Unsaturated acids fabric

Unsaturated polyesters are based on macromolecules with a polyester backbone in which an unsaturated acid or combination of a saturated with an unsaturated acid are condensed with a glycol. A three-dimensional structure is produced when the macromolecule is crosslinked through the unsaturation. Commercial unsaturated polyester resin formulations, neglecting consideration of additives, initiators, extenders, and fibrous reinforcing materials, consist essentially of a linear resin, a crosslinking (reactive diluent) monomer (ca. 18-40 wt. %), and inhibitors to retard crosslinking until the resin is used by the fabricator. The simplest member of the polyester series, ethylene maleate (or ethylene fumarate), is prepared as follows ... 

Uses. Phthabc anhydride is used mainly in plasticizers, unsaturated polyesters, and alkyd resins (qv). PhthaUc plasticizers consume 54% of the phthahc anhydride in the United States (33). The plasticizers (qv) are used mainly with poly(vinyl chloride) to produce flexible sheet such as wallpaper and upholstery fabric from normally rigid polymers. The plasticizers are of two types diesters of the same monohydric alcohol such as dibutyl phthalate, or mixed esters of two monohydric alcohols. The largest-volume plasticizer is di(2-ethylhexyl) phthalate [117-81-7] which is known commercially as dioctyl phthalate (DOP) and is the base to which other plasticizers are compared. The important phthahc acid esters and thek physical properties are Hsted in Table 12. The demand for phthahc acid in plasticizers is naturally tied to the growth of the flexible poly(vinyl chloride) market which is large and has been growing steadily. 

Miscellaneous Derivatives. Fimehc acid is used as an intermediate in some pharmaceuticals and in aroma chemicals ethylene brassylate is a synthetic musk (114). Salts of the diacids have shown utUity as surfactants and as corrosion inhibitors. The alkaline, ammonium, or organoamine salts of glutaric acid (115) or C-5—C-16 diacids (116) are useflil as noncorrosive components for antifreeze formulations, as are methylene azelaic acid and its alkah metal salt (117). Salts derived from C-21 diacids are used primarily as surfactants and find apphcation in detergents, fabric softeners, metal working fluids, and lubricants (118). The salts of the unsaturated C-20 diacid also exhibit anticorrosion properties, and the sodium salts of the branched C-20 diacids have the abUity to complex heavy metals from dilute aqueous solutions (88). 

Oxidation of n-hutane to maleic anhydride is becoming a major source for this important chemical. Maleic anhydride could also be produced by the catalytic oxidation of n-butenes (Chapter 9) and benzene (Chapter 10). The principal use of maleic anhydride is in the synthesis of unsaturated polyester resins. These resins are used to fabricate glass-fiber reinforced materials. Other uses include fumaric acid, alkyd resins, and pesticides. Maleic acid esters are important plasticizers and lubricants. Maleic anhydride could also be a precursor for 1,4-butanediol (Chapter 9). 

Uses. About 60% of the MA produced is used to make unsaturated polyester and aikyd resins, which are formed by reaction of MA with glycols. Polyester resins are used in the fabrication of glass fiber reinforced parts. Applications include boat hulls, automobile body parts, patio furniture, shower stalls, and pipe. Aikyd resins are mostly used in coatings (paint, varnish, lacquers, and enamels). MA also is widely used as a chemical intermediate in the manufacture of plasticizers and dibasic acids (fumaric, maleic, and succinic). About 15% of MA production goes into the manufacture of viscosity index improvers and dispersants used as additives in lube oils. Several agricultural chemicals are based on maleic anhydride, the best known being Malathion. 

The resulting unsaturated diols (practically monoglycerides of fatty acids, reaction 17.12) react with diisocyanates (for example with toluene diisocyanate) at around 80-90 °C, usually in a solvent such as toluene, xylene or naphtha. Unsaturated PU are obtained, which are crosslinked by a radical mechanism with the transformation of the multiple double bond in a crosslinked network (Figure 17.9). This reaction is used for the fabrication of urethane alkyd coatings. Other polyols may be used instead of glycerol ethylene glycol, neopentylglycol, trimethylolpropane, pentaerythritol and others. 

A microfluidic reaction system has also been used for the production of prodrugs. A multichannel membrane microreactor was fabricated and tested for Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate to produce a-cyanocinnamic acid ethyl ester, a known intermediate for the production of an antihypertensive drug [9]. Knoevenagel condensations of carbonylic coiiqtounds and malonic esters yield several important key products such as nitriles used in anionic polymerization, and the a,p-unsaturated ester intermediates employed in the synthesis of several therapeutic drugs that include niphendip-ine and nitrendipine. Unlike most condensation reactions. 

The fatty acids used to manufacture esterquats for fabric softeners usually have a high Cig and Cig content. The used fatty acids are tallow or palm based. The alkyl groups are partially or fully hardened. Softening performance and physical properties like dispersion viscosity and melting point depend on chain length and the degree of unsaturation of the alkyl chains in the esterquat [50]. Dispersion stability is an important item, especially in the United States for the ultraconcentrated formulations. 

---