks. The dynamic exchangeable characteristics of imine bonds can impart the networks with reprocessabilities and recyclabilities. This study reported a weldable, reprocessable, and water‐resistant polybenzoxazine vitrimer (C‐ABZ) crosslinked by dynamic imine bonds. It was synthesized through a condensation reaction between an aldehyde‐containing benzoxazine oligomer (O‐ABZ) and 1,12‐dodecanediamine. The resulting C‐ABZ was able to be welded and reprocessed due to the dynamic exchange of imine bonds. The tensile strengths of the welded C‐ABZ and the reprocessed C‐ABZ after three cycles of hot‐pressing were 76.7, 81.3, 70.8, and 58.1 Mpa, with corresponding tensile strength recovery ratios of 74.1 %, 78.6 %, 68.4 %, and 56.1 %, respectively. Furthermore, the polybenzoxazine backbone significantly improved the water resistance of the imine bonds. After immersing in water for 30 days at room temperature, the weight gain of C‐ABZ was less than 1 % with corresponding tensile strength and tensile strength retention ratio of 59.5 Mpa and 57.5 %, respectively. Although the heat resistance of C‐ABZ decreased slightly with increased hot‐pressing cycles, a glass transition temperature (Tg, tanδ) of 150 °C was retained after the third hot‐pressing. Overall, these findings demonstrate that the C‐ABZ possesses excellent comprehensive performances. [ABSTRACT FROM AUTHOR]

This study aims to enhance the performance of inorganic perovskite light‐emitting diodes (PeLEDs) by incorporating porous silica (p‐SiO2) to fabricate perovskite‐composite films for electroluminescence (EL) devices. This is because, in addition to the inorganic perovskite material, composites with inherently stable materials are needed for perovskite to ensure additional external stability. The introduced p‐SiO2 particles impede the crystal growth of perovskite during the anti‐solvent assisted crystallization process, resulting in the formation of smaller CsPbBr3 crystals in the CsPbBr3/p‐SiO2 composite film. Accordingly, compared to previous CsPbBr3 films, this composite film exhibits two folds with higher photoluminescence quantum yield (PLQY) due to improved crystalline formation. Surprisingly, the CsPbBr3/p‐SiO2 composite film additionally has good water‐resistant properties because the residual cetyltrimethylammonium bromide (CTAB) molecules are extracted from the p‐SiO2 particles and are oriented at the top surface of the CsPbBr3/p‐SiO2 composite film. The EL device fabricated with this composite film exhibits outstanding luminescence efficiency, with a current efficiency (CE) of 70.06 cd A−1 and an external quantum efficiency (EQE) of 16.97%, surpassing control samples by two folds of magnitude. Furthermore, the operational stability improves approximately sevenfold compared to the control, presenting a promising strategy for advancing the field of inorganic perovskite ELs. [ABSTRACT FROM AUTHOR]

This article is aimed at discussing the combined effect of mineral admixture and servicing temperature, especially in cold environment, on the properties of magnesium phosphate repair mortar (MPM). The influence mechanism of fly ash content on the microstructure and performance of MPM were firstly investigated, and then the evolution rules in properties of fly ash modified MPM cured at − 20 °C, 0 °C, 20 °C and 40 °C were further revealed. The results show that the incorporation of fly ash has no significant effect on the setting time and fluidity of MPM. When MPM is modified with 10 wt% and 15 wt% fly ash, its mechanical properties, adhesive strength, water resistance, and volume stability are effectively improved. Fly ash reduces the crystallinity and continuity of struvite enriched in hardened MPM, and its particles are embedded among struvite and unreacted MgO. The compressive strength of MPM-10 cured for various ages increases with the elevating of curing temperature, while the flexural strength, interfacial bonding strength, strength retention and linear shrinkage exhibits the opposite laws. When cured at 0 °C and − 20 °C, MPM-10 still has good early strength, water resistance and interfacial bonding properties, which indicates that MPM-10 provides with an ability of emergency repair of cracked components served in cold environments. [ABSTRACT FROM AUTHOR]

