Synthesis and characterization of Antibacterial Polyurethane Rigid Foam Nanocomposites by Incorporation of Tea Tree Oil as a Natural Biocide

Synthesis and characterization of novel Tea Tree Oil (TTO) loaded antibacterial polyurethane rigid foam is reported by using two distinct methods. In the first method, the mesoporous silica used as a carrier for TTO and followed by functionalization with 3-aminopropyltriethoxysilane (APTS), for preparing of NH2- MCM-41. In the second method, the fabrication of mesoporous silica nano containers (SiO2NCs) encapsulating TTO was performed by Sol-Gel procedure, which is known to display antibacterial properties. TTO is loaded in the core of the silica Nano containers that are stabilized by surfactants as CoreShell nanoparticles (TTO@NH2-SiO2NCs). Field Emission Scanning Electron Microscopic (FESEM), Transmission Electron Microscopic (TEM), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET), and Thermogravimetric Analysis (TGA) analyses were used to characterize morphological, structural, and thermal properties of the prepared nanoparticles, respectively. The prepared antibacterial polyurethane rigid foams by having 2.5, 5, 7 percentages of the nanoparticles were studied by FESEM, ATRFTIR, TGA and antibacterial performance assay method, respectively. The obtained results from Viable cell count (direct contact) method was exhibited that antibacterial polyurethane rigid foam containing 7% TTO-NH2-MCM-41 has a robust antibacterial activity with >99.9% of the loss of viability for Staphylococcus aureus bacteria

Green and inexpensive method to recover Bisphenol-A from polycarbonate wastes

Hydroglycolysis of polycarbonate waste from used compact discs was developed to recover Bisphenol-A (BPA) as a valuable material. Experiments were done in glycerin and water as an alternative green solvent. The effect of solvent ratios has been studied to evaluate BPA recovery. The use of 30% aqueous glycerin (pbw) led to 93 and 100% of BPA at reflux condition within 1.0 and 5.5 hours, respectively. Recovered BPAs were identified by spectroscopy methods and the results were compared with commercial sample data

Chemical recycling of semi-rigid polyurethane foams by using an eco-friendly and green method

Degradation of integral skin polyurethane foams (ISPUFs) was performed using diethylene glycol (DEG)/-sorbitol/water ternary green solvent system as an effective polyurethane bond destroying agent in combination with basic catalysts, namely sodium and potassium hydroxides, sodium acetate and sodium carbonate. The effects of studied catalysts were investigated and data showed the high performances of sodium hydroxide in recycling process. After completion of the reactions, appeared split phases contained recycled polyols in the upper phase. Reactions were studied using various DEG/-sorbitol/water ratios and the recovered polyols were characterized and data compared with an authentic sample

Environmentally benign chemical recycling of polycarbonate wastes: comparison of micro- and nano-TiO2 solid support efficiencies

Polycarbonate (PC) wastes, including optical discs (CDs) and digital optical discs (DVDs), were chemically recycled into valuable materials such as 4,4′-(propane-2,2-diyl)diphenol (BPA) and etherified derivatives of BPA using sodium hydroxide (NaOH) as the alkali metal catalyst and nanostructured titanium dioxide (nano-TiO2) and microstructured titanium dioxide (micro-TiO2) as the solid supports in the binary green system consisting of water and 2,2′-oxydi(ethan-1-ol) (DEG) under conventional heating method, and data were compared. In this study, the effects of various parameters, such as solvent composition, concentration of NaOH, and solid support, were studied on the reaction progress. In these reactions, the importance of water as the green solvent was investigated in achieving pure BPA as the valuable material. When used with 20% aqueous DEG (pbw), a pure BPA can be obtained at 70% yield in the presence of nano-TiO2 and micro-TiO2 as the solid supports. According to the results, the use of nano-TiO2 in comparison with micro-TiO2 accelerates the chemical recycling of PC wastes. The nano-TiO2 catalyst recovery shows that the recovered solid support is applicable for four cycles. The obtained products were characterized using spectroscopic methods, namely, 1H NMR, 13C NMR, and Fourier transform infrared spectroscopy as well as gas chromatography-mass spectrometry

Cloisite 15Aº nanoclay as an effective PTC for the epoxidation of hydroxyl terminated polybutadiene (HTPB)

