منو
مرتب سازی بر اساس: سال انتشار
(نزولی)
Publication Date: 2003
Journal of Chemical Research (3082342) (1)pp. 18-20
A combination of inorganic chloride salts [e.g. AlCl3, ZrCl4, and ZnCl2] and sodium nitrite in the presence of wet SiO2 was used as an effective oxidising agent for the oxidation of dihydropyridines to their corresponding pyridine derivatives under mild and heterogeneous conditions in moderate to excellent yields.
Publication Date: 2020
2025 29th International Computer Conference, Computer Society of Iran, CSICC 2025 pp. 87-104
Currently, the scientific community is devoting considerable attention to developing environment-friendly polymeric materials (bionanocomposite) due to their nontoxic, nonallergenic, biodegradable, and biocompatible nature. Numerous processing technologies have been announced by researchers to overcome the shortcomings of biopolymers. In recent years, scientific researchers have been trying to develop new processing technology that can be adopted in both industrial and academic sectors. Furthermore, they have the target that the processing methods for the synthesis of bionanocomposite materials should have various advantages like safe nature, time-efficient, eco-friendly, easy to operate, sustainable, low cost with excellent mechanical and physical properties, and good environmental impact. New more advanced manufacturing methods and techniques have been introduced. The purpose of this research, development, and advancement is to produce bionanocomposites from the pilot scale to the industrial level. Simply, we can say that different bionanocomposites are prepared by various ways because the processing methods have an effect on the properties of bionanocomposites. So, our main focus is to provide an overview of the processing methods or techniques of bionanocomposites that have been widely adopted. © 2020 Elsevier Inc. All rights reserved.
Publication Date: 2015
Synlett (09365214) 25(1)pp. 108-110
A new multicomponent domino reaction has been developed for the synthesis of 4-aminothiazole-2(3H)-thiones. Carbon disulfide was successfully used in the preparation of 4-aminothiazole-2(3H)-thione derivatives through reaction with primary amines and 2-bromo-2-arylacetonitriles in the presence of sodium carbonate and a catalytic amount of sodium iodide.
Publication Date: 2011
Journal Of The Iranian Chemical Society (1735207X) 8(2)pp. 513-524
12-Tungstophosphoric acid immobilized on [bmim][FeCl4] was found to be an efficient catalyst for chemoselective methoxymethylation and ethxoymethylation of alcohols and also one-pot conversion of MOM- or EOM-ethers to their corresponding acetates and TMS-ethers under thermal conditions and microwave irradiation. These procedures were simple, rapid and the corresponding products were obtained in high yields. The catalyst exhibited remarkable reactivity and was reusable.
Publication Date: 2010
Applied Organometallic Chemistry (02682605) 24(10)pp. 708-713
In the present work, highly efficient epoxidation of alkenes catalyzed by Mo(CO)(6) supported on multi-wall carbon nanotubes modified by 2-aminopyrazine, APyz-MWCNTs, is reported. The prepared catalyst was characterized by elemental analysis, scanning electron microscopy, FT IR and diffuses reflectance UV-vis spectroscopic methods. This new heterogenized catalysts, [Mo(CO)(6)@APyz-MWCNT], was used as a highly efficient catalyst for epoxidation of alkenes with tert-BuOOH. This robust catalyst was reused several times without loss of its catalytic activity. Copyright (C) 2010 John Wiley & Sons, Ltd.
