RESUMO
A novel catalyst based on layered double hydroxides coated with copper nitrate [LDH@(3-chloropropyl)trimethoxysilane@N1,N4-bis(4,6-diamino-1,3,5-triazin-2-yl)benzene-1,4-disulfonamide@Cu] was successfully synthesized. The structure of the new synthesized catalyst was investigated and confirmed using different analytical techniques, such as Fourier-transform infrared spectroscopy (FTIR), energy-scattered X-ray spectroscopy (EDX) mapping, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and heat gravity/heat derivatization (TGA/DSC). The skilled catalyst proved its efficiency for one-pot three-component synthesis of pyrano[2,3-d]pyrimidine and new dihydropyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine-dione derivatives. Using this efficient catalyst, products were synthesized with a high yield, in a short time, and under soft and solvent-free conditions. The catalyst can be recovered and reused four times without a significant loss of efficiency.
RESUMO
This research developed a new nanocatalyst by incorporating nanocopper iodide onto the surface of a layered double hydroxides modified. This new nanocatalyst enables the green synthesis of tetrahydrobenzo[b]pyrans and 2-amino-4H-chromene derivatives through a one-pot, three-component reaction, demonstrating remarkable activity and selectivity. Key advantages of this method include increased products yield (86-96%), rapid reaction kinetics (5-23 minutes), low reaction temperature (40 °C), synthesis of new products, straightforward purification methods, catalyst recyclability (up to 4 cycles), and solvent-free conditions.
RESUMO
A new heterogeneous nanocatalyst LDH@3-chloropyltrimethoxysilane@1,3-benzenedisulfonyl amine@Cu (LDH@TRMS@BDSA@Cu) was synthesized and confirmed by analyzes such as Fourier transform infrared spectroscopy, Field Emission Scanning Electron Microscopy, energy scattered X-ray spectroscopy (EDX), elemental mapping, X-ray diffraction analysis, heat gravity/heat derivatization (TGA) and differential scanning calorimetry. The newly synthesized nanocatalyst effectively catalyzed the reaction between different aryl aldehydes, malononitrile, different acetophenones and ammonium acetate in solvent-free conditions and they were converted into 2-amino-3-cyanopyridine derivatives with high efficiency. The reaction showed advantages such as simplicity, high stability, environmental friendliness, excellent efficiency and short time. Also, this catalyst is recyclable and was recycled 4 times without losing significant catalytic power.
RESUMO
A new magnetic nano-catalyst system based on graphene oxide was designed and manufactured (GO@Fe3O4@3-chloropropyltrimethoxysilane@(Z)-N'-(2-hydroxybenzylidene)-4-(pyridin-4-yl)benzohydrazide@Cu(II)), and it was checked and confirmed by various analyzes such as FTIR, XRD, EDX, MAPPING, TGA/DSC, VSM and FESEM. This nano-catalyst was used in the three-component one-pot synthesis of quinazoline derivatives. The products were obtained using this efficient catalyst with high efficiency in short time and solvent-free conditions. Easy separation and acceptable recyclability are other advantages of this new nano-catalyst. Also, the catalyst can be recycled 4 times without a significant change in its efficiency.
RESUMO
As a hydrophilic renewable polymer, starch has been widely used in biocompatible plastics as a filler for more than two decades. The present study aimed at investigating the effects of polyethylene glycol (PEG), as a plasticizer, on the physicochemical properties of a hybrid composite-polylactic acid (PLA) and thermoplastic starch (TPS). A solvent evaporation process was adopted to gelatinize the starch and disparate PEG contents ranging from 3 to 15 wt.% (with respect to the sample weight) were examined. It was revealed that the increase in the PEG content was accompanied by an increment in the starch gelatinization degree. Referring to the microstructural analyses, the TPS/PLA mixture yielded a ductile hybrid composite with a fine morphology and a uniform phase. Nevertheless, two different solvents, including acetone and ethanol, were used to assess if they had any effect on the hybrid's morphology, tensile strength and thermal properties. It was found that ethanol culminated in a porous hybrid composite with a finer morphology and better starch distribution in the PLA structure than acetone. As the result of PEG addition to the composite, the crystallinity and tensile strength were decreased, whereas the elongation increased. The hydrolytic degradation of samples was assessed under different pH and thermal conditions. Moreover, the microbial degradation of the PLA/TPS hybrid composite containing different PEG molar fractions was investigated in the soil for 45 days. The rate of degradation in both hydrolytic and biodegradation increased in the samples with a higher amount of PEG with ethanol solvent.