Amine-modified polymer

Liang, Z.-M., Yin, J., and Xu, H. J. Polyimide/montmorillonite nanocomposites based on thermally stable, rigid-rod aromatic amine modifies, Polymer (2003), 44, 1391-1399. 

Poly(hydroxystyrene-co-methyl methacrylate) [poly(HS-co-MMA)] can be modified to add amino groups onto the side chain of the polymer. The amine-modified polymer can react with two classes of active compounds the first class is aldehydes such as vanillin, p-hydroxybenzaldehyde, P-chlorobenzaldehyde and anisaldehyde, and the second class is phenolic esters such as p-hydroxymethylbenzoate, 2,4-dihydroxymethyl benzoate and methyl salicylate. 

Blends based on polyolefins have been compatibilized by reactive extrusion where functionalized polyolefins are used to form copolymers that bridge the phases. Maleic anhydride modified polyolefins and acrylic acid modified polyolefins are the commonly used modified polymers used as the compatibilizer in polyolefin-polyamide systems. The chemical reaction involved in the formation of block copolymers by the reaction of the amine end group on nylon and anhydride groups or carboxylic groups on modified polyolefins is shown in Scheme 1. 

Potyimides obtained by reacting pyromellitic dianhydride with aromatic amines can have ladder-like structures, and commercial materials are available which may be used to temperatures in excess of 300°C. They are, however, somewhat difficult to process and modified polymers such as the polyamide-imides are slightly more processable, but with some loss of heat resistance. One disadvantage of polyimides is their limited resistance to hydrolysis, and they may crack in aqueous environments above 100°C. 

A great variety of suitable polymers is accessible by polymerization of vinylic monomers, or by reaction of alcohols or amines with functionalized polymers such as chloromethylat polystyrene or methacryloylchloride. The functionality in the polymer may also a ligand which can bind transition metal complexes. Examples are poly-4-vinylpyridine and triphenylphosphine modified polymers. In all cases of reactively functionalized polymers, the loading with redox active species may also occur after film formation on the electrode surface but it was recognized that such a procedure may lead to inhomogeneous distribution of redox centers in the film... 

The efficacy of CE separation depends considerably on the type of capillary. Fused-silica capillaries without pretreatment are used most frequently. Its outside is coated with a polymer layer to make it flexible and to lessen the occurrence of breakage. The polymer coating has to be dissolved with acid or burned away at the detection point. Capillaries with an optically transparent outer coating have also found application in CE. The objectives of the development of chemically modified capillary walls were the elimination of electro-osmotic flow and the prevention of adsorption on the inner wall of the capillary. Another method to prevent the adsorption of cationic analyses and proteins is the use of mobile phase additives. The modification of the pH of the buffer, the addition of salts, amines and polymers have all been successfully employed for the improvement of separation. 

With these substrates we have made more extensive rate studies and determined more specifically defined kinetic parameters. If each amine-containing binding domain D on the modified polymer binds aspirin A reversibly in a step preceding aminolysis, the kinetic steps may be represented by... 

Cold-rolled steel panels were purchased from Advanced Coating Technologies, Inc. (Hillsdale, Michigan). Silane chemicals (methylsilane, trimethylsilane, and tetramethylsilane) were purchased from Petrarch Systems, Inc. The silane plasma-deposited steel was then dip-coated with a polymer film 10-25 pim thick. The polymer coating resins used were silane-modified polymers with functionalities such as hydroxyl, acrylate, or amine. 

The modified polymer was assayed for reactive amines and thiols using fluo-rescamine and 5,5 -dithiobis(2-nitrobenzoic acid) (Ellman s reagent), respectively. For amine determination, a 10-mg/mL solution of fluorescamine in... 

For the purposes of electrophoretic deposition, 1-methylpiperazine, a secondary-tertiary diamine, was chosen to attach a tertiary amine group to the polymer chain (see Figure 3). The stoichiometric ratio of amine to imide groups was adjusted in the range 0.25 to 0.65, and a ratio of 0.4 was found to be about optimum. The tertiary amine group was then available to be protonated with acid, forming the positively charged substituent requisite for emulsification and cathodic electrophoretic deposition. Both acetic acid and lactic acid were used successfully at a level stoichiometrically equivalent to that of the amine modifier. 

Initial experiments on the elimination of amine from the modified polymer by refluxing in DMAC were performed by J. Poler. 

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