Publication Date: 2011
Comptes Rendus Chimie (18781543) 14(10)pp. 869-877
Di[1,6-bis(3-methylimidazolium-1-yl)hexane] decatungstate dihydrate ([C-6(MIm)(2)](2) W10O32. 2H(2)O) as a new family of polyoxometalate-based dicationic ionic liquids (POM-DIL) is synthesized and employed as a novel and powerful heterogeneous catalyst in the synthesis of 4-arylidene-2-phenyl-5(4)-oxazolones (azlactones) under ultrasound-assisted solvent-free condition. On the basis of the results, the products were obtained in excellent yields under mild condition. Utilization of easy work-up and purification make it very interesting from an economic perspective. Moreover, a recycling study confirmed that the catalyst can be reused multiple times without significant loss of its activity. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
Publication Date: 2011
Tetrahedron Letters (00404039) 52(11)pp. 1213-1216
Nanosilica sulfuric acid is found to be a new, powerful and reusable heterogeneous catalyst for the rapid synthesis of 3-hydroxyphthalans via condensation of aromatic aldehydes and 3-hydroxybenzyl alcohols under conventional heating and microwave irradiation. Scale-up preparation of these heterocycles is also carried out. (C) 2011 Published by Elsevier Ltd.
Publication Date: 2014
Journal Of The Iranian Chemical Society (1735207X) 11(5)pp. 1493-1501
Di[1,6-bis(3-methylimidazolium-1-yl)hexane] decatangstate ([C-6(MIm)(2)](2)W10O32) was found to be a novel, powerful and effective catalyst for the preparation of N-benzoylglycine carbamides as derivatives of AT-130 via one-pot multicomponent reaction performed under microwave irradiations. The products were obtained in high to excellent yields, thus providing a unique strategy to the large-scale synthesis of these compounds.
Publication Date: 2013
Synlett (09365214) 24(9)pp. 1086-1090
The Lewis acidic room-temperature ionic liquid, [bmim][InCl4], was found to be an efficient catalyst for the regioselective synthesis of fully substituted pyrazoles and pyrazole-fused cyclohexanones through condensation of hydrazones with symmetrical and unsymmetrical 1,3-diketones. This procedure is simple, affording the corresponding products in good to high yields.
Publication Date: 2016
Journal of Organometallic Chemistry (0022328X) 809pp. 31-37
A new catalytic system based on Pd-NHC complex utilizing (4-pyridyl)bis(imidazolyl)methane as a bidentate NHC ligand supported on nano. silica is introduced. The catalyst was characterized by FT-IR spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy and elemental analysis. This heterogeneous catalytic system exhibited excellent activity in the Suzuki-Miyaura coupling reaction of various aryl halides with phenylboronic acid, and was reusable several times without significant loss of its catalytic activity. (C) 2016 Elsevier B.V. All rights reserved.
Publication Date: 2023
ChemistrySelect (23656549) 8(9)
This work synthesized a novel colorimetric ligand based on the compound quinazolinone (Sensor) and investigated it. The sensing activity of the sensor toward different cation was studied. The sensor demonstrated a highly selective colorimetric sensing toward Hg2+ with a detection limit of 0.1 ppb and visual color change from colorless to Purple in methanol-water solvents (v/v, 10,90). The cation binding character was determined using visual inspection, UV-Vis, and fluorescence analyses. In the computational part, the interaction between the receptor and Hg2+ ion was investigated using density functional theory (TD-DFT) and quantum theory of atoms in molecules (QTAIM) in the solution phase (in the presence of water as solvent and the CPCM model). Theoretical studies have shown that electronic properties such as energy gap, absorption energy, charge/energy transfer, and optical properties change dramatically in the presence of Hg2+ cations. Also, the effect of the electric field on the electronic properties of the sensor/Hg2+ complex improved the Hg2+ cation adsorption process.
Publication Date: 2011
Comptes Rendus Chimie (18781543) 14(10)pp. 953-956
In the present work, a mild and efficient method has been developed for the synthesis of acylals from aldehydes with acetic anhydride in the presence of molybdophosphoric acid encapsulated into dealuminated zeolite Y (MPA-DAZY) as a catalyst under solvent-free conditions at 45-55 degrees C in good to excellent yield. The deprotection of acylals has also been attained using this catalyst in acetonitrile. The catalyst was reused several times without efficient loss of its catalytic activity. (C) 2011 Published by Elsevier Masson SAS on behalf of Academie des sciences.
