بروندادهای پژوهشی
مرتب سازی بر اساس: سال انتشار
(نزولی) مقالات فارسی
۱۴۰۳
تاریخ انتشار: ۲۰۲۵/۰۷/۱۴
علوم و تکنولوژی پلیمر (10163255) (مقالات آماده انتشار)
فرضیه : خوردگی فلزات بهعنوان پدیدهای اجتنابناپذیر و مخرب چالشهای اقتصادی، زیستمحیطی و مهندسی شایان توجهی را در صنایع مختلف بهوجود میآورد. پوششدهی فلزات با پلییورتانها بهدلیل خواصی نظیر چسبندگی مناسب به سطح فلزات، مقاومت مکانیکی و شیمیایی بهعنوان راهحلی کارآمد و مقرونبهصرفه، نقشی کلیدی در پیشگیری از خوردگی ایفا میکند. توسعه این پوششها در راستای حذف مواد آلی فرار (VOCs) و استفاده از مواد اولیه طبیعی و بهبود کارایی ضدخوردگی آنها با استفاده از نانوذرات بسیار مورد توجه پژوهشگران قرار گرفته است. روشها : در این پژوهش پلییورتانهای آبپایه (WPU) دارای پلی ال زیست تجدیدپذیر و زیستسازگار روغن کرچک تهیه شد. بهمنظور بهبود مقاومت خوردگی پوششهای تهیهشده، دو نمونه آبپایه دارای نانوذرات گرافن اکسید (GO) خالص و نانوذرات گرافن اکسید (GO) اصلاحشده با پاراترشیوبوتیل کلیکس[4]آرن (BC4A) با روش پلیمرشدن درجا (In Situ) تهیه شد. ویژگیهای ساختاری نانوکامپوزیتها با استفاده ATR-FTIR، NMR، XRD، اندازهگیری زوایای تماس، SEM و TGA بررسی شد. در ادامه استفاده از روشهای EIS و PDS خاصیت ضدخوردگی این پوششها بررسی شد. یافتهها : آزمون DLS پایداری پراکنهها را تأیید کرد. بر اساس تصاویر SEM، نانوذرات C4A-GO در مقایسه با نانوذرات GO اصلاح نشده، قابلیت پخشپذیری بهتری در ماتریس پلیمری را نشان داد. بهمنظور بررسی خواص ضدخوردگی پوششها آزمونهای EIS و PDS استفاده شد. چگالی جریان خوردگی (Icorr ) و مقادیر مقاومت انتقال بار (Rct) برای نمونه WPU/C4A-GO به ترتیب A. cm-2 -9 10×8 و Ω. cm2 629610 بود که نشاندهنده قابلیت بالقوه آن بهعنوان پوشش ضدخوردگی است. بهطور کلی سنتز درجا پلییورتان با نانوذرات خواص ضدخوردگی پوششها را بهطور شایان توجهی بهبود میدهد که این موضوع به قرارگرفتن نانوذرات در ساختار پلیمری و ایجاد پیوندهای عرضی در ساختار پلییورتان و افزایش آبگریزی سطح نسبت داده میشود.
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.
Salehi N. ,
Mohammadi, A. ,
Alinezhad V. ,
Bochani S. ,
Kalantari-Hesari A. 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: 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: 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
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.
Mohammadi, A. ,
Kerdabadi Z.G. ,
Ayati najafabadi, S.A. ,
Pourali A. ,
Nejaddehbashi F. 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
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.
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
Abrishamkar S. ,
Mohammadi, A. ,
De La Vega J. ,
Wang D.-Y. ,
Kalali, Ehsan Naderi Publication Date: 2023
Polymer Degradation and Stability (01413910)
In this study, the effect of LbL coatings based on layered double hydroxide (LDH), graphene oxide (GO), and sodium p-sulfonatocalix[4]arene (SC4A) modified graphene oxide (GOSC4A) on the fire properties and dye adsorption behavior of flexible polyurethane foam was investigated. For this purpose, samples including neat PU foam and modified PU foams with 3, 6, and 9 bilayers of LDH-GO and LDH-GOSC4A coatings were prepared. SEM micrographs of the prepared foams confirmed the presence of LDH-GO and LDH-GOSC4A coatings on the foam surface and showed that the LDH-GOSC4A layers form a denser and more uniform coating on the PUF surface. Combustion studies of prepared foams using CCT and horizontal burning test demonstrated that at the same number of bilayers, foams including LDH-GOSC4A coatings showed better flame retardancy than LDH-GO coated foams. Therefore, the PUF/LDH-GOSC4A 9BL foam showed the best fire properties, and its PHRR, THR, and TSP values were reduced by 28.8, 11.8, and 36.3%, respectively, compared to uncoated PUF. Methylene blue (MB) adsorption studies revealed that adsorption of MB onto PUF/LDH-GOSC4A 9BL is well consistent with the pseudo-second-order kinetic model and its maximum adsorption capacity is 38.46 mg/g based on the Langmuir isotherm equation. © 2022
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.
