Polyamides alicyclic

Aromatic polyamides have not assumed the commercial importance of aliphatic polyamides largely because of production and processing difficulties. The former are due to such factors as slow reaction rates of aromatic amines and tendency to discolour during polymerization whilst the latter arise because of the extensive decomposition which generally accompanies fusion of the polymers. Nevertheless, aromatic polyamides have found some limited use in specialized applications and are considered in this section. Also described, are related polyamides which are based on alicyclic intermediates. Compared to aromatic polyamides, alicyclic polyamides (sometimes termed polycyclamides) are less difficult to prepare and process and they have found some application. Several... 

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... 

The fiftieth anniversary of the announcement of nylon as the first synthetic organic textile fiber by the Du Pont Co. on October 27,1938 was celebrated as a significant event by the textile industry in 1988 (1,2). The announcement was the culmination of the fundamental research efforts of W. H. Carothers and his team at Du Pont (3). Carothers synthesized diamines from C2 to C18 in order for them to react with a variety of aliphatic dicarboxylic acids to make polyamides for evaluation as fibers (4—10). Alicyclic and aromatic diamines and dicarboxylic acids were also included. Nylon-6,6 was ultimately selected for scale-up and development because of its favorable melting point ( 260° C), best balance of properties, and lower manufacturing cost. The pilot plant for nylon-6,6 was completed in Wilmington, Delaware, in July, 1938, and a product was introduced on the market as Exton brisdes for Dr. West s toothbrushes (2). The first nylon filament plant was built in 1939 at Seaford, Delaware, and nylon stockings went on sale on October 24,1939 only to residents of Wilmington, and then nationally, on May 15, 1940 (2). 

The solubility of these dyes is significantly enhanced by introduction of alkenyl [35], hydroxypropyl [36], or polyetheralkyl [37] moieties into the trialkylammonium group. The trialkylammonium group may also be a component of a heterocyclic ring [38], When the trialkylammonium residue contains an alkyl chain of more than 11 carbon atoms, the dyes become soluble in aliphatic and alicyclic hydrocarbons and can be used for the production of printing inks [39], With aromatic diamines as the diazo components, such as 4,4 -diaminodiphenyl sulfone, basic disazo dyes are obtained which are suitable for dyeing acid-modified polyamide materials [40],... 

Aliphatic and alicyclic molecules such as cyclohexane undergo photosubstitution with nitrosyl chloride (Pape, l%7). The reaction is of considerable industrial importance in the synthesis of 6-caprolactam, an intermediate in the manufacture of polyamides (nylon 6). (Cf. Fischer, 1978.) At long wavelengths a cage four-center transition state between alkane and an excited nitrosyl chloride molecule is involved, as indicated in Scheme 63. In contrast to light-induced halogenation, photonitrosation has a quantum yield smaller than unity, and is not a chain reaction. 

A commercially important polyamide based on an alicyclic diamine is Qiana (Structure IV), which was introduced by Du Pont in 1968. 

Alicyclic ketones produce esters of a, (o-dicarboxylic acids (entries 5, 6). An example is cyclohexanone, which gives dimethyl pimelate. These compounds, used for the production of polyesters and polyamides, have traditionally been synthetized in industry by oxidation of alicyclic ketones (74). 

Newer polyamides also contain alicyclic groups. Of course, products derived from cyclohexane can occur in cis or trans configurations with very... 

Alicyclic polyamides (poly cy do amides) result from l,4-bis(amino methyl)cyclohexane and aliphatic dicar boxy lie acids, e.g., suberic acid. They possess lower water absorption and better electrical insulation properties than aliphatic polyamides. They are used for injection-molded articles, often reinforced with 20-40% by wt of glass fiber. 

D.J. Liaw, W.H. Chen, C.K. Hu, K.R. Lee, J.Y Lai, High optical transparency, low dielectric constant and light color of novel organosoluble polyamides with bulky alicyclic pendent group. Polymer 48 (22) (2007) 6571-6580. 

For the production of alicyclic polyamides, the preferred polymer has been that based on 1,4-bis(aminomethyl)cyclohexane and suberic acid ... 

---