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International Journal of Molecular... Feb 2022The purpose of this review article is to outline the extended applications of polyurethane (PU)-based nanocomposites incorporated with conductive polymeric particles as... (Review)
Review
The purpose of this review article is to outline the extended applications of polyurethane (PU)-based nanocomposites incorporated with conductive polymeric particles as well as to condense an outline on the chemistry and fabrication of polyurethanes (PUs). Additionally, we discuss related research trends of PU-based conducting materials for EMI shielding, sensors, coating, films, and foams, in particular those from the past 10 years. PU is generally an electrical insulator and behaves as a dielectric material. The electrical conductivity of PU is imparted by the addition of metal nanoparticles, and increases with the enhancing aspect ratio and ordering in structure, as happens in the case of conducting polymer fibrils or reduced graphene oxide (rGO). Nanocomposites with good electrical conductivity exhibit noticeable changes based on the remarkable electric properties of nanomaterials such as graphene, RGO, and multi-walled carbon nanotubes (MWCNTs). Recently, conducting polymers, including PANI, PPY, PTh, and their derivatives, have been popularly engaged as incorporated fillers into PU substrates. This review also discusses additional challenges and future-oriented perspectives combined with here-and-now practicableness.
Topics: Electric Conductivity; Graphite; Nanocomposites; Nanotubes, Carbon; Polymers; Polyurethanes
PubMed: 35216059
DOI: 10.3390/ijms23041938 -
Environmental Science & Technology Oct 2021Today, polyurethanes are effectively not recycled and are made principally from nonrenewable, fossil-fuel-derived resources. This study provides the first...
Today, polyurethanes are effectively not recycled and are made principally from nonrenewable, fossil-fuel-derived resources. This study provides the first high-resolution material flow analysis of polyurethane flows through the U.S. economy, tracking back to fossil fuels and covering polyurethane-relevant raw materials, trade, production, manufacturing, uses, historical stocks, and waste management. According to our analysis, in 2016, 2900 thousand tonnes (kt) of polyurethane were produced in the United States and 920 kt were imported for consumption, 2000 kt entered the postconsumer waste streams, and 390 kt were recycled and returned to the market in the form of carpet underlayment. The domestic production of polyurethane consumed 1100 kt of crude oil and 1100 kt of natural gas. With the developed polyurethane flow map, we point out the limitation of the existing mechanical recycling methods and identify that glycolysis, a chemical recycling method, can be used to recycle the main components of postconsumer polyurethane waste. We also explore how targeting biobased pathways could influence the supply chain and downstream markets of polyurethane and reduce the consumption of fossil fuels and the exposure to toxic precursors in polyurethane production.
Topics: Natural Gas; Petroleum; Polyurethanes; Recycling; United States; Waste Management
PubMed: 34618441
DOI: 10.1021/acs.est.1c03654 -
International Journal of Molecular... Jan 2023Fluorescent dendrimers have wide applications in biomedical and materials science. Here, we report the synthesis of fluorescent polyurethane homodendrimers and Janus...
Fluorescent dendrimers have wide applications in biomedical and materials science. Here, we report the synthesis of fluorescent polyurethane homodendrimers and Janus dendrimers, which often pose challenges due to the inherent reactivity of isocyanates. Polyurethane dendrons (G1-G3) were synthesized via a convergent method using a one-pot multicomponent Curtius reaction as a crucial step to establish urethane linkages. The alkyne periphery of the G1-G3 dendrons was modified by a copper catalyzed azide-alkyne click reaction (CuAAC) to form fluorescent dendrons. In the reaction of the surfaces functionalized two different dendrons with a difunctional core, a mixture of three dendrimers consisting of two homodendrimers and a Janus dendrimer were obtained. The Janus dendrimer accounted for a higher proportion in the products' distribution, being as high as 93% for G3. The photophysical properties of Janus dendrimers showed the fluorescence resonance energy transfer (FRET) from one to the other fluorophore of the dendrimer. The FRET observation accompanied by a large Stokes shift make these dendrimers potential candidates for the detection and tracking of interactions between the biomolecules, as well as potential candidates for fluorescence imaging.
Topics: Dendrimers; Polyurethanes; Alkynes; Fluorescent Dyes; Azides
PubMed: 36675178
DOI: 10.3390/ijms24021662 -
ACS Biomaterials Science & Engineering Nov 2023The solid-aqueous boundary formed upon biomaterial implantation provides a playground for most biochemical reactions and physiological processes involved in implant-host...