Mohammadi, A. ,
Sahabi M. ,
Burujeny, S.B. ,
Abdolvand, H. ,
Makvandi, P. Publication Date: 2022
Biomaterials Advances (27729508)
The underprivileged pharmacodynamic action of curcumin, which arose from its low water solubility and rapid metabolism, restricts its therapeutic performance. In this study, (2-Hydroxy isopropyl)-β-cyclodextrin (HPβCD) as a macrocycle host molecule was employed to enhance the availability and control release of curcumin by forming a host-guest inclusion complex within an in-situ forming alginate hydrogel. The formation of the inclusion complexes of curcumin with a single host molecule was characterized by FTIR, XRD, TGA, SEM, and DLS analyses. The inclusion complex of curcumin and HPβCD (HPβCD-Cur) showed a high encapsulation efficiency of 88.2 %. According to DLS results, aqueous dispersion of HPβCD-Cur exhibited a unimodal histogram after 2 and 7 days with average particles size of 207.5 and 230.6 nm, respectively. This observation could be because of the formation of an inclusion complex that effectively distributed in solution and prevented curcumin agglomeration. The prepared alginate hydrogel containing HPβCD-Cur demonstrated >87 % reduction in colonies of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, which significantly is higher than that for Alg/Cur (<69 %). The Alg/HPβCD-Cur hydrogel exhibited a high water uptake of 470 % after 2 h, and a curcumin cumulative release of 80 % over 72 h, with proper cytocompatibility. Consequently, it was shown that the HPβCD carrier could act as an apt host molecule that can properly encapsulate curcumin and enhance its release from the Alg/HPβCD-Cur hydrogel. © 2022 Elsevier B.V.
Publication Date: 2022
Iranian Journal of Polymer Science and Technology (10163255) (1)
Today, the prevalence of bacterial infections and their resulting human and financial losses has led scientists constantly to seek solutions to develop knowledge in controlling these pathogenic microorganisms. Bacterial adhesion and their growth on different surfaces cause the accumulation of these microorganisms and the formation of biofilms. These developed microcolonies can grow and detach from the surface and spread infections. Therefore, the best way to prevent spreading the infections and diseases is to prevent the formation of biofilms using antimicrobial surfaces. In this regard, one of the most important tools introduced is the use of antibacterial polymer coatings. Polyurethanes have received much attention due to their unique properties such as biocompatibility, the possibility of using various raw materials, and controllable properties. In recent years, waterborne polyurethanes have been extensively studied due to less frequent use of volatile organic compounds (VOCs) in their preparations, easy fabrication, low viscosity, the possibility of spraying, high adhesion to different surfaces, high abrasion resistance, ability to disperse a variety of additives, and rapid film formation in biomedical fields such as antibacterial coatings, wound dressings, and biological products. In this review article, first, the various methods of preparing antibacterial polymer coatings are described. These methods include the use of nanostructures, combined with antibacterial polymers, and the use of antibacterial monomers. As a result, polyurethanes and waterborne polyurethanes have been developed. The following is a review of studies on the preparation of antibacterial waterborne polyurethanes using different strategies such as the addition of nanostructures, blending with antibacterial polymers, drug loading, the use of antibacterial monomers, and polymer surface modification. The products developed during these studies have been proposed for a variety of applications such as medical equipment coating, wound dressings and packaging industry. © 2022 Iran Polymer Society. All rights reserved.
