Polyester plastic isophthalate

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). 

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. 

Isophthalic (tf -phthalic) acid [121-91-5] (IPA) is selected to enhance thermal endurance as well as to produce stronger, more resilient cross-linked plastics that demonstrate improved resistance to chemical attack. Terephthalic (/>-phthalic) acid [100-21-0] (TA) provides somewhat similar properties as isophthalic acid but is only used in selective formulations due to the limited solubility of these polyester polymers in styrene [100-42-5] (see Phthalic acid AND OTHERBENZENEPOLYC ARBOX YLIC ACIDS). 

Reactions of the Methyl Groups. These reactions include oxidation, polycondensation, and ammoxidation. PX can be oxidized to both terephthalic acid and dimethyl terephthalate, which are then condensed with ethylene glycol to form polyesters. Oxidation of OX yields phthalic anhydride, which is used in the production of esters. These are used as plasticizers for synthetic polymers. MX is oxidized to isophthalic acid, which is also converted to esters and eventually used in plasticizers and resins (see Phthalic ACIDS and otherbenzenepolycarboxylic acids). 

Terephthalic acid (benzene 1,4-dicarboxylate, TPA) and isophthalic acid (benzene 1,3-dicarboxylate, IPA) are reactive bi-functional acids used as monomers to make plastics and coatings. TPA is a starting material for polyethylene terephthalate (PET). TPA and IPA are used to make polyester lacquers and coatings including the internal coatings of food cans. 

Unsaturated Polyester Resins. Unsaturated polyester resins are widely used as fiber-reinforced plastics, coating materials, tire cords, films, and casting or molding resins. Organic titanates such as TYZOR TPT, TYZOR TBT, or TYZOR TOT can be used to catalyze the preparation of the resins, which involves the polyesterification of a mixture of a- and p-unsaturated polybasic acids, such as maleic or fumade acid, and alicydic polybasic acids, such as adipic or isophthalic acid with polyhydroxyalcohols (489). 

Beilstein Handbook Reference) AI3-02247 BRN 1912251 Dimethyl 1,3-benzenedi-carboxylate Dimethyl isophthalate Dimethyl m-phthalate Dimethylester kyseliny isoftalove EINECS 215-951-9 HSDB 6138 Isophthalic acid dimethyl ester Methyl 3-(carbomethoxy)benzoate Methyl isophthalate Morflex 1129 NSC 15313 Uniplex 270. Chemical intermediate in the synthesis of polyesters. Used as a plasticizer, modifies clarity and melting point of PET resins used in films, blow-molded bottles, and similar products. Needles mp = 67.5° bp = 282° d = 1.194 Xm = 280, 288 nm (MeOH) slightly soluble in H2O, Morfiex Unitex. 

In standard classification for vinyl plastics used in biomedical applications, a plasticizer is specified with prefix letter The letter is followed by a number from 1 to 14 which characterizes the type of plasticizer (e g., 1 - none, 2 - adipic acid derivative, 3 -azelaic, 4 - benzoic, 5 - citric, 6 - isophthalic, 7 - myristic, 8 - phosphoric, 9 - phthalic, 10 - sebacic, 11 - terephthalic, 12 - poly ether, 13 - polyethylene glycol, 14 - polyesters, 999 - other). The second letter specifies secondary plasticizer (e.g., A - none, B - alkyl epoxy stearates, C - epoxidized tall oil, D - epoxidized soybean oil, E - epoxidized linseed oil, F - epoxidized sunflower oil, Z - other). This classification is used to guide design engineers. Classification is not applicable to long-term implants. If there is a conflict between provisions of this standard and detailed specification for a particular device, the latter takes precedence. 

After removal of water and cooling, the fluid polyester may be dissolved in a reactive monomer in the same kettle, or it may be shipped to users who add the monomer and catalyst in their plants. Styrene is most widely used as the reactive monomer. Others sometimes used as diallyl phthalate, diallyl isophthalate, and triallyl cyanurate. A peroxide catalyst is generally used for the final co-polymerization. These unsaturated polyesters are thermosetting and are most widely used in reinforced plastics for making boat hulls, trays containers, and panels, and in potting of electrical assemblies. 

Unlike typical polyesters, vinyl esters have no internal ester linkage and, therefore, are less susceptible to hydrolysis. In addition, the great accessibility of the vinyl sites essentially ensures their complete consumption in polymerization reactions. Accelerators, stabilizers, and initiators have also received study for these systems.Isophthalic acid and bisphenol-A based polyesters are in competition with the vinyl esters for the corrosion-resistance reinforced plastics market. 

High molecular weight linear polyesters from 1,4-butanediol (H0-(CH2 40H) and terephthalic acid (para- (COOH)2) are successful engineering plastics. They are not used as a blister (see-through) packaging material, however. A polymer for the blister-packaging market is made from the two monomers above plus isophthalic acid (meta- (COOH)2). Explain the difference in applications. 

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