Application Of Polyurethane Research Articles

Photochemical versus thermal thiol‐ene “click chemistry” for renewable polyols with application in polyurethanes

AbstractThe primary goal of the study was to compare the efficacy of two approaches, photochemical and thermal, in producing polyols from renewable soybean oil through thiol‐ene reactions. The thiol‐ene reaction was initiated with UV light in the presence of 2‐hydroxy‐2‐methylpropiophenone as a photo‐initiator or via a thermal pathway utilizing radical initiator 2,2′‐Azobis(2‐methylpropionitrile). The resulting polyols were analyzed using standard analytical techniques including Fourier transform infrared (FT‐IR) and nuclear magnetic resonance (NMR) spectroscopies. It was observed that the polyols obtained through the photochemical route exhibited better outcome compared with those synthesized using the thermal treatment. Additionally, we employed computational chemistry technique using density functional theory (DFT) calculation to get insights into various product yields. The DFT results revealed that the hydrogen bond network likely contributed to the improved stability, hence obtained higher product yield of the polyol MSBO‐TMPAE compared with that of MSBO‐GAE. Our study also focuses on applying the synthesized polyols in polyurethane rigid foams and casts. The polyurethanes prepared from these polyols have comparable thermal and mechanical properties to that of the commercially available polyurethanes.

Synthesis and application of Aromatic Schiff base waterborne polyurethane as visible-light triggered self-healing polymer and anticorrosion coating using h-BN/GO/NiO nano-composite

Herein, a self-healing waterborne polyurethane (WPU) based on a novel visible light-stimulated healing agent from the aromatic Schiff base family (SBWPU) was synthesized. Moreover, this polymer exhibited remarkable mechanical properties, making it an ideal matrix for the preparation of a new nano-composite coating using hexagonal-boron nitride/graphene oxide/nickel oxide (h-BN/GO/NiO) nano-composite for anti-corrosion applications. SBWPU containing 15 wt % of synthesized healing agent (SBWPU-15) demonstrated favorable healing properties (80.03 %) under a visible light lamp after 24 h (at ambient temperature). SBWPU containing 20 % of the healing agent (SBWPU-20) showed high mechanical properties (20.80 MPa) and an increase in its hydrophobic properties. Additionally, its water absorption rate decreased, making it an attractive option as a polymer matrix for anti-corrosion coating applications. The nano-composite coatings (CSBWPU) were formulated by introducing varying amounts of h-BN/GO/NiO into the SBWPU-20. The coatings displayed an increase in contact angle and a decrease in water absorption rate. The electrochemical impedance spectroscopy (EIS) results revealed that the 0.75-CSBWPU, containing 0.75 % nano-composite, had the highest corrosion resistance (1.58 × 1010 Ω cm2) after 90 days of immersion in seawater. This work offers a potentially helpful concept for developing an eco-friendly, secure, uncomplicated accessibility self-healing polymeric system with controllable mechanical features, which are also favorable for designing novel corrosion protection composite coatings.

Preparation and properties of room temperature foaming lignin-based non-isocyanate polyurethane foams

The preparation and application of biomass-based non-isocyanate polyurethane (NIPU) is an essential and meaningful hot topic research work in the field of polyurethane industry, due to its advantages of sustainability of raw materials and no highly toxic isocyanate used in the synthesis. Lignin, as the second most renewable natural polymer on earth, was used in this paper to synthesize lignin-based non-isocyanate polyurethane (L-NIPU) resins. Subsequently, L-NIPU foams were prepared by self-foaming at room temperature with the addition of maleic acid as an initiator and glutaraldehyde as a cross-linker, and their properties were investigated. Results show that L-NIPU foams are lightweight (0.11–0.18 g/cm3), have low thermal conductivity (0.033–0.04 W/m·K), and have excellent compressive strength. When the addition of maleic acid and glutaraldehyde is respectively 18 % and 25 % (based on L-NIPU resin quality), the compressive strength can be as high as 0.5 MPa, and the thermal conductivity is only 0.03559 W/m·K, so it can be used as an insulating board in buildings. In addition, FT-IR and XPS analyses showed that maleic acid and glutaraldehyde can react with the amino group in L-NIPU to form a cross-linked network structure, which ensures the favorable mechanical properties of the foam.

