Modification with adipic

Figure 1.112 Phosphate groups can be modified with adipic acid dihydrazide in the presence of a carbodi-imide to produce hydrazide derivatives. This is a common modification route for the 5 -phosphate group of oligonucleotides.

Alkyd Resins. The phthalic alkyds class includes modifications with phenolics, maleic alkyds, adipic acid, and oils and fatty acids, and excludes modifications with styrene and rosin. The nonbenzenoid alkyd resins (maleic) class includes modifications with phenolics and oils and fatty acids and excludes modifications with styrene, phthalic alkyds, and rosin. 

Miscellaneous Resins. Under this classification the aniline-formaldehyde class excludes modifications with phenolics. The polyamide class excludes modifications of phthalic alkyds by adipic acid. 

In the particular case of polysaccharides, this reaction has been used for the modification of several types of biopolymers with different applications [28, 29]. As an example, a monoaldehyde derivative of P CD (2) was prepared from the hydrolysis of product 1 and then grafted, by a reductive amination-type reaction, onto an alginate derivative selectively modified with adipic dihydrazide (alg-ADH) (Scheme 7.5). The new polymeric materials obtained, alg-ADH intermediate and jS-CD-grafted alginate were fully characterized in terms of chemical integrity and purity by high-resolution NMR spectroscopy [30]. 

Most proteins contain an abundance of carboxylic acid groups from C-terminal functionalities and aspartic and glutamic acid side chains. These groups are readily modified with bis-hydrazide compounds to yield useful hydrazide-activated derivatives. Both carbohydrazide and adipic acid dihydrazide have been employed in forming these modifications using the carbodi-imide reaction (Wilchek and Bayer, 1987). 

The following protocol describes the modification of DNA or RNA probes at their 5 -phosphate ends with a bis-hydrazide compound, such as adipic acid dihydrazide or carbohydrazide. A similar procedure for coupling the diamine compound cystamine can be found in Section 2.2 (this chapter). 

Modification of this procedure was applied to the analysis of neutral and amino sugars in mucins [440]. A mixture of 0.2% of ethylene glycol succinate, 0.2% of ethylene glycol adipate and 1.4% of silicone XE-60 was used as the stationary phase and the analysis was effected with temperature programming at l°C/min from 150 to 205°C. Similar results could be obtained, however, on a column packed with 3% of OV-225. Partially ethylated alditol acetates were used to determine the components of polysaccharides [441],... 

BASF s Ecoflex is based on a co-polyester from terephthalic acid, adipic acid and 1,4-butanediol. The content of terephthalic acid in the polymer is approximately 42-45 mol% (with regard to the dicarboxylic monomers). Modification of the basic co-polyester lead to a flexible material, which is especially suitable for film applications. 

Michaels, A.S. Tausch, F.W., Jr. Modification of growth rate and habit of adipic acid crystals with surfactants. J. Phys. Chem. 1961, 65, mO-mi. 

Starches have been chemically modified to improve their solution and gelling characteristics for food applications. Common modifications involve the cross linking of the starch chains, formation of esters and ethers, and partial depolymerization. Chemical modifications that have been approved in the United States for food use, involve esterification with acetic anhydride, succinic anhydride, mixed acid anhydrides of acetic and adipic acids, and 1-octenylsuccinic anhydride to give low degrees of substitution (d.s.), such as 0.09 [31]. Phosphate starch esters have been prepared by reaction with phosphorus oxychloride, sodium trimetaphosphate, and sodium tripolyphosphate the maximum phosphate d.s. permitted in the US is 0.002. Starch ethers, approved for food use, have been prepared by reaction with propylene oxide to give hydroxypropyl derivatives [31]. 

The yield is reported to be improved by the following modification of the method described. In a 3-I. three-necked flask provided with a stirrer, reflux condenser, and dropping fuimel, set in asbestos-sodium silicate stoppers (5, 9), are placed 1900 cc. of 50 per cent nitric acid (1262 cc. of nitric acid, sp. gr. 1.42, diluted to 1900 cc.) and i g. of ammonium vanadate. The flask is surrounded by a water bath heated to 50-60°, and, while the mixture is stirred, 357 g. (3.5 moles) of commercial cyclohexanol is added very slowly so that the temperature of the bath is maintained at 50-60°. This requires about six to eight hours. The reaction is completed by heating the water bath to boiling until the evolution of nitrogen oxides has ceased (about one hour). The hot reaction mixture is siphoned off and allowed to cool. The yield of crude adipic acid is 372 g. (72 per cent of the theoretical amount). 

Limestone Long-Term Test with One Scrubber Loop and Without Forced Oxidation. Perhaps the most straightforward illustration of the effectiveness of adipic acid is demonstrated by a long-term limestone test conducted on the Shawnee TCA system, in which the additive was introduced without any system modifications. 

In another commercial modification, glycols, usually a mixture of ethylene and propylene glycols, are reacted with aliphatic diacids such as adipic acid to produce hydroxyl-terminated polyesters with molecular weights of approximately 2000, The hydroxyl functions are then allowed to react with aromatic... 

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