Alkyd resins synthesis

Alkyd resin synthesis. This synthesis consists of two steps. In the first step, a triglyceride oil is reacted at ca. 250°C with polyols, such as glycerol or pentaery-thritol, in tire presence of a basic catalyst to form a monoglyceride. In the second step, phthalic anhydride, with or without another dibasic acid such as maleic anhydride, is added to the reaction medium and reacted at high temperature. The resulting product is a branched polyester (Scheme 2.56). 

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. 

The safety considerations involved in alkyd resin manufacture, including plants, processes, and materials has recently been reviewed [36]. It is suggested that this reference be consulted before getting involved in alkyd resin synthesis. 

A typical oil-modified alkyd resin synthesis using linseed oil is given in Preparation 2-2. More recent examples of alkyd resin preparation are shown in Table VI. 

Alkyd resins completely based on renewable resources have been the subject of a few studies. EP 0741 175 A2 to Hoechst describes waterborne alkyd emulsions based on renewable resources. The patent describes the use of sorbitol (easily derived from starch) as the polyhydric alcohol part and succinic acid anhydride as the polycarboxylic acid part. Hajek described the use of sorbitol and xylitol in alkyd resin synthesis, whereas Bagchi et al. described the partial replacement of conventional polyols, i.e., glycerol and pentaerythritol, by sorbitol. 

Different chemical procedures may be used for the synthesis of alkyd resins. The choice is usually dictated by the selection of the starting ingredients. 

Processes have been developed separating pure metaxylene from other Cj aromatics.Metaxylene is a raw material for the manufacture of isophthalic acid. The major outlets for the acid are in the synthesis of unsaturated polyester and alkyd resins, and for the production of isophthalic esters (plasticizers). 

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). 

Acetaldehyde is a colorless liquid with a pungent odor. It is a reactive compound with no direct use except for the synthesis of other compounds. For example, it is oxidized to acetic acid and acetic anhydride. It is a reactant in the production of 2-ethylhexanol for the synthesis of plasticizers and also in the production of pentaerithritol, a polyhydric compound used in alkyd resins. 

Since anhydrides are much more reactive than carboxylic acids, reaction kinetics is controlled by the second step. The scope and apphcations of this reaction are the same as direct polyesterification but are practically limited to the synthesis of unsaturated polyesters and alkyd resins from phtliahc and maleic anhydrides (see Sections 2.4.2.1 and 2.4.23). 

Alkali metal (haloarylsulfonyl)thio-phenoxides, 364 Alkaline hydrolysis of nylon-6,6, 568-569 of PET, 549-550 Alkyd resins, 18, 30-31, 59-60 synthesis and cure of, 102 Alkylphenolic resins, 376 Alkylphenols, 376, 400 Allophanates, 227... 

Chemoenzymatic synthesis of alkyds (oil-based polyester resins) was demonstrated. PPL-catalyzed transesterification of triglycerides with an excess of 1,4-cyclohexanedimethanol mainly produced 2-monoglycerides, followed by thermal polymerization with phthalic anhydride to give the alkyd resins with molecular weight of several thousands. The reaction of the enzymatically obtained alcoholysis product with toluene diisocyanate produced the alkyd-urethane. 

Several applications of hyperbranched polymers as precursors for synthesis of crosslinked materials have been reported [91-97] but systematic studies of crosslinking kinetics, gelation, network formation and network properties are still missing. These studies include application of hyperbranched aliphatic polyesters as hydroxy group containing precursors in alkyd resins by which the hardness of alkyd films was improved [94], Several studies involved the modification of hyperbranched polyesters to introduce polymerizable unsaturated C=C double bonds (maleate or acrylic groups). A crosslinked network was formed by free-radical homopolymerization or copolymerization. 

Uses Solvent for nitrocellulose cellulose acetate cellulose acetobutyrate cellulose aceto-propionate, waxes, fats, dyestuffs, vinyl, and alkyd resins experimental propellant fuel additive organic synthesis (FriedeLCrafts reactions) manufacture of pharmaceuticals and pesticides. 