Wood adhesives were made using defatted soy flour, casein, sodium hydroxide (NaOH) and ethylene diamine. These eco-friendly wood adhesives are used to substitute formaldehyde-derived adhesives in order to decrease formaldehyde and volatile organic compounds emissions from the adhesives that are utilised in plywood. The features of adhesively-glued wood joints in terms of performance such as tensile strength, water resistance and chemical resistance were gauged in this study. The results revealed that adhesives showing good performance and eco-friendly adhesive system was prepared for wood joints. [ABSTRACT FROM AUTHOR]

Biodegradable films are considered an alternative to petroleum‐based plastics to solve environmental problems. In this study, potato flour films are prepared with dispersions at pH 3, 5, 7, 9, and 11. The film‐forming dispersion at pH 7 shows the highest apparent viscosity. Dispersions at alkaline conditions show a reduction in particle size, resulting in a smooth film surface. Films at alkaline conditions present a yellow appearance and have the lower transmittance. The film at pH 5 has the highest retrogradation enthalpy and glass transition temperature, while its moisture content and solubility are the lowest. The water contact angle increases from 33.33° to 93.67° with the increase in pH. However, pH has no significant effect on the water vapor permeability. The tensile strength and elongation at break increase slightly with the increase in pH. Overall, pH modifies the properties of potato flour films. Film with appropriate performance can be selected based on actual needs, such as the use of packaging materials for food preservation. [ABSTRACT FROM AUTHOR]

[Display omitted] The construction of metal–organic frameworks (MOFs) with highly efficient capture for volatile organic compounds (VOCs) adsorption under humid conditions is a significant yet formidable task. Herein, series of fluorinated UiO-67 modified with trifluoroacetic acid (TFA) and 4-fluorobenzoic acid were successfully synthesized for VOCs adsorption under high humidity conditions. Experiments results showed that UiO-67 modified with 4-fluorobenzoic acid (67-F) presented excellent adsorption capacity of 345 mg/g for toluene adsorption and exhibited great water resistance (10.0 vol% H 2 O, 374 mg/g toluene adsorption capacity). Characterization results indicated that the introduction of 4-fluorobenzoic acid induced the competitive coordination between 4-fluorobenzoic acid and 4,4-biphenyl dicarboxylic acid (BPDC) with Zr4+, causing the formation of abundant defects to provide extra adsorption sites. Meanwhile, the benzene ring in 4-fluorobenzoic acid enhanced the π-π conjugation, causing the further promotion of VOCs adsorption capacity. More importantly, the water resistance mechanism was investigated and elucidated that the introduction of F decreased the surface energy of 67-F and its affinity with water. Meanwhile, the metal complex induced by the fluorinated modification produced an electron-dense pore environment, which greatly improved its chemical and water stability. This work provided a strategy for preparing an adsorbent with high water resistance for real-world VOCs adsorption at high humidity conditions. [ABSTRACT FROM AUTHOR]

Waste paper pulp (WP) is considered an eco-friendly alternative to petrochemical plastic. However, certain properties of WP limit its application in packaging. Starch–acid cross-linking reportedly improves the physical and barrier properties of cellulose-based materials. Therefore, this study aims to investigate the effect of starch–citric acid (CA) cross-linking on the physical and barrier properties of WP. Herein, WP/starch–CA-cross-linked composite sheets (WPSAs) were fabricated, and their physical, barrier, and thermal properties and morphology were investigated. The results indicated that introducing CA into WP/starch (WPS) reduced water absorption up to 39.5% compared to that of the control. Additionally, the surface and cross-section morphology, tensile strength, contact angle, and thermal properties improved as the concentration of CA increased. The highest tensile strength was obtained for WPSA with 5% of CA, providing 1445% and 26% values higher than that of the control and WPS, respectively. Moreover, the contact angle of this WPSA was superior at 116.83°. The thermal stability was also improved by increasing the glass transition temperature and decreasing the weight loss and decomposition rate. Furthermore, the addition of CA into WPS increased the system R-values up to 38% compared to that of the control, indicating improvement in the thermal-insulation property. However, introducing more than 5% of CA negatively affected the morphology, tensile strength, and contact angle. Thus, adding 5% of CA improves the physical and barrier properties of WPSA, which can be utilised for biodegradable packaging. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two novel chiral nematic cellulose nanocrystal (CNC) composite films composed of CNCs, gluconic acid (GA), polyvinyl pyrrolidone or polyacrylamide (CNC-GA-PVP and CNC-GA-PAM) were fabricated mainly by evaporation-induced self-assembly process. The visible iridescent color and chiral nematic structure of the obtained CNC-based films could be readily regulated by altering the content of GA in a wide color range. Both CNC composite films possessed good tensile strength. Worthy to be mentioned, the CNC-GA-PAM films exhibited rather high flexibility (elongation reached 222.53%) and could be curled into any shape, indicating the effective contribution of the polymer cross-linked networks from the non-ionic PAM. The reversible humidity responses were also observed for both CNC films with good sensitivity, probably due to the high hygroscopicity of GA. In addition, the CNC-GA-PAM films revealed exceptional water resistance without losing the regular chiral structure and structural color of CNCs. The influences of the content of tougheners and adding way of the polymers on the properties of CNC films were further investigated. This work presents a novel strategy for construction of multifunctional CNC-based nanomaterials for various applications. [ABSTRACT FROM AUTHOR]

