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In this work, a biologically active curcumin molecule is used as an antibacterial agent, and the insertion of this naturally occurring biomolecule into the backbone of water-dispersible polyurethane has been successfully achieved to synthesize bio-based antibacterial textile finishes. These curcumin-based water-dispersible polyurethane (CUR-WDPU) dispersions were prepared by utilizing isophorone diisocyanate (IPDI), polyethylene glycol (PEG), dimethylolpropionic acid (DMPA) and triethylamine (TEA) following the prepolymer mixing process by incorporating variable molar quantities of curcumin (CUR). Structure elucidation of synthesized CUR-WDPU dispersions was obtained through Fourier transformed infrared spectroscopy (FTIR) which confirmed the insertion of CUR into the WDPU backbone. Using the pad-dry-cure procedure, the varying varieties of plain weave polyester/cotton blended dyed and printed textile samples were treated with synthesized CUR-WDPU finishes. The antibacterial activities of these treated textiles have been assessed, and the outcomes revealed that the insertion of curcumin into the PU polymer chain has significantly boosted the antibacterial activities of PU dispersions. These newly prepared CUR-WDPUs dispersions are proved to be eco-friendly antimicrobial finishes because these are containing natural bioactive agents such as curcumin, showing potential antibacterial applications on polyester/cotton textiles. Predominantly, this research work is an attempt toward the greener approach of novel bio-based finishing materials preferably useful for textile diligences. Future investigations of these finishes will explore the other textile assets of poly-cotton textiles without adversely influencing their color fastness and mechanical properties. [ABSTRACT FROM AUTHOR]

This research is aimed at synthesizing some novel bio-based ecofriendly finishes for textile applications. A series of curcumin based aqueous polyurethane (PU) dispersions (CUR-WDPU-IPDI) was prepared using polyethylene glycol (PEG), isophorone diisocyanate (IPDI) and dimethylolpropanoic acid (DMPA) via conventional pre-polymer process. The dual functionality is incorporated by hindering the polyurethane pre-polymer with isocyanate (-NCO) groups and curcumin was utilized to extend the polymeric chain to achieve the CUR-WDPU-IPDI dispersion. Structural characteristics of the synthesized polymer were investigated by Fourier Transform Infrared (FT-IR) spectrophotometer. The performance of PU dispersions for increasing the color fastness properties (washing, rubbing and perspiration fastness) of plain weave fabrics (poly/cotton, dyed and printed) was studied. Furthermore, the mechanical strength (pilling, tearing and tensile strength) of the said fabric (dyed, printed and white) was also evaluated. Results clearly exhibited that the color fastness properties and mechanical strength of the dyed, printed and white fabrics were improved significantly after treating with the PU finishes. These synthesized curcumin-based water dispersible polyurethanes (CUR-WDPU-IPDI) finishing agents are greener products which are particularly derivatized from bio-resources. Owing to their biocompatibility, copious availability, less noxious, greener methodology and ecofriendly nature, these can be utilized as attractive ecofriendly alternatives for textile applications. [ABSTRACT FROM AUTHOR]

Cerebral intracranial aneurysms are serious problems that can lead to stroke, coma, and even death. The effect of blood flow on cerebral aneurysms and their relationship with rupture are unknown. In addition, postural changes and their relevance to haemodynamics of blood flow are difficult to measure in vivo using clinical imaging alone. Computational simulations investigating the detailed haemodynamics in cerebral aneurysms have been developed in recent times not only to understand the progression and rupture but also for clinical evaluation and treatment. In the present study, the haemodynamics of a patient-specific case of a large aneurysm on the left side internal carotid bifurcation (LICA) and no aneurysm on the right side internal carotid bifurcation (RICA) was investigated. The simulation of these patient-specific models using fluid–structure interaction provides a valuable comparison of flow behavior between normal and aneurysm models. The influences of postural changes were investigated during standing, sleeping, and head-down (HD) position. Significant changes in flow were observed during the HD position and quit high arterial blood pressure in the internal carotid artery (ICA) aneurysm model was established when compared to the normal ICA model. The velocity increased abruptly during the HD position by more than four times (LICA and RICA) and wall shear stress by four times (LICA) to ten times (RICA). The complex spiral flow and higher pressures prevailing within the dome increase the risk of aneurysm rupture. [ABSTRACT FROM AUTHOR]

