Thermal evaluation of cashew nutshell liquid as new bioadditives for poly(methyl methacrylate)

In this study, the thermal-oxidative stability of poly(methyl methacrylate), PMMA, 1 % additivated with replenishable phenolic lipids is evaluated by thermogravimetric (TG/DTG) analyses and differential scanning calorimetry (DSC) analyses. Since technical cashew nutshell liquid (CNSL), a byproduct from the cashew industry, is composed basically of two phenolic lipids, cardanol and cardol, the utilization of this industrial waste and its main components as a new source of bioadditives for use as antioxidants is evaluated. The TG analyses revealed that addition of the phenolic constituent of CNSL increased the thermal stability of PMMA films considerably. The results obtained were also confirmed by DSC analyses.     

Evaluation of antioxidants on the thermo-oxidative stability of soybean biodiesel

This work shows the evaluation of three antioxidants (2,6-di-t-butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-oxidative stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the oxidative stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-oxidative stability of the soybean biodiesel as follows: soybean biodiesel < soybean biodiesel + BHT < soybean biodiesel + HC < soybean biodiesel + AHC. In the Rancimat method, the results showed that the antioxidants influenced the biodiesel stability with an increase of at least 71 %.     

Thermo-oxidative evaluation of new cardol derivatives as antioxidants for mineral oils

In this study, the thermo-oxidative stability of two new phosphorylated derivatives of cardol, a compound from the cashew (Anacardium occidentale L.) industry waste CNSL (cashew nutshell liquid), were evaluated. The antioxidant capacity of these new molecules upon two mineral oils, NH10 and NH20 were also studied by thermogravimetric analysis (TG/DTG), observing the onset and offset temperatures variation. The results showed that both MP and DP Cardol increased considerably the onset and offset temperatures of NH10 and NH20 oils.     

Synthesis,characterization and monitoring of trans-[Ru{P(OMe)3}4Cl2] by reversed-phase high-performance liquid chromatography and 31P-n.m.r.

P(OMe₃)₃ reacts with RuCl₃ · 3H₂O to produce the complex trans-[Ru{P(OMe)₃}₄Cl₂] from which the complexes trans-[Ru{P(OMe)₃}₄S₂]²⁺ and cis-[Ru{P(OMe)₃}₂S₄]²⁺ (S = Solvent) can be prepared by solvation in neutral and acidic solution, respectively. The aquation takes place with a specific rate of 1.0 × 10^–2 min^–1 (pH = 3.0) and 5.4 × 10^–3 min^–1 (pH 7.0) The trans-[Ru{P(OMe)₃}₄Cl₂] complex has been characterized by elemental analysis; electronic spectra [_max = 408 nm] ( = 1.7 × 10² M^–1 cm^–1), _max = 250 nm ( = 3.5 × 10³ M^–1 cm^–1) and a shoulder at = 280 nm ( 8.3 × 10² M^–1 cm^–1)]; cyclic voltametry ( = 0.75 V versus s.c.e.); HPLC (t _R = 5.7 min); and ³¹P-n.m.r. ( = 131 p.p.m.). In acidic solutions the ³¹P-n.m.r. variations point to a reaction intermediate, characterized as the complex ion trans-[Ru{P(OMe)₃}₄S₂]²⁺ ( = 136 p.p.m.) followed by the formation of the proposed product, cis-[Ru{P(OMe)₃}₂S₄]²⁺ ( = 145 p.p.m.). For this same complex, at pH = 7.0, the results show the formation of the trans-[Ru{P(OMe)₃}₄S₂]²⁺ ( = 136 p.p.m.). The HPLC results for the trans-[Ru{P(OMe)₃}₄Cl₂] complex show that the different species are present at different pH values. In acidic media a less polar species (t _R = 4.3 min) compared with the starting material (t _R = 5.7 min) was formed. At neutral pH (t _R = 4.6 min) the species generated were not modified, however they exhibited different properties from the species obtained at a lower pH.     

