Polyurethane Coatings Derived from 1,2,3-Triazole-Functionalized Soybean Oil-Based Polyols: Studying their Physical, Mechanical, Thermal, and Biological Properties

Non-Isocyanate Urethane Acrylate Derived from Isophorone Diamine: Synthesis, Characterization and Its Application in 3D Printing

In this paper, urethane-based acrylates (UA) were prepared via an environmentally friendly non-isocyanate route. Isophorone diamine (IPDA) reacted with ethylene carbonate (EC), producing carbamate containing amine and hydroxyl groups, which further reacted with neopentyl glycol diacrylate (NPGDA) by aza Michael addition, forming UA. The structures of the obtained intermediates and UA were characterized by 1H NMR and electrospray ionization high-resolution mass spectrometry (ESI-HRMS). The photopolymerization kinetics of UA were investigated by infrared spectroscopy. The composite with obtained UA can be UV cured quickly to form a transparent film with a tensile strength of 21 MPa and elongation at break of 16%. After UV curing, the mono-functional urethane acrylate was copolymerized into the cross-linked network in the form of side chains. The hydroxyl and carbamate bonds on the side chains have high mobility, which make them easy to form stronger dynamic hydrogen bonds during the tensile process, giving the material a higher tensile strength and elongation at break. Therefore, the hydrogen bonding model of a cross-linked network is proposed. The composite with UA can be 3D printed into models.

Natural Additives Improving Polyurethane Antimicrobial Activity

In recent years, there has been a growing interest in using polymers with antibacterial and antifungal properties; therefore, the present review is focused on the effect of natural compounds on the antibacterial and antifungal properties of polyurethane (PUR). This topic is important because materials and objects made with this polymer can be used as antibacterial and antifungal ones in places where hygiene and sterile conditions are particularly required (e.g., in healthcare, construction industries, cosmetology, pharmacology, or food industries) and thus can become another possibility in comparison to commonly used disinfectants, which mostly show high toxicity to the environment and the human health. The review presents the possibilities of using natural extracts as antibacterial, antifungal, and antiviral additives, which, in contrast to the currently used antibiotics, have a much wider effect. Antibiotics fight bacterial infections by killing bacteria (bactericidal effect) or slowing and stopping their growth (bacteriostatic effect) and effect on different kinds of fungi, but they do not fight viruses; therefore, compounds of natural origin can find wide use as biocidal substances. Fungi grow in almost any environment, and they reproduce easily in dirt and wet spaces; thus, the development of antifungal PUR foams is focused on avoiding fungal infections and inhibiting growth. Polymers are susceptible to microorganism adhesion and, consequently, are treated and modified to inhibit fungal and bacterial growth. The ability of micro-organisms to grow on polyurethanes can cause human health problems during the use and storage of polymers, making it necessary to use additives that eliminate bacteria, viruses, and fungi.

Laponite/amoxicillin-functionalized PLA nanofibrous as osteoinductive and antibacterial scaffolds

In this study, Amoxicillin (AMX) was loaded on laponite (LAP) nanoplates and then immobilized on the surface of electrospun polylactic acid (PLA) nanofibers to fabricate scaffolds with osteoinductive and antibacterial activities. The highest loading efficiency (49%) was obtained when the concentrations of AMX and LAP were 3 mg/mL and 1 mg/mL, respectively. FTIR and XRD spectroscopies and zeta potentiometry confirmed the successful encapsulating of AMX within LAP nanoplates. The immobilization of AMX-loaded LAPs on the surface of PLA nanofibers was verified by SEM and FTIR spectroscopy. In vitro release study showed a two-phase AMX release profile for the scaffolds; an initial burst release within the first 48 h and a later sustained release up to 21 days. In vitro antibacterial tests against Staphylococcus aureus and Escherichia coli presented the ability of scaffolds to inhibit the growth of both bacteria. The biocompatibility assays revealed the attachment and viability of human bone marrow mesenchymal stem cells (hBMSCs) cultured on the surface of scaffolds (p ≤ 0.05). The increased ALKALINE PHOSPHATASE (ALP) activity (p ≤ 0.001), calcium deposition, and expression of ALP and OSTEONECTIN genes indicated the osteoinductivity of functionalized scaffolds for hBMSCs. These LAP/AMX-functionalized scaffolds might be desirable candida for the treatment of bone defects.