The solid-aqueous boundary formed upon biomaterial implantation provides a playground for most biochemical reactions and physiological processes involved in implant-host interactions. Therefore, for biomaterial development, optimization, and application, it is essential to understand the biomaterial-water interface in depth. In this study, oxygen plasma-functionalized polyurethane surfaces that can be successfully utilized in contact with the tissue of the respiratory system were prepared and investigated. Through experiments, the influence of plasma treatment on the physicochemical properties of polyurethane was investigated by atomic force microscopy, attenuated total reflection infrared spectroscopy, differential thermal analysis, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and contact angle measurements, supplemented with biological tests using the A549 cell line and two bacteria strains ( and ). The molecular interpretation of the experimental findings was achieved by molecular dynamics simulations employing newly developed, fully atomistic models of unmodified and plasma-functionalized polyurethane materials to characterize the polyurethane-water interfaces at the nanoscale in detail. The experimentally obtained polar and dispersive surface free energies were consistent with the calculated free energies, verifying the adequacy of the developed models. A 20% substitution of the polymeric chain termini by their oxidized variants was observed in the experimentally obtained plasma-modified polyurethane surface, indicating the surface saturation with oxygen-containing functional groups.
Topics: Polyurethanes; Biocompatible Materials; Surface Properties; Water; Oxygen
PubMed: 37909715
DOI: 10.1021/acsbiomaterials.3c01367 -
International Journal of Nanomedicine 2022Polyurethane (PU) has wide application and popularity as medical apparatus due to its unique structural properties relationship. However, there are still some problems... (Review)
Review
Polyurethane (PU) has wide application and popularity as medical apparatus due to its unique structural properties relationship. However, there are still some problems with medical PUs, such as a lack of functionality, insufficient long-term implantation safety, undesired stability, etc. With the rapid development of nanotechnology, the nanomodification of medical PU provides new solutions to these clinical problems. The introduction of nanomaterials could optimize the biocompatibility, antibacterial effect, mechanical strength, and degradation of PUs via blending or surface modification, therefore expanding the application range of medical PUs. This review summarizes the current applications of nano-modified medical PUs in diverse fields. Furthermore, the underlying mechanisms in efficiency optimization are analyzed in terms of the enhanced biological and mechanical properties critical for medical use. We also conclude the preparation schemes and related parameters of nano-modified medical PUs, with discussions about the limitations and prospects. This review indicates the current status of nano-modified medical PUs and contributes to inspiring novel and appropriate designing of PUs for desired clinical requirements.
Topics: Humans; Polyurethanes; Biocompatible Materials; Nanostructures; Suppuration
PubMed: 36600880
DOI: 10.2147/IJN.S393207 -
Scientific Reports Mar 2022Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds...
Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds resembling the extracellular matrix (ECM) of blood vessels are promising vascular graft materials. In the present study, polyurethane (PU) was blended with ECM proteins collagen and elastin (Col-El) and gelatin (Gel) to produce fibrous scaffolds by using the rotary jet spinning (RJS) technique, and their effects on in vitro properties were evaluated. Morphological and structural characterization of the scaffolds was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Micrometric fibers with nanometric rugosity were obtained. Col-El and Gel reduced the mechanical strength and increased the hydrophilicity and degradation rates of PU. No platelet adhesion or activation was observed. The addition of proteins to the PU blend increased the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs). Therefore, PU-Col-El and PU-Gel scaffolds are promising biomaterials for vascular graft applications.
Topics: Bioprosthesis; Blood Vessel Prosthesis; Extracellular Matrix; Human Umbilical Vein Endothelial Cells; Humans; Polyurethanes
PubMed: 35347181
DOI: 10.1038/s41598-022-09040-z -
International Journal of Molecular... Jul 2022With the intensive development of polymeric biomaterials in recent years, research using drug delivery systems (DDSs) has become an essential strategy for cancer... (Review)
Review
With the intensive development of polymeric biomaterials in recent years, research using drug delivery systems (DDSs) has become an essential strategy for cancer therapy. Various DDSs are expected to have more advantages in anti-neoplastic effects, including easy preparation, high pharmacology efficiency, low toxicity, tumor-targeting ability, and high drug-controlled release. Polyurethanes (PUs) are a very important kind of polymers widely used in medicine, pharmacy, and biomaterial engineering. Biodegradable and non-biodegradable PUs are a significant group of these biomaterials. PUs can be synthesized by adequately selecting building blocks (a polyol, a di- or multi-isocyanate, and a chain extender) with suitable physicochemical and biological properties for applications in anti-cancer DDSs technology. Currently, there are few comprehensive reports on a summary of polyurethane DDSs (PU-DDSs) applied for tumor therapy. This study reviewed state-of-the-art PUs designed for anti-cancer PU-DDSs. We studied successful applications and prospects for further development of effective methods for obtaining PUs as biomaterials for oncology.
Topics: Biocompatible Materials; Drug Delivery Systems; Humans; Neoplasms; Polyurethanes; Suppuration
PubMed: 35897757
DOI: 10.3390/ijms23158181 -
International Journal of Molecular... Oct 2022The synthetic polymers used to protect artworks from deterioration process can be colonized by the fungi and bacteria responsible for the biodeterioration process. In...
