نتایج جستجو برای: resin catalyst

تعداد نتایج: 75512  

2014
Phillip A. Lichtor Scott J. Miller

We describe mechanistic investigations of a catalyst (1) that leads to selective epoxidation of farnesol at the 6,7-position, remote from the hydroxyl directing group. The experimental lineage of peptide 1 and a number of resin-bound peptide analogues were examined to reveal the importance of four N-terminal residues. We examined the selectivity of truncated analogues to find that a trimer is s...

2013
Els De Canck Inmaculada Dosuna-Rodríguez Eric M. Gaigneaux Pascal Van Der Voort

A Periodic Mesoporous Organosilica (PMO) functionalized with sulfonic acid groups has been successfully synthesized via a sequence of post-synthetic modification steps of a trans-ethenylene bridged PMO material. The double bond is functionalized via a bromination and subsequent substitution obtaining a thiol functionality. This is followed by an oxidation towards a sulfonic acid group. After fu...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی مشهد - دانشکده دندانپزشکی 1390

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

2008
M. Kim S. O. Salley Y. S. Ng

Biodiesel, produced by the transesterification of vegetable oils or animal fats with methanol, is a promising alternative diesel fuel. In this study, a series of strong base anion resins with different basicity, pore structure, degree of cross-linking, and particle size were investigated as heterogeneous catalysts for the transesterification of soybean oil with methanol. A trace amount of CH3ON...

Journal: :Journal of prosthodontics : official journal of the American College of Prosthodontists 2009
Rosario Prisco Giancarlo Cozzolino Paolo Vigolo

PURPOSE Shrinkage of resinous die materials during setting reaction limits their acceptance, even though these materials show several advantages compared to stone die materials with respect to strength, abrasion resistance, and detail reproduction. The purpose of this study was to determine if retarding the setting reaction during polymerization and altering the base-to-catalyst ratio, as sugge...

2018
Md Nahid Pervez Faizan Shafiq Zahid Sarwar Muhammad Munib Jilani Yingjie Cai

In this study, the influence and optimization of the factors of a non-formaldehyde resin finishing process on cotton fabric using a Taguchi-based grey relational analysis were experimentally investigated. An L27 orthogonal array was selected for five parameters and three levels by applying Taguchi's design of experiments. The Taguchi technique was coupled with a grey relational analysis to obta...

Journal: :Journal of the American Chemical Society 2011
Steffen Müller Matthew J Webber Benjamin List

The first catalytic asymmetric Fischer indolization is reported. In the presence of a 5 mol % loading of a novel spirocyclic chiral phosphoric acid, 4-substituted cyclohexanone-derived phenylhydrazones undergo a highly enantioselective indolization. Efficient catalyst turnover was achieved by the addition of a weakly acidic cation exchange resin, which removes the generated ammonia. The reactio...

2009
Hui Pan Chung-Yun Hse Todd F. Shupe

Wood liquefaction was conducted using phenol as a reagent solvent with a weak acid catalyst in two different reactors: (Alma et al., 1995a.) an atmospheric glass reactor and (Alma et al., 1995b.) a sealed Parr reactor. Residues were characterized by wet chemical analyses, Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). The FT-IR spectra of the liquefied wood residu...

2013
A. R. Jones B. J. Blaiszik S. R. White N. R. Sottos

Full recovery of interfacial bond strength after complete fiber/matrix debonding is achieved with a microencapsulated solvent-based healing chemistry. The surface of a glass fiber is functionalized with microcapsules containing varying concentrations of reactive epoxy resin and ethyl phenylacetate (EPA) solvent. Microbond specimens consisting of a single fiber and a microdroplet of epoxy are te...

2012
G. RATHIKA NATH

Crosslinked functionalized polymers are highly efficient in immobilizing transition metal ions. The activity of Fe(III), Co(II), Ni(II) and Cu(II) complexes of polystyrene bound Isoxazole resin have been tested towards the decomposition of hydrogen peroxide. The decomposition reaction followed a first order dependence on the concentration of both the substrates and the catalyst. The metal compl...

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