Developing non-isocyanate urethane-methacrylate photo-monomers for 3D printing application

Urethane-methacrylate photo-monomers were prepared via a non-isocyanate route for the 3D printing application. The monomers were synthesized through reacting aliphatic amines, i.e. 1,6-hexanediamine, 1,4-butanediol bis(3-aminopropyl) ether, or n-butylamine, with cyclic carbonates, i.e. ethylene carbonate or propylene carbonate, followed by the methacrylation of the generated hydroxylurethanes. The effects of the chemical structure of monomers on their photo-reactivity and physicomechanical properties of the cured samples were studied. Propylene carbonate generated side methyl groups within the urethane block, which significantly limited the crystallization of the monomers resulting in high photo-reactivity (R_p,max = 6.59 × 10⁻² s⁻¹) and conversion (DBC_total = 85%). The ether bonds of 1,4-butanediol bis(3-aminopropyl) ether decreased the intermolecular hydrogen bonding between urethane blocks, which not only improved the photo-reactivity (R_p,max = 8.18 × 10⁻² s⁻¹) and conversion (DBC_total = 86%) of the monomer but led to a high crosslinking density (ν_c = 5140 mol m⁻³) and more flexibility for the cured sample. An ink was developed based on the monomers and successfully 3D printed on a digital light processing machine. In the absence of toxic isocyanates and tin compounds, the non-isocyanate route can be employed to develop urethane-methacrylates with desirable photo-reactivity and physicomechanical properties as good candidates to formulate inks for 3D printing of biomedical materials.

Synthesis of urethane-methacrylate photo-monomers via a non-isocyanate route for 3D printing of flexible biomedical materials.

Vanadium Pentoxide-Enwrapped Polydiphenylamine/Polyurethane Nanocomposite: High-Performance Anticorrosive Coating

Nanocomposite coatings with synergistic properties hold a potential in long-term corrosion protection for carbon steel. Polydiphenylamine (PDPA) and vanadium pentoxide (V₂O₅) have rarely been used as a corrosion inhibitor. Moreover, oleo polyurethanes are always demanded in the field of anticorrosive coatings. In view of this, we have synthesized safflower oil polyurethane (SFPU) and their nanocomposites using V₂O₅-enwrapped PDPA (V₂O₅-PDPA) as nanofiller. Fourier-transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis were used to characterize the structural, morphological, and thermal properties of these coatings. Corrosion resistance performance of these coatings in 5 wt % NaCl solution was determined by electrochemical measurements and salt spray tests. These studies exhibited very low I_corr (7.45 × 10^-11 A cm^-2), high E_corr (-0.04 V), impedance (1.69 × 10¹¹ Ω cm²), and phase angle (84°) after the exposure of 30 days. An immersion test, in 1 M H₂SO₄ solution for 24 h, was also performed to investigate the effect of oxidizing acid on the surface of coatings. These results revealed the superior anticorrosive activity of nanocomposite coatings compared to those of plain SFPU and other such reported systems. The superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries.

A novel of PEG-conjugated phthalocyanine and evaluation of its photocytotoxicity and antibacterial properties for photodynamic therapy