A novel green series of hydroxyethyl cellulose (HEC) based polyurethane (PUs) prepolymersblended with TiO2 nanoparticles were synthesized by reaction of Isophorone diisocyanate (IPDI), hydroxyl-terminated polybutadiene (HTPB), and hydroxyethyl cellulose (HEC). The chain was further extended with 1,4-butanediol (BDO) to get final HEC based polyurethane bio nanocomposites (FPUNC). A mixture of HEC based polymer and TiO2 nanoparticles was formed in solution polymerization, in which the TiO2 nanoparticles dispersed depending on interaction of TiO2 nanoparticles with polymer chains. The molecular structure of the synthesized PU bionanocomposites was confirmed by FTIR. A series of FPUNCs was prepared by varying the percent composition of the TiO2 nanoparticles into the PU matrix. The morphology of the bionanocomposites was carried out by X-ray diffraction (XRD) studies and scanning electron microscopy (SEM). SEM images verified the good dispersion of TiO2 nanoparticles into PU matrix. The thermal stability of the synthesized FPUNCs was done by thermal gravimetric analysis (TGA), and the FPUNC12 with 5% contents of TiO2 nanoparticles showed better thermal stability. The resultant HEC-TiO2 based FPUNCs material have promising bio-degradable and bio functional materials with good thermal properties and have potential applications in the field of biomaterials. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane belongs to a polymeric organosilicon compounds that is widely used as silicon-based organic polymer. Polydimethylsiloxane is a basically optically clear, inert, nontoxic and inflammable material which is widely used in medical devices, as an elastomer, antifoaming agent, heat-resistant lubricants, fire retardants, in cosmetics and for other valuable domestic applications. This comprehensive review of polydimethylsiloxane describes synthesis, characterization, surface modifications and formation of vital biodegradable films/membranes that can facilitate improvements in modern research. Polydimethylsiloxane is viscoelastic, hydrophobic, cytocompatible and herbicidal penetrant that provides water-repellent coatings in textile industry. In this study, copolymers of polydimethylsiloxane were thoroughly studied based on polyimides, carboxyesters, hydroxyethyleneoxide, degradation with polystyrene, cross-linking with block copolymers, phosphorus-based, gelatin-based and polyurethanes, which can be used for modern manufacturing purposes in all kinds of industrial world. [ABSTRACT FROM AUTHOR]

As the use of high performance textiles has grown, the need for chemical finishes to provide the fabric properties required in the special applications has grown accordingly. In this project, a series of water dispersible polyurethanes dispersion (CS-PUs) with multipurpose performance profile was developed using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), 2,2-dimethylol propionic acid (DMPA) and chitosan (CS) for textile applications. In two step synthesis process, NCO functional PU prepolymers prepared by reacting IPDI, PEG, and DMPA were extended with varying molar quantities of chitosan followed by structural characterization through FTIR. The prepared CS-PU dispersions were applied onto the dyed and printed poly-cotton blend fabrics. The performance behavior of the treated fabric in terms of crease recovery, tear strength, tensile strength, and antibacterial properties was evaluated by applying standard test methods. These investigations show that the CS-PU dispersions can be applied as antibacterial textile finishes with significant improvement in the physical and mechanical properties of poly-cotton fabrics. [ABSTRACT FROM AUTHOR]

