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Various petroleum based mineral oils like Distillate Aromatic Extract (DAE), Treated Distillate Aromatic Extract (TDAE), Residual Aromatic Extract (RAE) and Naphthenic oils are used for extension of emulsion polymerized Styrene Butadiene Rubber (E-SBR). Vegetable oils are alternate to these petroleum oil from sustainability point of view as vegetable oils have no Polycyclic Aromatic (PCA) content. They improve abrasion resistance leads to less rubber particulates spread in the environment and reduce rolling resistance leads to lower fuel consumption. However, introduction of few vegetable oils leads to slow down the cure reaction due to high unsaturation to saturation ratio. Presence of high fatty acid content in vegetable oils help in better rubber-filler interaction. In the present research, vegetable origin oils as such without any modification (Decas, Palmolein, Groundnut, Soybean, Mustard and Coconut) extended Styrene Butadiene Rubber (OE-SBR) were characterized in standard American Society for Testing and Materials (ASTM) compound recipe for various processing, different vulcanizate and other performance properties. Curative's dosages were adjusted in the recipe of vegetable oil extended SBR's to achieve the 300% modulus value like naphthenic oil. Vegetable oil extended Emulsion Styrene Butadiene Rubber (E-SBR) grades (Prepared with Palmolein and Coconut oils) were showing comparable rheometric and stress-strain properties, high reinforcement index (around 5%), better rubber-filler interaction parameter (around 12%), better abrasion resistance (around 23%) and comparable tanδ value @0°, 30° and 60°C as compared to naphthenic oil extended SBR based compound. [ABSTRACT FROM AUTHOR]

Currently emulsion polymerized Styrene Butadiene Rubber (E-SBR) is extended with various petroleum based mineral oils like Distillate Aromatic Extract (DAE), Treated Distillate Aromatic Extract (TDAE), Residual Aromatic Extract (RAE) and Naphthenic oils. It is obvious that introduction of vegetable oil should result in almost zero Polycyclic Aromatic Content (PCA) content and therefore, are environmentally friendly, renewable, and sustainable. In the present work, vegetable oil extended Styrene Butadiene Rubber (OE-SBR) were characterized for chemical properties and found that all the properties were meeting the specification requirements of mineral oils extended grades. These rubbers were also evaluated in standard Passenger Car Radial (PCR) tire tread compound recipe for various processing, different vulcanizate and other performance properties. The developed grades with vegetable oils required less mixing energy (around 10% for master batch and 15% for final batch) and shown better flow behavior (around 15% power law index and 20% activation energy reduction), better carbon dispersion (around 20%), high reinforcement index (around 15%), better rubber-filler interaction parameter (around 20%), better abrasion resistance (around 20%) and lower tanδ value @60°C (around 15%) as compared to TDAE oil extended SBR based compound. This may help to improve life of a PCR tire and reduction in fuel consumption of the vehicle. [ABSTRACT FROM AUTHOR]

Various semiconductors have been used as photocatalysts for removal of different dyes from their aqueous solutions. Zinc sulphide semiconductor is used in the present investigation as a photocatalyst for the removal of rose Bengal dye. Effect of different parameters, which affect the rate of reaction; like pH, concentration of dye, amount of semiconductor and light intensity have been studied. A mechanism has also been proposed in which hydroxyl radicals are shown as an active oxidizing species.

Magnesium ferrite was used to catalyse the cannizaro reaction of benzaldehyde in the presence of potassium hydroxide. Magnesium ferrite was prepared by hydrothermal process. Similarly Copper, nickel, cobalt, zinc etc. were prepared by same method. It was characterized by Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction Spectroscopy (XRD), and Energy Dispersive X-Ray Spectroscopy (EDX). The crystalline size of magnesium ferrite was found to have 82.47 nm. These magnesium ferrites are nano-flowers in shape. It was found that the yield of the product (benzoic acid) in the presence of Mg ferrite was 49% which is almost 3.4 times the yield obtained in the absence of catalyst. Other metal ferrites were also used as a catalyst but we get higher yield with magnesium ferrite. A comparitive study was made with different metal ferrites as catalyst and found that the activity of metal ferrites followed the order- ... [ABSTRACT FROM AUTHOR]

Using the batch adsorption technique, an eco-friendly polymer composite made of chitosan, polyaniline, and iron (III) oxide was developed for removal of dye contamination from wastewater. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), EDX (energy dispersive X-ray analysis), and thermogravimetric-derived thermogravimetric (TG-DTG) techniques were used to characterize the sample. According to EDX, the Ch-PANI-Fe2O3 hybrid composite has the following weight ratios: C 34.25%, N 0.48%, O 50.51%, and Fe 3.08%. The nanocomposite's surface was rough with pleats, which was evident from the SEM and TEM images. This surface structure likely contributed to the nanocomposite's higher dye adsorption rate (91.5%). According to SEM analysis, the proportion of Fe2O3 nanoparticles to the chitosan–polyaniline composite changed the hybrids' morphology from granular to an irregular, globular-like structure, which was supported by EDX. The results demonstrated that this polymer matrix (chitosan-PANI-Fe2O3) nanocomposite can be employed as an adsorbent for the effective removal of methyl orange dye, as well as for the removal of dye contamination from wastewater with reusability. [ABSTRACT FROM AUTHOR]