Publication Date: 2023
Sensors and Actuators B: Chemical (0925-4005) 379
A reversible multichannel chemosensor IPBTO [E)-5-(4-(1H-imidazo[4,5-b]phenazin-2-yl) benzylidene)-2-thioxothiazolidin-4-one] was fabricated as a D-pi-A system and used for the detection of cyanide ion (CN-) in aqueous solutions. This chemosensor exhibited a switch-off fluorescence response at 566 nm for CN- in the presence of other tested anions. The detection limit of IPBTO toward CN- was 0.7 mu M with the association constant being 2.0 x 106 M-1. The reversibility and reusability aspects of this chemosensor were investigated for five consecutive runs, and good results were obtained. In addition, IPBTO as a bioimaging agent with good cell viability was deployed for the detection of CN- in MDA-MB-231 cells. Excellent potential for sensing CN- was also realized for this chemosensor in food and environmental samples. Besides, IPBTO was self-assembled on the gold electrode surface (Au-IPBTO SAM) and used for accumulation and detection of CN- in aqueous media. This modified electrode was characterized by ATR surface analysis, and the electrochemical behavior of the electrode was studied utilizing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Our results have conclusively revealed that this electrochemical sensor could be successfully used to detect CN-.
Publication Date: 2012
ADVANCED SYNTHESIS & CATALYSIS (16154150) 354(16)pp. 3095-3104
An efficient protocol for the excellent diastereoselective synthesis of pyrazolines via a three-component reaction of aldehydes, hydrazines and dimethyl acetylenedicarboxylate (DMAD) in the presence of a bifunctional Bronsted acidic ionic liquid as a reusable catalyst under solvent-free conditions is reported. Easy work-up, short reaction times, high yields of the products and an environmentally benign procedure avoiding toxic organic solvents are other significant features of this method.
Publication Date: 2025
Journal of Materials Chemistry B (2050750X) (21)
Light-induced antibacterial effects aim to overcome the limitations of antibiotic-resistant bacteria and provide an effective solution for wound healing applications. This research focuses on developing a multifunctional wound dressing based on waterborne polyurethane (WPU) adorned with a hybrid photo nano-sensitizer (ZnO@PDA/Ag) that demonstrates near-infrared (NIR)-triggered synergistic photothermal and photodynamic effects. Through a facile synthesis process, zinc oxide (ZnO) nanoparticles were coated with polydopamine (PDA) to enhance biocompatibility, photothermic effect, and charge transfer efficiency due to a surface sensitization and passivation strategy. The synthesis was followed by the in situ reduction and decoration of plasmon silver nanoparticles (Ag NPs) to augment photodynamic activity. The structure, chemical composition, and morphology of the ZnO@PDA/Ag nano-sensitizer were examined and the results confirmed the successful synthesis. Furthermore, based on photo-thermal and fluorescence signal measurements under near-infrared (NIR) irradiation, the ZnO@PDA/Ag nanoparticles in aqueous dispersions exhibit effective light-to-heat conversion, as well as a strong ability for NIR-induced singlet oxygen generation. The WPU films incorporating the ZnO@PDA/Ag nano-sensitizer exhibit complete phototherapy inhibition of both Gram-negative E. coli and Gram-positive S. aureus bacteria. In addition, the films exhibited an appropriate biocompatibility in contact with L929 fibroblast cells. Moreover, in vivo studies in a rat wound model demonstrated accelerated wound healing and tissue regeneration with the application of ZnO@PDA/Ag in WPU nanocomposite film, particularly under NIR light irradiation. Histological analysis confirmed the formation of mature epithelial layers and minimal inflammatory response, indicating the potential of this film for clinical wound management. © 2025 The Royal Society of Chemistry.
