Dicarboxylic acids aliphatic, 290 Table

Aliphatic framework molecules most common in organic acids include alkanes (saturated hydrocarbons) and alkenes (unsaturated hydrocarbons). These saturated and unsaturated aliphatic carboxylic acids may be acyclic (straight or branched chains) or alicyclic (aliphatic rings). Acyclic aliphatic monocarboxylic acids are also referred to as fatty acids (Table 1). The first five saturated acids (formic to valeric) of this type are sometimes referred to as short-chain, low-molecular-weight, or volatile fatty acids. Although a nomenclature for these acids has been established by the International Union of Pure and Applied Chemistry (lUPAC), the convention of using the trivial names for the first five saturated acids has remained. Similarly, trivial names are used for the aliphatic dicarboxylic acids (Table 2) that are saturated with two to four carbon atoms (C2-C4) and unsaturated with four carbon atoms (C4). Alicyclic carboxylic acids contain one or more saturated or partially unsaturated rings. These acids most commonly occur... 

Unsubstituted aliphatic dicarboxylic acids. HOOC (CH ) COOH. are most often referred to by their trivial names for n = 2 to 10 (Table I). Higher homologucs are named using the IUPAC system by adding the suffix dioic to the parent hydrocarbon. 

TABLE 1. PHYSICAL PROPERTIES OF C.—C ALIPHATIC DICARBOXYLIC ACIDS... 

Furthermore, when aliphatic dicarboxylic acid compounds (41-46) were used as hosts, a 1 1 complex (47) of oxalic acid (41) with 1, and a 1 2 complex (48) of acetylenedicarboxylic acid (42) with 1 were obtained (Table 5). Although the... 

Table 5 Inclusion complexation of Cl-MIT by aliphatic dicarboxylic acid host compounds.

A sufficient separation of all these compounds, therefore, is only achieved by using two AS4 columns in series. However, the separation of the two stereoisomers, maleic acid and fumaric acid, is much easier. It is obtained under standard conditions and is shown in Fig. 3-87. In contrast to monocarboxylic acids, the retention of aliphatic dicarboxylic acids increases with decreasing pK value. The corresponding data are summarized in Table 3-20. This finding is explained by the charge-stabilizing effect exerted by the +1-effect of the methylene groups which decreases from succinic acid to oxalic acid ... 

Table 3-21. Comparison of elution order and pK values [86] between hydroxy-substituted and unsubstituted aliphatic dicarboxylic acids.

Surprisingly, by using the reactions via 5 and 6 in Scheme 2, polyamides of high molecular weight are obtained directly from dicarboxylic acids and diamines in N-methylpyrrolidone (NMP) solutions containing pyridine (Table 1)1S. A combination of aromatic diamines with aliphatic dicarboxylic acids gives polymers of higher viscosity than the use of an aliphatic diamine alone. On the other hand, 4,4 -diaminodi-phenylsulfone yields low viscous polymers, probably because of the lower basicity. 

Table 8.2 Aliphatic dicarboxylic acids used for polyester poh ol synthesis...

Table 13.8 presents chemical compounds that have been identified as primary organic aerosol components (Rogge et al., 1991, 1993a-e) together with their annual average ambient mass concentrations in the Los Angeles air basin. These ambient concentrations are the cumulative results of a variety of primary sources and secondary aerosol production. Normal alkanoic acids, aliphatic dicarboxylic acids, and aromatic polycarboxylic acids are... 

Since inhibited plastics, especially films, are mostly based on PE (see 1.3), the value of Ciim estimated towards PE of such PI as esters of aromatic and aliphatic dicarboxylic acids and mineral oils reaches 5 wt%. Polyatomic alcohols and vegetable oils are less compatible with PE, Cuni is about 2% (Table 1.5). 

TABLE III Initial Degrees of Polymerization of Diallyl Esters of Aliphatic Dicarboxylic Acids [46] ... 

In the bulk polymerization of the diallyl esters of the aliphatic dicarboxylic acids, the initial degrees of polymerization are quite large (Table III). 

Instead of the conventional binder pol5miers described above, biodegradable polymers may be used advantageously, such as aliphatic-aromatic copolyesters. A preferred aliphatic dicarboxylic acid is adipic acid and as aromatic dicarboxylic acid terephthalic acid can be used. As a glycol component 1,4-butanediol has been suggested. The natural cellulose fibers are selected from hemp, sisal, flax, kenaf, cotton, jute, or coconut (32). Commercial natural cellulose containing fibers are summarized in Table 5.10. 

Table 2. Examples of trivial names and lUPAC names for acyclic (i.e., straight or branched chains) aliphatic dicarboxylic acids. Preferred names are italicized...

TABLE 7.6 Performance Comparisons of Low-Temperature Aliphatic Dicarboxylic Acid Esters in PVC at 50 phr and 70A Hardness ... 

Dicarboxylic acids are readily converted into cyclic anhydrides when heated alone or in acetic anhydride. Heat 0.5 g of the acid in 2-3 ml of refluxing acetic anhydride for 30 minutes. Remove most of the excess reagent by distillation and crystallise the residual cyclic anhydride from chloroform or toluene. The melting points of aliphatic and aromatic anhydrides are to be found in Tables 10.23 and 10.24 respectively. For conversion of the anhydrides into anilic acids see Section 9.6.16, below. 

Plasticizers include the esters of a few aliphatic and aromatic mono and dicarboxylic acids, aliphatic and aromatic phosphorus acid esters, ethers, alcohols, ketones, amines, amides, and non-polar and chlorinated hydrocarbons. These additives are used in various mixtures. For their separation and qualitative detection, thin-layer chromatography (TLC) is preferred. Usually Kieselgur plates, 0.25 mm thick, activated at 110°C for 30 min, in the saturated vapor are used. Methylene chloride and mixtures of diisopropyl ether/petether at temperatures between 40 to 60°C have been successfully used as the mobile phase. Refer to Table 1. 

The commercial flexibilizing reactive diluents are predominantly glycidyl derivatives of glycols, dimerized acids, or reaction products of dicarboxylic acids with epoxy resins. The properties of certain polyepoxy diluents are summarized in Table 8.3. Some of, but not all, these materials provide good reactivity with aliphatic primary amines at room temperature. 

As a dicarboxylic acid Gabler et al. used primarily terephthalic acid and in some cases isophthalic acid also. As diamine they used a number of branched aliphatic products, and the emphasis was on products having C-6 chain members separating the two NH2 groups. Table I lists some of Gabler s products. 

The development of unsaturated polyanhydrides responded to the necessity of improving the mechanical properties of the polymers in applications such as the temporary replacement of bone. " Unsaturated polyanhydrides, prepared by melt or solution polymerization, include homopolymers of fumaric acid (FA), acetylene-dicarboxylic acid (ACDA), and 4,4 -stilbenzenedi-carboxylic acid (STDA). The chemical structures of poly(FA) and poly(ACDA) are shown in Table 1. These polymers are highly crystalline and insoluble in common organic solvents. The double bonds of these monomers make them suitable for further crosslinking to improve mechanical properties of polyanhydrides. When copolymerized with aliphatic diacids, less crystalline polymers with enhanced solubility in chlorinated solvents result. 

Carbonaceous chondrites, and in particular the Murchison meteorite, have a rich organic inventory, including carboxylic acids, amino acids, sulphonic acids dicarboximides and dicarboxylic acids, aliphatic and aromatic hydrocarbons and other classes of organic molecules (Table I) (for detailed reviews see 4, 19,... 

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