INDEX Dicarboxylic acid

Numerous references to derivatives of 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid as defoliants, herbicides, fungicides, etc., are cited in index volumes of Chem. Ahstr. since Vol. 46 (1952). 

Once the maximum injection volume is decided, the maximum sample load should be determined. In this example, the amount of the mono- and dicarboxylic acids was increased from 10 to 100 mg (of each acid) per injection in 1 mL of mobile phase. At first glance, the overlap between peaks suggested that the electronics of the refractive index detector were saturated... 

Table 22 lists four polymer series of PEIs which contain an ether, sulphone or carbonyl linked diphenyl tetracarboxylimide unit [36]. Each of the four series contains two imide and two ester groups and have four aromatic co-monomers. Polymer series 7 and 9 also contain two units of p-aminophenol in conjunction with a bicyclic aromatic dicarboxylic acid, whereas polymer series 6 and 8 are based on m-aminophenol. The Mesogenic Index correctly predicts that series 6, 8 and 9 give rise to isotropic copolymers. However, in the case of series 7, in which the variable monomer was based on ether or thioether diphenol derivatives, thermotropic phases were observed in all three cases. When all four series are viewed as a whole it is clear that an MI value of 9.5 represents a borderline condition for a mesophase to occur. It also corresponds with the minimum value for a mesophase observed in NCPT-based PEIs. 

Azelaic acid (nonanedioic acid, 1,7-heptane-dicarboxylic acid) n. HOOC(CH2)7COOH. A yellowish-white crystalline powder, derived from a fatty acid such as oleic acid by oxidation with ozone. It is an intermediate used in the production of plasticizers, polyamides and alkyd resins. Acid value, 595.5 mol wt, 188.2 mp, 106°C bp, 237°C/15mmHg. For plasticizers derived from azelaic acid. Merck Index (2001) 13th edn. Merck and Company Inc., Whitehouse Station, NJ. 

Isophthalic acid (benzene-1,3-dicarboxylic acid, IPA) n. C6H4-(COOH)2. Used instead of phthahc anhydride in making unsaturated polyester resins that, when cured, have good stifihess and resistance to heat and chemicals. Molecular weight, 166.13. Crystalline powder, which melts at 345-348° C sublimes without decomposition. Merck index, 13th edn. Merck and Co. Inc., Whitehouse Station, NJ, 2001. 

Crocetin, 8,8 -diapo-4r,4r-carotenedioic acid (carotenoid-dicarboxylic acid) is the main dyestuff produced by stamens of the saffron plant. Crocus sativus L. and by the seeds of Gardenia jasminoides Ellis (Schweppe, 1992 Merck Index, 1996). It has the Colour Index (1971) designation Cl 75100. 

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