Synthesis and Application of Dendritic Waterborne Polyurethane with Long Alkyl Chains and Silicone Chains as a Fluorine-Free Water Repellent

With environmental and health issues being raised, researchers have shifted their study from fluorinated to fluorine-free waterproof agents. However, most of the reported fluorine-free water repellents exhibit a significant drawback in their poor stability and durability of water repellency. In addition, the use of higher concentrations in these repellents results in the fabric becoming stiff, which negatively impacts the hand of the treated fabrics. To address these issues, dendrimer-like waterborne polyurethane prepolymers were initially synthesized using isophorone diisocyanate, polytetrahydrofuran, N-methyldiethanolamine, and trimethylolpropane as the primary materials. In this synthesis, sorbitan tristearate served as the dendrimer-like blocking agent, while single-ended bis-hydroxypropyl silicone oil was employed as functional monomers to enhance the hand and water repellency of the prepolymers. Then, dendrimer-like waterborne polyurethane was finished on the cotton fabric using a pad–dry–cure procedure. The test results showed that the water contact angle of dendrimer-like waterborne polyurethane film increased from 104.28° to 107.00° with the content of single-ended bis-hydroxypropyl silicone oil increasing, and the water contact angle of dendrimer-like waterborne polyurethane-finished fabrics reached 148.6° alone with a standard spray test rating of 90–95. In addition, the water contact angle of dendrimer-like waterborne polyurethane-finished fabrics was still greater than 140° even after five standard washes. The single-ended bis-hydroxypropyl silicone oil addition facilitated similar hand to the original fabric in dendrimer-like waterborne polyurethane-finished fabrics with high concentrations, surpassing market water repellents. This work is of great significance for improving the stability and durability of water repellency, and the hand of waterborne polyurethane fluorine-free water repellents in the textile industry.

Significantly suppressing CO release achieved by the catalysis effect of nanostructured rare earth/manganese oxides: Application in flame retardant thermoplastic polyurethane

There is significant smoke and toxic volatiles generated from the combustion of thermoplastic polyurethane (TPU), which has compromised its application and posed a significant threat to human life. Here, the hydrothermal-citrate complexation method synthesised the rare earth Mn-based composite catalyst and blended with TPU to mitigate smoke release and toxic gas generation during TPU combustion. The results demonstrate that the inclusion of 3 wt% Mn-La and Mn-Ce catalysts into TPU leads to a 41.3% and 33.6% decrease in maximum smoke density (Ds max), respectively, along with a 52.4% and 50.5% reduction in peak CO production rate (pCOPR). The mechanism of rare earth Mn-based catalyst-based smoke suppression and toxicity reduction in TPU is explained at a microscopic scale based on density functional theory (DFT) research: the introduction of catalyst bolsters the adsorption of O2 and CO on the surface of TPU nanocomposites and facilitates the oxidation of CO. Additionally, it can expedite the formation of dense carbon layers and impede heat and mass transfer. The TPU nanocomposites exhibit excellent flame retardancy and effective smoke suppression. A feasible strategy for manufacturing fire-safety TPU nanocomposites with favorable comprehensive properties is proposed.

Preparation and Characterization of Glucose-Based Self-Blowing Non-Isocyanate Polyurethane (NIPU) Foams with Different Acid Catalysts.

The preparation and application of non-isocyanate polyurethane (NIPU) from biomass raw materials as a substitute for traditional polyurethane (PU) has recently become a research hot topic as it avoids the toxicity and moisture sensitivity of isocyanate-based PU. In the work presented here, self-blowing GNIPU non-isocyanate polyurethane (NIPU) rigid foams were prepared at room temperature, based on glucose, with acids as catalysts and glutaraldehyde as a cross-linker. The effects of different acids and glutaraldehyde addition on foam morphology and properties were investigated. The water absorption, compressive resistance, fire resistance, and limiting oxygen index (LOI) were tested to evaluate the relevant properties of the foams, and scanning electron microscopy (SEM) was used to observe the foams' cell structure. The results show that all these foams have a similar apparent density, while their 24 h water absorption is different. The foam prepared with phosphoric acid as a catalyst presented a better compressive strength compared to the other types prepared with different catalysts when above 65% compression. It also presents the best fire resistance with an LOI value of 24.3% (great than 22%), indicating that it possesses a good level of flame retardancy. Thermogravimetric analysis also showed that phosphoric acid catalysis slightly improved the GNIPU foams' thermal stability. This is mainly due to the flame-retardant effect of the phosphate ion. In addition, scanning electron microscopy (SEM) results showed that all the GNIPU foams exhibited similar open-cell morphologies with the cell pore sizes mainly distributed in the 200-250 μm range.

