Carboxymethyl poly

S.Y. Nam, H.J. Chun, Y.M. Lee, Pervaporation separation of water-isopropanol mixtures using carboxymethylated poly(vinyl alcohol) composite membranes, J. Appl. Polym. Sci. 72 (1999) 241— 249. 

Carboxymethylated poly(vinyl alcohol) Aminoacetalyzed poly(vinyl alcohol) 152-157... 

Table 12. Mechanical properties of the complexes of aminoacetalized poly(vinyl alcohol) (PC)-carboxymethylated poly(vinyl alcohol) (PA) and sulfonated poly(vinyl alcohol) (PSA)-poly(vinyl alcohol) acetalized with 2,2-diethoxyethyltrimethylammonium (PTC)4415... 

Zalipsky, S. and Barany, G., Eacile synthesis of a-hydroxy co-carboxymethyl poly(ethylene oxide). Journal of Bioactive and Compatible Polymers, 5(2), 227, 1990. 

Garrett, Q., Chatelier, R.C., Griesser, H.J., Milthorpe, B.K. Effect of charged groups on the adsorption and penetration of proteins onto and into carboxymethylated poly (HEMA) hydrogels. Biomaterials 19(23), 2175-2186 (1998)... 

Table I. Immobilisation of heparin and ES-HS onto 10 different polymers. Poljnners are functionalised either with carboxyl or amino groups before GAG type 2 immobilisation. Roman numbers refer to the immobilisation concepts in Figure 1. Abbreviations PVC polyvinyl chloride, PU polyurethane, PE polyethylene, PP polypropylene, PA 6.6 polyamide 6.6, PESU polyethersulphone, PS polystyrene, PC polycarbonate, ANPAU N-(4-azido-2-nitrophoiyl)-l 1-aminoundecanoic acid, CM-PEG carboxymethyl-poly hylene...

Lead azide is not readily dead-pressed, ie, pressed to a point where it can no longer be initiated. However, this condition is somewhat dependent on the output of the mixture used to ignite the lead azide and the degree of confinement of the system. Because lead azide is a nonconductor, it may be mixed with flaked graphite to form a conductive mix for use in low energy electric detonators. A number of different types of lead azide have been prepared to improve its handling characteristics and performance and to decrease sensitivity. In addition to the dextrinated lead azide commonly used in the United States, service lead azide, which contains a minimum of 97% lead azide and no protective colloid, is used in the United Kingdom. Other varieties include colloidal lead azide (3—4 pm), poly(vinyl alcohol)-coated lead azide, and British RE) 1333 and RE) 1343 lead azide which is precipitated in the presence of carboxymethyl cellulose (88—92). 

The main polymers used as thickeners are modified celluloses and poly(acrylic acid). Several different modified celluloses are available, including methyl-, hydroxypropyl methyl-, and sodium carboxymethyl-cellulose and their properties vary according to the number and distribution of the substituents and according to relative molar mass of the parent cellulose. Hence a range of materials is available, some of which dissolve more readily than others, and which provide a wide spread of possible solution viscosities. Poly(acrylic acid) is also used as a thickener, and is also available in a range of relative molar masses which give rise to give solutions of different viscosities. 

Synthetic examples include the poly(meth)acrylates used as flocculating agents for water purification. Biological examples are the proteins, nucleic acids, and pectins. Chemically modified biopolymers of this class are carboxymethyl cellulose and the lignin sulfonates. Polyelectrolytes with cationic and anionic substituents in the same macromolecule are called polyampholytes. 

Sodium carboxymethyl cellulose Poly(vinyl pryidine)... 

Cellulose disintegrants have been studied as insoluble matrices for sustained release tablets. Anionically charged carboxymethyl cellulose (sodium salt) was found to be inferior to methyl cellulose and poly(vinyl pyrollidone) as a binding agent for oxyphenbutazone tablets [291], However sodium carboxymethyl cellulose has found application as a dispersing agent for ibuprofen microspheres... 

The bioadhesive characteristics of tablets for oral use made from modified starch, poly(acrylic acid), polyethylene glycol) and sodium carboxymethyl cellulose were recently investigated [406]. In this work, the force and energy adhesion were determined in vitro, and maximum adhesion times were evaluated in vivo in humans [406], In the in vitro, studies, the poly(acrylic add) gave the best performance, however in vivo bioadhesion was not strongly correletated with... 

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. 