Curcumin (CUR) has been investigated for its poor accessibility to a site of action or absorption and rapid metabolism to cope with the limited medication and cure applications. This article reviews numerous approaches, such as encapsulated surfactant/polymeric micelles, liposomes, micro/nano-spheres, nano-suspensions/composites, nanocomplex, films, and hydrogels for effective transfer of CUR to target sites. Chitosan (CS), and chitosan derivatives have been found to enhance therapeutic efficacy of CUR. CS/modified-CS based alginate, cyclodextrin, starch, dextran sulfate, ZnO, phytosomes, and poly(butyl) cyanoacrylate drug delivery matrices improved bioavailability, prolonged drug loading and permeability, sustained release rate, improved solubility and stability (prevent metabolic degradation) of CUR, consequently promoting various clinical applications. CS based polysaccharide, protein, and metal oxide drug delivery nano formulations advantageously participated to improve biological activities of CUR. We have attempted to summarize these delivery approaches, and reviewed future trends/strategies to permit the introduction of CUR as practical therapeutic drug. [ABSTRACT FROM AUTHOR]

Human biosynthetic insulin is a polypeptide hormone that plays an important and essential role in control of the level of carbohydrate, protein, and fat metabolism in the blood. Human pancreatic insulin was labeled with Tc to form a new radiopharmaceutical with a labeling yield of 99 ± 1% under optimum conditions: 0.1 mL insulin, pH 7, 25 μg stannous chloride, 1 mL (19 mCi) of pertechnetate, room temperature, and 10 min reaction time. The Tc-insulin complex was examined using paper chromatography, ITLC, electrophoresis, and HPLC. In addition, in vitro and in vivo study of Tc-insulin complex was performed at different time intervals. [ABSTRACT FROM AUTHOR]

Environmentally friendly waterborne polyurethane (WPU) coatings are used extensively due to their low VOCs emission than solvent based PU coatings. Additionally, WPU coatings have low temperature flexibility, pH stability, water resistance, superior solvent resistance, outstanding weathering resistance and desirable chemical and mechanical properties. This review provides an overview on the recent developments of WPU coatings and their value added applications in the coatings and paint industry. UV-cured WPU coatings provide an important class of green and ecofriendly coatings with outstanding mechanical properties and rapid curing system. Hyper-branched polyurethanes (PUs) show interesting properties, such as high solubility, reactivity and good rheological behavior owing to multiple end groups, compact molecular structure and diminishing chain entanglement. Inherently, WPU coatings have reduced stiffness and mechanical strength that can be increased by the addition of nanoparticles, like Ag, Cu, TiO, SiO and many more. Fire retardants, commonly phosphorous, are incorporated in the WPU structure to increase the flame retardancy of WPU coatings. [ABSTRACT FROM AUTHOR]

The dispersibility of diamond has been improved by reforming its surface with 2-propanol-2-yl $${[({\rm CH}_{3})_{2}{\rm C}^{{\cdot}}{\rm OH}]}$$ radicals. These radicals were produced by the photochemical breakdown of 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (HPHMP) under ultraviolet (UV) radiations. The diamond particles were mixed with HPHMP in acetone and were placed under UV rays for the generation of required free radicals which were in situ reformed the diamond surface. Fourier transform infrared, nuclear magnetic resonance spectroscopy and scanning electron microscopy (SEM) confirmed the structural and surface reforming of diamond. The thermogravimetric analysis, thermogravimetric analysis-mass spectrometry spectrogram confirmed the surface reforming of diamond with 2-propanol-2-yl radicals. The dispersion behavior of the diamond after reforming was observed by SEM analysis and revealed an improvement in dispersibility in common solvents. [ABSTRACT FROM AUTHOR]

The present research work was performed to study the properties of polyurethanes (PU) based on aliphatic diisocayanate and the effect of chemical structure of chain extenders. Two series of PUs were synthesized via two steps polymerization technique. The PU samples constituted on hexamethylene diisocayanate (HDI), hydroxy-terminated polybutadiene (HTPB) and blends 1, 4 butanediol (BDO)/bisphenol A (BPA) and or 1, 4 butanediol (BDO)/ bisphenol S (BPS) were prepared. Structural characterization was done using Fourier transform infrared spectroscopy during and after the synthesis. The FTIR analysis confirmed the existence of proposed bisphenol A (BPA) and bisphenol S (BPS) based PU structures. Differential scanning calorimeter (DSC) analysis gives information about the thermal transition of all the polymer samples. Because of the difference of polarity between hard and soft segments of PU, microphase separation can occur. The degree of phase separation in the prepared PU was confirmed using scanning electron microscope (SEM) technique. The SEM techniques present a distinctive chance to directly visualize the morphology of the polyurethanes. [ABSTRACT FROM AUTHOR]

