Aliphatic polyamides, synthesis

Alcohols, reaction of isocyanates with, 224-225 Alcoholysis, 69 Alicyclic dianhydrides, 297 Alignment coating, for liquid crystal devices, 269-270 Aliphatic AA-BB-type polyamides, synthesis of, 164-173 Aliphatic AB-type polyamides, 173-180 Aliphatic acids, 60... 

Aliphatic-aromatic copoly imides, 268 Aliphatic-aromatic polyesters, 18, 19 Aliphatic degradable polyesters, 41 Aliphatic diacids, polyamide synthesis from, 183-184... 

Aromatic nitrations, 17 160-161 by-products of, 17 161 kinetics of, 17 162 Aromatic nitriles, 17 243 Aromatic nucleophilic displacement, polyimide synthesis via, 20 273 Aromatic phosphines, 19 60, 62 Aromatic poly(monosulfide ketone)s, 23 709 Aromatic poly(monosulfide)s, 23 706 Aromatic polyamide copolymers, laboratory synthesis of, 19 720 Aromatic polyamide fibers, 24 614 Aromatic polyamides, 10 210-212 19 713-738. See also Aliphatic polyamides (PA)... 

Later, Ikawa et al. studied the the high-pressure synthesis of aliphatic polyamides such as 11-nylon and 12-nylon starting from the corresponding co-amino acids (Eq.7) [31,32]. 

The high temperature melt polycondensation method involving a diamine and a diacid has been successfully used in the synthesis of aliphatic polyamides, especially in the fabrication of nylon [le, f]. Neverthele this method is not applicaUe to the preparation of wholly aromatic polyamides because the potential polyamides either do not melt or melt at high temperature with decomposition. Many aromatic diacids will decarboxylate and the aromatic diamines are readily oxidized and have a tendency to sublime [Id]. Scientists from the Du Pont company then developed low temperature polycondensation methods either in solution or at the interface of two solvents. Solution polycondensation involves a diamine and a diacid chloride reacting in an amide solvent such as N-methylpyrrolidone (NMP), hexamethylphosphoramide (HMPA), or dimethylacetamide (DMAc) (Scheme 1) [3]. 

M. Vera, A. Rodrfguez-Galan, J. Puiggali, New method of synthesis of poly(ester amide)s derived from the incorporation of glycolic acid residues into aliphatic polyamide, Macromol. Rapid Commun. 25 (2004) 812-817. 

In the series of papers, synthesis of aliphatic polyamides and polyimides under microwave irradiation was described by Imai et al. [67-71]. The reactions were carried out in a modified domestic microwave oven with a small hole on the top of the oven so that nitrogen was introduced to a 30 ml wide-mouth vial adapted as a reaction vessel. In the case of polyamides synthesis, they were prepared of both CO-amino acids and nylon salt type monomers while polyimides were obtained from the salt form of monomers composed of aliphatic diamines and pyromellitic acid or its diethyl ester in the presence of a small amount of a polar organic medium (Fig. 11). 

The superior properties of aramid materials were the reason why significant research effort has been devoted to their synthesis. In 1989 there were at least 100 different chemical compositions of aromatic and aromatic-aliphatic polyamides [5] and there are indications that the number has doubled until today. This fact led the U.S. Federal TVade Commission to adopt a definition for aramid designating fibers of the aromatic polyamide type in which at least 85% of the amide linkages are attached directly to two aromatic rings. The compounds corresponding to this definition that have reached commercial stage are only four (Scheme 8.1) poly(r vphenylene isophthalamide) (MPDI), poly(p-phenylene terephthalamide) (PPTA), copoly(p-phenylene-3,4-diphenyl ether terephthalamide) (ODA-PPTA), and poly[5-amino-2(p-aminophenyl) benzimidazole terephthalamide] (SVM).The process of commercialization of every compound has always been the result of a constant trade-off between properties, processability and price. 

