Cellulosics, modified

Cellulose, modified by the introduction of ionic groups, is available in paper form or as a powder for use in TLC and is particularly useful for the separation of macromolecules and biological materials. Cation exchangers are produced by introducing acidic groups, e g. —0CH2S03H (sulphomethyl,... 

The chain overlap parameter has been very successful at superimposing the data from the systems without hydrophobic modification, producing the continuous curve. However, it is clear from Flynn s work that once the hydrophobes are introduced into the polymer the viscosity rapidly increases at lower values of the chain overlap parameter. Increasing the mole percentage of hydrophobes also increases the viscosity at lower values of the chain overlap parameter. The position and number of the hydrophobes on a chain are important in determining the structure that forms and the onset of the increase in viscosity. The addition of side chains to hydroxyethyl cellulose modifies the network modulus as a function of concentration. This is discussed further in Section 2.3.4. 

Cellulose, Microcrystalline, 95 Cellulose, Modified, (SI) 14 Cellulose, Powdered, 96 Centrifuge, Defined, 4 Ceric Ammonium Nitrate TS, 851 Ceric Sulfate, 0.01 N, 856 Ceric Sulfate, 0.1 N, 856 Chamomile Oil, English Type, 98, 578 Chamomile Oil, German Type, 98, 578 Chamomile Oil, Hungarian Type, 98 Changes in Format to the Food Chemicals Codex, Fourth Edition, xv Chemical Formulas and Atomic Weights, 3... 

Co(acac)3 is frequently used as a probe for enantioseparation efficiency of col-umns " . A monolytic capillary silica gel column was functionalized with methacrylate residues in two steps, as shown in equation and then it was impregnated with cellulose or amylose (51a, b) which was modified so that 30% of the R groups were the methacrylate group 52 and the rest was identical to R (53). For further stability of the column, the polymeric modifier was immobilized on the silica gel by in situ copolymerization with an olefinic monomer such as 2,3-dimethylbutadiene. Only the column containing cellulose modified as in 51a was able to separate the Co(acac)3 racemic mixture, whereas neither cellulose nor amylose modified as in 51b did, although they were successful in resolving other racemic mixtures ° °. ... 

The adsorption mechanism of mercury by modified cellulose seems to be related to the number of proton present in solution. This kind of phenomenon was already observed by Miyamoto [8] who studied mercury adsorption by keratine gel and by Marchant [17] who utilized cellulose modified with thiol groups. 

The present book is a follow-up of a previous one with the title Analytical Pyrolysis of Natural Organic Polymers published by Elsevier as vol. 20 in the series Techniques and Instrumentation in Analytical Chemistry. In addition to the discussion on pyrolysis of various natural polymers, the previous book contains information on chemically modified celluloses, modified starches, etc. For this reason, the present book does not include synthetically modified natural polymers. Information on the pyrolysis process and pyrolytic techniques in general also can be found in the book on natural polymers. 

Glyceraldehyde is used in nutrition in the preparation of polyesters and adhesives as a cellulose modifier and in the tanning of leather. It is also used in biochemical research the two isomers are used as reference chemicals because each is one of the... 

Use Intermediate, especially for quaternary ammonium compounds dehydrohalogenating catalyst corrosion inhibitor acid neutralizer potting compounds adhesives cellulose modifier. 

See cellophane cellulose acetate cellulose, modified nitrocellulose rayon carboxymethylcellulose. 

Use Biochemical research intermediate nutrition prepraration of polyesters, adhesives cellulose modifier leather tanning. 

Intermolecular crosslinking of cellulose by formaldehyde has also been established by chemical means. Rao, Roberts and Rowland isolated formaldehyde crosslinked constituents from ball-milled cotton cellulose modified with formaldehyde in a swollen state and... 

Most commercially prepared plates are 20 cm x 20 cm and are coated with a 0.25-mm-thick layer of adsorbent. The plate backing is usually glass, plastic, or aluminum. The coating is usually silica gel (Si02) or alumina (AljOj) cellulose, modified cellulose, kieselghur, ion exchange resins, and octyldecylsilane on glass beads are used less often. 

The optimum temperature for growth of this organism was said to be 60°-68° C. Borne of the carbohydrates which it fermented in their experiments were resistant celluloses, modified resistant celluloses, hemicelluloses, starches, sugars, etc. 

Sorbents based on cellulose modified with weak anion exchange groups were also used for preconcentration of PGE. Since the analytes are more weakly retained by these materials, they can be elueted more easily with mineral acids or thiourea solution (Godlewska-Zylkiewicz et al. 2000). The method worked well for determination of Pd with ETAAS, but an unidentified interference, probably caused by deteriorating resin, prohibited Pd-quantification with ICP-MS. 

As shown in Table 6.1, the water absorption of methyl cellulose-modified systems increases with rising polymer-cement ratio. By contrast, the water permeation decreases with an increase in the polymer-cement ratio, as represented in Fig. 6.2.f l Methyl cellulose causes a considerable swelling due to water absorption, and seals capillary cavities in the modified systems, and hence decreases permeability. 

Table 6.1 Properties of Methyl Cellulose-Modified Pastes and Mortars. 5 1 1... 

Figure 6.2 Polymer-cement ratio vs. relative water permeation of methyl cellulose-modified mortars.

Figure 6.3 Relationship between dry curing period and drying shrinkage of methyl cellulose- modified mortars.

Properties Dens. 1.25 m.p. 98 C flash pt. (COC) 260 C ref. index 1.577 Uses Piasticizer for PVC, PVAc, VCA, PS, cellulosics modifier for coatings pharmaceutical raw material film-former in cosmetics dispersant for cosmetics, pharmaceuticals in food-pkg. adhesives Regulatory FDA 21 CFR 175.105... 

Toxicology LD50 (oral, rat) 265 mg/kg, (skin, rabbit) 1660 mg/kg poison by ing. mod. toxic by inh., skin contact corrosive severe skin and eye irritant TSCA listed Precaution Flamm. exposed to heat or flame Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx Uses Intermediate dehydrohalogenating catalyst corrosion inhibitor acid neutralizer potting compounds adhesives paints cellulose modifier catalyst for rigid PU foam, polyester resins epoxy resin curative, accelerator... 

Synonyms 2,3-Dihydroxypropanal Glyceric aldehyde Glycerose Empirical CsHeOs Formula HOCH2CH2OCHO Properties Tasteless cryst. insol. in benzene, petroleum ether, pentane m.w. 90.09 m.p. 145 C Toxicology LDLo (oral, rat) 5 g/kg Uses Biochemical research intermediate nutrition preparation of polyesters adhesives cellulose modifier leather tanning... 

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