Publication Date: 2025
Polymers (20734360) (7)
An advanced, eco-friendly, and fully bio-based flame retardant (FR) system has been created and applied to the cellulose structure of the cotton fabric through a layer-by-layer coating method. This study examines the flame-retardant mechanism of protein-based and phosphorus-containing coatings to improve fire resistance. During combustion, the phosphate groups (−PO₄2−) in phosphorus containing flame retardant layers interact with the amino groups (–NH2) of protein, forming ester bonds, which results in the generation of a crosslinked network between the amino groups and the phosphate groups. This structure greatly enhances the thermal stability of the residual char, hence improving fire resistance. Cone calorimeter and flammability tests show significant improvements in fire safety, including lower peak heat release rates, reduced smoke production, and higher char residue, all contributing to better flame-retardant performance. pHRR, THR, and TSP of the flame-retarded cotton fabric demonstrated 25, 54, and 72% reduction, respectively. These findings suggest that LbL-assembled protein–phosphorus-based coatings provide a promising, sustainable solution for creating efficient flame-retardant materials. © 2025 by the authors.
Publication Date: 2025
Progress in Organic Coatings (03009440)
The rapid development of chemical industries and oil spills during extraction and transportation have caused severe environmental pollution. Polyurethane foams “PUF” are widely used to remove oil from water due to their three-dimensional porous networks, which provide high absorption capacity. However, their effectiveness in oil/water separation applications, may decrease with repeated use as a result of structural and chemical degradation, and loss of hydrophobicity. In this research, to address this limitation and increase in their long-term stability and durability, fluorinated waterborne polyurethanes containing Fluorolink E10-H-modified nano-silica (WPU/Fl@SiO2) were synthesized and applied to coat PUFs by the dip-coating technique. This strategy offers several advantages, including low VOC emissions, a one-stage and scalable modification method, minimal material usage, and reduced time and energy consumption. The prepared nanostructures, WPU nanocomposites, and modified foams were analyzed by FTIR, XRD, TGA, DLS, FE-SEM, contact angle, and oil/solvents removal tests. The findings confirmed that the PUF/W10 sample, coated with WPU-Fl@SiO2 containing 10 wt% of nanostructures, in addition to the high surface roughness, has the highest contact angle (164.9°) and superior adsorption capacity for Xylene (42 g/g) and ethyl acetate (52 g/g). Moreover PUF/W10 sample showed an acceptable oil/water performance after 50 absorption cycles compared to unmodified and other modified foam samples The PUF/W10 sample performed well in different temperature ranges and corrosive environments, including acidic, alkaline, and strong salt solutions. Moreover, this foam displayed a continuous, efficient, and selective oil/water separation capability under a simple vacuum system. This research highlights the potential of PUFs coated with WPU-Fl@SiO2 aqueous dispersion as effective and durable materials for oil/solvent separation from water. © 2024 Elsevier B.V.
Publication Date: 2024
Iranian Journal of Polymer Science and Technology (10163255) (3)
Metal corrosion poses a global threat, causing significant economical and environmental damage in various industries. Extensive research has been conductedtodevelopefficientandcost-effectivesolutionstopreventcorrosion while adhering to environmental regulations. Recently, waterborne polyurethanes, prepared by dispersing polyurethanes in water through various methods, have been increasingly used for coating various surfaces due to their advantages such as low emission of volatile organic compounds (VOCs), environmental compatibility, low viscosity, rapid coating capability, and low production cost. Waterborne polyurethane coatings are considered suitable for anti-corrosion applications due to their mechanical strength, flexibility, high abrasion resistance, and the ability to design structures and incorporate various nanoparticles. Recent research has shown that graphene-based nanostructures, such as graphene, graphene oxide (GO), and reduced graphene oxide (rGO), are used as corrosion-inhibiting nanostructures in the formulation of anti-corrosion coatings due to their high surface area and resistance to oxygen, water, and corrosive agents. Incorporating these nanostructures into waterborne polyurethanes has enhanced the anti-corrosion properties of the resulting coatings. However, the application of these nanostructures in waterborne polyurethane matrices faces limitations such as non-uniform dispersion, low stability of aqueous dispersions, and the formation of agglomerates. This review paper elucidates the phenomenon of corrosion and various anti-corrosion testing methods, introducing waterborne polyurethanes and graphene-based nanostructures. Subsequently, it reviews related articles on the preparation of waterborne polyurethane coatings containing different graphene-based nanostructures and their anti-corrosion performance. Additionally, recent advancements in the development of waterborne polyurethane/graphene-based nanostructure anti-corrosion coatings with specific structural features, such as self-healing and ultraviolet curing capabilities, are examined. Furthermore, multi-functional anti-corrosion coatings with properties like anti-fouling, superhydrophobicity, and antibacterial characteristics for specific applications are described. © 2024 Iran Polymer Society. All rights reserved.