The reaction of 4-phenyl-3-buten-4-olide with benzylamine was investigated as a model for polyamide synthesis. Linear polyamides were prepared from ringopening polyaddition of 4,4 -disubstituted bis(3-buten-4-olide) in m-cresol u g aliphatic diamines. Further studies have investigated the production of hydroxy-substituted polyamides from 4,4 -disubstituted bis(4-butanoiide) and polyamide production from 2,2 -p-phenylene bis-oxazolones by similar ring opening reactions with diamines. ... 

S. Zulfiqar, Z. Ahmad, M. Ishaq, and M. I. Sarwar, Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials Synthesis, nanostmcture and properties. Materials Science and Engineering A, 525 (2009), 30-36. 

The synthesis of aliphatic polyamides under microwave irradiation has already been reported in a number of papers. " Polyamides were prepared from both co-amino acids and diamines together with dicarboxylic acids (i.e., the nylon salt-type monomers) in the presence of a small amount of a polar organic medium (Figure 32). 

Figure 32 Synthesis of aliphatic polyamides from co-amino acids as well as diamines and dicarboxylic acids.

Synthesis of fiber-forming aromatic polyamides and their properties. Aromatic polyamides do not melt totally below their decomposition temperature. For this reason, in contrast to aliphatic polyamides, they cannot be synthesized... 

Another method of synthesis of polymers containing sirlfonic groups is condensation of polymers with sulfocompounds. The authors [3] have shown possibility of obtaining of films on the basis of products of compatible condensation of aliphatic polyamides, n - phenolsuUbnic acid and formaldehyde in the medium of organic solvent. The authors [4] suggest preparing film material by condensation of dissolved... 

Imai (1996a) developed a new facile method for the rapid synthesis of aliphatic polyamides and polyimides from polycondensation of ra-antino acids and nylon salts. The polymerization reactions were carried out in domestic nticrowave oven in the presence of a small amount of a polar organic medium. Suitable organic media for the polyamide synthesis are tetramethylenesulfone (TMS) amide-type solvents such as N-cyclohexyl-2-pyrrolidone (CHP), 1, 3-dimethyl-2-imidazoUdone (DMI), phenolic solvents like m-cresol and o-chlorophenol, etc. and for the polyimide synthesis amide-type solvents such as N-methyl-2-pyrrolidone (NMP), CHP and DMI. In polyamide synthesis, the polycondensation was almost complete within 5 min, producing a series of polyamides with inherent viscosities aroimd 0.5 dL/g, and the polyimides having the viscosity values above 0.5 dL/g were obtained within 2 min. 

The use of HMF or the corresponding dialdehyde precursors obviously applies to the synthesis of monomers for polycondensation reactions as shown by the examples given in Scheme 2. ITiese difimctional structures again mimic the corresponding well-known aliphatic and aromatic counterparts used in the preparation of polyesters, polyamides, polyurethanes, etc. 

Hyperbranched polymers are formed by polymerization of AB,-monomers as first theoretically discussed by Flory. A wide variety of hyperbranched polymer structures such as aromatic polyethers and polyesters, aliphatic polyesters. polyphenylenes, and aromatic polyamides have been described in the literature. The structure of hyperbranched polymers allows some defects, i.e. the degree of branching (DB) is less than one. The synthesis of hyperbranched polymers can often be simplified compared to the one of dendrimers since it is not necessary to use protection/deprotection steps. The most common synthetic route follows a one-pot procedure " where AB,-monomers are condensated in the presence of a catalyst. Another method using a core molecule and an AB,-monomer has been described. ... 

Other Preparative Reactions. Polyamidation has been an active area of research for many years, and numerous methods have been developed for polyamide formation. The synthesis of polyamides has been extensively reviewed (54). In addition, many of the methods used to prepare simple amides are applicable to polyamides (55,56). Polyamides of aromatic diamines and aliphatic diacids can also be made by the reaction of the corresponding aromatic diisocyanate and diacids (57). 

The chemistry of rotaxanes has progressed well in accordance with the interest in their unique structures and the expectation of development as parts of molecular machines and molecular devices. It was in 1976 that Ogata et al. [69] reported the synthesis of the inclusion complex with polyamide. When /3-CD was stirred with aliphatic diamines in water, precipitates were... 

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