1,4-Cyclohexane dimethanol

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... 

FIGURE 2 Glass transition temperature of a polymer prepared from 3,9- bis ( ethylidene- 2,4,8,10-tetraoxaspiro [ 5,5 ] undecane ) and mixtures of trans-cyclohexane dimethanol and 1,6-hexanediol as a function of mol% 1,6-hexanediol. (From Ref. 13.)... 

FIGURE 8 Cumulative release of methylene blue (o), [1,4 - 14c] succinic acid (a), and polymer weight loss ( ) from polymer discs prepared from 3,9-bis(ethylidene-2,4,8,10-tetraoxaspiro[5,5Jundecane) and a 50 50 mole ratio of trans - cyclohexane dimethanol and 1,6-hexanediol at pH 7.4 and 37°C. Polymer contains 0.1 wt% [1,4 — [succinic anhydride and 0.3 wt% methylene blue. (From Ref. 

FIGURE 13 Cumulative release of -nitroacetanilide (PNAC) from polyester discs prepai ed from 3,9-bis(ethylidene-2,4,8,10-tetraoxas-piro[5,5]undecane) and a 60 10 30 mole ratio of trans-cyclohexane dimethanol, 1,6-hexanediol, and triethylene glycol at pH 7.4 and 37 C. PNAC content 2 wt% (o) 0 mol%, ( ) 0.25 mol%, ( ) 0.50 mol% 9,10-dihydroxystearic acid. (From Ref. 23.)... 

FIGURE 25 HPLC chromatograms of polymer samples hydrolyzed to cleave all ortho ester bonds. Samples were prepared at either 130, 145, or leO C. Polymer prepared from 3,9-bis(ethylidene-2,4,8,10-tetraoxaspiro)5,5]undecane) and a 25 75 mole ratio of trans-cyclohexane dimethanol and 1,6-hexanediol and contained 3 wt% phthalic anhydride and 7.5 wt% cyclobenzaprine hydrochloride (CBP). 

Theobromine was determined by GC in various foods (bitter chocolate, milk chocolate, chocolate cake, cocoa powder, chocolate milk), and results are given in graphs and tables.27 Homogenized samples were boiled in alkaline aqueous media, then fat was extracted with n-hexane. The aqueous layer was acidified with diluted HC1 and NaCl was added. Theobromine was extracted from this treated aqueous solution with dichloromethane and the extract was evaporated to dryness. The residue was redissolved in dichloromethane containing an internal standard. GC analysis was performed on a column packed with 1% cyclohexane dimethanol succinate on Gaschrom Q, with FID. Average recoveries were 99 to 101%, coefficient of variation was less than 3% and the limit of detection for theobromine in foods was about 0.005%. 

The SSP process is obviously limited by the melting point of the prepolymer and the equilibrium temperature of the polymer process. The SSP reaction becomes too slow at temperatures below 190 °C in commercial processing. Temperatures below this level are only of scientific interest or applicable in the case of thermally sensitive polyesters. The increase in IV for the most common polyesters decreases in relation to the glycolic component, as shown in Figure 5.15 however, this figure does not show the behavior of cyclohexane dimethanol (CHDM) and PEN [30],... 

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. 

Cyclohexane dimethanol divinyl ether (donor)-alkyl maleimide (acceptor)... 

Since the energy of the boat form is 23 kJ mol-1 above the chair form, the chair conformation Is the only one that is considered in these calculations. Moreover, the equatorial, equatorial conformation is the most favoured one in transA,4-cyclohexane dimethanol. 

Neopentyl glycol adipate Cyclohexane dimethanol adipate Tetramethyl cyclobutanediol adipate Neopentyl glycol succinate Butane-1,4-diol succinate Phenyl diethanolamine succinate Ethylene glycol sebacate Neopentyl glycol sebacate Ethylene glycol isophthalate Ethylene glycol phthalate... 

Cyclohexane dimethanol diglycidyl ether Resorcinol diglycidyl ether... 

Butane diol is an important chain extender for polyurethanes. 1,4 Cyclohexane dimethanol is also used. 

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