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101.
Smita Kacker Jang Sub Kim Ayusman Sen 《Angewandte Chemie (International ed. in English)》1998,37(9):1251-1253
From a methyl ligand, CO, and an imine a chelating amide ligand is formed by insertion of the C=N bond into the metal–acyl bond in cationic palladium(II ) complexes (see reaction below). The cationic acylpalladium complexes are obtained from CO and readily accessible palladium starting materials. LL=diphosphane ligand. 相似文献
102.
Effect of poly (lactic acid)‐graft‐glycidyl methacrylate as a compatibilizer on properties of poly (lactic acid)/banana fiber biocomposites 下载免费PDF全文
The main aim of this study was to synthesis of poly (lactic acid) (PLA)‐graft‐glycidyl methacrylate (GMA) as well as its influence on the properties of PLA/banana fiber biocomposites. PLA‐graft‐GMA graft copolymer (GC) was synthesized by melt blending PLA with GMA using benzoyl peroxide and dicumyl peroxide as initiators. Graft copolymerization was confirmed by FTIR and 1H‐NMR spectroscopic studies. PLA/silane treated banana fiber (SiB) biocomposites with various GC concentrations were prepared by melt blending followed by injection molding techniques. The influence of GC content on the mechanical, thermal and moisture resistance properties of the composite was investigated. The addition of 15 wt% GC content in the biocomposite provided optimum tensile and flexural strength, which is attributed to the greater compatibility between fiber and PLA matrix. The thermal properties of biocomposites have been evaluated using thermogravimetric analysis which provided evidence of improved interfacial adhesion between SiB and PLA by the addition of GC. Additionally, GC enhanced the moisture absorption resistance of biocomposites. These results indicated that GC is indeed a good candidate as a compatibilizing agent to improve the compatibility in PLA/fiber biocomposites. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
103.
Multifunctional epoxy‐polydimethylsiloxane nanocomposite coatings with antifouling and anticorrosion characteristics have been developed via in situ polymerization method at different loading (1, 3, and 6.5 wt.%) of ZnO nanoparticles to cater marine applications. A detailed comparative analysis has been carried out between epoxy‐polydimethylsiloxane control (EPC) and ZnO‐reinforced coatings to determine the influence of ZnO loading on various properties. The incorporation of ZnO in EPC led to increase in root mean square (RMS) roughness to 126.75 nm and improved hydrophobicity showing maximum contact angle of 123.5° with low surface energy of 19.75 mN/m of nanocomposite coating as compared with control coating. The differential scanning calorimetry (DSC) result indicated improved glass transition temperature of nanocomposite coatings with highest Tg obtained at 83.69°C in case of 1 wt.% loading of ZnO. The increase in hydrophobicity of the system was accompanied by upgraded anticorrosion performance exhibiting 98.8% corrosion inhibition efficiency (CIE) as compared with control coating and lower corrosion rate of 0.12 × 10?3 mm/year. The Taber abrasion resistance and pull‐off adhesion strength results indicated an increment of 34.7% and 150.7%, respectively, in case of nanocomposite coating as compared with the control coating. The hardness of nanocomposite coatings was also improved, and maximum hardness was found to be 65.75 MPa for nanocomposite coating with 1 wt.% of ZnO. Our study showed that the nanocomposite coating was efficient in inhibiting accumulation of marine bacteria and preventing biofouling for more than 8 months. The developed environment‐friendly and efficient nanocomposite material has a promising future as a high‐performance anticorrosive and antifouling coating for marine applications. 相似文献
104.
105.
Madhukar S. Said Ashish A. Chinchansure Laxman Nawale Ankita Durge Ashish Wadhwani Smita S. Kulkarni 《Natural product research》2015,29(22):2080-2086
Phytochemical investigation of the methanol extract of the aerial parts of Polygonum glabrum afforded one new natural product ( ? )-2-methoxy-2-butenolide-3-cinnamate (1) along with six known compounds, β-hydroxyfriedalanol (2), 3-hydroxy-5-methoxystilbene (3), ( ? ) pinocembrin (4), sitosterol-(6′-O-palmitoyl)-3-O-β-d-glucopyranoside (5), ( ? ) pinocembrin-5-methyl ether (6) and sitosterol-3-O-β-d-glucopyranoside (7). Compound 1 showed promising in vitro anti-HIV-1 activity against primary isolates HIV-1UG070 (X4, subtype D) and HIV-1VB59 (R5, subtype C) assayed using TZM-bl cell line with IC50 in the range of 15.68–22.43 μg/mL. The extract showed TI in the range of 19.19–27.37 with IC50 in the range of 10.90–15.55 μg/mL. Compounds 1, 3 and 4 exhibited in vitro anti-mycobacterium activity against Mycobacterium tuberculosis H37Ra with IC50 values of 1.43, 3.33 and 1.11 μg/mL in dormant phase and 2.27, 3.33 and 1.21 μg/mL in active phase, respectively. Compound 4 was found to be the most active antiproliferative with IC50 values of 1.88–11.00 μg/mL against THP-1, A549, Panc-1, HeLa and MCF7 cell lines. 相似文献
106.
