Cellulose derivatives, “aminated

Unit cells of pure cellulose fall into five different classes, I—IV and x. This organization, with recent subclasses, is used here, but Cellulose x is not discussed because there has been no recent work on it. Crystalline complexes with alkaU (50), water (51), or amines (ethylenediamine, diaminopropane, and hydrazine) (52), and crystalline cellulose derivatives also exist. Those stmctures provide models for the interactions of various agents with cellulose, as well as additional information on the cellulose backbone itself. Usually, as shown in Eigure la, there are two residues in the repeated distance. However, in one of the alkah complexes (53), the backbone takes a three-fold hehcal shape. Nitrocellulose [9004-70-0] heUces have 2.5 residues per turn, with the repeat observed after two turns (54). 

The hemocompatibility of poly(amido-amine) polyelectrolyte complexes was recently studied by Xi, Zhang and coworkers [499, 500]. The poly(amido-amine) was based on piperazine and methylene bisacrylamide, and the polyelectrolyte complexes were obtained from the reaction of poly(amido-amine) with alginic acid, carboxymethyl cellulose or poly(methacrylic acid). Complexes of polyamido-amine and alginic acid with a 1 2 ratio gave the best hemocompatibility. Finally, the blood compatibility of polyelectrolyte complexes based on anionic and cationic cellulose derivatives were studied by Ito et al. [338], In vivo, good blood compatibility of complexes formed from quaternary hy-droxyethyl cellulose reacted with carboxymethyl cellulose and cellulose sulfate was observed. 

Many types of derivatives of cellulose have been used to prepare affinity adsorbents.51 0-(2-Aminoethyl)cellulose and 0-(carboxy-methyl)cellulose can be coupled to carbohydrates bearing carboxyl or primary amino groups by the carbodiimide method.52,53 Cellulose derivatives bearing amino groups can be coupled to reducing carbohydrates by reductive-amination reactions25 in which the Schiff base produced in the initial reaction is reduced with sodium cyanoborohy-dride.54... 

Soon after the application of sulfonylation to sugar derivatives, the action of hydrazine17 on l,2 5,6-di-0-isopropylidene-3-0-tosyl-D-glucose, and of ammonia297 on l,2 3,4-di-0-isopropylidene-6-0-tosyl-D-galactose, was found to proceed similarly. Immediate application of this principle to preparation298 of aminated cellulose derivatives,86299 of possible... 

Besides the cellulose structures I-IV and their subclasses, cellulose forms a variety of crystalline complexes. Soda celluloses were mentioned above, and there is an extensive array of complexes with amines [236]. Soda cellulose IV [237] is actually a hydrate of cellulose and contains no sodium (historically, cellulose hydrate meant cellulose II, which is now known to contain no water ). Many cellulose derivatives such as the nitrate (see above) and the triacetate [238] also give diffraction patterns. The most recent analysis of triacetate I shows a single-chain unit cell [239]. 

Mishnick and co-workers have developed several techniques for determining the positions of substitutions on monosaccharide units and distribution of substituents along deriva-tized polysaccharide chains, primarily cellulose derivatives. Examples are found in references [61,62,63,64,65,66,67,68,69,70]. An important method involves perdeuteromethylation followed by partial acid-catalyzed hydrolysis, then reductive amination with propylamine, and finally permethylation to yield completely O- and A-alkylated charged oligosaccharides that are analyzed by MALDI-TOF-MS [68,70]. Statistical methods are then applied. 

ECTEOLA-cellulose. (epichlorohydrin triethanolamine cellulose). A dry, powdered cellulose derivative containing tertiary amine groups. 

Cellulose derivatives can be cross linked with oxalyl chloride in p-dioxane solution containing a tertiary amine as the catalyst.181 The product from cellulose acetate swells to a gel in a variety of organic solvents. 

H. Baumann, A. Richter, D. Klemm, and V. Faust, Concepts for preparation of novel regioselective modified cellulose derivatives svdfated, aminated, carboxy-lated and acetylated for hemobompatible ultrathin coatings on biomaterials, Macromol. Chem. Phys., 201 (2000) 1950-1962. 

Amphotropic behavior can be found for a large number of different chemical structures. Additional information is given in other chapters of this Handbook. Typical classes of amphotropic materials are for instance classical soaps (see lyotropics), transition metal soaps (see metallomesogens), viologens, quartemary amines and other ionic surfactants (see lyotropics), block copolymers (see polymer liquid crystals), cellulose derivatives (see cellulose liquid crystals) and partially fluorinated paraffines, diols, peptide surfactants, lecithins, lipids, alkylated sugars and inositols, naturally occurring glycosides and silanols, which are discussed in this chapter. 

CHIRALCEL OD/OJ cellulose derivative CHIRALPAK AD/AS/H amylose derivative CHIRALPAK lA immobihsed amylose CHIRALPAK IB immobilised cellulose CROWNPAK 18-crown 6 type ether Particular separations versatile broad range broad range for amino acids and orimarv amines DIACEL... 

AMINES Uformite MX-61 (Rohm and Haas). CELLULOSE DERIVATIVES ... 

Applying reactions, deoxyceUulose products are available where the hydroxyl groups of the AGU are partially or completely replaced by other functional groups, that is, the reaction takes place at the carbon atoms. Considraable interest has found halodeoxycelluloses as starting material for reactions yielding cellulose derivatives with intaest-ing properties (Table 16.9) [47-52]. Recent studies comprise the introduction of amine/ammonium functions either by introduction of azide moieties and subsequent reduction or by using various di- and tti-anrines for the reaction. 

A few methods are known for attaching amino acid units to the hydroxyl group of polysaccharides, including the reaction of acid chlorides of amino acids with polyhydroxy polymers in a basic medium,2 or with aminated cellulose derivatives,or amine derivatives, 2 or by simple esterification of the polyhydroxy polymer with N-acetyl amino acids. Single amino acid substituents can not be considered grafts, at best these derivatives could be used as macroinitiators. 

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