Polyamide precursor resins

The preparation of nylon resins from lactam precursors involves ring opening, which is facihtated by a controlled amount of water in the reaction mixture. The salt complex condenses internally to produce the polyamide (57). The synthesis of nylon-6 [25038-54-4] from S-caprolactam is as follows ... 

Phenol is a material of major commercial importance. One of its earliest uses was as a disinfectant (carbolic acid). Earlier in the twentieth century, it became important as a feedstock for resins such as Bakelite , and in the latter part of the century it also became very important as a precursor for caprolactone and caprolactam and hence polyester and polyamide manufacture. The two major methods for phenol production nowadays are by the catalytic oxidation of benzoic acid and catalytic decomposition of cumene hydroperoxide (Scheme 4.55). 

Polyamides are well-known industrial products having applications in many areas (7). For instance, the Nylon polymers (water-insoluble polyamides) are widely used in fibers. A water-soluble poly(aminoamide), derived from adipic acid and diethylene triamine, is the precursor to a well-known industrial resin (2). This poly(aminoamide) is currently produced by a chemical reaction at elevated temperatures which is accompanied by the formation of some branched structures. Subsequent derivatization of this polyamide produces a water-soluble resin, known for its ability to impart wet strength to paper and paper products (2a, 2b) and shrink proofing to wools and other textiles (2c). 

Hasegawa et al (1995) developed a new cementitious material by combining calcium aluminate cement with a methanolic solution of a phenol resin precursor. The water-free mix must be processed by high-shear mixing in a twin-roller mill in a way similar to that used in the production of MDF materials. The rheology of the resin-cement paste may be improved by adding to the system small amounts of a modifier such as alcohol-soluble polyamide and a plasticizer. A typical mix proportion is as follows ... 

For completeness, after discussing the histories of carbon fibers derived from cellulose, PAN, and pitch, the category of "other precursors" should be covered. The tremendous activity in carbon fiber research and development is reflected in the large number of precursors which have been converted into carbon fibers. Besides the "big three", the list [34] includes phenolic polymers, phenol formaldehyde resin, furan resins [35], polyacenaphthalene, polyacrylether, polyamide, polyphenylene, polyacetylene, polyimide, polybenzimidazole, polybenzimidazonium salt, polytriazoles, modified... 

Activated carbon fibers and cloths are commercially prepared from rayon, PAN, phenolic resins, acetate, petroleum and coal tar pitch, etc. Most commercial activated carbon cloths are produced from viscous rayon impregnated with a solution of a Lewis acid before the heat treatment, although some other precursors such as Kynol, polyamide, etc., are also used. 

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