Mohammadi, A. ,
Abdolvand, H. ,
Ayati najafabadi, S.A. ,
Nejaddehbashi F. ,
Burujeny, S.B. Publication Date: 2022
ACS Applied Bio Materials (25766422) (12)
Curcumin has a limited clinical application because of its extremely poor accessibility. In the present study, improved curcumin bioavailability within a castor oil polyurethane/layered double hydroxide (LDH) wound cover was achieved by preparing a curcumin p-sulfonic acid calix[4]arene (SC4A) inclusion complex. Then, it was utilized to intercalate MgAl-layered double hydroxide (MgAl-LDH) nanosheets. The incorporation of the nanostructure into a PU/Cur-SC4A-LDH film provided bacteria-killing performance against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. This finding is due to an increase in curcumin bioavailability in the PU matrix. Furthermore, all PU nanocomposites exhibited appropriate cytocompatibility based on an MTT assay. Mainly, the proliferation of L929 fibroblast cells in contact with the PU/Cur-SC4A-LDH sample was significantly further enhanced than that for other nanocomposites within 7 days. This observation can be related to the better availability of curcumin on the film's surface, which causes an improvement in the proliferation rate of cells. Regarding the histological results, the hematoxylin and eosin (H&E) images showed faster epidermal layer formation and a larger quantity of matured hair follicles for PU/Cur-SC4A-LDH-healed wounds in comparison with those for the negative control over a period of 28 days. Thus, this practical healing ability of the PU/Cur-SC4A-LDH nanocomposite makes it a promising candidate as a wound dressing film. copy; 2022 American Chemical Society. © 2022 American Chemical Society. All rights reserved.
Publication Date: 2021
ACS Symposium Series (00976156)
Polyurethane foams (PUFs) are the largest group of polyurethane products and can be classified into rigid and flexible foams. Rigid PUFs are mainly used for heat insulation in the refrigeration, construction, and automotive industries. Flexible PUFs are also widely used in the fabrication of car seats and furniture. In general, PUFs are highly flammable because of their porous structure, large surface area, and good air permeability. Flame retardants containing phosphorus, halogen, nitrogen, and silicone can partially reduce the flammability of PUFs. Also, the presence of thermally stable groups such as carbodiimide, isocyanurate, and nitrogen-containing heterocycles in the structure of PUFs can increase their fire resistance. In the last two decades a new technique called layer-by-layer (LbL) assembly has been introduced for the preparation of flame-retardant nanocoatings on the surfaces of polymeric foams. In this method, polymers, nanoparticles, and various compounds are deposited on the surface of polymeric foams in thin layers through secondary interactions such as electrostatic forces, hydrogen bonds, and van der Waals interactions. This chapter presents an overview of the combustion mechanism and flame retardancy of PUFs and introduces LbL assembly techniques, applications of this method in improving the fire resistance of PUFs, and the flame retardation mechanism of LbL coatings on the PUFs. Finally, some suggestions are discussed to improve the flame retardancy of LbL coatings. © 2021 American Chemical Society. All rights reserved.
Publication Date: 2020
International Journal of Biological Macromolecules (01418130)
The present research describes the in situ preparation of novel alginate nanocomposite beads impregnated with unmodified MgAl-NO3 layered double hydroxide (LDH) and a sulfonate containing calix[4]arene-intercalated LDH (SuLDH). The effect of intercalation of LDH on the methylene blue adsorption efficiency of Alg/SuLDH beads was investigated and compared with Alg/LDH and pure alginate beads (Alg). The prepared beads were characterized by FTIR, XRD, TGA, SEM, BET, and swelling ratio analysis. Among samples, the Alg/SuLDH beads showed the highest thermal stability, crystallinity, water swelling ratio, and specific surface area. In addition, based on the batch adsorption studies, Alg/SuLDH beads exhibited higher adsorption efficiency compared to Alg/LDH and Alg beads. The obtained equilibrium adsorption data were modeled by the Langmuir and Freundlich adsorption isotherm models. Regarding the Langmuir model, the maximum adsorption capacity of Alg beads, Alg/LDH, and Alg/SuLDH nanocomposite beads was obtained 540.54, 598.80, and 653.59.36 mg/g, respectively. The kinetic adsorption studies also demonstrated that the adsorption of MB by all samples well obey the pseudo-second-order kinetic model. This study proposes the Alg/SuLDH beads as a highly developed adsorbent for removal of MB from wastewaters. The reusability experiments showed that the Alg/SuLDH beads retained 72.55% of initial activity after 5 cycles. © 2020 Elsevier B.V.