A Short Review on Radiopaque Polyurethanes in Medicine: Physical Principles, Effect of Nanoparticles, Processing, Properties, and Applications

Polyurethanes are used in a wide range of biomedical applications due to their variety of physical–chemical, mechanical, and structural properties, and biotic and abiotic degradation. They are widely used in bio-imaging procedures when metallic-based filler particles are incorporated, making the final product radiopaque. It would be advantageous, however, if polyurethanes with intrinsic radiopacity could be produced in their synthesis, avoiding a series of disadvantages in the processing and final product and also presenting potential antimicrobial activities. This review’s objective was to study the radiopacifying characteristics of nanoparticles, the physical principles of radiopacity, and the variety of medical applications of polyurethanes with nanoparticles. It was found in this study that the synthetization of radiopaque polyurethanes is not only possible but the efficiency of synthetization was improved when using atoms with high electron density as part of the backbone or when grafted, making them great multipurpose materials.

Rapid photo‐responsive dynamic disulfide strategy for accessing self‐healing, reconfigurable shape of high‐strength shape memory polyurethane

AbstractEnabling soft shape memory polyurethane (SMPU) with self‐healing is an effective strategy to extend its service life; however, the tradeoff between high mechanical strength and rapid self‐healing to meet the practical applications remains a challenge. Herein, we prepared a polyurethane (PU) with polycarbonate diol as a soft segment, incorporating urea bonds and dynamic disulfide bonds through chain extenders. This material, denoted as PU‐NSS75, exhibited a remarkable tensile strength of 51.4 MPa, attributed to the synergistic energy dissipation effect of urea hydrogen bonding and dynamic disulfide bonds during stretching, leading to enhanced mechanical properties of the PU. The dynamic nature of the bonds, including hydrogen bonding and disulfide bonds, endowed the PU with exceptional self‐healing capabilities. Furthermore, leveraging the reversible mechanism of disulfide bonds under UV irradiation at room temperature, PU‐NSS75 achieved complete self‐healing within 1 min. This photoinduced dynamic chemical bonding also facilitated rapid reconfigure the original shape of the soft SMPU at room temperature, thus broadening its potential applications. This study offers a design approach to enhance soft shape memory polyurethane materials, while the rapid self‐healing and shape reconfiguration provide new avenues for expanding the applications of shape memory polyurethanes.

Closing the loop of polyurethane adhesives: Acidolysis process optimization

Polyurethane adhesive (PUA) are a specialized application of polyurethanes. Acidolysis of PUA waste yield a recycled polyol with tunable properties. This process was optimized by response surface methodology to predict the domain of parameters where the lowest of viscosity, hydroxyl, and acid values could be achieved. Relationships between temperature, polyurethane-to-polyol, and polyurethane-to-acid ratios, and viscosity, molecular weight, hydroxyl and acid values were established and optimal conditions were validated for a robust process. The polyurethane-to-acid ratio had the most significant influence on the acid value of the product. Hydroxyl value, viscosity and molecular weight were primarily affected by the polyurethane-to-polyol ratio. Using a recycled polyol obtained at 205 °C, a polyurethane-to-polyol ratio of 1.4 kg/kg, and a polyurethane-to-acid ratio of 50 kg/kg, we successfully produced a new adhesive incorporating up to 28 % recycled material. This demonstrated adhesion properties for wood applications on par with those of virgin adhesives, without experiencing crash phenomena.

Constructing a catalytical NO-generation coating on a polyurethane surface to enhance hemocompatibility and promote endothelial cell growth

Polyurethanes (PU) is widely applied in the blood-contact biomaterials. However, its biocompatibility still cannot meet the requirements for long-term service. In this work, a polydopamine (PDA) layer was first prepared on the PU surface, and then an anticoagulant polymer with an endothelial glycosaminoglycan-mimicking structure capable of catalyzing the release of nitric oxide (NO) gas molecules 6-arm-poly (ethy1ene glycol)-Heparin-Selenocystamine (PEG-Hep-SeCA) was grafted on the PDA-modified PU surface to construct a bioactive coating with the capacity to catalyze the release of NO from the endogenous donors. The findings indicated that the modified PU surfaces had excellent hydrophilicity, selective albumin adsorption as well as good blood compatibility and endothelial cell growth properties. The hemocompatibility and endothelial cell growth were further significantly improved in the case of catalytic NO generation. Therefore, the surface modification strategy of this study can significantly improve the biocompatibility of PU and thus lay the foundation for future clinical applications of medical polyurethane.

Recent Advances in the Preparation and Application of Bio-Based Polyurethanes.

