Diamines polyamides from

Polyamides from diamines and dibasic acids. The polyamides formed from abphatic diamines (ethylene- to decamethylene-diamine) and abphatic dibasic acids (oxabc to sebacic acid) possess the unusual property of forming strong fibres. By suitable treatment, the fibres may be obtained quite elastic and tough, and retain a high wet strength. These prpperties render them important from the commercial point of view polyamides of this type are cabed nylons The Nylon of commerce (a 66 Nylon, named after number of carbon atoms in the two components) is prepared by heating adipic acid and hexamethylenediamine in an autoclave ... 

Figure 18.10. Melting points of polyamides from aliphatic diamines A, with adipic acid, B, with sebacic acid. (After Coffmann et al )...

Special terminology based on trade names has been employed for some polymers. Although trade names should be avoided, one must be familiar with those that are firmly established and commonly used. An example of trade-name nomenclature is the use of the name nylon for the polyamides from unsubstituted, nonbranched aliphatic monomers. Two numbers are added onto the word nylon with the first number indicating the number of methylene groups in the diamine portion of the polyamide and the second number the number of carbon atoms in the diacyl portion. Thus poly(hexamethylene adipamide) and polyfhexamethylene sebacamide) are nylon 6,6 and nylon 6,10, respectively. Variants of these names are frequently employed. The literature contains such variations of nylon 6,6 as nylon 66, 66 nylon, nylon 6/6, 6,6 nylon, and 6-6 nylon. Polyamides from single monomers are denoted by a single number to denote the number of carbon atoms in the repeating unit. Poly(e-caprolactam) or poly(6-aminocaproic acid) is nylon 6. 

Some of the most familiar reactions falling into the polycondensation class are those leading to polyamides derived from dicarboxylic acids and diamines, polyesters from glycols and dicarboxylic acids, polyurethanes from polyols and polyisocyanates, and polyureas from diamines and diisocyanates. Similar polymer formations utilizing bifunctional acid chlorides with polyols or polyamines also fall into this class. The condensations of aldehydes or ketones with a variety of active hydrogen compounds such as phenols and diamines are in this group. Some of the less familar polycondensation reactions include the formation of polyethers from bifunctional halogen compounds and the sodium salts of bis-phenols, and the addition of bis-thiols to diolefins under certain conditions. 

Since 1935, when Carothers discovered the fiber-forming properties of polyamides, many chemists in the world have studied the synthesis of the raw materials for various polyamides, aliphatic diamines, aliphatic dibasic acids, caprolactam, and the w-amino fatty acids. The known synthetic routes to polyamides from w-amino fatty acids are as follows ... 

There is an alternative naming system for synthetic polyamides from unsubstituted nonbranched aliphatic monomers. A polyamide made from either an amino acid or a lactam is called nylon x, where x is the number of carbon atoms in the repeating unit. A nylon made from a diamine and a dibasic acid is designated by two numbers, in which the first represents the number of carbons in the diamine chain and the second the number of carbons in the dibasic acid. 

Several aromatic polyamides from aromatic dicarboxyiic acids and diamines were prepared by the reaction in the presence of P4VP (MW = 1.0 x 10s), and the results were summarized in Table 5. Combination of TPA with diamines, especially with MDA and 4,4 -diaminodiphenylether, gave polymers of satisfactory viscosities up to five times higher than those obtained in the absence of the matrix. On the other hand, the reactions of IPA and diamines, and of p- and m-ABA were almost not affected by P4VP. 

In a patent application filed in 2000 (granted in 2004) Cheng et al. [44] used selected commercial lipases to synthesize polyamides from diesters and diamines with the following general structures ... 

In this work we attempted to make polyamides using both lipases and proteases. To our knowledge no one previous to our work 6,7) has made a pure polyamide from a diacid/diester and a diamine via these enzymes. 

Nylon. Nylon is a trade name for high-molecular weight polyamides that result from condensation polymerization of dibasic acids and diamines, or from u)-amino acids. Nylon can be extruded from a melt as monofilaments, or spun from a solution of formic acid, HCOOH, and phenol, C5H5OH. The resulting fibers have a low density, are elastic and lustrous, and mass for mass are stronger than steel. However, they are also low melting and difficult to dye. 

E. E. Paschke, W. Poppe, and D. P. Sinclair. Amorphous polyamide from neopentyl diamine. US Patent 5 081223, assigned to Amoco Corporation (Chicago, IL), January 14,1992. 

H. W. Hill, Jr., L. S. Kwolek, and W. P. Morgan. Polyamides from reaction of aromatic diacid halide dissolved in cyclic nonaromatic oxygenated organic solvent and an aromatic diamine. US Patent 3 006 899, assigned to Du Pont, October 31,1961. 

R. J. Perry. Preparation of aromatic polyamides from carbon monoxide, a diamine and an aromatic chloride. US Patent 5 693 746, assigned to Eastman Chemical Company (Kingsport, TN), December 2, 1997. 

Vapor-phase polymerization has been described in the patent literature as an alternative route to aromatic polyamides from aromatic diamines and aromatic diacid chlorides [81]. The reaction is carried out in the gas phase by mixing vapors of the two monomers in the presence of an inert gas. The temperature at the reaction zone has to be higher than the glass transition temperature of the polymer to achieve segmental mobility of the growing polymer chain. 

The polyamide from the above dimer acid condensed with a diamine, like ethylene diamine, can be illustrated as follows ... 

C. Preparations of many other wholly aromatic polyamides from aromatic diacid chlorides and CHAPTER 6 aromatic diamines were reported in the literatureJ In addition, several polymers are manufactured... 

The polymerization reaction takes place in a homogeneous dimethylacetamide solution, with catalytic amounts of PdCl2(PPh3)2 and an HBr scavenger. The carbonylation polycondensation proceeds rapidly at 115 C and is almost complete in 1.5 hours. This reaction was also used to prepare many aromatic-aliphatic polyamides from corresponding aliphatic diamines with aromatic dibromides. 

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