1.4- Cyclohexylene glycol

Another amorphous terephthalate has also been introduced commercially. This is a copolymer based on 1,4-cyclohexylene glycol with a combination of terephthalic acid and isophthalic acid. The copolymer is claimed to have excellent optical properties, have low moulding shrinkage and be relatively easy to vaccum form. As with other terephthalates it is considered in more detail in Chapter 25. 

In 1972 Eastman Kodak introduced a copolymer produced by reacting 1,4-cyclohexylene glycol with a mixture of isophthalic and terephthalic acids. Thus the polymer contains 1,4-cyclohexanedimethyloxy units (I), terephthalic acid units (II) and isophthalic acid units (III) Figure 25.20). 

A similar product is Kodar PETG 6703 in which one acid (terephthalic acid) is reacted with a mixture of glycols (ethylene glycol and 1,4-cyclohexylene glycol). A related glass-reinforced grade (Ektar PCTG) has also been offered. 

In 1958, Eastman Kodak introduced a more hydrophobic polyester fiber under the trade name Kodel. The raw material for this polyester is dimethyl terephthalate. Reduction leads to 1,4-cyclohexylene glycol, which is used with dimethyl terephthalate in the polycondensation (ester exchange) reaction. 

Eastman Kodak also introduced in 1972 a copolyester based on 1,4-cyclohexylene glycol and a mixture of terephthahc and isophthahc acids. The product is sold as Kodar PETG. Being irregular in structure, the polymer is amorphous and gives products of brilliant clarity. 

Kodar PETG Eastman Chem. Intern. Copolyester based on 1,4-cyclohexylene glycol and a mixture of terephthalic and isophthalic acids... 

CAS 105-08-8 EINECS/ELINCS 203-268-9 Synonyms Bis (hydroxymethyl)-1,4 cyclohexane 1,4-Bis (hydroxymethyl) cyclohexane 1,4-Bls (hydroxymethyl) cyclohexane (cis and trans) CHDM Cyclohexane-1,4-dlmethanol 1,4-Cyclohexylene glycol 1,4-Dlmethylolcyclohexane Hexahydro-2-oxo-1,4-cyclohexanedimethanol Classification Nonaromatic alcohol Definition Mixed cIs and trans-isomer prod. 

Cyclohex-1,2-ylenediaminetetra (acetic acid) trans-1,2-Cyclohexylenediaminetetraacetic acid (1,2-Cyclohexylenedinitrilo) tetraacetic acid. See Cyclohexanediamine tetraacetic acid 1,4-Cyclohexylene glycol. See 1,4-Cyclohexanedimethanol Cyclohexylene oxide. See Cyclohexene oxide Cyclohexyl epoxystearate Empiricai C24H44O3 Properties M.w. 380.61 Uses Plasticizer and costabilizer for PVC 1 -Cyclohexylethanol... 

Kodar PETG PETG, a thermoplastic copolyester of 1,4 cyclohexylene glycol and mixture of iso- and terephthalic acids Eastman Chem. 

Polycyclohexylenedimethylene terephthalate (PCT). Another polyalky-lene terephthalate polyester of significant commercial importance is PCT a condensation product of the reaction between dimethyl terephthalate and 1,4-cyclohexylene glycol, as shown in Fig. 1.20. 

Polycyclohexylenedimethylene terephthalate (PCI) is a condensation product of the reaction between dimethyl terephthalate and 1,4-cyclohexylene glycol. This material is biaxially oriented into films, and although it is mechanically weaker than PET, it offers superior water and weather resistance. PCT also differentiates itself from PET and PBT by its higher heat-distortion temperature. Copolymers of PCT include an acid-modified polyester and a glycol-modified polyester. Major suppliers of PCT are Eastman Chemical (Thermix, Eastar) and GE Plastics (Valox). 

A third class of terephthalate polyester consists of polymers based on 1,4-dimethylolcyclohexane (1,4-cyclohexylene glycol). Three polymers of this type are commercially available and are described in this section. 

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