Amid environmental pollution and resource depletion, developing and utilizing biomass resources as alternatives to petroleum is a prominent research focus. Driven by environmental protection and sustainable development, the shift from petroleum-based to bio-based polyurethane is a prevailing trend in polyurethane material development. Biomass sources such as vegetable oil, polysaccharides, and lignin offer extensive application prospects in bio-based polyurethane production. Functional modifications of these polyurethanes can further expand their application range. This article explores the preparation of various bio-based polyurethanes, their applications across different fields, and their anticipated future development and uses.

Preparation of Hydroxyl-Terminated Polybutadiene by the Pyrolysis Method and Its Application in Polyurethane

Preparation of Hydroxyl-Terminated Polybutadiene by the Pyrolysis Method and Its Application in Polyurethane

Production, thermal recycling, and application of cardanol-based polyurethane foam with phenol-carbamate bonds

The economic processing, sustainable recycling, and environmentally friendly application of polyurethane (PU) foams are important issues that need to be addressed urgently. In this study, we propose a strategy for the comprehensive utilization of cardanol and cashew shells to design cardanol-based PU (CPU) foams and wood-plastic films that can be recycled and reused. Firstly, cardanol-based polyphenols (CBPs) with a phenolic hydroxyl content of 3.29 mmol/g were prepared by Friedel-Crafts alkylation reaction using cardanol and guaiacol as raw materials. Subsequently, CPU foams were prepared by reacting CBPs with isocyanate, and the vertical and parallel compressive strengths could reach up to 0.27 MPa and 0.32 MPa, respectively, when the addition of CBPs was 80 %. These CPU foams, containing dynamic phenol-carbamate bonds, could be hot-pressed into transparent and smooth CPU films with tensile strengths of up to 30.5 MPa and could be re-formed at least three times. Finally, CPU foam and cashew shell waste were mixed and hot-pressed to produce a green wood-plastic composite with a tensile strength of up to 38.8 MPa. The resulting CPU-Wood films could be repaired or reshaped at least five times (38.0 MPa and 38.1 MPa) and could be formed into various shapes. This research paves the way for large-scale industrial production of recyclable and regenerative bio-based foams, making effective use of waste materials to achieve environmentally friendly production processes.

Preparation and Application of UV Curable Waterborne Organosilicon Acrylic Polyurethane with Controllable Silicon Content

Preparation and Application of UV Curable Waterborne Organosilicon Acrylic Polyurethane with Controllable Silicon Content

Utilization of Plant Oils for Sustainable Polyurethane Adhesives: A Review.

The utilization of plant oils as a renewable resource for the production of polyurethane adhesives presents a promising way to improve sustainability and reduce environmental impact. This review explores the potential of various vegetable oils, including waste oils, in the synthesis of polyurethanes as an alternative to conventional petroleum-based raw materials. The investigation highlights the environmental challenges associated with conventional polyurethane production and highlights the benefits of switching to bio-renewable oils. By examining the feasibility and potential applications of vegetable oil-based polyurethanes, this study emphasizes the importance of further research and development in this area to realize the full potential of sustainable polyurethane adhesives. Further research and development in this area are key to overcoming the challenges and realizing the full potential of plant-oil-based polyurethanes in various industrial applications.

Synthesis and Application of Silane-Modified Castor Oil-Based Waterborne Polyurethane as a Fluorine-Free and Durable Water Repellent

Synthesis and Application of Silane-Modified Castor Oil-Based Waterborne Polyurethane as a Fluorine-Free and Durable Water Repellent

Synthesis and application of silicone-modified polyurethane as a slip-elastic finishing agent for polyamide fabrics

Despite the wide application of polyamide in clothing and home textiles, its inherent stiffness hardly meets consumers' preference for a smooth and elastic hand feel. In this study, a new hydroxyl silane coupling agent (KHS), 1-(4-(4-(4-(trimethoxysilyl)butyl)piperazin-1-yl)-3-(3-(trimethoxysilyl)propoxy) propan-2-ol, was synthesized and used to prepare a series of silicone-modified polyurethane (KHS-PU). KHS-PU then was finished onto the polyamide fabric via a pad-dry-cure procedure. The finishing process was optimized using the Minitab software. The morphology and elemental distribution of KHS-PU finished polyamide fabric were characterized using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), respectively. The hand evaluation tests demonstrated that KHS-PU not only significantly enhanced the fabric's smooth and elastic properties, specifically evidenced by a 23 % reduction in surface friction coefficient, a 13 % decrease in bending average stiffness, a 10 % reduction in compression work, and a 40 % increase in compression recovery rate, but also exhibited good wash durability. In addition, the thermal and mechanical properties of KHS-PU finished fabric were further investigated. This work provides a valuable contribution to the field of surface science and textile engineering, offering insights into advanced fabric finishing techniques.