Self-assembled hollow microspheres poly( o-chloroaniline) (POC) have been synthesized by simple oxidative polymerization of o-chloroaniline using camphor-sulfonic acid (CSA) as dopant acid and ammonium persulfate (APS) as oxidant. The POC microspheres were characterized by means of FTIR, XRD and SEM analysis. Adsorption characteristics of POC spheres were studied by using methyl orange (MO) as adsorbate. It was found that adsorption of MO by POC was better described by pseudo-second-order kinetics than any other kinetic model, such as the pseudo-first-order and intra-particle diffusion models. Langmuir adsorption isotherm model was the best to fit experimental data. The results showed that hollow microspheres of POC can be used as novel and low-cost adsorbent for removal of organic dye from waste water. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUs) prepolymers blended with bentonite nanoclay and without bentonite nanoclay were prepared by the reaction of toluene-2,4-diisocyanate (TDI) and hydroxyl terminated polybutadiene (HTPB), and the chain was further extended with 1,4-butane diol (1,4-BDO) to get final polyurethane nanocomposites (PUNC). A mixture of polymer and bentonite clay enriched in montmorillonite (MMT) was formed in solution polymerization, in which MMT dispersed depending on interaction of MMT with polymer chains. The molecular structure of the monomers and the prepared PU nanocomposites was confirmed by FTIR. A series of PUNCs were prepared by varying the percent compositions of bentonite nanoclay into the PU matrix. The existence of the clay in to the PU was confirmed by scanning electron microscope (SEM). SEM images verified the good dispersion of the bentonite nanoclay in PU matrix. [ABSTRACT FROM AUTHOR]

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness. A series of aqueous polyurethane dispersions containing carboxylate anion as hydrophilic pendant groups were synthesized through step growth polymerization reaction using hexamethylene diisocyanate (HDI), 1,4-butanediol (1,4-BDO), dimethylol propionic acid (DMPA) and polyethylene glycol (PEG) of different molecular weight. Effect of PEG molecular weight was investigated on molecular structure, contact angle measurement, and physical and adhesive properties of PU emulsions. Fourier transform infrared spectroscopy (FT-IR) was used to check the completion of polymerization reaction. Contact angle measurement indicated that the hydrophilicity of polymer increases by increasing molecular weight of PEG with a corresponding decrease in contact angle. Results of T-peel test showed a decrease in peel strength by increasing molecular weight of PEG. Moreover, solid contents%, drying time and storage stability suggested fast drying properties and greater stability of aqueous PU dispersions. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUs) prepolymer was prepared by the reaction of toluene-2,4-diisocyanate (TDI) and poly caprolactone diols and the chain was further extended with 1,4-butane diol (1,4-BDO) to get final polyurethane (PU). FTIR spectra of the monomers, PU prepolymer, chain extender and final PU confirmed the reaction progress. A series of blends were prepared by varying the percent compositions of prepared PU, procured polymethyl methacylates (PMMA) and titanium dioxide (TiO). Pellets were formed from the prepared blends (PU-PMMA/TiO) using a self-designed mechanical tool. Scanning electron microscope (SEM) images were also taken to confirm the incorporation of the TiO contents into the prepared blends. Mechanical properties such as hardness and compressive strength were studied and discussed. The results of the study reveal that the blended sample having 80% PU, 20% PMMA content with 2.5 g TiO in 100 g mixture of PU and PMMA is very suitable for suggesting dental materials. [ABSTRACT FROM AUTHOR]

Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties. [ABSTRACT FROM AUTHOR]