Polymer resin terephthalic acid

Dimethyl terephthalate (DMT) is produced either by the esterification of terephthalic acid or the esterification of monomethyl terephthalate produced by oxidation of methyl p-toluate. DMT is consumed in the production of polyethylene terephthalate, the polymer used in the manufacture of polyester fibers, films and bottle resins. Terephthalic acid (TPA) is also used in the production of polyethylene terephthalate but does not consume methanol. Since TPA is continuing to increase its share of the market, DMT is expected to exhibit slower growth than the overall market for polyethylene terephthalate. 

Application Production of polymer-grade terephthalic acid (MTA). MTA is an excellent raw material to produce polyethylene tereph-thalate resin (PET), which is used for engineering plastics, packaging materials—like bottles and other food containers—as well as films. Also, integrated polyester producers use MTA to make various types of fibers. 

Small amounts of polymer-grade terephthaHc acid and dimethyl terephthalate are used as polymer raw materials for a variety of appHcations, eg, adhesives and coatings. They are also used to make high performance polymers or engineering resins. Poly(ethylene terephthalate) is itself an engineering resin, although one more widely used is poly (butylene) terephthalate, formed by reaction with 1,4-butanediol as the comonomer. 

RPLC-PDA is frequently used for quality control, such as the determination of free Irganox 1098 in PA4.6 (at 278 nm after dissolution/precipitation), of free Irganox 1010/1076 in PP (at 278 nm after extraction with MTBE, thus avoiding dissolution of polymer waxes), of Luperco 802 in PP (at 218 nm, after extraction with HCC13), and of Tinuvin 122 in HDPE (at 225 nm as diol). The advantages of the use of HSLC over conventional LC in QC of plastics and additives have been demonstrated, e.g. for AOs in PE, mixed phthalate esters and residual terephthalic acid in PET and partially cured epoxy resins [557],... 

Compared with other polymeric materials. LCPs have very high unidirectional properties. Iei/nt7 1 (Celanese Corp.t resins are primarily aromatic polyesters based on p-hydroxybenzoic acid and hydroxynaphthoic acid monomers. Xytlar " (Celanese Carp.) injection molding resins are polyesters based on terephthalic acid. />. p -dihydruxybiphenyl and p-hydroxybenzoic acid Differences in monomers are primarily responsible for the differences in specific properties and end uses. The fibrous nature of the polymers imparls good impact strengths. 

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). 

Polyesterification. High molecular weight linear polyester resins, such as poly(ethylene terephthalate) (PET), poly(propylene terephthalate) (PPT), and poly(butylene terephthalate) (PBT), can be produced by either transesterification of dimethyl terephthalate (DMT) with an excess of the corresponding diol or by direct esterification of terephthalic acid (TPA). Tetraalkyl titanates, such as TYZOR TPT or —TYZOR TBT, have been found to be excellent catalysts for either of these reactions. However, in the case of PET, the residual titanate catalyst reacts with trace quantities of aldehydic impurities produced in the polymerization process to generate a yellow discoloration of the polymer (468,469). In the case of PPT and PBT, where the color of polymer is not as critical, organic titanates are the catalyst of choice because of their greater reactivity than antimony or tin (470). Numerous processing variations have been described in the literature to minimize formation of tetrahydrofuran in the PBT process (471—472). 

Glyptal resin makes a strong, solid polymer matrix for electronic parts. Glyptal is made from terephthalic acid and glycerol. Draw the stmcture of Glyptal , and explain its remarkable strength and rigidity. 

Terephthalic Acid (Dimethyl Terephthalate). Terephthalic acid (TPA) and dimethyl terephthalate (DMT) are precursors for polyethylene terephthalate (PET), which in turn is used in the production of polyester fibers and film polyester thermoplastic PET bottles, and other resins. In 1999 the total U.S. production was more than 9 billion lb. In the past, the relative ease of producing high-quality DMT gave it the largest share of the terephthalate market. The trend is now toward TPA, as the result of technological advances that permit better purification of TPA and the use of the acid directly in polymer formation. The capacity is about 3 to 1 split in favor of TPA process. 

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. 

Polymer concretes show excellent mechanical properties and chemical resistance compared with conventional cement concretes. Polymer concretes can be cured quickly by the use of curing agents. Thus, the applications of polymer concretes are being increased. One of the popular polymers for polymer concretes is unsaturated polyester (UPE) resin. The properties of UPE resin can be modified by changing its molecular features. For the synthesis of the resin, phthalic anhydride or isophthalic acid as well as maleic anhydride can be employed to modify the mechanical properties or hydrothermal resistance. Terephthalic acid which is also used for the synthesis of poly ethylene terephthalate (PET) enhances the thermal resistance of the cured UPE resin. However, the synthesis of unsaturated polyester resin from terephthalic acid is difficult. One method to synthesize unsaturated polyester from terephthalic acid is the use of recycled PET. 

It might then be oxidized enzymatically with hydrogen peroxide to produce a polymer, as described in Chap. 9. A final cure with diisocyanates or bisoxazolines would yield the equivalent of a phenol-formaldehyde resin without use of the carcinogenic formaldehyde. Terephthalic acid for polyethylene terephthalate) might be made by the oxidation of p-cymene, although two carbon atoms would be... 