Microwave‐assisted solvent‐free synthesis of novel benzoxazines: A faster and environmentally friendly route to the development of bio‐based thermosetting resins

Microwave‐assisted organic synthesis (MAOS) is a well‐established technique that has been used in the enhancement of chemical reactions. Here, the versatility of MAOS is explored describing an environmentally friendly one‐pot route to novel bio‐based benzoxazines under solvent‐free conditions. The lignin derivative, guaiacol, along with paraformaldehyde and different conjugated and nonconjugated amines are successfully fused into guaiacol‐derived 3,4‐dihydro‐2H‐1,3‐benzoxazines. The reactions conducted under microwave irradiation are completed much faster than those under traditional heating, reducing the reaction time from hours to only 6 min, with good yields. The chemical structures of novel benzoxazines are confirmed by ¹H and ¹³C NMR spectroscopy, FTIR, and HR‐MS. The thermal behavior of the resins are evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), showing that these polymers have good thermal stability and wide processing‐window, with onset temperature of polymerization above 230 °C. These results indicate dramatic improvement over the traditional methodologies for the production of this class of resins, which are usually obtained by time‐consuming procedures and in the presence of toxic solvents. Therefore, MAOS can be considered a green and efficient strategy for the synthesis of eco‐friendly benzoxazines. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3534–3544     

Magnetic nanoparticles for a new drug delivery system to control quercetin releasing for cancer chemotherapy

Quercetin belongs to the chemical class of flavonoids and can be found in many common foods, such as apples, nuts, berries, etc. It has been demonstrated that quercetin has a wide array of biological effects that are considered beneficial to health treatment, mainly as anticancer. However, therapeutic applications of quercetin have been restricted to oral administration due to its sparing solubility in water and instability in physiological medium. A drug delivery methodology was proposed in this work to study a new quercetin release system in the form of magnetite?Cquercetin?Ccopolymer (MQC). These materials were characterized through XRD, TEM, IR, and Thermal analysis. In addition, the magnetization curves and quercetin releasing experiments were performed. It was observed a nanoparticle average diameter of 11.5 and 32.5?nm at Fe₃O₄ and MQC, respectively. The presence of magnetic nanoparticles in this system offers the promise of targeting specific organs within the body. These results indicate the great potential for future applications of the MQC to be used as a new quercetin release system.     

Thiophosphate esters of cashew nutshell liquid derivatives as new antioxidants for poly(methyl methacrylate)

In this work, poly(methyl methacrylate) films 1% additivated with new thiophosphate esters antioxidants derived from technical Cashew Nutshell Liquid (CNSL), a byproduct of the cashew nut (Anacardium occidentale L.) industry, were investigated by thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) measurements under inert (N₂) and oxidative (synthetic air) atmospheres. Three new products were synthesized and characterized by GC/MS, ¹H and ³¹P NMR. The analyses were focused on the onset (T _e) and offset temperature (T _o) of degradation of the films, and on the maximum degradation temperature (T _MAX). It was observed that the thermal stability of the films increased with the addition of the thiophosphate ester antioxidants, which indicates that CNSL could be used as a natural source of phenolic material for the synthesis of antioxidants.     

Bio-based benzoxazines synthesized in a deep eutectic solvent: A greener approach toward vesicular nanosystems

A green synthesis of benzoxazines, based upon reaction of cardanol with formaldehyde and primary amines, is achieved in high yields using choline chloride-urea mixture as deep eutectic solvent. Then, it is demonstrated how the cardanol-based benxoxazines can be employed as only component for the preparation of a nanovesicular systems.     

Use of novel cardanol-porphyrin hybrids and their TiO₂-based composites for the photodegradation of 4-nitrophenol in water

Cardanol, a well known hazardous byproduct of the cashew industry, has been used as starting material for the synthesis of useful differently substituted "cardanol-based" porphyrins and their zinc(II), copper(II), cobalt(II) and Fe(III) complexes. Novel composites prepared by impregnation of polycrystalline TiO? powder with an opportune amount of "cardanol-based" porphyrins, which act as sensitizers for the improvement of the photo-catalytic activity of the bare TiO?, have been used in the photodegradation in water of 4-nitrophenol (4-NP), which is a toxic and bio-refractory pollutant, dangerous for ecosystems and human health.     

Detection of trace elements in pure indium by flame,Zeeman graphite furnace and hydride generation atomic absorption spectrometry

An atomic absorption spectrometric method for the chemical characterization of very pure indium metal is described that permits the determination of 21 elements, usually present at trace levels, without matrix removal, preliminary analyte separation or concentration. For each element the detection limit obtained is reported.