Publication Date: 2024
Iranian Journal of Polymer Science and Technology (10163255) (2)
The production and consumption of synthetic polymers have faced limitations such as strict environmental laws, limited supply of raw materials, and high production costs. Therefore, natural polymers, especially polysaccharides like starch, cellulose, hemicellulose, chitin, chitosan, alginate, glucomannan, and agar, have found wide applications for various industrial uses due to their properties, such as biocompatibility and biodegradability. However, the main problem with these polymers is their weak mechanical properties and processability, which have limited their use. Alginate is a biodegradable, biocompatible, non-toxic, hydrophilic, and inexpensive biopolymer that is found as part of the structural components of bacteria and brown algae in nature. Alginate can be easily modified through some physical and chemical processes and its various derivatives. The new alginate derivatives have different structures, functions, and properties, including improved mechanical strength, cell affinity, and gelation properties. Polyurethanes have a wide range of applications in various industries, such as automotive, electronics, textiles, medical devices, coatings, and insulation, due to their unique physical and chemical properties that can be tuned, such as flexibility, hardness, impact resistance, and moisture resistance. Considering the above features of alginate and polyurethanes, extensive research has been conducted on the combination of these two materials to create new materials with special properties and novel characteristics. This article is an introduction on alginate and its derivatives as a natural polymer; and while discussing their structure, properties and applications, an such extended review is presented on polyurethane/ alginate mixtures in various forms as films, elastomeric membranes, nanocomposites, hydrogels, supramolecular ionic networks, porous scaffolds, and foams in various applications such as drug delivery systems, wound dressings, fire-resistant materials, and adsorbents. © 2024 Iran Polymer Society. All rights reserved.
Publication Date: 2024
Journal of Applied Polymer Science (00218995) (3)
Self-healing coatings can restore their performance after inevitable damage and are promising in the industry owing to their longer service life and lower repair cost. The use of Diels–Alder reaction bonds is well-known to generate thermally self-healing coatings. In this study, a series of cross-linked self-healing polyurethane (PU) coatings were synthesized through Diels–Alder reactions of p-tert-butyl calix[4]arene bearing furan groups (C4A-FA) as a new chain extender and a bismaleimide (BMI) polyether amine as a Diels–Alder cross-linking agent. Adding C4A-FA to PUs improves their mechanical properties, thermal stability, and self-healing ability. Additionally, these modifications can result in the formation of composite networks with PU that exhibit thermoreversibility and self-healing properties. These changes have led to PUs containing modified calix[4]arene (C4A-FA) having better properties compared with unmodified calix[4]arene PUs. The properties of prepared coatings were evaluated by Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), and tensile tests compared with a typical PU sample. The tensile and TGA results show an improvement in the thermal and mechanical properties of the polymers by increasing the C4A-FA content. By replacing 15% of butandiol (BDO) with C4A-FA in PU pure, the tensile strength increased from 1.69 to 5.14 MPa. Furthermore, adding diels–alder (DA) bonds enhanced the tensile strength to 10.49 MPa for PU-C4A15-DA. According to DSC results, a broad endothermic peak from nearly 80–140°C confirmed the retro-DA reactions in the synthesized thermoreversible samples. The healing efficiency of the PU-C4A15-DA sample was obtained at 92.5% (measured by tensile test), which is the highest value among cross-linked self-healing PUs reported in the literature. © 2023 Wiley Periodicals LLC.