Application of thiourea polyurethane foam/zinc oxide nanocomposite for anticancer effects and antimicrobial potential

There is a continuous need to fabricate new antimicrobial agents due to the continuous development of microbial drug resistance. Recently, zinc oxide nanoparticles (ZnONPs) have emerged as a promising choice for developing new drugs owing to their exceptional broad-spectrum antimicrobial and anticancer action. In the current work, thiourea polyurethane foam/zinc oxide nanocomposite was synthesized by coupling ZnONPs and thiourea polyurethane foam (TPUF) to test its antimicrobial and anticancer activities. Ultraviolet–visible spectra, Fourier transform infrared, X-ray diffraction (XRD), zeta potential and dynamic light scattering analyses were investigated to study the characterization of thiourea polyurethane foam/zinc oxide nanocomposite (TPUF/ZnO). The synthesized TPUF/ZnO was examined as an antimicrobial agent against gram-positive bacterium (Bacillus cereus), gram-negative bacterium (Escherichia coli), and fungus (Aspergillus niger). The results of the agar well-diffusion test showed good inhibition zones against E. coli (16 mm), B. cereus (13 mm), and A. niger (26 mm). The minimum inhibition concentration (MIC) values of TPUF/ZnO against B. cereus and E. coli were 350 μg/mL and 400 μg/mL. TEM of TPUF/ZnO-treated B. cereus and E. coli bacteria displayed different ultrastructural modifications such as separation of the plasma membrane from the cell wall and vacuole formation that led to a complete lysis and bacterial death. The anticancer activity of TPUF/ZnO was also evaluated against liver and breast cancer cell lines (HepG-2 and MCF-7). TPUF/ZnO showed good cytotoxicity activities against HepG-2, and MCF-7, with IC50 values of 77.08 ± 1.36 and 109.01 ± 3.98 µg/ml, respectively. Thus, TPUF/ZnO could be a promising raw material in the field of food packaging and provide a possible anticancer compound for hepatocellular carcinoma and breast carcinoma.Graphic abstract

Study of the Characteristics of Polyurethane as a Sustainable Material used for Buildings, Polymer Composite, Biomedical, and Electronics Application

This research is focused on studying the characteristics of Polyurethane in engineering applications as a sustainable material employed for buildings and as reinforcement for polymer composite, electronics, and biomedical applications. This study discussed and reviewed papers cut across the Polyurethane Formation, Engineering Attributes of Polyurethane, and Polyurethane Applications in various fields such as Buildings, Polymer Composite Materials, Biomedical, and Electronic, which has proven that Polyurethane is a multi-functional material that has been employed in biomedical engineering used for tissue, wound treatment, breast implant, drug delivery systems. Also, it has been applied for sensors, actuators, Flexible electronics, Energy harvesters and storage, and Shape memory applications. Furthermore, its application in buildings, Polyurethane (PU) foam as an insulation material embedded in the aluminium roofing system for sustainable human comfort. This study also identifies the challenges of Polyurethane and provides sustainable solutions. In conclusion, site materials and structural application have shown excellent performance from studying the Polyurethane characteristics as embedded materials for roofing sheets.

Advancements and Applications of Polyurethane Curing Technology in Railway Track Bed Construction in China

This paper examines the application of polyurethane curing technology in the construction of railway track beds, with a specific focus on its implementation in China’s rapidly developing railway infrastructure. The study begins by identifying the limitations of traditional ballasted track beds, especially under the demands of high-speed and heavyload railways. It then methodically analyzes the advantages of polyurethane-cured track beds, highlighting their improved mechanical properties, including enhanced stability and durability. The paper further explores the benefits of transitioning to prefabricated polyurethane track beds, emphasizing significant cost reductions, better construction quality, and enhanced maintainability. Through a detailed review of experimental data and practical applications, the paper demonstrates the efficacy of polyurethane track beds in various railway settings. A critical part of the research involves optimizing the structural parameters of polyurethane track beds to achieve the best balance of mechanical and damping properties. The conclusion of the paper underscores the potential of polyurethane curing technology as a transformative approach to railway track bed construction, offering a solution to the challenges posed by traditional methods and aligning with the evolving needs of modern railways.