Publication Date: 2020
Materials Science and Engineering C (09284931)
In this study, a polyurethane nanocomposite film (PU/CS-GO) was synthesized by incorporating chitosan-modified GO nanosheets (CS-GO) into PU matrices. The successful synthesis of unmodified GO and CS-GO nanosheets was confirmed by FTIR, XRD, Raman, SEM, EDS, and TGA analyses. In comparison with polyurethane nanocomposite containing unmodified graphene oxide (PU/GO), the effect of the modification of GO with chitosan on different properties such as morphological, thermal, thermo-mechanical, wettability, antibacterial, and biocompatibility properties was evaluated by various analyses including XRD, FE-SEM, TGA, DMTA, contact angle, antibacterial studies, and MTT assay. FE-SEM images exhibited better dispersion of CS-GO nanosheets within polyurethane matrices compared to GO nanosheets. According to DMTA results, PU/CS-GO showed a higher glass transition temperature (Tg) and storage modulus values than PU/GO sample. Based on antibacterial and MTT assays, in comparison with PU/GO, the PU/CS-GO nanocomposite demonstrated better biocompatibility and also antibacterial activity against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. Based on results, the PU/CS-GO nanocomposite can be suggested as a promising material for antibacterial wound dressing. © 2020 Elsevier B.V.
Publication Date: 2020
Iranian Journal of Polymer Science and Technology (10163255) (5)
Nowadays, polymer nanocomposites have attracted much attention in research activities due to their high mechanical strength, high thermal stability, low-cost, with possibility for their applications in many areas. Polyurethanes (PUs), as a main group of polymers, show a diverse and controllable range of physical and mechanical properties due to their tailored properties depending on the nature of precursors like polyols and isocyanates. This diversity and controllability of their properties make different types of PUs (elastomers, fibers, foams, hydrogels, and coatings) preferred candidates for a variety of uses, including transportation, clothing, furniture, and biomaterials. Many studies have been performed on polyurethane nanocomposites using different types of nanostructures such as graphene-like nanosheets, carbon nanotubes, metal oxides, and so on. Layered double hydroxides (LDHs) are eco-friendly layered mineral nanostructures with positively charged layers and anion-exchange capability. Depending on the types of anions and structure of layers, the LDHs nanostructures can be used broadly for the applications such as catalysts, drug delivery, separation technology, and also as a UV absorbent, corrosion, and a flame inhibitor for polymers. Recently, LDHs nanostructures are used in the fabrication of polyurethane nanocomposites to improve their mechanical, thermal, and flame properties. In this review, in addition to the description of LDH nanostructures, polyurethanes and their applications, LDH-based polyurethane nanocomposites are discussed in detail. © 2020 Iran Polymer Society. All rights reserved.
Mohammadi, A. ,
Akbar M.U. ,
Rehman F.-U. ,
Ibrahim M. ,
Barikani, M. ,
Mohammadi M. ,
Sobhani H. ,
Farrukh M.A. 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: 2019
Carbohydrate Polymers (01448617)
In this study, a series of polyurethane (PU) films based on three different type of chain extenders including glycerol, sodium alginate (SA) and nanocomposite of tetrasodium thiacalix[4]arene tetrasulfonate-sodium alginate (TS-SA) were synthesized. The effect of SA and TS-SA chain extenders on different properties of the PU films were studied using FTIR, XRD, DSC, TGA, SEM, AFM, and tensile analysis and the obtained results were compared with the polyurethane film extended with glycerol. The TGA and tensile studies confirmed that incorporation of TS-SA into the polyurethane backbone provide the superior thermal and mechanical properties compared to SA. Moreover, the influence of the SA and TS-SA chain extenders on hydrophilicity of the prepared films was also investigated by contact angle measurement. The results showed that the hydrophilicity of PU/TS-SA is higher than the PU/Gly and PU/SA samples. In comparison with PU/Gly and PU/SA samples, the PU/TS-SA sample showed significant performance in water desalination via reverse osmosis technique due to its favorable porosity and improved hydrophilicity. The AFM analysis confirmed that the PU/TS-SA sample has the highest surface rouphness which cause an increase in the flux and anti-fouling property of this sample. Therefore, PU/TS-SA sample can be introduced as an efficient membrane for water desalination with enhanced thermal stability, mechanical properties, high salt rejection and water permeability. © 2018 Elsevier Ltd
Publication Date: 2016
Materials Science and Engineering C (09284931)
In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use. © 2016 Elsevier B.V. All rights reserved.
