Dimethanol terephthalate

Ester Single Tg SEM 11 was made from ethylene glycol and cyclohexane-1,4-dimethanol terephthalate Papadopoulou and Kalfoglou (1997a)... 

See listed abbreviations in Polymers forCoextmded Films section. Poly(ethylene glycol-co-cyclohexane-l,4-dimethanol terephthalate). 

PCXA Copolyester poly(cyclo-hexane-dimethanol-terephthalate acid) acid... 

The principal solvolysis reactions for PET are methanolysis with dimethyl terephthalate and ethylene glycol as products, glycolysis with a mixture of polyols and BHET as products, and hydrolysis to form terephthalic acid and ethylene glycol. The preferred route is methanolysis because the DMT is easily purified by distillation for subsequent repolymerization. However, because PET bottles are copolyesters, the products of the methanolysis of postconsumer PET are often a mixture of glycols, alcohols, and phthalate derivatives. The separation and purification of the various products make methanolysis a cosdy process. In addition to the major product DMT, methanol, ethylene glycol, diethylene glycol, and 1,4-cyclohexane dimethanol have to be recovered to make the process economical.1... 

Prepolymer produced via the terephthalic acid (TPA) monomer route shows an increased reactivity in comparison with that produced by the dimethanol tereph-thalate (DMT) monomer process [49], This behavior is possibly caused by the enhanced CEG content, which is usually higher in products from the TPA process as a result of insufficient conversion of the acid monomer in the esterification reaction (Figure 5.23). The increased reactivity may be caused by an autocatalytic influence of the carboxylic groups which seems to be disturbed by an unbalanced content of OH groups in the case of degradation. 

When the full improved property potential of PEN compared to PET is not needed for an end-use application, copolyesters may be considered. Common available comonomers which may be used include terephthalic acid and isoph-thalic acid (IPA), DEG and cyclohexane dimethanol glycols. 

One critical issue is the evaluation alternative. In the case of methanolysis, the alternatives are to make DMT and EG by depolymerization or secure materials from traditional petrochemical sources. For hydrolysis, the alternatives are TPA and EG by depolymerization or from traditional sources. For both technologies, the amount of copolymerizing isophthalate and/or 1,4-cyclohexane dimethanol is likely to be too little to justify the cost of recovery. For the various forms of glycolysis and the methanolysis/BHET hybrid, the alternative is the BHET and BHET-like materials made by the combination of a terephthalate and isophthalate plus EG and various glycols. Market prices exist for TPA and EG. BHET is not an item of commerce, and so the value must be imputed from the market price for TPA (the modern terephthaloyl) and EG, plus a conversion cost. 

The following substances are recommended starting materials for unsaturated polyesters fumaric acid, maleic acid, methacrylic acid, adipic acid, phthalic acid, resi-nic acid, isophthalic acid, terephthalic acid, hydrated or halogenated phthalic acids, aliphatic and substituted aliphatic single and multi-functional alcohols up to C)8, alkoxylated and hydrated phenols and bisphenols, styrene, vinyltoluene, acrylic acid and methacrylic acid esters of the Ci-C4 alcohols, and tricyclodecane dimethanol. 

PCTG Poly (cyclohexane dimethanol-co-ethylene glycol terephthalate)... 

Ester Single Tg I was Ardel D-lOO II was made from cyclohexane dimethanol and terephthalic acid/isophthalic acid (80-87 % tere) (Kodar A-150) and another copolymer with tere/iso ratio of 70/30 Robeson (1985)... 

Ester Single 7g II was made from terephthalic acid and 1,4-cyclohexane-dimethanol and up to 60 mol% ethylene glycol A23... 

Polycyclohexylendeimethylene tere-phthalate [PCT, poly( cyclohexane-1,4-dimethylene terephthalate)] n. The newest member of the commercial thermoplastic-polyester family, PCT is produced by reacting 1,4-cyclohexane dimethanol with dimethyl terephthalate. It is superior to its siblings (PET and PBT) in that it can serve... 

Eastman PA-l-2CNCp is a cyclohexane dimethanol, neopentyl glycol, 1,6 hexane diol, isophthalic acid, terephthalic acid, 1,4-cyclohexane dicarboxylic acid polyester of acid value 4 and 60% solids in Solvesso 150 solvent. The formulation is available from Eastman Chemical (publication N-330B). Eastman C-11 ketone is a ketone solvent blend with BR 200-240 °C supplied by Eastman Chemical. 

Another property recently reported in detail for polyarylate is in the polymer blend area. An early French patent [33] noted that Bisphenol A polyarylate and poly(ethylene terephthalate) yield interesting mixtures. Further studies by Kimura et al. [34] and Robeson [35] found that with modest ester-exchange polyarylate and poly(ethylene terephthalate) form miscible mixtures (thus transparent with Tg values between the constituent values). Polyarylate and poly(butylene terephthalate) were noted to be miscible without ester-exchange [36]. Miscibility of three different cyclohexane dimethanol based polyesters with polyarylate was observed under minimum time and temperature exposure conditions [35]. 

Figure 3.12 Gas chromatograms of hydrolysates of (a) silyl derivative of polyethylene terephthalate, (b) silyl derivative of ethylene glycol 1,4 butane diol and trans isomers of 1,4 cyclohexane diol dimethanol and (c) silyl derivative of iso- phthalic and terephthalic acids derived from a polyester. Reproduced with permission from B.J. Allen, G.M. Elser, K.P. Keller and H.D. Kinder, Analytical Chemistry, 1977, 49, 741. 1977, ACS...

In addition to degradation rate dependence on crystallinity, it turns out that the crystalline zones within a plastic are enzymatically hydrolyzed more slowly than amorphous zones. [917], [920], and [921] show that crystallinity in PCL films increases during degradation, i. e., the amorphous phases are reduced. An analogous effect can be observed in the degradation of copolymers made from 1,4-butane-diol, 1,4-cyclohexane dimethanol, succinic acid, and terephthalic acid, where degra-... 

PETG polyester based on cyclohexane dimethanol/ethylene glycol/terephthalic acid... 

Copolyester Single Tg n was made fiom terephthalic acid and a mixture of ethylene glycol and 1,4-cyclohexane dimethanol 965... 

---