Publication Date: 2023
Heliyon (24058440) (11)
Wound infections are a significant issue that can hinder the wound healing process. One way to address this problem is by enhancing the antibacterial activity of wound dressings. Accordingly, this work focuses on developing a castor-oil-based antibacterial polyurethane nanocomposite film impregnated with silver nanoparticles (AgNPs) decorated on the surface of reduced graphene oxide (rGO) nanostructures (Ag@rGO). To this aim, rGOs act as a platform to stabilize AgNPs and improve their bioavailability and dispersion quality within the PU film. The microwave-assisted synthesis of Ag@rGO nanohybrids was proved by FTIR, XRD, TGA, FE-SEM, EDS, and TEM analyses. Compared to PU/GO, the effect of Ag@rGO nanohybrids on thermo-mechanical features, morphology, antibacterial activity, cytocompatibility, and in vivo wound healing was assessed. SEM photomicrographs revealed the enhanced dispersion of Ag@rGO nanohybrids compared to GO nanosheets. Besides, according to XRD results, PU/Ag@rGO nanocomposite film demonstrated higher microphase mixing, which could be due to the finely dispersed Ag@rGO nanostructures interrupting the hydrogen bonding interactions in the hard segments. Moreover, PU/Ag@rGO nanocomposite showed excellent antibacterial behavior with completely killing E. coli and S. aureus bacteria. In vitro and in vivo wound healing studies displayed PU/Ag@rGO film effectively stimulated fibroblast cells proliferation, migration and re-epithelialization. However, the prepared antibacterial PU/Ag@rGO nanocomposite film has the potential to be used as a biomaterial for dermal wound healing applications. © 2023 The Authors
Publication Date: 2023
Progress in Organic Coatings (03009440)
The development of antibacterial nanocomposite coatings has been well studied in response to antibiotic resistance concerns. In this regard, silver nanoparticles incorporated waterborne polyurethanes (WPUs) are among the most attractive area due to their unique properties such as biocompatibility, reduced use of volatile organic compounds (VOC), easy construction, low viscosity, high adhesion to various surfaces, and rapid film formation. In this project, silver nanoparticles (AgNPs) were in-situ formed and simultaneously stabilized in the presence of sodium p-sulfonatocalix [4]arene (p-SC4A) as both reducing and stabilizing agents. Subsequently, the p-SC4A-stabilized AgNPs (p-SC4A/Ag) were incorporated into waterborne polyurethane, which was synthesized by the prepolymer mixing method. Examination of the structure and morphology of p-SC4A/Ag nanostructures using FT-IR, XRD, UV, SEM, and TEM analyses confirmed the synthesis of p-SC4A/Ag NPs with a smaller size than 50 nm. In addition, the various properties of WPU films with and without SC4A/Ag were evaluated by ATR-FTIR, XRD, SEM, ICP, TGA, and contact angle tests. The results showed that using p-SC4A macrocycles not only solves the agglomeration problem of silver nanostructures in waterborne polyurethane dispersions but also significantly improves bacteria-killing efficiency against the gram-positive S. aureus and gram-negative E. coli bacteria relative to pure WPU. The biocompatibility of WPU films was also evaluated, and the results showed that samples containing SC4A/Ag NPs have good biocompatibility in contact with L929 fibroblast cells. © 2023
Publication Date: 2023
ACS Symposium Series (00976156)
Polyurethane foams (PUFs), divided into flexible and rigid types, are one of the most widely used polyurethane products in the furniture, automobile, insulation, and construction industries. About 15 million tons of polyurethane are annually produced for various applications due to the diversity of their raw materials. Polyurethanes (PU) are conventionally derived from two main parts, polyols and isocyanates. The PUF formulation significantly affects the final foam’s structure, properties, and morphology. Several organic and inorganic nanostructures, such as graphite, graphene, graphene oxide, carbon black, carbon nanotube, and nano clays, have been used to fabricate composite foams to enhance their performance. Applications of polyurethane composite foams are mainly focused on aerospace and automotive industries, radar absorption and electromagnetic interference shielding, oil absorbent, sensors, fireproofing, shape memory, and biomedical materials. In this chapter, after a description on the raw materials, fabrication methods, properties of PUFs, their different applications have been elaborated in detail, Moreover, isocyanate-free synthesis of polyurethane foams and also their recycling methods will be discussed as two main environmental protection strategies. © 2023 American Chemical Society. All rights reserved.