Publication Date: 2016
Progress in Color, Colorants and Coatings (20082134) (2)
The inhibitive effect of apricot gum (AG) on mild steel in 0.5 M phosphoric acid solution was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), linear polarization resistance and electrochemical noise (EN) techniques. The inhibition efficiency increased with AG concentration up to a certain value and decreased with increasing temperature. Polarization curves indicated that AG acts as a mixed type inhibitor. The EN data were analyzed by statistical and wavelet methods. The results obtained from analysis of EN data was in good agreement with those achieved by the polarization and EIS measurements. The adsorption of the inhibitor on the alloy surface in 0.5 M H3PO4 followed the Langmuir isotherm. According to the calculated values of both free energy and enthalpy of adsorption, it was revealed that the adsorption of inhibitor on the steel surface was a combination of physical and chemical adsorption. The morphologies of the uninhibited and inhibited mild steel surfaces in 0.5 M H3PO4 which were analyzed by scanning electron microscope (SEM) showed that the alloy surface damage is significantly decreased due to the presence of inhibitor. © Institute for Color Science and Technology.
Publication Date: 2015
Polymer International (09598103) (3)
A series of polyurethane elastomers containing various thiacalix[4]arene derivatives in a mixture with glycerol as chain extenders were synthesized. A series of polyurethane elastomers (PUEs) derived from three thiacalix[4]arene derivatives (TC4As), namely p-tert-butylthiacalix[4]arene, tetrasodium thiacalix[4]arenetetrasulfonate and thiacalix[4]arenetetrasulfonic acid, as a portion of chain extender in a mixture with glycerol were synthesized. The effects of the chemical structure of TC4As used as chain extenders on the various properties of the prepared PUEs were investigated and compared with PUE extended with only glycerol as chain extender using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy and a universal tensile tester. Moreover, the effect of the introduction of TC4As as a portion of chain extender on the hydrophobicity of the PUEs was also evaluated. DSC, FTIR spectroscopy and XRD revealed that the degree of phase separation and crystallinity in TC4A-based PUEs was much higher than that of the glycerol-based ones. Thus, it was concluded that the presence of TC4As in TC4A-based PUEs seems to favour the formation of a more ordered structure due to an increase in the degree of phase separation. The TGA results also showed that, with incorporation of TC4As into the polyurethane backbone, the thermal stability of PUEs was improved. © 2014 Society of Chemical Industry.
Publication Date: 2015
Polymer Bulletin (01700839) (2)
In this study, biocompatible magnetic Fe3O4/polyurethane elastomer nanocomposites were synthesized using in situ polymerization method. Pure Fe3O4 nanoparticles were synthesized by coprecipitation method and characterized by X-ray diffraction, Fourier transform infrared (FTIR), vibrating sample magnetometer and transmission electron microscopy. The chemical structure, thermal properties, and mechanical properties of the Fe3O4/PU nanocomposites, as well as the evaluation of effect of nanoparticles content on thermal and mechanical properties, were studied by FTIR, thermogravimetric analyzer (TGA), dynamic mechanical thermal analysis (DMTA), and tensile analysis. The dispersion and morphology of the nanoparticles in the nanocomposites were studied by scanning electron microscopy (SEM) technique. SEM results confirmed that nanoparticles tend to be more agglomerated in polyurethane matrices with increasing of nanoparticles content. TGA analysis also showed a decrease in the thermal stability of Fe3O4/polyurethane nanocomposites compared to pure polyurethane, which was attributed to disruption of hydrogen bonds between polyurethane chains by Fe3O4 nanoparticles. DMTA results also showed an increase in glass transition temperature of Fe3O4/PU nanocomposites compared to pure polyurethane. Biocompatibility studies demonstrated that fabricated nanocomposites can be good candidates for biomedical application. © 2014, Springer-Verlag Berlin Heidelberg.