Terephthalic acid, hexahydro-. See 1,4-Cyclohexanedicarboxylic acid 1,4(8)-Terpadiene. See Terpinolene Terpene polymer resin. SeeTerpene resin... 

Neopentyl glycol Pentaerythrityl triallyl ether Terephthalic acid Tripropylene glycol comonomer, unsaturated polyesters Dipropylene glycol comonomer, vinyl acetate Bis (2-ethylhexyl) maleate Diisooctyl maleate comonomer, vinyl emulsion polymers Bis (2-ethylhexyl) maleate comonomer, vinyl resins Dibutyl fumarate Dibutyl maleate comonomer, vinyl/acrylic resins Benzyl methacrylate... 

Polyesters. Main chain of their macromolecules is characterized by repeated — CO—O— groups. Unsaturated polyester resins are thermosets used mainly for manufacturing glass fibre-reinforced plastics products. The most wide-spread type of thermoplastic polyesters are polymers of an aromatic dicarboxylic acid (mainly terephthalic acid) and an aliphatic diol (e. g. ethyleneglycol or butanediol). The most important representatives of this group are poly(ethylene terephthalate) and poly-(butylene terephthalate). Polyarylate aromatic polyester is a high-temperature thermoplastic of an aromatic dicarboxylic acid (terephthalic acid) and an aromatic diol (bisphenol-A). In the chemical sense, polycarbonate is also a polyester. 

Water and carbonated beverage bottles are made predominantly from poly(ethylene terephthalate) (PET). The polymer is made by condensation reaction of ethylene glycol with either terephthalic acid or its dimethyl ester. The process in practice includes three steps prepolymer formation, melt condensation to increase viscosity, and solid-state polymerization at 180-230°C to yield a resin with an average molecular weight that is high enough for use as bottle resins. Antimony trioxide is used as a catalyst in polymerization (Duh, 2002). 

Electrical conductivity measurements have been reported on a wide range of polymers including carbon nanofibre reinforced HOPE [52], carbon black filled LDPE-ethylene methyl acrylate composites [28], carbon black filled HDPE [53], carbon black reinforced PP [27], talc filled PP [54], copper particle modified epoxy resins [55], epoxy and epoxy-haematite nanorod composites [56], polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blends [57], polyacrylonitrile based carbon fibre/PC composites [58], PC/MnCli composite films [59], titanocene polyester derivatives of terephthalic acid [60], lithium trifluoromethane sulfonamide doped PS-block-polyethylene oxide (PEO) copolymers [61], boron containing PVA derived ceramic organic semiconductors [62], sodium lanthanum tetrafluoride complexed with PEO [63], PC, acrylonitrile butadiene [64], blends of polyethylene dioxythiophene/ polystyrene sulfonate, PVC and PEO [65], EVA copolymer/carbon fibre conductive composites [66], carbon nanofibre modified thermotropic liquid crystalline polymers [67], PPY [68], PPY/PP/montmorillonite composites [69], carbon fibre reinforced PDMS-PPY composites [29], PANI [70], epoxy resin/PANI dodecylbenzene sulfonic acid blends [71], PANI/PA 6,6 composites [72], carbon fibre EVA composites [66], HDPE carbon fibre nanocomposites [52] and PPS [73]. 

Aromatic polyesters or polyarylates have become an important class of high performance thermoplastic resins. Polymers based on bisphenol A with a mixture of isophthalic and terephthalic acids (APE) have been commercially available since the early 1970 s when Unitika first commercialized its U-Polymer in Japan. Since that time, other companies worldwide have entered the market with polymers of similar composition. Among those which have been active in this area are Teijin, Hooker, Union Carbide, Bayer and Dynamit Nobell>2.3,4. 

The properties similar to polycarbonates show polyarylate resins, synthesized usually by polycondensation process from terephthalic acid, isophthalic acid chloride, and BPA (Fig. 7.18). Polyarylates exhibit good impact strength, high deflection temperature, good chemical, thermal, weather and UV resistance as well as the dimensional stability higher than that of polycarbonates. Other important polymers with industrial significance, derived from BPA, are unsaturated polyesters (e.g., epoxyfuma-rate resins) [78], polyetherimides and polyether ether ketones (Fig. 7.18). 

Adipic acid dimethyi adipate (polyesters), acrylamide (acrylonitrile co-polymers), acrylonitrile (acrylamide co-polymers), acrylic acid (acrylic polymers), buta-1,3-dlene (PS co-polymers, elastomers), butan-1,4-diol (polyesters), 2,2-bis(4-hydroxyphenyl)butan-1-ol (polyesters), 1,1-bis(4-hydroxyphenyl)cyclohexane (polyesters), 4,4 -(propane-2,2-diyl)-dlphenol known as bisphenol A (polyesters), ethyleneglycol (polyestere), formaldehyde (phenol-formaldehyde resins), isophthalic acid (PET), caprolactame and C -C,2 aminocar-boxyllc acids and their lactames (polyamides), melamine (amino-formaldehyde resins), methacryllc acid and methyl methacrylate (acrylic polymers), methylstyrene (PS and co-polymers), propyleneglycol (polyesters), sebacic acid and dimethyl sebacate (polyesters), styrene (PS and co-polymers), terephthalic acid and dimethyl terephthalate (PET), vinyl acetate (vinyl acetate co-polymers), vinyl chloride (PVC and co-polymers), vinylldenechlorlde (PVdC and co-polymers)... 

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