Synthesis of monomers for the preparation of the methyl ester polyisocyanides begin with a-amino acid esters. These polyisocyanides were developed to yield optically active polymers which could be characterized first as non-electrolytes, and, after hydrolysis, as polyelectrolytes in aqueous media. As predicted, poly[a(carboxymethyl) alkyl isocyanides] are soluble in various solvents. Unfortunately, a low ceiling temperature, some instability to alkali and especially to... 

The poly[a(carboxymethyl)alkyl isocyanides] are also soluble polyisocyanides, but exhibit a time dependent-viscosity behavior. The description of this phenomenon is given after the following sections in which viscometry in di-and trichloroacetic acid is described. 

Fig. 11. Concentration dependence of reduced viscosities of various unfractionated samples of poly[(a-carboxymethyl)ethyl isocyanide] in 1,2-dichloroethane at 30° C (9)...

The viscosity behavior of poly[(a-carboxymethyl)ethyl isocyanide] may be studied in neutral organic solvents. The concentration dependence of its reduced specific viscosity in 1,2-dichloroethane is shown in Fig. 11. A linear dependence indicates that the coefficients of higher concentration terms of the usual virial equations are negligibly small—a case which should be found with molecules, such as stiff rods, that give few intermolecular entanglements in dilute solution. 

The unusually high observed initial intrinsic viscosity was at first thought to be due to molecular aggregation of polymer chains, made possible by presumed interaction of the carboxyl ester groups. Molecular association is known in many polymeric systems, but in those cases the association process is also apparent in osmometric data. No evidence of association is observed in the osmometric data of poly[(a-carboxymethyl)ethyl isocyanide]. Moreover, it would be expected that, if molecular association would have taken place, different values of [>7] would have been observed upon changing of solvents. Such change is not observed upon addition of triethyl amine (i.e. 10% volume) to 1,2-dichloroethane, or by solvent change to p-dioxane. 

The viscometric data of poly[(a-carboxymethyl)ethyl isocyanide] in simple solvents surprisingly also show a very slow temperature-dependent viscosity decay phenomenon (8,9). Still more surprising, gel permeation chromatography shows no evidence of changes in the hydrodynamic volume over the time periods of decay. 

Thermogravimetry and gel permeation chromatography data show that poly[(a-carboxymethyl)alkyl isocyanides) also undergo degradation which becomes rapid at temperatures above 50° C. However, at room temperature this process is sufficiently slow so as not to confuse the observations reported above. Other polyisocyanides, including copolymers of the above with a-phenylethyl isocyanide, are being synthesized which may prove less complex subjects of study of the phenomena described above. 

Poly[(a-carboxymethyl)ethyl isocyanide] may be saponified with sodium hydroxide in methanol at room temperature in 5 days or at reflux in 20hrs, attended by discoloration. Aqueous solutions of the isolated salt do not show viscosities expected of polyanions. Attempt to isolate the free polycarboxylic acid by acidification is accompanied by decarboxylation, which is to be expected on the basis of its chemical structure (55). 

Polyisocyanides degrade thermally over a wide range of accessable temperatures (Fig. 12). The poly[a(carboxymethyl)alkyl isocyanides] show incipient decomposition at 50° C, but polyarylisocyanides exhibit some temperature resistance. 

Macromolecular chemistry covers a particularly wide field which includes natural polymeric material, such as proteins, cellulose, gums and natural rubber industrial derivatives of natural polymers, such as sodium carboxymethyl cellulose, rayon and vulcanised rubber and the purely synthetic polymers, such as polythene (polyethylene), Teflon (polytetrafluoroethylene), polystyrene, Perspex (poly (methyl... 

Radioimmunoassay methods have been developed for pentazocine which were shown to be both sensitive and specific. An early method utilized tritium labeled pentazocine at 1.5 Ci/mmol. Antibodies were produced in rabbits to both an azoben-zoic acid and a carboxymethyl derivative of pentazocine coupled by carbodiimide condensation to poly-L-lysine. No cross reactivity was found for metabolites and benzomorphan analogs to the former antiserum with only conjugated pentazocine crossreacting with the latter antiserum (62). 

Terbutaline, benzoin Charged polyacrylamide gel 50 mg/ml Poly P-cyclo-dextrin, 50 mg/ml carboxymethyl P-cyclo-dextrin, 5% Tween 20, 200 mM Tris, 300 m AT boric acid buffer, pH 9.0 700 mm x 75 pm i.d. 350 mm effective length, chiral separation 160... 

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