Publication Date: 2014
International Journal of Biological Macromolecules (01418130)
In this study, superparamagnetic sodium alginate-coated Fe3O4 nanoparticles (Alg-Fe3O4) as a novel magnetic adsorbent were prepared by in situ coprecipitation method, in which Fe3O4 nanoparticles were precipitated from FeCl3 and FeCl2 under alkaline medium in the presence of sodium alginate. The Alg-Fe3O4 nanoparticles were used for removal of malachite green (MG) from aqueous solutions using batch adsorption technique. The characterization of synthesized nanoparticles was performed using XRD, FTIR, TEM, TGA and vibrating sample magnetometer (VSM) techniques. FTIR analysis of synthesized nanoparticles provided the evidence that sodium alginate was successfully coated on the surface of Fe3O4 nanoparticles. The FT-IR and TGA characterization showed that the Alg-Fe3O4 nanoparticles contained about 14% (w/w) of sodium alginate. Moreover, TEM analysis indicated that the average diameter of the Alg-Fe3O4 nanoparticles was about 12nm. The effects of adsorbent dosage, pH and temperature were investigated on the adsorption properties of MG onto Alg-Fe3O4 nanoparticles. The equilibrium adsorption data were modeled using the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 47.84mg/g. The kinetics of adsorption of MG onto Alg-Fe3O4 nanoparticles were investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results showed that the adsorption of MG onto nanoparticles followed pseudo-second-order kinetic model. © 2014 Elsevier B.V.
Publication Date: 2014
Reactive and Functional Polymers (13815148)
In this study, a new type of flexible polyurethane foam containing p-tert-butyl thiacalix[4]arene (TC4A) macrocycle was synthesized. TC4A macrocycle was incorporated into polyurethane foam as a part of crosslinking agent as well as glycerol. Structural, morphological, thermal and mechanical properties of this prepared foam were studied and compared with a polyurethane foam based on only glycerol as crosslinking agent, by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), Thermal gravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The effect of introduction of TC4A crosslinker on cream time, rise time, apparent density, and water absorbency of the PU foams was evaluated. Moreover, it was shown that new TC4A-based polyurethane foam (TC-PUF) can be a high performance adsorbent for removal of malachite green from aqueous media using batch adsorption technique. The adsorption results indicated that TC-PUF has a high adsorption capacity of 58.82 mg/g for malachite green due to the presence of TC4A macrocycles in the structure of polyurethane foam. The kinetics of adsorption of malachite green was also investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results of kinetic studies showed that the adsorption of malachite green onto TC-PUF followed pseudo-second-order kinetic model. © 2014 Elsevier Ltd. All rights reserved.
Publication Date: 2014
Materials Characterization (10445803)
In this study, superparamagnetic thiodiglycol coated Fe3O 4 nanoparticles (TDG-Fe3O4) were synthesized using in situ coprecipitation method in alkali media and were characterized by XRD, FTIR, TGA, VSM, TEM, and SEM. TGA and FTIR results confirmed the binding of thiodiglycol onto the surface of Fe3O4 nanoparticles. XRD pattern showed the presence of peaks corresponding to the inverse spinel structure of Fe3O4 nanoparticles. In addition, the magnetic properties of nanoparticles determined by VSM exhibited TDG-Fe 3O4 nanoparticles that have superparamagnetic property with high enough saturation magnetization of 44.55 emu/g. TEM and SEM results showed that TDG-Fe3O4 nanoparticles have good dispersion and are smaller and less agglomerated than pure Fe3O4 nanoparticles due to reduction in attractive forces between the nanoparticles by thiodiglycol. Additionally, the result of DTG analysis of TDG-Fe 3O4 nanoparticles suggested that thiodiglycol molecules were bonded to the surface of the Fe3O4 nanoparticles with different binding modes. © 2014 Elsevier Inc.