Over the course of fifteen selected chapters, this book explores the production, chemistry, and applications of waterborne polyurethanes (WBPUs). The first chapter is a conceptual introduction to WBPUs, and the following eight chapters cover different kinds of waterborne polyurethanes, such as those made with natural and synthetic polymers, polyurethane/acrylic hybrids, waterborne polyurethane nanocomposites, and even light stimuli responsive and conductive WBPUs. The remaining six chapters cover various applications of WBPUs ranging from textile treatment and food packing to biomedical applications such as drug delivery. © 2023 by Nova Science Publishers, Inc. All rights reserved.
Waterborne polyurethane/acrylate hybrids have attracted significant attention due to some features, such as low toxicity, environmental compatibility, and enhanced physical and chemical properties. In comparison with neat WBPUs, WBPU/acrylate hybrids exhibit improved properties, including solvent and alkali resistance and thermal, mechanical and thermos-mechanical properties. Furthermore, the fabrication of WBPU/acrylate hybrids overcomes the polyurethane/ polyacrylate blend problems like phase separation. The WBPU/acrylate hybrids are prepared by a strong chemical bond between the two components of waterborne polyurethane and acrylate monomers. These hybrids are synthesized by different approaches such as interpenetrating networks, seeded emulsion, and semi-emulsion polymerization. In addition, recently, to reduce the toxicity effect of isocyanates, a non-isocyanate method has been also developed to synthesize WBPU/acrylate hybrids. WBPU/acrylate hybrids have outstanding performances, such as excellent adhesion to the substrates, weather stability, durability, flexibility, and abrasion resistance. The purpose of this book chapter is to study raw materials, the synthesis methods, properties, and applications of the waterborne polyurethane/acrylate hybrids. © 2023 Nova Science Publishers, Inc.
Nowadays, it is rare to find a place where adhesive is not used. The increasing growth of industries has expanded the need for this helpful substance. Therefore, sources, synthesis, advances, chemistry, and marketing are very important. Waterborne polyurethane adhesive is a versatile material for different applications such as textile, packaging, automotive, transportation, and footwear. This is due to safety considerations for the environment. Excellent chemical, physical and mechanical performances of this advanced material have been drawing large research focus on its chemistry, synthesis, and modification. Changes to raw material, processing, and techniques can enhance the adhesive properties and performance to make it suitable for desired applications. In this book chapter, raw materials, production processes, advances, and modifications in waterborne polyurethane adhesive have been discussed. Recent advances in these kinds of adhesives are comprehensively illustrated. Also, the market forecast and the effect of various factors on its economy have been briefly mentioned. © 2023 Nova Science Publishers, Inc.
Polyurethanes (PUs) are one of the most diverse categories of polymers. They are available in different forms, such as adhesives, coatings, elastomers, and foams. PUs have unique properties such as desired mechanical, chemical, and abrasion resistance properties. But one of the disadvantages of typical PUs is using organic solvents, which are harmful to human health and the environment. In this regard, the researchers introduced and developed an environmentally friendly alternative to solvent-based PUs, called waterborne polyurethanes (WBPUs). WBPUs, without or with little volatile organic compounds (VOCs), can form thin films with excellent adhesion on many substrates, including metal, glass, and wood at room temperature. Other characteristics of WBPUs are low viscosity, non-toxicity, nonflammability, and cost-effectiveness. Due to the non-dissolution of typical PUs in water, it is necessary to use specific strategies to disperse them in water, by using various processes and raw materials. In this chapter, after an introduction to waterborne polyurethanes, their structure, required raw materials, synthesis methods, and various applications are discussed. In the end, the challenges of this type of polyurethanes are addressed, especially in the preparation process and their industrialization. © 2023 Nova Science Publishers, Inc.