The present invention is to provide a novel benzothiazole-type polymerizable dye containing a urethane bond. A series of monomeric dyes have been prepared by diazotization of various 2-aminobenzothiiazole and coupled with Resorcinol. The polymeric dyes have been prepared by polycondensation of monomeric dyes with hexamethylene diisocyanate (HMDI), and they are characterized by molecular weight, non-aqueous conductometric titration, thermogravimetry analysis, IR, visible spectroscopy, and elemental analysis. The monomeric dyes have also been characterized by elemental analysis and IR spectra. The purity of all the dyes have been checked by thin layer chromatography, and their dyeing performance on nylon and polyester was assessed. The dyeing on polyester fiber had yellow, orange and pink shades with moderate to good light and wash fastness. Polymerizations of monomeric dyes with HMDI on dyed polyester have also been carried out. Color and dyeability of the polymeric dyes have been discussed by comparing them with their corresponding monomeric dyes. The percentage dye bath exhaustion and fixation on fiber have been found to be from good to very good. The dyeing of monomeric dyes showed very good color fastness properties, and their corresponding polymeric dyes showed excellent fastness to light, washing, perspiration, solvent resistance, and sublimation. 相似文献
107.
108.
Lakshmi Unnikrishnan Smita Mohanty Sanjay K. Nayak 《Journal of Thermal Analysis and Calorimetry》2014,118(1):405-416
The present work focuses on the effect of organically modified nanoclays on the fire resistance and processability characteristics of poly(methyl methacrylate) (PMMA). PMMA nanocomposite of cloisite 30B (methyl tallow bis-2 hydroxyethyl quarternary ammonium salt modifier) (C30B) was prepared by melt blending technique. A comparative study of flame retardant characteristics of virgin and filled matrix was carried out using cone calorimeter at a heat flux of 50 kW m?2, and the service temperature range was analyzed from thermogravimetric analysis. Parallel plate rheometry revealed the variation in processability as a function of C30B reinforcement and corresponding melt strength of the samples was evaluated through complex viscosity, storage, and loss modulus. Similarly, application-level modulus values were evaluated through viscoelastic properties by dynamic mechanical analysis. Supportive information for the observations from the above characterization was conducted using morphological studies by X-ray diffraction and transmission electron microscopy. 相似文献
109.
Harvey DJ Crispin M Scanlan C Singer BB Lucka L Chang VT Radcliffe CM Thobhani S Yuen CT Rudd PM 《Rapid communications in mass spectrometry : RCM》2008,22(7):1047-1052
Negative ion tandem mass spectrometry (MS/MS) spectra of three isomeric triantennary N-linked glycans provided clear differentiation between the isomers and confirmed the occurrence of an isomer that was substituted with galactose on a bisecting GlcNAc (1 --> 4-substituted on the core mannose) residue recently reported by Takegawa et al. from N-glycans released from human immunoglobulin G (IgG). We extend this analysis of human serum IgG to reveal an analogue of the fucosylated triantennary glycan reported by Takegawa et al. together with a third compound that lacked both the sialic acid and the fucose residues. In addition, we demonstrate the biosynthesis of bisected hybrid-type glycans with the galactose modification, with and without core fucose, on the stem cell marker glycoprotein, 19A, expressed in a partially ricin-resistant human embryonic kidney cell line. It would appear, therefore, that this modification of N-linked glycans containing a galactosylated bisecting GlcNAc residue may be more common than originally thought. Negative ion MS/MS analysis of glycans is likely to prove an invaluable tool in the analysis and monitoring of therapeutic glycoproteins. 相似文献
110.
Bhupendra M. Mistry Niketan S. Patel Mayank J. Patel Smita Jauhari 《Research on Chemical Intermediates》2011,37(6):659-671
The inhibition effect of 1,3,5-triazinyl urea derivatives, viz. 1-(4-cyclohexyl amino)-6-(3,4-dimethoxy phenyl ethyl amino)-1,3,5-triazin-2-yl)-3-p-tolyurea (4-CADT) and 1-(4-chlorophenyl)-3-(4-(cyclohexyl amino)-6-(3,4-dimethoxy phenyl ethyl amino)-1,3,5-triazin-2-yl) urea (4-CCADT), were evaluated against mild steel (MS) corrosion in 1 N HCl solutions using conventional weight loss, potentiodynamic polarization, linear polarization, electrochemical impedance spectroscopy, and scanning electron microscopic studies. The losses in weights of MS samples have proved that both were efficient corrosion inhibitors. The mixed mode of inhibition was confirmed by electrochemical polarizations and the results of electrochemical impedance spectroscopy have shown the changes in the impedance parameters like charge transfer resistance and double-layer capacitance to confirm the strong adsorption on the MS surface inhibition of MS. The changes in concentrations of the inhibitors were due to the adsorption of the molecules evaluated leading to the formation of a protective layer on the surface of MS. The inhibition action of these compounds was assumed to occur via adsorption on the steel surface through the active centers contained in the molecules. 相似文献