The aggregate-to-binders ratio (A/Bs) is an important parameter for the design and preparation of repair mortars. In this paper, the influences of A/Bs on the physical and mechanical properties of red-mud-modified magnesium phosphate repair mortar (RMPM) were systematically investigated. By exploring the capillary absorption characteristics of RMPM, the effect mechanism of A/Bs on its water resistance and mechanical properties was further clarified. The results indicated that the fluidity of fresh RMPM reduced with an increase in A/Bs, and its setting time was first shortened and then prolonged. The compressive strength, flexural strength, interfacial bonding strength, and water resistance of RMPM increased and then decreased with the increasing A/Bs and reached the maximum when the A/Bs was 1.0. The capillary absorption of RMPM was a linear correlation with the square root of the immersion time, and whose slope, that is, the capillary absorption coefficient, and capillary porosity decreased and then increased with the increase in A/Bs. Capillary porosity had a linear relationship with the strength retention rate, which indicated that A/Bs produced a significant effect on the water resistance of RMPM by modifying its capillary pore characteristics. When the A/Bs was 1.0, RMPM had the lowest capillary absorption coefficient and capillary porosity, and thus possesses appropriate mechanical properties and water resistance. [ABSTRACT FROM AUTHOR]

Traditional two-component waterborne polyurethane (2K WPU) has low water resistance, which limits its application in the wide field. In this work, fluorine-modified 2K WPU films (2K-WFPUs) were successfully prepared using a fluorine-modified acrylate emulsion as hydroxyl component and a hydrophilically modified polyisocyanate as curing agent. Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy analysis indicate that hexafluorobutyl acrylate (HFBA) was successfully introduced into the 2K-WFPUs. The effects of HFBA content on the surface, thermal stability, water resistance, mechanical, and application properties of 2K-WFPUs were investigated. Compared with the unmodified film, with the increase in HFBA level from 0 to 8%, the static water contact angle of 2K-WFPUs increased from 66° to 92°, the surface-free energy decreased from 42.7 to 28.4 mJ m−2, the water absorption reduced from 15.9 to 9.9%. Thermogravimetric analysis shows that the thermal stabilities of 2K-WFPUs were improved remarkably. Meanwhile, adding HFBA did not weaken the impact resistance, flexibility, and adhesion of 2K-WFPUs and maintained the highest level. The fluorine-modified 2K WPU coatings have potential application in wood furniture and automotive finishing. [ABSTRACT FROM AUTHOR]

Highlights Despite the continued dominance of detrimental formaldehyde‐based binders in the wood reconstituted products, there is a growing push to develop more environmentally friendly alternatives. Cellulose‐based biomass adhesives have been extensively researched and documented. However, their industrial application is limited due to inadequate water resistance and suboptimal coating ability. In this study, a cellulose‐derived wood binder with a hyperbranched entangling structure was synthesized by covalently cross‐linking branched polyethylenimine and oxycellulose through Schiff base formation. The dry/wet bonding strength of the prepared plywood was 2.07 and 1.52 MPa, respectively, exhibiting a remarkable increase and breakthrough compared to that of pure oxidized cellulose binder. This can be attributed to the formation of a water‐resistant Schiff base tangle network, which enhances the toughness of the adhesive. Notably, the pure cellulose adhesive tends to agglomerate on the wood surface, whereas the hyperbranched modified cellulose adhesive exhibits a more uniform coating ability. This study further demonstrates the reliable potential of tangle structures based on Schiff base reactions in the development of biomass‐based adhesives. A high bonding strength cellulose‐based wood adhesive was prepared. The Schiff base reactions have been used to construct cross‐linked structures. The cross‐linked network structure provides excellent water resistance. The cured cellulose‐based adhesive has excellent dry/wet bonding strength. [ABSTRACT FROM AUTHOR]