Corrosion is a common phenomenon between materials and substances in their environment. Corrosion limits the use of metals for various purposes and increases costs in industries. Many advanced methods have been reported to prevent the corrosion of metal tools. This chapter discusses many topics related to corrosion mechanisms, inhibition routes, corrosion analysis, and mechanisms of waterborne polyurethane and its composites for corrosion protection. Waterborne polyurethane is an eco-friendly polymer that is ideal for a wide range of applications due to its properties, such as flexibility at low temperatures, moisture resistance, resistance to pH changes, quick drying, and easy cleaning. To create an effective coating, it is necessary to prepare highly stable dispersions with practical inhibitory effects, proper packing, high cross-linking density, suitable additive content, and strong adhesion to the substrate. In this chapter, the current literature and research on using waterborne polyurethane and its composites as an anti-corrosion coating are studied in detail to provide a comprehensive overview of how anticorrosion coatings work and what can improve their anti-corrosion properties. © 2023 Nova Science Publishers, Inc.
Waterborne polyurethanes (WBPUs) have been studied as potential lightresponsive polymers due to their outstanding performance after incorporating light-sensitive components without decreasing their mechanical and physical properties. Photoluminescent WBPUs are lightresponsive WBPUs that can be synthesized by adding nanofillers such as carbon quantum dots and incorporating fluorophores like fluorescein, rhodamine, anthraquinone, naphthalene, and benzophenone as chain extenders or as grafting groups. These photoluminescent WBPUs can be applied as surface coatings, labels, LEDs, and fluorescent sensors. Similarly, by covalently bonding a chromophore to the WBPUs matrix, a self-colored WBPU can be synthesized, which is usually a better option than physically blending the WBPU with a coloring dye. By covalent bonding, the self-colored WBPU has lower color migration and higher water resistance and can be used in coatings, packaging, and textiles. Photochromic WBPUs have also attracted considerable attention due to their various potential applications. Photochromic WBPUs have been developed by adding small photochromic molecules (chromophores) within the polymer backbone. Different molecules such as spiropyran, spirooxazine, and azobenzene have been used to synthesize photochromic WBPUs. © 2023 Nova Science Publishers, Inc.
Publication Date: 2023
Iranian Journal of Polymer Science and Technology (10163255) (1)
Today, the specialists’ attention on polyurethanes is increasing day by day due to easy synthesis, available raw materials, favorable mechanical properties, biocompatibility, and the possibility of providing different products, such as water-based polyurethanes, foams, hydrogels and glues. Chitosan is a natural polymer that is extracted from the deacetylation of chitin and contains glucosamine and N-acetyl glucosamine units. This non-toxic natural polymer has very useful properties such as antimicrobial activity, biocompatibility, biodegradability, and tissue repair and regeneration effects. One of the weaknesses of chitosan is its poor solubility and processability due to its strong intra- and intermolecular hydrogen bonding. Therefore, chitosan has been used mainly in modified form or in combination with other polymers in various applications. The combination of synthetic polymers with natural polymers is of particular importance because natural polymers such as chitosan can show some properties such as biocompatibility, biodegradability, low toxicity, high cell viability, and internal tissue growth; while the synthetic polymers have other characteristics such as favorable processing, mechanical and physical properties, and appropriate chemical and thermal stability. Recently, chitosan has been used in combination with polyurethanes to improve its mechanical properties, thermal stability, biodegradability, antimicrobial properties and biological activity. During these studies, products in various forms such as composite, elastomer, fiber, foam, scaffold, and hydrogel have been prepared for different applications. In this review, polyurethanes containing chitosan and their synthesis methods for various applications are discussed. The products prepared in these studies have been suggested for various applications such as antibacterial coating, wound dressing, tissue engineering scaffold, fabric modification, fibers, hydrogels and foams. © 2023 The authors.
کتاب ها
(ترجمه)
ترجمه: فاطمه رفیع منزلت اصفهان - جهاد دانشگاهی، واحد صنعتی اصفهان 1400
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آدرس اصفهان، میدان آزادی، دانشگاه اصفهان
