Polyester alkyd resins

The polyester alkyd resins are lower in cost than the DAP resins but are weaker mechanically, have a lower resistance to cracking round inserts and do not maintain their electrical properties so well under severe humid conditions. Fast-curing grades are available which will cure in as little as 20 seconds. 

Organotin compounds such as monobutyltin oxide, the main substance used, accounting for 70% of consumption, dibutyltin oxide, monooctyltin oxide, and dioctyltin oxide are used in certain esterification and transesterification reactions, at concentrations between 0.001% and 0.5% by weight. They are used in the production of substances such as phthalates, polyesters, alkyd resins, fatty acid esters, and adipates and in trans-esterifications. These substances are in turn used as plasticizers, synthetic lubricants, and coatings. Organo-tins are used as catalysts to reduce the formation of unwanted by-products and also provide the required colour properties (ETICA, 2002). 

Mixed xylenes are used as an octane improver in gasoline and for commercial solvents, particularly in industrial cleaning operations. By far, most of the commercial activity is with the individual isomers. Para-xylene, the most important, is principally used in the manufacture of terephthalic acid and dimethyl terephthalate en route to polyester plastics and fibers (Dacron, films such as Mylar, and fabricated products such as PET plastic bottles). Ortho-xylene is used to make phthalic anhydride, which in turn is used to make polyester, alkyd resins, and PVC plasticizers. Meta-xylene is used to a limited extent to make isophthahc acid, a monomer used in making thermally stable polyimide, polyester, and alkyd resins. 

Isophthalic acid is made by the same process as TPA, liquid phase air oxidation. Yields are about 80%. Isophthalic does have some unique redeeming value—it will enhance, to some extent, the mechanical and temperature sensitive properties of polyesters, alkyd resins, and glass reinforced plastics. 

Maleic anhydride is a cyclic anhydride with one double bond in the ring and two double-bonded oxygens hanging off the ring. The resulting reactivity leads to maleics use in making polymers, unsaturated polyesters, alkyd resins, plasticizers, and dicarboxylic acids. 

A wide variety of thermosetting polyester (alkyd) resins can be made by similar procedures. The following polybasic acids and anhydrides and poly-hydric alcohols are among the other popular ingredients in alkyd formulations ... 

Maleic anhydride is an important intermediate in the chemical industry [8-9]. It is used in polycondensation and addition reactions. The end products of these reactions are polyesters, alkyd resins, lacquers, plasticizers, copolymers and lubricants. For example, the copolymer of styrene and maleic anhydride is an engineering plastic. 

Use Curing epoxy resins, electrical laminating and filament winding, intermediate for polyesters, alkyd resins, and plasticizers. 

The main commercial thermosets are urea-formaldehyde resins (UF), melamine-formaldehyde resins (MF), phenol-formaldehyde resins (PF), epoxy resins, unsaturated polyesters, alkyd resins and polyurethanes. Changes in thermoset consumption in Western Europe during the period 1994-1996 are shown in Table 1.2. UF/MF resins and polyurethanes are produced in the greatest quantities, making up about 70% of the total thermosets market. 

The polyester alkyd resins are cheaper than the DAP alkyd resins but are mechanically weaker and do not maintain their electrical properties as well under severe humid conditions. Some pertinent properties of the polyester molding composition as compared in Table 4.13 along with those of a GP phenolic composition. The alkyd molding compositions are used almost entirely in electrical applications where the cheaper phenolic and amino resins are not suitable. 

SN > 200 Polyvinylacetate and copolymers polyacrylates and polymethacrylates Polyesters Alkyd resins Cellulose esters... 

The polyester (alkyd) resins based on phthalic anhydride and glycerol have been used as surface coatings for many years, but they are also the basis of a large number of cross-linkable polymers used in engineering materials. These generally contain a proportion of an unsaturated dicar-boxylic acid derived from maleic or fumaric acids ... 

Uses Intermediate for paints polyester alkyd resin comonomer poly-... 

Toxicology LD50 (oral, rat) 10,400 mg/kg, (IP, mouse) 4200 mg/kg mildly toxic by ing. and IP routes primary eye irritant TSCA listed Precaution Combustible Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and fumes Uses Intermediate for paints polyester alkyd resin comonomer polyurethanes other high polymers plasticizers Manuf./Distrib. Aldrich http //www.sigma-aidrich.com] Allchem Ind. 

Polyester resins are polycondensates prepared in two different forms saturated and unsaturated. Saturated polyesters, alkyd resins, are produced from dicarbox-ylic acids and polyalcohols. Dicarboxylic acids, chiefly phthalic acid or maleic acid, are mainly used in their anhydride forms. Glycerol, pentaerythriol or trimeth-ylolpropane are the most-used polyalcohols. The saturated polyesters synthesized in this way are also named unmodified alkyd resins, which are macromolecules commonly used as plasticizers for other plastic materials. Alkyd resins can be modified by oil-containing fatty acids to be used in water-based paints and surface coatings (Bjorkner 1992 Kanerva et al. i996a,b Tarvainen 1996). 

Table 5.5 shows that some polymers have a particularly high dielectric constant that is, these polymers have greater ability to store power in a given volume of polymer. These are polyesters, alkyd resins, phenol-formaldehyde, nylon 6,6, nylon 6,10, urea formaldehyde, and plastized polyvinyl chloride (PVC), all of which have dielectric constant values of >5 at 1 kHz. Tsuchiya and coworkers [14] discussed... 

PAK n Abbreviation for Polyester Alkyd Resin. See Alkyd Resin. 

G.i Polyester E polyesters ->Alkyd resins are the most important p. based on RR. The esters of - azeleic acid, -+brassylic acid and - sebacic acid with polyols are other commercial p. used in hydrophobic molded goods. -> Ester oils are used as ->plastics additives and in - lubricants. 

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