AbstractThis work aims to add an epoxy-ended co-monomer to polyvinyl acetate (PVAc) emulsion adhesive-based wood adhesive to improve its resistance to heat and moisture. Here, glycidyl methacrylate (GMA), vinyl neodecanoate (VeoVa), and vinyl acetate (VAc) emulsion copolymers have been created and evaluated as wood adhesives. To prepare the emulsion-based adhesive samples, a polyvinyl alcohol (PVA) solution, aluminium chloride solution, preservatives, and a plasticizer are added. Following that, the poly(VAc–VeoVa–GMA) based adhesive sample is compared with the VAc, VeoVa, and methyl methacrylate (MMA) (poly(VAc-VeoVa-MMA)) co-polymer-based adhesive. Tensile shear strength of wood joints under dry and wet conditions was tested in compliance with EN 204-205 standard to assess the adhesives’ performance. The EN 14257 standard, which defines the shear stress of wood joints at 80 °C, was used to assess the heat resistance of the wood adhesives. Tests on the hardness of films confirmed the results of differential scanning calorimetry, which indicated that the glass transition temperature in the GMA-based adhesive was significantly higher than in the MMA-based adhesive. After 6 h of bonding, EN 204 shows that the tensile shear strength of a GMA-based adhesive increased by 15.56% in a dry environment, by 16.67% in a wet environment and 37.84% heat resistance when compared to a co-polymer-based adhesive based on MMA. The approach that was developed provides a simple and useful way of developing adhesives with enhanced heat, water, and bonding strength resistance. [ABSTRACT FROM AUTHOR]

Bio-based solutions for solid timber gluing have always been a very sensitive topic in wood technology. In this work, we optimize the gluing conditions of a starch–tannin formulation, which allows high performance in dry conditions and resistance to water dipping for 3 h, allowing for the D2 classification to be reached according to EN 204. It was observed that the starch–tannin formulations enhanced their performance by increasing the heating temperature, achieving satisfactory results at 140 °C for 13 min. The proportion of polyphenols in the mixture enhances the water resistance but is only tolerated until 20–30%. In particular, the addition of 10% tannin–hexamine enhances the water-resistant properties of starch for both quebracho and chestnut extract. The application of the jet of cold atmospheric plasma allows for good results with more viscous formulations, increasing their penetration in wood. Solid-state 13C-NMR analysis was also performed, and the spectroscopic information suggests establishing a coordination complex between starch and tannin. [ABSTRACT FROM AUTHOR]

A novel seaweed and mussel inspired bilayer anti-oil-fouling and antifogging coating was proposed. The coating shows water resistance, mechanical durability, and long-term environmental stability. The coating performs good in anti-oil-fouling and anti-fogging. [Display omitted] Ecofriendly fabrication of anti-oil-fouling materials is of interest. Surfaces with underwater superoleophobicity have been fabricated which exhibit limited mechanical durability and water resistance. In this study, we report on a bioinspired bilayer design of a transparent anti-oil-fouling coating. Seaweed surfaces show anti-oil-fouling in the sea due to its high surface hydration ability. Mussels can adhere tightly onto a surface with good stability in the sea by virtue of its levodopa-containing secretions. The surface layer was fabricated using a crosslinked combination of carboxymethyl cellulose (CMC) and sodium alginate (AlgS) inspired by seaweed, with the addition of calcium ions. Polydopamine (PDA), a derivative of levodopa, was used as the underlayer to enhance bonding strength and water resistance. Oil that adhered to the coated surface was spontaneously detached upon immersion in water. The mechanism underlying this anti-oil-fouling effect was elucidated using Gibbs free energy theory. The coating exhibited mechanical durability and water resistance. The coating is transparent and preserves the original color of the substrate. The coated glass showed stable anti-fogging and anti-frost performance. These coatings hold promise for a wide range of anti-oil-fouling applications. [ABSTRACT FROM AUTHOR]

