1,4-cyclohexane dimethanol CHDM

Copolymers also exist such as PETG, offered by Eastman Plastics. The G indicates the use of a second glycol in the polymer, i.e. 1, 4-cyclohexane-dimethanol (CHDM). The resulting copolymer is an amorphous plastic which has a high degree of clarity, low haze, good resistance to acids, alkalis and many oils and excellent fragrance retention. 

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],... 

Crystallized PET does not exhibit a glass transition any more and would not become really pliable until the crystals start softening on approaching the melt region. Hence, crystallized preform cannot be blown into bottles unless special means are used. To slow down crystallization, the polymer is usually modified into a copolymer or by additives. Copolymers are formed by using diacids, glycols, or cyclohexane dimethanol (CHDM) [8], In all cases, retardation of crystallization opens a window for molding amorphous preforms. The crystallinity level in preforms is usually less than 4%. 

Other diacids and diols have recently been finding favour as ingredients of gelcoat resins. Examples of these are CHDA (1,4-cyclohexane dicarboxylic acid) MP diol (2-methyl-l,3-propanediol) CHDM (cyclohexane dimethanol) 1,5-propanediol and 1,6-hexanediol. Use of these components can bring about further improvements in weathering properties as well as other desirable features. 

F = number average functionality TMPD = 2,2,4-trimethyl-1,3-pentanediol CHDM = cyclohexane dimethanol BEPD = 2-butyl-2-ethyl-1,3-propanediol HBPA = hydrogenated bisphenol A TMP = trimethylol propane TME = trimethybl ethane... 

Cyclohexanedimethanol CAS 105-08-8 EINECS/ELINCS 203-268-9 Synonyms Bis (hydroxymethyl)-1,4 cyclohexane 1,4-Bis (hydroxymethyl) cyclohexane 1,4-Bis (hydroxymethyl) cyclohexane (cis and trans) CHDM Cyclohexane-1,4-dimethanol... 

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