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81.
This investigation reports a one pot preparation of poly(meth)acrylate grafted EPDM via reverse ATRP and evaluation of their physical and mechanical properties. The graft copolymerization of 2-ethylhexyl acrylate and methyl methacrylate was carried out from EPDM using reverse ATRP in toluene at 90 °C using CuBr2 as catalyst in combination with PMDETA as ligand and AIBN as thermal initiator. The grafted EPDMs were separated from the reaction mixture, purified and then characterized by FT-IR, 1H NMR, DMA and TGA analyses. Surface energies and tensile properties were evaluated by Goniometer and UTM respectively. Acrylate grafted EPDMs showed better thermal stability, better tensile property, whereas methacrylate grafted EPDMs showed higher surface energy and better oil resistance property than the pristine EPDM. Surface morphologies of grafted EPDMs were analyzed by AFM and SEM analyses. This one pot grafting approach led to very high grafting percentage without undesirable homopolymerization and gelation. 相似文献
82.
Minati Chatterjee Ranjan Sen Mrinmay Pal Milan Naskar Mukul Paul Shyamal Bhadra Kamal Dasgupta Dibyendu Ganguli Tarun Bandyopadhyay Aharon Gedanken Renata Reisfeld 《光学学报》2003,23(Z1)
Rare earth (RE) doped optical fibres were fabricated by using RE oxides coated silica nanoparticles. The fibre properties are comparable to those prepared by conventional techniques. The process offers better control over RE incorporation and homogeneity in the preform. 相似文献
83.
David E. Portlock Dinabandhu Naskar Laura WestRyszard Ostaszewski Jack J. Chen 《Tetrahedron letters》2003,44(27):5121-5124
Five-dimensional libraries of dipeptide amides are readily prepared using a solid-phase tandem Petasis-Ugi multi-component condensation protocol on either a RINK amine or Universal RINK isonitrile resin. The method is practical and can be automated to prepare a large number of compounds useful for high throughput biological screening. 相似文献
84.
Dinabandhu Naskar Amrita RoyWilliam L. Seibel Laura WestDavid E. Portlock 《Tetrahedron letters》2003,44(33):6297-6300
The synthetic utility of a tandem Petasis-Ugi multi-component condensation and 1,3-diisopropylcarbodiimide condensation reactions have been employed to efficiently prepare two to four-dimensional libraries of aza-β-lactams. 相似文献
85.
Chanda K Maiti B Yellol GS Chien MH Kuo ML Sun CM 《Organic & biomolecular chemistry》2011,9(6):1917-1926
An efficient soluble polymer-supported method has been developed for the parallel synthesis of substituted benzimidazole linked benzoxazoles using focused microwave irradiation. The key step involves the amidation of 4-hydroxy-3-nitrobenzoic acid with polymer-immobilized o-phenylenediamine. Application of mild acidic conditions promoted the ring closure to furnish the benzimidazole ring. After hydrogenation of the nitro-group to amine, the resulted polymer conjugates underwent efficient ring closure with various alkyl, aryl and heteroaryl isothiocyanates to generate the polymer-bound benzimidazolyl benzoxazoles. The polymer-bound compounds were finally cleaved from the support to furnish benzimidazole linked benzoxazole derivatives. The efficacy of the resultant angular bis-heterocyclic library was studied against vascular endothelial growth factor receptor (VEGFR-3). The preliminary screening of these novel compounds exhibits moderate to high inhibition (IC(50) = 0.56-1.42 μM). This protocol provides an easy access to novel angular bis-heterocycles which have potential for the discovery of novel leads for targeted cancer therapeutics. 相似文献
86.
R. Rajeshbabu U. Gohs K. Naskar V. Thakur U. Wagenknecht G. Heinrich 《Radiation Physics and Chemistry》2011,80(12):1398-1405
Thermoplastic vulcanizates (TPVs) based on 50/50 composition of PP/EOC blend were prepared by electron induced reactive processing. To facilitate dynamic crosslinking in the PP/EOC blend, a 1.5 MeV electron accelerator was directly coupled to an internal mixer to induce chemical reactions via high energy electrons under dynamic conditions of melt mixing process. This kind of setup has been conceptualized for the first time in our laboratory and termed as electron induced reactive processing (EIReP) technique. Mechanical, morphological, and rheological properties of PP/EOC TPVs were studied with special reference to the exposure time (16–64 s) keeping absorbed dose (100 kGy) and electron energy (1.5 MeV) invariable. Chain scission dominates over chain crosslinking in both EOC as well as PP phases with the increase in exposure time. The primary factor is found to be the predominance of oxidative degradation during electron induced reactive processing in air atmosphere. The above observation was supported by Fourier Transform Infrared analyses and gel content values. Furthermore, it was found that mechanical properties depend not only on the extent of degradation in the blend system but also on the state and the mode of dispersion of the blend components. 相似文献
87.
Barnali Dutta Sujay Kr. Nayek Faizuddin Ahmed 《International journal of quantum chemistry》2024,124(1):e27267
A study on the effect of point like global monopole topological defects on the energy eigenvalues of the diatomic molecules , , , embedded with Shifted Deng–Fan Oscillator Potential under the influence of Aharonov–Bohm flux field has been made here. Asymptotic Iteration Method (AIM) is used to find out the bound state solutions for arbitrary states by solving the non-relativistic Schrödinger equation. A Pekeris-type approximation has been used to approximate the centrifugal barrier term. It is observed that, energy levels of the diatomic molecules is significantly affected by the global effects of the point like global monopole, flux field and effective potential field. 相似文献
88.
CuCl catalyzes efficient synthesis of aminoindolizine scaffolds by one-pot reactions in PEG of pyridine- or quinoline-2-carboxaldehydes with secondary amines and terminal alkynes via tandem C-H activation, coupling, and cyclization reactions. The reactions are easy to perform, atom-economic, environment friendly, broad in scope, and allow the generation of a number of biologically potent aminoindolizine frameworks from readily accessible starting materials. 相似文献
89.
90.
Shuvankar Naskar Prof. Dr. Jens Müller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16214-16218
By applying caged thymidine residues, DNA duplexes were created in which HgII-mediated base pair formation can be triggered by irradiation with light. When a bidentate ligand was used as the complementary nucleobase, an unprecedented stepwise formation of different metal-mediated base pairs was achieved. 相似文献