Polymer support cellulose

R. Aparaschivei, M. Holban, V. Sunel, M. Popa, and J. Desbrieres, Synthesis and characterization of new heterocyclic compounds with potential antituberculosis activity and their immobilization on polymer supports. Cellulose Chem.Technol, 46 (5-6), 301-306, 2012. 

As for the solid support, several polymer-supported amines were tested (Fig. 2). For either the pyrazole and isoxazole synthesis, the best results were given by aniline-functionalized cellulose, which has also the advantage of a relatively low cost. For the 2-aminopyrimidine library, polystyrene-based piperazine and piperidine gave products with a much higher purity compared with other secondary non-cyclic or primary amines, hi both cases, the resins could be reused for up to four times before degradation in their behavior was observed. This reusability could be further enhanced (up to 10 cycles for cellulose-based aniline) when the microwave-assisted protocols were used. 

Chromatographic resolution is also dependent on column efficiency (i). Column efficiency is directly dependent on the nature of the support matrix and how well that support is packed in its column. Available chromatographic supports are based on dextran, agarose, polystyrene, acrylic, cellulose, silica gel and a variety of other polymers. Althou cellulosic supports are manufactured in both microcrystalline and leaded forms, most supports are beaded. Newer supports may use hybrid bead construction where the base support is coated with a second materid (e.g., dextran or silica coated with agarose). 

Various transition metal catalysts, including those based on Rh, Pt, Pd, Co, and Ti, have been bound to polymer supports—mainly through the phosphenation reaction described by Eq. 9-65 for polystyrene but also including other polymers, such as silica and cellulose, and also through other reactions (e.g., alkylation of titanocene by chloromethylated polystyrene). Transition-metal polymer catalysts have been studied in hydrogenation, hydroformylation, and hydrosilation reactions [Chauvin et al., 1977 Mathur et al., 1980]. 

In a dilferent study, the 1-4-p glucose dimer cellubiose was used as a model substrate for cellulose. Using a polymer supported ruthenium... 

Kamaike K, Hasegawa Y, Ishido Y, Efficient synthesis of an oligonucleotide on a cellulose acetate derivative as a novel polymer-support using a phosphotriester approach, Tetrahedron Lett., 29 647-650, 1988. 

Microwave-assisted synthetic methodologies can also be divided into two main categories (a) methodologies in which the reactant(s) or reagent(s) are previously covalently linked to a solnble (e.g., polyethylene glycol) or nonsoluble (e.g., Wang resin, Merrifield resin, Tenta Gel, and cellulose) polymer support, and (b) parallel, simnltaneous or sequential synthesis without use of a polymer support. 

These include membranes made of liquid electroactive substances or with electroactive substances dissolved in a suitable non-volatile, water-immiscible solvent (mediator). In early designs, the organic phase was placed between two aqueous phases in bulk or with the support of a thin, porous cellulose sheet, sintered glass, or the like. As work with these sensors proceeded, more durable polymer supports were developed, most often poly(vinyl chloride) (PVC). An electroactive... 

The unique behavior of cellulose acetate was supported recently by Koros (42). He found that of all glassy polymers Investigated, cellulose acetate had the highest solubility selectivity, defined as the ratio of the solubilities of two gases C0 and CH. Its extremely high solubility value of 8.9 measured at 35°C and 20 atm exceeds the values of the other polymers listed below by factors of... 

The chosen polymer support influences the reaction as well. Various polymer supports are described above. Studies of the hydrogenation of 2-propen-2-ol with Pd(0) catalysts showed interesting efficiency and selectivity differences dependant on the polymer resin chosen. Zharmagambetova et al. [16] studied three different organic polymer supports for Pd(0) nanoclusters and compared them to the inorganic A1203. Organic polymers included poly-2-vinlypyridine (PVP), cellulose and styrene-divinyl benzene (STY-DVB) copolymer. The cellulose and STY-DVB... 

The choice of the polymer support for the liquid membrane matrix is function of not only pore size but also of chemicid compatibili fill. For a ILM with a long lifetime, a matrix material which is inert to the liquid phase is required. The cellulose acetate/nitrate supports used in these experiments, which lost their initial structural... 

Hemicellulose is a group of polysaccharides that can be found in the plant s cell wall that surrounds the cellulose, protein, lignin, and other materials that covalently bonded, hydrogen bonds, ionic bonds and interactions hydrophoby [35]. In plants, hemicellulose is a second polymer after cellulose that abundance in wood and cereals. It consists of approximately one-quarter to one-third of the plant material. This amount varies according to the type of plants, such as corn steins [28.0%], wheat straw [38.8%), rice straw [35.8%), and rye straw [36.9%). Hemicellulose serves as a supporter to cell wall and as an adhesive between single cells In plants [10]. 

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