A series of cerium-based high-entropy oxide catalysts (the ratio of CeO2 and HEO is 1:1) was prepared by a solid-state reaction method, which exploit their unique structural and performance advantages. The Ce-HEO-T samples can achieve 100% toluene conversion rate above 328°C when they were used as catalysts directly. Subsequently, the Ce-HEO-500 exhibited the lowest temperature for toluene oxidation was used as a support to deposit different amounts of Au for a further performance improvement. Among all of prepared samples, Au/Ce-HEO-500 with a moderate content of Au (0.5 wt%) exhibited the lowest temperature for complete combustion of toluene (260°C), which decreased nearly 70°C compared with Ce-HEO-500 support. Moreover, it also showed excellent stability for 60 h with 98% toluene conversion rate. Most importantly, under the condition of 5 vol.% H2O vapour, the toluene conversion rate remained unchanged and even increased slightly compared with that in dry air, exhibiting excellent water resistance. Combined with the characterizations of XRD, SEM, TEM, BET, Raman, H2-TPR and XPS, it was found that the high dispersion of active Au NPs, the special high-entropy structure and the synergistic effect between Au and Ce, Co, Cu are the key factors when improving the catalytic performance in the Au/Ce-HEO-500 catalyst. [ABSTRACT FROM AUTHOR]

The present study utilizes starch as the primary raw material for preparing a water‐resistant biomass adhesive to replace formaldehyde‐based resin adhesive, which is subsequently used in plywood production. The preparation process of starch‐based adhesive (SBA) was optimized using response surface methodology (RSM), and the effects of the mass ratio of starch to tannic acid, the dosages of phragmites fiber and boric acid on wet‐bond strength were studied. The quadratic regression model of SBA showed significant results (p < 0.0001). The optimal preparation condition was that the mass ratio between starch and tannic acid was 5:2, in the dosages of 2.9% for phragmites fibers and 3.2% for boric acid. The wet‐bond strength of the plywood prepared with this adhesive was 1.73 MPa. Characterization analysis showed that the hydroxyl group on the surface of starch and tannic acid had complexation with boric acid, which improved the wet‐bond strength, water resistance, and, thermal stability of the adhesive. The alkali‐treated phragmites fibers had better compatibility with the starch matrix than the original fiber, which improved the cohesion of the SBA and increased the wet‐bond strength by 26%. Highlights: The phragmites fibers have been used to reinforce starch‐based adhesives.Boric acid facilitates the formation of crosslinked structures.The phenolic hydroxyl group in tannins provides excellent water resistance.Phragmites fiber exhibits good compatibility with the adhesive matrix.The cured starch‐based adhesive has excellent wet‐bond strength. [ABSTRACT FROM AUTHOR]

The object of this study is fine-grained concrete from the waste of mining and processing plants. These wastes are fine-grained dusty sands of polymineral composition. Their use as an aggregate for concrete is restrained by high water consumption, which does not make it possible to obtain sufficient strength for concrete. Therefore, the problem to be solved was the substantiation of the composition of fine-grained concrete from these wastes with mineral and chemical additives, which would ensure obtaining physical-mechanical and hydrophysical properties reasonable for the production of construction articles. The composition of fine-grained concrete from the waste at the Poltava Mining and Processing Plant and slag Portland cement in a ratio of 3:1 and additives of micro silica (15 % of the cement mass) and polycarboxylate superplasticizer (2 % of the cement mass) with W/C=0.5 was obtained. The compressive strength of this concrete reaches 40 MPa, which exceeds the strength of fine-grained concrete of a similar composition on natural fine-grained sand by 3 times. This is due to a greater degree of cement hydration, a greater number of formed hydration products, the presence of silica and quartz particles, a more uniform alternation of gel, silica particles, and crystal hydrates in the structure of cement stone. As a result, the structure contains a larger number of electro heterogeneous contacts between particles and grains that have negative (quartz, calcium hydro silicates) and positive (crystal hydrates of portlandite, hydro aluminates and calcium hydrosulfoaluminate) surface charges. This is what determines the achieved strength and water resistance of fine-grained concrete. The resulting composition of fine-grained concrete is recommended for the production of construction articles [ABSTRACT FROM AUTHOR]