A poly(ethylene glycol) (PEG)-conjugated silicon(IV) phthalocyanine axially substituted with (PEG1000) chains (SiPc-PEG) was synthesized, and this novel phthalocyanine was characterized by [Formula: see text]H-NMR, FT-IR and UV-Vis spectrophotometric methods. Elemental analysis data were beneficial for the evaluation of the chemical structure of the new compound. The total number of (O–CH[Formula: see text]–CH[Formula: see text] units was calculated as 44 and the structure of the new PEG-conjugated silicon phthalocyanine was determined by the use of integral areas in [Formula: see text]H-NMR spectrum and the ratio of SiPc:PEG1000 was found as 1:2. The photophysical and photochemical properties were determined in both DMSO and aqueous solutions. In addition, the photocytotoxicity of the novel PEG-conjugated silicon(IV) phthalocyanine was also examined by testing against human cervical-carcinoma (HeLa) and hepato-carcinoma cells (HuH-7). The IC[Formula: see text] value for the SiPc-PEG compound was determined as 0.28 [Formula: see text]M for HeLa cells and 0.4 [Formula: see text]M for HuH-7 cells. These results imply that HeLa cells are apparently more responsive to photodynamic therapy (PDT) treatment by SiPc-PEG than HuH-7 cells at low concentrations (up to 0.5 [Formula: see text]M) of the studied photosensitizer. Additionally, SiPc-PEG showed antibacterial activity against Escherichia coli at 48 h of incubation, the viabilities of E.coli cultures exposed to 1000 [Formula: see text]g/mL and 2500 [Formula: see text]g/mL SiPc-PEG concentration were reduced by about 90%, and the additional growth inhibitory effect of photoactivation was also observed clearly at these efficient concentrations. To conclude, the novel compound may have a high potential for photodynamic therapy.

Green click synthesis of β-hydroxy-1,2,3-triazoles in water in the presence of a Cu(ii)–azide catalyst: a new function for Cu(ii)–azide complexes

A new method for preparing 1,2,3-triazols via a [3+2]-cycloaddition reaction is introduced. The effect of reaction temperature on the epoxide ring opening reactions is also investigated.

Hyperbranched polyesters as biodegradable and antibacterial additives

Herein, we present novel hyperbranched poly(amino-ester)s functionalized with quaternary ammonium salts.

Click Cross-Linking-Improved Waterborne Polymers for Environment-Friendly Coatings and Adhesives

Waterborne polymers, including waterborne polyurethanes (WPU), polyester dispersions (PED), and polyacrylate emulsions (PAE), are employed as environmentally friendly water-based coatings and adhesives. An efficient, fast, stable, and safe cross-linking strategy is always desirable to impart waterborne polymers with improved mechanical properties and water/solvent/thermal and abrasion resistance. For the first time, click chemistry was introduced into waterborne polymer systems as a cross-linking strategy. Click cross-linking rendered waterborne polymer films with significantly improved tensile strength, hardness, adhesion strength, and water/solvent resistance compared to traditional waterborne polymer films. For example, click cross-linked WPU (WPU-click) has dramatically improved the mechanical strength (tensile strength increased from 0.43 to 6.47 MPa, and Young's modulus increased from 3 to 40 MPa), hardness (increased from 59 to 73.1 MPa), and water resistance (water absorption percentage dropped from 200% to less than 20%); click cross-linked PED (PED-click) film also possessed more than 3 times higher tensile strength (∼28 MPa) than that of normal PED (∼8 MPa). The adhesion strength of click cross-linked PAE (PAE-click) to polypropylene (PP) was also improved (from 3 to 5.5 MPa). In addition, extra click groups can be preserved after click cross-linking for further functionalization of the waterborne polymeric coatings/adhesives. In this work, we have demonstrated that click modification could serve as a convenient and powerful approach to significantly improve the performance of a variety of traditional coatings and adhesives.

Dendrons as active clicking tool for generating non-leaching antibacterial materials

Dendrons with a focal point and quaternary ammonium peripheral groups are tools for making non-active polymers and surfaces antibacterial.

Synthesis and assessment of novel anticorrosive polyurethane coatings containing an amine-functionalized nanoclay additive prepared by the cathodic electrophoretic deposition method

Cathodic electrophoretic deposition (CEPD) was utilized to cover a mild steel cathode in an aqueous solution consisting of a newly synthesized two-component one-pack waterborne polyurethane resin.

Microstructure and antibacterial performance of functionalized polyurethane based on polysiloxane tethered cationic biocides

The designed polyurethane containing polysiloxanes tethered quaternary ammonium salt groups exhibited special surface migrations, low surface free energy and excellent antibacterial activity towardsEscherichia coli.

The impact of 1,2,3-triazoles in the design of functional coatings

This review article presents an overview of the application of 1,2,3-triazoles in the design of various high performance organic coatings with properties like anti-corrosive, anti-microbial, self-healing, hybrid nanocomposite, bio degradableetc.