نتایج جستجو برای: anhydride maleic

تعداد نتایج: 5633  

Journal: :Bioresources 2023

The chemical modification of wood can be directed to improve various properties, e.g., the dimensional stability, hardness and/or durability against weathering. In this study, a Romanian softwood species Abies alba Mill. was treated and chemically modified using two cyclic acid anhydrides, i.e., maleic succinic, its interfacial properties relative unmodified wood. Structural changes, with focus...

2009
A.S.W. Chan M. Groves C. Malardier-Jugroot

Our research focuses on the characterization of the association and the properties in aqueous solution of nanostructures, particularly on nanotubes composed of amphiphilic alternating copolymers. These copolymers constitute a pH sensitive hydrophilic group (maleic anhydride) alternating with a hydrophobic group. To investigate the role of the nature of the hydrophobic groups on the association,...

2017
Matheus Poletto

In this work, post-consumer polypropylene and wood flour from Pinus elliottii were used to produce wood plastic composites. The effect of polypropylene grafted with itaconic acid used as a coupling agent on mechanical properties, thermal stability and morphology of the composites was investigated and compared with the composite developed with polypropylene grafted with maleic anhydride, commonl...

1997
Vladimir Ondrus

New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino acids 3a-f in the presence of Et3N with release of furan to give the requisite novel chiral imides 4a-f in good to moderate yields. The stereosele...

Journal: :Chemical communications 2002
Yu-Lei Zhu Hong-Wei Xiang Gui-Sheng Wu Liang Bai Yong-Wang Li

A coupling process of the hydrogenation of maleic anhydride and the dehydrogenation of 1,4-butanediol has been invented for the synthesis of gamma-butyrolactone over a Cu-Zn catalyst, realizing optimal hydrogen utilization and better energy efficiency.

2009
Ruxanda Bodîrlău Carmen Alice Teacă Iuliana Spiridon

Chemical modification of hardwood sawdust from ash-tree species was carried out with a solution of maleic anhydride in acetone. Wood polymers, lignin, and cellulose were isolated from the wood sawdust and modified by the same method. Samples were characterized by Fourier transform infrared spectroscopy (FTIR), providing evidence that maleic anhydride esterifies the free hydroxyl groups of the w...

2015
ILHAN UZUN

Firstly, chitin was modified via ring-opening reaction with maleic anhydride in lithium chloride/ N,N-dimethylacetamide. Then, both chitin and chitin modified with maleic anhydride (CMA) were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) method, ultraviolet-visible (UV-Vis) spectroscopy, and scanning electron microscopy (SEM). Thermogravimetric analysi...

2005
M. Hävecker N. Pinna K. Weiß H. Sack-Kongehl R. E. Jentoft D. Wang M. Swoboda M. Niederberger J. Urban D. S. Su R. Schlögl

We studied unsupported VxOy nanoparticles prepared by a novel non-aqueous route in the selective oxidation of n-butane to maleic anhydride. The evolution of the electronic and geometric structure of the material was characterized by X-ray photoemission spectroscopy, electron energyloss spectroscopy, transmission electron microscopy and electron diffraction before and after the reaction at diffe...

Journal: :Acta pharmaceutica 2005
Marijana Zovko Monika Barbarić Branka Zorc Anita Hafner Jelena Filipović-Grcić

Two types of polymer-drug conjugates were synthesized starting from styrene-maleic acid anhydride copolymer (SMA). Fenoprofen and gemfibrozil were chosen as model drugs because of their short plasma half lives. Both drugs were first converted to their 2-aminoethylamides, which possess free amino groups capable of reacting with SMA anhydride rings. By modifying the degree and type of substitutio...

2015

The effect of Ni doping (1%, 2%, and 5%) on vanadium phosphate catalysts prepared via VOPO4·2H2O was described and discussed. At low levels, the Ni dopant significantly enhanced the amount of the active lattice oxygen species O− and lowered the reduction peak temperature corresponding to the reduction of V5+ and V4+ phases. A combination of powder X-ray diffraction, temperature-programmed reduc...

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