Maleic anhydrides esters

The use of a polymer monolayer to form LB films to be gas treated to form CdS nanoparticles has been reported [174]. The polymer use was poly (maleic anhydride) ester-... 

The Diels-Alder Reaction consists in the direct combination of a compound containing a conjugated diene system u ith a reagent which possesses a double or triple bond activated bj suitable adjacent groups. Examples of such reagents are maleic anhydride, p-benzoquinone, acraldehyde and acetylene dicarboxylic esters. Combination always occurs at the 1,4 positions of the diene system ... 

Unsaturated Polyesters. Unsaturated polyesters are produced by reaction between two types of dibasic acids, one of which is unsaturated, and an alcohol to produce an ester. Double bonds in the body of the unsaturated dibasic acid are obtained by using maleic anhydride or fumaric acid. 

MixedPhosphona.te Esters. Unsaturated, mixed phosphonate esters have been prepared from monoesters of 1,4-cyclohexanedimethanol and unsaturated dicarboxyhc acids. Eor example, maleic anhydride reacts with this diol to form the maleate, which is treated with benzenephosphonic acid to yield an unsaturated product. These esters have been used as flame-retardant additives for thermoplastic and thermosetting resias (97). 

Ethyl and butyl esters of poly(vinyl methyl ether)/maleic anhydride (PVM/MA) copolymer were introduced in the early 1960s for use in hair sprays. These polymers also have free carboxy acid groups that can be neutralized. Recommended neutralization is 10%, but products can be found in the range of 5—30%, and recommended neutralizers include ammonium hydroxide, aminomethyl propanol, and triisopropano1 amine. These were the most widely used polymers in hair sprays before their use decreased dramatically in the early 1990s. 

Free-radical reaction rates of maleic anhydride and its derivatives depend on polar and steric factors. Substituents added to maleic anhydride that decrease planarity of the transition state decrease the reaction rate. The reactivity decreases in the order maleic anhydride > fumarate ester > maleate ester. 

Alkenylsuccinic anhydrides made from several linear alpha olefins are used in paper sizing, detergents, and other uses. Sulfosuccinic acid esters serve as surface active agents. Alkyd resins (qv) are used as surface coatings. Chlorendric anhydride [115-27-5] is used as a flame resistant component (see Flame retardants). Tetrahydrophthalic acid [88-98-2] and hexahydrophthalic anhydride [85-42-7] have specialty resin appHcations. Gas barrier films made by grafting maleic anhydride to polypropylene [25085-53-4] film are used in food packaging (qv). Poly(maleic anhydride) [24937-72-2] is used as a scale preventer and corrosion inhibitor (see Corrosion and corrosion control). Maleic anhydride forms copolymers with ethylene glycol methyl vinyl ethers which are partially esterified for biomedical and pharmaceutical uses (189) (see Pharmaceuticals). 

DADC may be polymerised industrially with small amounts of other miscible Hquid monomers. Some acryflc ester monomers and maleic anhydride may accelerate polymerisation. Copolymerisation with methacrylates, diaHyl phthalates, triaHyl isocyanurate, maleates, maleimides, and unsaturated polyesters are among the examples in the early Hterature. Copolymers of DADC with poly-functional unsaturated esters give castings of high clarity for eyeglass lenses and other optical appHcations (20). 

Poly(methyl vinyl ether-i o-maleic anhydride) and their monoalkyl ester derivatives have been shown on rabbits to be neither primary irritants nor primary sensiti2ers to skin and eyes. The acute oral toxicities on white rats of the two copolymers are, respectively, 29 g/kg and 25 g/kg body weight. 

The products of these reactions with maleic anhydride, termed maleated oils, react with polyols to give moderate mol wt derivatives that dry faster than the unmodified oils. For example, maleated, esterified soybean oil is a drying oil with a drying rate comparable to that of a bodied linseed oil with a similar viscosity. Maleated linseed oil can be converted to a water-dilutable form by hydrolysis with aqueous ammonium hydroxide to convert the anhydride groups to ammonium salts of the diacid. Such products have not found significant commercial use, but similar reactions with alkyds and epoxy esters are used on a large scale to make water-dilutable derivatives. 

Dibasic acid anhydrides such as phthaUc anhydride and maleic anhydride readily react with alcohols to form the monoalkyl ester ... 

Over the past years considerable attention has been paid to the dispersing system since this controls the porosity of the particle. This is important both to ensure quick removal of vinyl chloride monomer after polymerisation and also to achieve easy processing and dry blendable polymers. Amongst materials quoted as protective colloids are vinyl acetate-maleic anhydride copolymers, fatty acid esters of glycerol, ethylene glycol and pentaerythritol, and, more recently, mixed cellulose ethers and partially hydrolysed polyfvinyl acetate). Much recent emphasis has been on mixed systems. 

An example of this methodology was its use in the synthesis of vitamin Be, pyridoxine 12. Cycloaddition of oxazole 9, prepared from ethyl A-acetylalanate and P2O5, with maleic anhydride initially gave 10. Upon exposure to acidic ethanol, the oxabicyclooctane system fragments to afford pyridine 11. Reduction of the ester substituents with LiAlIU generated the desired product 12. 

Diels et al. showed that acetylenedicarboxylic acid and 1-methyl-pyrrole gave l-methyl-2-pyrrylmaleic anhydride (41) and a second compound. The anhydride on hydrogenation and conversion to the corresponding dimethyl ester gave the same product as obtained from 1-methylpyrrole and maleic anhydride, followed by hydrolysis and... 

Methylindole and acetylenedicarboxylic acid is reported to give two unidentified products, but with the dimethyl ester the crs and trans (61) adducts were obtained. It was suggested that the major product had the trans configuration but this was not proved. Hydrogenation of both adducts gave the corresponding succinic ester, which was also obtained from 2-methylindole and maleic anhydride, followed by esterification. 

For the ordinary Diels-Alder reaction the dienophile preferentially is of the electron-poor type electron-withdrawing substituents have a rate enhancing effect. Ethylene and simple alkenes are less reactive. Substituent Z in 2 can be e.g. CHO, COR, COOH, COOR, CN, Ar, NO2, halogen, C=C. Good dienophiles are for example maleic anhydride, acrolein, acrylonitrile, dehydrobenzene, tetracya-noethylene (TCNE), acetylene dicarboxylic esters. The diene preferentially is of the electron-rich type thus it should not bear an electron-withdrawing substituent. 

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). 

A further type of ester resin is the unsaturated polyester where the unsaturation is built into the backbone by the use of maleic anhydride ... 

This is a linear polyester containing phthalic anhydride to ensure hydrocarbon solubility and maleic anhydride to enable copolymerisation to take place, esterified with 2-propanediol. The ester is dissolved in styrene which initially acts as the solvent and subsequently as film former when it is copolymerised with the double bond in the ester by free radical induced polymerisation. 

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