The synthetic polymers used to protect artworks from deterioration process can be colonized by the fungi and bacteria responsible for the biodeterioration process. In this study, the susceptibility of synthetic polyacrylics and polyurethane resins to microorganisms ( ATCC 9642, ATCC 15233, ATCC 6205, ATCC 16022, BC01, LS1 and ATCC 9027) was investigated. The microbial attack was simulated alone and with a biocide and the related growth was observed up to 21 days for bacteria and 28 days for fungi. The polyacrylic and polyurethane resins were subjected to microbial attack, regardless of the biocide treatment, with a fungal growth from 60% to the complete coverage of the plate surface. showed the greatest adaptation ability and was found in all the examined resins. was visible in all the different resins, regardless of the presence of biocide. An environmental scanning electron microscope (ESEM) revealed the presence of fungal conidia and hyphae in the inoculated resins and the Fourier transform IR spectroscopy (FTIR-ATR) indicated chemical transformations in the IR spectra, particularly the hydrolysis of esters, with some differences between the polyacrylic and polyurethane resins, which were probably due to their different chemical features. Overall, our data stress that the chemical, physical and biological deterioration caused by microorganisms capable of degrading synthetic polymers is still a problem in art restoration and that new strategies must be considered to counteract this phenomenon.
Topics: Bacteria; Disinfectants; Esters; Fungi; Penicillium; Polymers; Polyurethanes
PubMed: 36233025
DOI: 10.3390/ijms231911725 -
Journal of the Royal Society, Interface Jun 2009Surface modification is an important and predominant technique for obtaining biofunction and biocompatibility in metals for biomedical use. The surface modification... (Review)
Review
Surface modification is an important and predominant technique for obtaining biofunction and biocompatibility in metals for biomedical use. The surface modification technique is a process that changes the surface composition, structure and morphology of a material, leaving the bulk mechanical properties intact. A tremendous number of surface modification techniques using dry and wet processes to improve the hard tissue compatibility of titanium have been developed. Some are now commercially available. Most of these processes have been developed by Japanese institutions since the 1990 s. A second approach is the immobilization of biofunctional molecules to the metal surface to control the adsorption of proteins and adhesion of cells, platelets and bacteria. The immobilization of poly(ethylene glycol) to a metal surface with electrodeposition and its effect on biofunction are reviewed. The creation of a metal-polymer composite is another way to obtain metal-based biofunctional materials. The relationship between the shear bonding strength and the chemical structure at the bonding interface of a Ti-segmentated polyurethane composite through a silane coupling agent is explained.
Topics: Adsorption; Biocompatible Materials; Bone Remodeling; Bone Substitutes; Coated Materials, Biocompatible; Durapatite; Electroplating; Japan; Polyethylene Glycols; Polyurethanes; Shear Strength; Surface Properties; Titanium
PubMed: 19158014
DOI: 10.1098/rsif.2008.0427.focus -
International Journal of Environmental... Sep 2021Several different dental implant microgeometries have been investigated in the literature for use in low-density bone sites. The polyurethane solid rigid blocks...
An In Vitro Analysis on Polyurethane Foam Blocks of the Insertion Torque (IT) Values, Removal Torque Values (RTVs), and Resonance Frequency Analysis (RFA) Values in Tapered and Cylindrical Implants.
BACKGROUND
Several different dental implant microgeometries have been investigated in the literature for use in low-density bone sites. The polyurethane solid rigid blocks represent an optimal in vitro study model for dental implants, because their composition is characterized by symmetrical linear chains of monomers of hexa-methylene sequences producing a self-polymerization process. The aim of the present investigation was to evaluate the primary stability of cylindrical and tapered implants positioned into low-density polyurethane solid rigid blocks.
MATERIALS AND METHODS
Two different macrogeometries, cylindrical (4 mm diameter and 10 mm length) and tapered dental implants (4.20 mm diameter and 10 mm length), were investigated in the present study. The implants were inserted into 10 PCF and 20 PCF polyurethane blocks, with and without an additional cortical layer. The insertion torque (IT) values, the removal torque values (RTVs), and the resonance frequency analysis (RFA) values were measured and recorded.
RESULTS
A total of 80 sites were tested, and a significant increased primary stability (PS) was detected in favour of tapered dental implants when compared to cylindrical implants in all experimental conditions ( < 0.05). Higher IT, RT, and RFA values were measured in tapered implants in 10 and 20 PCF polyurethane blocks, both with and without the additional cortical layer.
CONCLUSIONS
Both implants showed sufficient primary stability in poor density substrates, while, on the other hand, the tapered microgeometry showed characteristics that could also lead to clinical application in low-density posterior maxillary sites, even with a drastically decreased bone cortical component.
Topics: Bone Density; Dental Implants; Maxilla; Polyurethanes; Resonance Frequency Analysis; Torque
PubMed: 34501824
DOI: 10.3390/ijerph18179238