Publication Date: 2013
Polymers for Advanced Technologies (10991581) (11)
In this study, two types of magnetic polyurethane (PU) elastomer nanocomposites using polycaprolactone (PCL) and polytetramethylene glycol (PTMG) as polyols were synthesized by incorporating thiodiglycolic acid surface modified Fe3O4 nanoparticles (TSM-Fe3O4) into PU matrices through in situ polymerization method. TSM-Fe3O4 nanoparticles were prepared using in situ coprecipitation method in alkali media and were characterized by X-ray diffraction, Fourier Transform Infrared Spectrophotometer, Transmission Electron Microscopy, and Vibrating Sample Magnetometer. The effects of PCL and PTMG polyols on the properties of the resultant PUs were studied. The morphology and dispersion of the nanoparticles in the magnetic nanocomposites were studied by Scanning Electron Microscope. It was observed that dispersion of nanoparticles in PTMG-based magnetic nanocomposite was better than PCL-based magnetic nanocomposite. Furthermore, the effect of polyol structure on thermal and mechanical properties of nanocomposite was investigated by Thermogravimetric Analysis and Dynamic Mechanical Thermal Analysis. A decrease in the thermal stability of magnetic nanocomposites was found compared to pure PUs. Furthermore, DMTA results showed that increase in glass transition temperature of PTMG-based magnetic nanocomposite is higher than PCL-based magnetic nanocomposite, which is attributed to better dispersion of TSM-Fe3O4 nanoparticles in PTMG-based PU matrix. Additionally, magnetic nanocomposites exhibited a lower level of hydrophilicity compared to pure PUs. These observations were attributed to the hydrophobic behavior of TSM-Fe3O4 nanoparticles. Moreover, study of fibroblast cells interaction with magnetic nanocomposites showed that the products can be a good candidate for biomedical application. © 2013 John Wiley & Sons, Ltd.
Publication Date: 2013
Journal of Materials Science (15734803) (21)
Magnetic polyurethane elastomer nanocomposites were prepared by incorporating pure and thiodiglycolic acid (TDGA) surface-modified Fe 3O4 nanoparticles into polyurethane matrix using in situ polymerization method. Surface modification of Fe3O4 nanoparticles was carried out to enhance the dispersion of the nanoparticles in polyurethane matrix. Pure and TDGA surface-modified Fe3O4 nanoparticles were synthesized by coprecipitation method and characterized by Fourier Transform Infrared Spectroscopy, X-ray diffraction, and Vibrating Sample Magnetometer. The morphology and dispersion of the nanoparticles in the magnetic polyurethane elastomer nanocomposites were studied by Scanning Electron Microscope. It was observed that surface modification of Fe3O 4 nanoparticles with TDGA enhanced the dispersion of the nanoparticles in polyurethane matrices. Furthermore, effect of surface modification of Fe3O4 nanoparticles on thermal and mechanical properties of magnetic polyurethane elastomer nanocomposite was investigated by thermogravimetric analysis, dynamic mechanical thermal analysis, and an Instron type Tensile Tester. It was concluded that surface modification of Fe3O4 nanoparticles allowed preparation of the magnetic nanocomposites with better mechanical properties. Moreover, study of fibroblast cells interaction with magnetic nanocomposites showed that the products can be a good candidate for biomedical application due to their in vitro biocompatibility and non-toxicity. © 2013 Springer Science+Business Media New York.
Mohammadi, A. ,
Hosseini, D. ,
Sarfjoo, Mohammad Reza ,
Mirsafaei, Razieh Publication Date: 0
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.
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.
Garza, Andrea Rodríguez ,
Zavaleta, Gabriel Alejandro Nagore ,
Haider, Farhan ,
Mohammadi, A. ,
Burujeny, S.B. Publication Date: 0
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.
Hydrogels are polymers that are three-dimensionally cross-linked and possess an impressive capacity to absorb large quantities of water or biofluids while maintaining their integrity. Hydrogels have unique properties that make them highly valuable in diverse industries, including food, packaging, pharmaceuticals, agriculture, biomedical and bioengineering applications, manufacture of technical and electronic devices, and adsorbents for the removal of pollutants for environmental applications. In order to effectively improve the properties of hydrogels, two-dimensional (2D) nanomaterials have been introduced into their structure. Incorporating these nanomaterials not only increases the mechanical characteristics of hydrogels but also offers a wide range of versatile properties, such as electrical, thermal, optical, acoustic, magnetic, and more. Metal carbides, nitrides, or carbonitrides (MXenes) are highly regarded among the available 2D nanomaterials due to their exceptional combination of metal conductivity, solubility, high dimensionality, and adjustable properties. Hydrogels incorporated with MXenes offer exciting and versatile properties such as hydrophilicity, metal conductivity, and wide adjustable properties. Moreover, hydrogels, an excellent and versatile platform, can significantly improve the stability of MXene nanosheets. With respect to hydrogel structures and gelation mechanisms, MXene-based hydrogel possesses amazing properties and has great potential for different applications such as energy storage, catalysis, tissue engineering, and so on. © 2024 John Wiley & Sons Ltd.
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.
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.
University of Isfahan
Address: Isfahan, Azadi Square, University of Isfahan