Improvement of hydrophysical properties and corrosion resistance of self-compacting concrete to the effects of alternate freezing–thawing and aggressive soils of Southern and Central Kazakhstan is of interest to a wide range of researchers from the side of practical application of the obtained results in construction practice. It is proposed to form a spatially reinforced fine crystalline structure of a cement matrix with the maximum dense packing by using a complex modifier (hyperplasticizer + polymer + microsilica + fibro fibers) in the composition of self-compacting concretes (SCCs). The introduction of the calculated amount of the above additives increases the operational reliability of the current SCC compositions, increasing the water resistance to W16, frost resistance to F = 500, increasing the compressive strength by 20%, and reducing the mass loss of samples during corrosion leaching to 50%. It has been experimentally established that the proposed addition of the complex modifier (hyperplasticizer + polymer + microsilica + fibro fibers) to the SCC composition allows obtaining self-compacting concrete of high quality with improved performance characteristics (compressive strength, water resistance, frost resistance, and corrosion resistance). Studies have shown that the complex modifier-modified SCC compositions have a high degree of resistance in aggressive environments and leaching corrosion. Based on the results of the conducted tests, it is possible to recommend the obtained SCC compositions for the production of building products working in the zone of alternating freezing–thawing and aggressive soils. [ABSTRACT FROM AUTHOR]

Gypsum-based composites were prepared via a slurry casting process using construction gypsum as the binding material and poplar fibers as reinforcing material. The effects of different fiber content and curing time on the mechanical properties, water resistance, and flame retardancy of these composites were investigated, and the influence mechanism was characterized by infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry. The results showed that the best composite mechanical strength was achieved with 10% poplar fiber- content, and the absolute dry flexural and compressive strengths reached 3.59 and 8.06 MPa, respectively. Compared with pure gypsum, the flexural strength and compressive strength increased by 10% and 19%, respectively. The inclusion of fibers somewhat prevented the migration of free water within the composites and enhanced their water resistance. At 10% fiber content, the composite's 24 h water absorption rate was 34.3%, 8% lower than that of pure gypsum, with a softening coefficient of 0.55. However, fiber content increases the porosity of gypsum-based composites. When heated, this increased porosity accelerates' heat conduction within the matrix, raising the peak and total exothermic rates, thereby weakening the composites' inherently flame-retardant properties. Poplar-fiber-reinforced gypsum-based composites offered superior performance in commercial applications, compared to pure gypsum board, providing a sustainable and green alternative for ceilings, partitions, and other applications, while broadening the prospects for gypsum-based composites in the engineering field. [ABSTRACT FROM AUTHOR]

Magnesium oxysulfate (MOS) cement, a building material, can be considered the result of the hydration reaction between magnesium sulfate, caustic-burned magnesia powder, and water. Despite its desirable properties, such as limited mechanical strength and water resistance, MOS cement can hinder its use in engineering applications. We employed several testing methods to assess the impact of sodium gluconate (SG) addition on the compressive strength, microstructure, moisture resistance, coagulation time, pH profile, micropore parameters, phase composition, and thermal decomposition of MOS cement's hydration products. The addition of sodium gluconate improves the stability of the hydration film surrounding active magnesium oxide in magnesium sulfate. This extension in the setting time of MOS cement is observed. Additionally, it inhibits the creation of magnesium hydroxide while facilitating the formation of numerous needlelike structures corresponding to the 5Mg(OH)2·MgSO4·7H2O (5·1·7 phase). Consequently, the mechanical strength and water resistance of MOS cement are substantially improved compared to the unmodified sample. [ABSTRACT FROM AUTHOR]