Polyacetal resins have a repeating unit of -O-CH2-. They are strong, stiff polymers for valves, hoses, and tube connectors. Pentaerythritol finds end-uses in alkyd resins and explosives (pentaerythritol tetranitrate). To appreciate this synthesis, the student should review two condensation reactions, the crossed aldol and the crossed Cannizzaro. Acetaldehyde reacts with 3 mol of formaldehyde in three successive aldol condensations. This product then undergoes a Cannizzaro reaction with formaldehyde. 

The major uses of mixed xylene are in aviation gasoline and protective coatings, and as a solvent for alkyd resins, lacquers, enamels and rubber cements. wetrr-Xylene is used as a solvent, as an intermediate for dyes and organic synthesis, especially isophthalic acid and insecticides, and in aviation fuel or// o-xylene is used in manufacture of phthalic anhydride, vitamin and pharmaceutical synthesis, dyes, insecticides, motor fuels para-xylene is used in synthesis of terephthalic acid for polyester resins and fibres, vitamin and pharmaceutical syntheses, and insecticides (Lewis, 1993). 

Lmoleic acid [60-33-3] - [ALKYD RESINS] (Vol 2) - [TALL OIL] (Vol 23) - [CASTOR OIL] (Vol 5) - [COSMETICS] (Vol 7) - [CARBOXYLICACIDS-SURVEY] (Vol 5) -m dimer acid feedstocks [DIMER ACIDS] (Vol 8) -m drying oils pRYING OILS] (Vol 8) -enzymatic oxidation pNZYTffiS IN ORGANIC SYNTHESIS] (Vol 9) -m fats and oils [CARBOXYLIC ACIDS - ECONOMIC ASPECTS] (Vol 5) -as radioprotective agent [RADIOPROTECTIVEAGENTS] (Vol 20) -m soybeans and other oilseeds [SOYBEANS AND OTHER OILSEEDS] (Vol 22)... 

Behr and coworkers have reported on some promising approaches using 8-lactone as the starting compound for exploitable specialty chemicals. One such strategy involves the three-step synthesis of 2-ethylheptanoic acid, an interesting building block for new alkyd resins (as used in printing inks, baked enamels, and... 

The new applications are to be found outside the traditional commercial applications of glycerol in food additives, pharmaceuticals, cosmetics and personal care products and also various industrial applications, such as the synthesis of polyethers, polyols and alkyd resins, detergents, explosives, etc. [85]. The use of low-quality glycerol from biodiesel production for these applications is often avoided, however. Additional fields of applications as a C3 building block have been widely investigated and in a few cases even commercialized, e.g. the production of epichlorohydrin via the EPICEROL process of Solvay Chemicals. 

On the other hand, although o-phthalic acid, or rather its anhydride, had long been produced in enormous amounts for use in the manufacture of alkyd resins, the para derivative was less well known and not available on a large scale. The synthesis is a straightforward one, however, from p-xylene, which is oxidized to terephthalic acid, either by means of nitric acid in the older process or by air (catalyzed) in the newer one. In the early years this compound then was converted to the easily purified dimethyl ester in order to obtain a colorless polymer adequate for the manufacture of commercially acceptable fibers. 

Use Organic synthesis, lacquers, product of hydrotropic salts, alkyd resins, polyamides, polyester adhesives, low-temperature plasticizers, urethane elastomers. 

Use Alkyd resins, plasticizers, hardener for resins, polyesters, synthesis of phenolphthalein and other phthaleins, many other dyes, chlorinated products, pharmaceutical intermediates, insecticides, diethyl phthalate, dimethyl phthalate, laboratory reagent. 

Use Paint vehicles, source of rosin, alkyd resins, soaps, cutting oils and emulsifiers, driers, flotation agents, oil-well drilling muds, core oils, lubricants and greases, asphalt derivatives, rubber reclaiming, synthesis of cortisone and sex hormones, chemical intermediates. 

Use Aviation gasoline protective coatings solvent for alkyd resins, lacquers, enamels, rubber cements synthesis of organic chemicals. 

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