This study describes a novel route to synthesize vinyl pyridine-styrene-butadiene terpolymer rubber (VP rubber) montmorillonite clay nanocomposites by latex blending technique. The pyridine moiety of the VP rubber was modified with methyl iodide to form the pyridinium ion during latex blending. Cation exchange reaction of the pyridinium ion of the VP rubber latex with sodium montmorillonite occurred during latex stage mixing which helped to form VP rubber-montmorillonite clay nanocomposites. Coagulation of the latex-clay slurry produced nanocomposites master batch. The master batch was compounded with acrylonitrile butadiene rubber (NBR). Fourier Transform Infrared Spectroscopy (FTIR) confirmed the modification of the pyridine moiety of VP rubber. Wide angle X-ray diffraction (WAXD), scanning electron microscopy-energy dispersive X-ray spectrophotometry (SEM-EDS) and transmission electron microscopy (TEM) provided the evidences of formation of nanocomposite. Remarkable improvements in the mechanical properties were found by addition of small amount of modified clay. POLYM. ENG. SCI., 51:1675-1681, 2011. © 2011 Society of Plastics Engineers, INTRODUCTION The polymer clay nanocomposites have gained attention of researchers due to some major advantages that nanocomposites have over conventional composite. They are, lighter weight due to low filler loading [...]

In the present study, naturally occurring unfractionated bentonite clay was used to prepare styrene butadiene rubber/bentonite clay nanocomposite by latex stage blending. The bentonite clay was organo-modified by in situ resol formation by the reaction of resorcinol and formaldehyde. The latex clay mixture was co-coagulated with acid. The resulting clay masterbatch was compounded and evaluated by Fourier Transform Infrared spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDS), Scanning Electron Microscopy, Thermogravimetric analysis, and Differential Scanning Calorimetry. XRD showed that the interplanar distance of the in situ resol-modified bentonite clay increased from 1.23 to 1.41 nm for the unmodified bentonite. TEM analysis indicated partial exfoliation and/or intercalation. EDS (Si and AI mapping) of the clay revealed the nature of the dispersion in the nanocomposites vis-a-vis the conventional styrene-butadiene rubber (SBR)/bentonite clay composite. Thermogravimetric analysis was used to compare the decomposition trends of the SBR/clay nanocomposites with the SBR/ clay composite. The glass transition temperature of SBR/clay nanocomposites increased as compared with that of neat SBR. Substantial improvement in most of the other mechanical properties was also observed in case of the nanocomposites. POLYM. ENG. SCI., 49:1279-1290, 2009. [C] 2009 Society of Plastics Engineers, INTRODUCTION Carbon black (CB) and silica are widely used as reinforcing fillers in the rubber industry. About 5 million metric tons of CB and ~250,000 tons of different silica grades [...]

The combination of Darunavir (DRV) and Ritonavir (RTV) at a dose of 800/100mg has exhibit durable efficacy in both untreated and treated HIV positive patients with no observed DRV resistance-associated mutations (RAMs) and the RTV improves the pharmacokinetic profile of DRV by enhancing its bioavailability. Hence a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed and validated for the simultaneous quantification of Darunavir (DRV) and Ritonavir (RTV) in human plasma. The chromatographic separation has been accomplished on Thermo Hypersil Gold (50×4.6mm, 3μ) analytical column using isocratic elution using 0.1% Formic Acid buffer solution/Acetonitrile (50:50, v/v) at a flow rate of 0.6 mL/min. The linearity of the method ranged 150.000 ng/mL to 15000.000 ng/mL & 10.000 ng/mL to 3000.00 ng/mL for DRV & RTV respectively, using 100 μL of plasma. The method was completely validated for its sensitivity, selectivity, linearity, accuracy and precision, recovery, matrix effect, stability, and dilution integrity. The absolute recovery for DRV ranged from 79.12 to 72.71 % while for RTV it ranged from 63.39% to 66.99 %. For DRV-D9 and RTV-D6 the recovery rates are 94.19 and 80.05% respectively. The method exhibit good intra-day and inter-day precision with low % CV of less than 5.0% at each quality control level for both the analytes. The developed method has been applied successfully for pharmacokinetic study in healthy humans by oral administration of Darunavir/Ritonavir tablets 400/50 mg (dose; 02x400/50 mg) in 77 healthy male volunteers under fed condition. [ABSTRACT FROM AUTHOR]

In the treatment of hepatitis C, direct-acting antivirals (DAA) are highly efficient and well tolerated with a series of DAA combinations available for treatment. A sensitive high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for the simultaneous quantification of Sofosbuvir (SOF) and Daclatasvir (DAC) in human plasma. Sofosbuvir D6 (SOF D6) and Daclatasvir 13C2 ²H6 (DAC 13C2 ²H6) are used as internal standard (IS). Quantification for both the analytes has been attained with MS-MS detection in positive ion mode using an Acquity UPLC system (Waters) equipped with Waters Xevo TQ MS system with a Gemini NX 5μ C18 (50 × 2.0mm) (Phenomenex) column, and a gradient mobile phase consisting 5 mM Ammonium Formate buffer: Acetonitrile at a flow rate of 0.300 mL/min is used as mobile phase to separate the analytes and detection is performed by electrospray ionization technique using the mass spectrometer. Full validation is performed for bio-analytical methods with respect to linearity, precision, accuracy, selectivity, carry-over, stability and dilution integrity. Linearity is obtained over a concentration range of 10.002 -3000.488 and 10.004 -3001.218 ng mL-1 for SOF and DAC respectively by applying weighted least-squares linear regression method (1/x2). The developed method was applied successfully in bioequivalence and/or clinical studies in 48 male subjects for the simultaneous quantification of SOF and DAC. [ABSTRACT FROM AUTHOR]