A simple method is reported for the epoxidation of hydroxyl-terminated polybutadiene (HTPB) by using in-situ generated dimethyl dioxirane (DMD) as an oxidant and Cloisite 15Aº nanoclay as a phase-transfer catalyst (PTC). In order to find the optimum reaction conditions, real time analyses of the products as well as epoxidation progress, followed by ¹HNMR and FTIR techniques at various reaction times and different PTC concentrations, were done. Obtained data revealed the selectivity of DMD/ Cloisite 15Aº in predominant cis double bonds epoxidation in comparison with trans and pendant vinyl functional groups

Preparation of novel magnetic polyurethane foam nanocomposites by using core-shell nanoparticles

Abstract Iron oxide magnetic nanoparticles (NP's) converted to the core- shell structres by reacting with by n-(2-aminoethyl)-3-aminopropyl trimethoxysilane (AEAP) incorporated in polyurethane flexible (PUF) foam formulations. Fourier transform spectra, thermal gravimetric analysis, scanning electron images, thermo-mechanical analysis and magnetic properties of the prepared nanocomposites were studied. Obtained data shown that by the increasing of the amine modified magnetic iron oxide NP's up to 3% in the polymer matrix, thermal and magnetic properties improved in comparison with pristine foams. In addition, due to the presence of functional groups on the magnetic NP's surface, hard phases formation decrease in the bulk polymer and cause decreasing of glass transition temperature

Nanosilica reinforced epoxy floor coating composites: preparation and thermophysical characterization

In this study, flooring grade epoxy/nanoSiO2 nanocomposites were prepared by in-situ polymerization method. Nano silica was treated by coupling agent in order to surface treating and introducing of reactive functional groups to achieving adequate bonding between polar inorganic nano particles and epoxy organic polymer. γ-Aminopropyltriethoxysilane (Amino A-100) was used as an effective and commercially available coupling agent and nano silica treated in acetone media. SEM observations of cured samples revealed that the nano silica was completely dispersed into polymer matrix into nanoscale particles. Thermal and physical properties of prepared samples were investigated and data showed improvements in physical and mechanical properties of the flooring samples in comparison with unfilled resin

Dipodal Silane-modified Nano Fe3O4/Polyurethane Magnetic Nanocomposites: Preparation and Characterization

Magnetic nanocomposites were prepared by incorporation of pure Fe3O4 and surface-modified Fe3O4 nanoparticles (dipodal silane-modified Fe3O4) into a polyurethane elastomer matrix by in situ polymerization method. In preparation of these magnetic nanocomposites, polycaprolactone (PCL) was used as a polyester polyol. Because of dipole-dipole interactions between nanoparticles and a large surface area to volume ratio, the magnetic iron oxide nanoparticles tended to agglomerate. Furthermore, the most important challenge was to coat the surface of magnetic Fe3O4 nanoparticles in order to prepare well dispersed and stabilized Fe3O4 magnetic nanoparticles. It was observed that surface modification of Fe3O4 nanoparticles enhanced the dispersion of the nanoparticles in polyurethane matrices and allowed magnetic nanocomposites to be prepared with better properties. Surface modification of Fe3O4 was performed by dipodal silane synthesized based on 3-aminopropyltriethoxysilane (APTS) and γ-glycidoxypropyl trimethoxysilane (GPTS). Dipodal silane-coated magnetic nanoparticles (DScMNPs) were synthesized and incorporated into the polyurethane elastomer matrix as reinforcing agents. The formation of dipodal silane was investigated by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR) and transmission electron microscopy (TEM). Characterization and study on the magnetic polyurethane elastomer nanocomposites were performed by FTIR, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and dynamic mechanical thermal analysis (DMTA). The VSM results showed that the synthesized polyurethane elastomer nanocomposites had a superparamagnetic behavior. The TGA results showed that the thermal stability of dipodal silane-modified Fe3O4/PU nanocomposite was higher than that of Fe3O4/PU nanocomposite. This could be attributed to better dispersion and compatibility of dipodal silane-modified Fe3O4 nanoparticles in the polyurethane matrix compared to pure Fe3O4 nanoparticles

Recovery of Terephthalic Acid by employing magnetic nanoparticles as a solid support

Abstract The aim of this research work is focused on the improvement of Terephthalic acid recovery from PET wastes by using organically modified nano-Fe3O4@Cyanuric Chloride as the solid support. The performance of organically modified nano magnetic was examined in detail and the obtained results were compared with the unsupported reaction data. Required reaction time for complete glycolysis of the wastes, consumption of the solvent as well as catalyst decreases up 99%, 37.5% and 40% respectively. Result showed that nano-Fe 3O4@Cyanuric Chloride delivered good performance as solid support in depolymerizing of PET to the terephthalic acid