Alkyd resins component

Precipitation in methanol has shown that many commercially available styrenated alkyds are blends of the alkyd and polystyrene. An attempt to produce copolymers by adding styrene and benzoyl peroxide or di-tert-bulyl peroxide to a commercial soy-linseed medium alkyd (Cargill Company Alkyd Resin Product No. 5150) in a nitrogen atmosphere, were also unsuccessful. However, blends containing at least 40% styrene were compatible with the alkyd resin, and the coatings were slightly hazy, last drying, harder, and more chemical resistant than the alkyd resins component. 

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). 

If the total alkyds consumed in recent years is classified by their dibasic acid component, about 50% belongs to the unmodified phthaHc type, about 28% modified phthaHc type, about 13% based on isophthaHc, and the balance based on polybasic acids other than phthaHc or isophthaHc. The top alkyd resin manufacturers in the U.S. are Cargill, Reichhold, a subsidiary of Dainippon Ink Chemicals, Inc., and Spencer KeUog, now a part of NL Industries, Inc. The median price (52,53), of general types of alkyd resin, soHds base, was 1.98/kg in Nov. 1990 compared to about 440 in 1955, about 660 in 1975, and about 1.54 in 1983, reflecting the increases in raw material cost. 

The most important coating appHcation for the nonreactive polyamide resins is in producing thixotropy. Typical coating resins such as alkyds, modified alkyds, natural and synthetic ester oils, varnishes, and natural vegetable oils can be made thixotropic by the addition of dimer acid-based polyamide resins (see Alkyd resins). Specialty high performance coating appHcations often requite the properties imparted by dimer acid components. 

Modified alkyd resins In this group one finds styrenated alkyds, vinyl toluenated alkyds, oil-modified vinyl resins, acrylic alkyds, silicone alkyds and polyurethane alkyds. The modifying component usually has a number of effects. It always increases the molecular weight of the alkyd polymer, and may impart hardness, durability, or chemical resistance. It also affects the solubility of the polymer in solvents. 

The typical alkyd resin (see above) is eomprised of three basic components an aromatic diacid such as phthalic anhydride which together with a polyol such as glycerol, forms the backbone of the resin molecule and along which are distributed the fatty acids derived from vegetable oils. The solubility, film hardness and colour of alkyd resins depend on the nature of the modifying fatty acid which in most cases contributes some colour to the film. 

These are the most important components of paint. Coatings can be either clear or opaque (containing pigments) and either solvent- or water-based. With solvent-based paints, after application, most of the solvent is lost through evaporation. These solvent-based coatings are mostly alkyds (name derived from alkyl/acid) or modified alkyd resins. Normally they contain 30% polymer solids higher solids content is limited by the increasing viscosity of the system. 

Microgels have also been detected as a component of alkyd resins, an early but still important binder of organic coatings [316-321] and are accountable for their ability to fill pores, fissures and other irregularities of the substrate such as wood. This property may be explained by the size of the microgels which prevents the paint becoming soaked up by the substrate. 

Fumaric acid, a metabolite of many fungi, lichens moss and some plants, and mainly used as the diacid component in alkyd resins, is produced commercially to some extent by fermentation of glucose in Rhizopus arrhizus yet productivity improvements appear essential for the product to be an option for replacing its petrochemical production by catalytic isomerization of maleic acid. 

Unsaturated polyesters in which the alkene double bond resides in a fatty acid component such as oleic (IX) and linoleic (X) acids are referred to as alkyds or alkyd resins (Sec. 2-12a). 

Reduced furan rings occur in many important anhydrides, lactones, hemiacetals and ethers. Maleic anhydride is frequently used as a dienophile in Diels-Alder reactions and it is a component of alkyd resins. Several unsaturated y-lactones are natural products, while the furanose sugars are cyclic hemiacetals. 

The main reactions involved in alkyd resin synthesis aie poly condensation by esterification and ester interchange. Figure 1 uses the following symbols to represent the basic components of an alkyd resin. 

Organic components of polishes are widespread. Thus most products emit complex VOC mixtures that may consist of alkanes, various alcohols, acetates, C2-C4-benzenes, terpenes and derivatives of naphthalene. This is illustrated by the range of compounds emitted by a furniture polish (Figure 15.2b) and a shoe polish (Figure 15.2c). Many modern floor waxes are based on natural ingredients like alkyd resins. On oxidative degradation of unsaturated fatty acids, volatile aliphatic aldehydes (C5-C11) with unpleasant smell (Ruth, 1986) are formed and the emission rates may remain at high levels over months and even years (Salthammer, 1999). 

Thermoset resins covers an extremely wide range, including phenol formaldehyde polymers, aminopolymers, PUs, epoxies, and thermoset polyesters, which include the alkyd and unsaturated vinyl ester resins. Of special interest at the present time are those that comprise the resin component of liber-reinforced composites that are finding increasing use in commercial and defense sectors, where fire resistance is of paramount importance. Typical resins used are those listed in Table 2.4 along with typical, respective LOI values in descending order of increased inherent fire resistance. 

On the whole, the miniemulsion polymerization process proved to be effective for incorporating an alkyd resin into acrylic coated copolymers. The reaction produced stable, small particle size latexes that contain graft copolymer of the acrylic and alkyd components. Attempts at macroemulsion hybrid polymerization were unsuccessful. 

Each of the three principal components of alkyd resins—the polybasic acids, the polyols, and the monobasic acids— has a large variety to be chosen from. The selection of each one of these ingredients will affect the properties of the resin. As will be shown later, the choice of ingredients may even affect the choice of manufacturing processes. To both the resin manufacturers and the users, the selection of the proper ingredients is a major decision. 

Use Alkyd resins are used as vehicles in exterior house paints, marine paints, and baking enamels. Molded alkyd resins are used for electrical components, distributor caps, encapsulation, and a variety of similar applications. 

The following compounds are most commonly used for the polyol component of alkyd resins glycerol, ethylene glycol, penta-erythrltol, propylene glycol, dipentaerythritol, neopentyl glycol, sorbitol, diethylene glycol, trimethylolethane, dipropylene glycol, trimethylolpropane, and cyclohexanedimethanol. The structures of... 

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