Non-precious metal catalysts with enhanced low-temperature activity and improved water resistance are highly demanded for emission control. CuO-based catalysts are promising alternatives to precious metal catalysts due to their acceptable activity and cost-effectiveness. However, there is an urgent need to further enhance their low-temperature activity and water resistance for industrial applications. Herein, CuO catalysts supported by various SiO2-TiO2 supports were prepared and evaluated for CO oxidation and NO reduction by CO reactions under the testing conditions with and without water. Among the studied catalysts with different SiO2 contents, CuO/5SiO2-TiO2, in which CuO was supported by SiO2-TiO2 with 5 wt.% SiO2, exhibited the best performance for CO oxidation. Compared with CuO/TiO2 and CuO/SiO2 reference catalysts, the CuO/5SiO2-TiO2 catalyst showed enhanced catalytic activity in both CO oxidation and NO reduction by CO under dry and wet conditions. Comprehensive characterizations revealed that the presence of SiO2 in TiO2 support facilitated the CuO/5SiO2-TiO2 catalyst with a high dispersion and reduced oxidation states of CuOx species. This not only improved the low-temperature reducibility but also enhanced the adsorption of reactive CO species. As a result, the CuO/5SiO2-TiO2 catalyst demonstrated superior catalytic activity. Furthermore, the inclusion of SiO2 in the catalyst inhibited H2O adsorption, contributing to the enhanced water resistance on CuO/5SiO2-TiO2 catalyst. These advantages in catalytic activity and water resistance make CuO/5SiO2-TiO2 a promising candidate for applications in emission control. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rooftop solar modules are usually held in place by racks or frames that are mechanically attached to a roof structure and/or by heavyweight, ballasted footing mounts. These mounts ensure that the panel system remains in position against wind load. However, mechanical connectors create penetrations into the water-resistant layer of the roof, whereas ballasted footing mounts cause a significant additional load on the load-bearing structure of roof. For these reasons, adhesive connection seems to be a beneficial solution. Acrylic adhesive tapes, marked as VHBTM, may provide sufficient strength, and they have no need for mechanical fasteners or ballast. Acrylic adhesive tapes also provide a comfortable, fast, and efficient bonding process with no curing compared to liquid adhesives. On the other hand, resistance to water at load-bearing joints has not been sufficiently studied yet and could be critical for connections exposed to the outdoor environment. The present study aims at the determination of water resistance and durability of the VHBTM tapes from the GPH series, which are typically used to bond a variety of substrates including many metals. The mechanical properties and failure modes are compared for the specimens before and after a 21-day immersion in water. A significant reduction in strength was observed, depending on the substrate material. The study of chemical changes in the acrylic tape and in its leachate through infrared spectroscopy (FT-IR), X-ray fluorescence, and X-ray diffraction analyses clarified the reduction in mechanical properties. The selected VHBTM tape demonstrated strong resistance to the effects of water. However, the overall strength of the joint after immersion was significantly impacted by the decrease in adhesion to a specific substrate. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-precious metal catalysts with enhanced low-temperature activity and improved water resistance are highly demanded for emission control. CuO-based catalysts are promising alternatives to precious metal catalysts due to their acceptable activity and cost-effectiveness. However, there is an urgent need to further enhance their low-temperature activity and water resistance for industrial applications. Herein, CuO catalysts supported by various SiO2-TiO2 supports were prepared and evaluated for CO oxidation and NO reduction by CO reactions under the testing conditions with and without water. Among the studied catalysts with different SiO2 contents, CuO/5SiO2-TiO2, in which CuO was supported by SiO2-TiO2 with 5 wt.% SiO2, exhibited the best performance for CO oxidation. Compared with CuO/TiO2 and CuO/SiO2 reference catalysts, the CuO/5SiO2-TiO2 catalyst showed enhanced catalytic activity in both CO oxidation and NO reduction by CO under dry and wet conditions. Comprehensive characterizations revealed that the presence of SiO2 in TiO2 support facilitated the CuO/5SiO2-TiO2 catalyst with a high dispersion and reduced oxidation states of CuOx species. This not only improved the low-temperature reducibility but also enhanced the adsorption of reactive CO species. As a result, the CuO/5SiO2-TiO2 catalyst demonstrated superior catalytic activity. Furthermore, the inclusion of SiO2 in the catalyst inhibited H2O adsorption, contributing to the enhanced water resistance on CuO/5SiO2-TiO2 catalyst. These advantages in catalytic activity and water resistance make CuO/5SiO2-TiO2 a promising candidate for applications in emission control. [ABSTRACT FROM AUTHOR]