Polyesters alkyd

Aromatic polyester Unsaturated polyester Alkyd molding compounds ... 

The polyester alkyd moulding compositions are also based on a resin similar to those used for laminating. They are prepared by blending the resin with cellulose pulp, mineral filler, lubricants, pigments and peroxide curing agents on... 

This monomer has been used as the basis of a laminating resin and as a reactive diluent in polyester laminating resins, but at the present time its principal value is in moulding compositions. It is possible to heat the monomer under carefully controlled conditions to give a soluble and stable partial polymer in the form of a white powder. The powder may then be blended with fillers, peroxide catalysts and other ingredients in the same manner as the polyester alkyds to form a moulding powder. Similar materials may be obtained from diallyl isophthalate. 

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. 

P-FGP DMC (GP) Polyester alkyd DAP alkyd DAIP alkyd Units... 

It has been estimated that in the United States somewhat over half of the surface coatings are of the polyester (alkyd) type. 

Weathering Many plastics has short lives when exposed to outdoor conditions. The better materials include acrylic, chlorotri-fluorethylene, vinylidene fluoride, chlorinated polyether, polyester, alkyd, and black linear poly-ethylene. Black materials are best for outdoor service. Some of the styrene copolymers are suitable for certain outdoor uses (Chapter 2, WEATHERING/ ENVIRONMENT). 

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. 

Phenolic, epoxy, urea, melamine, and polyester (alkyd) polymers are cross-linked (thermoset) plastics. They are solvent-resistant and are not softened by heat. Unlike the thermoplastic step reaction polymers, which are produced by the condensation of two difunctional reactants, these network polymers are produced from reactants at least one of which has a degree of functionality higher than two. 

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. 

The acid-crosslinkable prepolymers are polyester-alkyd, urea-formaldehyde, or melamine-formaldehyde resin adducts combined with a "blocked" acid catalyst that becomes "unblocked" at the dryer temperatures f7, 11, 12). e. g., a melamine-polyester resin adduct with "blocked" -toluenesulphonic acid catalyst (12). These acid-crosslinkable prepolymers are stable on the press distribution system but are converted to tiiree-dimensional polymer networks by heating to 275-325° F. 

Use Polyester, alkyd polyurethane and other high polymers, plasticizers. 

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

MAJOR POLYMER APPLICATIONS melamine resin, polyester, alkyd, acrylic, rubber, PP, ABS, PVC... 

MAJOR POLYMER APPLICATIONS pol5nirethane, epoxy, silicone, polychloroprene, PSF, acrylics, PVC, polyesters, alkyd, fluoroelastomers, NR, SBR... 

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. 

Four types of polyester molding compounds may be recognized [14] (1) dough-molding compound (DMC), (2) sheet-molding compound (SMC), (3) alkyd-molding compositions, sometimes referred to as polyester alkyds, (4) diallyl phthalate (DAP) and diallyl isophthalate (DAIP) compounds. 

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