1,3-Propanediol comparative data

Of the seven hydroxyl-containing peroxides listed in Table 2, six are tert-butylperoxy derivatives. Although the fert-butyl group kinetically stabilizes the peroxide so that its combustion enthalpy can be measured, its presence makes finding suitable reference compounds such as hydrocarbons and ethers to compare in reactions 2-9 more difficult. Reaction 6 is the only reaction for which there are enthalpy of formation data for the requisite comparison compounds. Three hydroxy peroxides, all from the same source, have remarkably consistent enthalpies of reaction 6 in both the liquid and gas phases. The mean values derived from the viciwaZ-dioxygen substimted alcohols, 2-tert-butylperoxyethanol, 2-fert-pentylperoxyethanol and 3-fert-butylperoxy-1,2-propanediol, are —304.0 + 4.1 kJmol (Iq) and —257.1 + 6.0 kJmol (g). However, these values... 

All copolymers have a higher solubility, higher glass transition temperature, and a better thermal stability than PET. The thermal properties are comparable to those of PEN, and for 1,3-propanediol modified samples these properties are even better than those of PEN. Longer alkyl side chains in the alcohol decrease the thermal properties. Chemical resistance data are collected in Table 11.9. The chemical resistance is expressed at the retention of elongation at a break after chemical treatment. 

The melting point variation for these polyesters with increasing methylene units in the diacid moiety, in comparison to the corresponding for 1,2-ethanediol and 1,4-butanediol can be seen in Figure 5. To construct the plots, data from the paper of Muller et al were also used [4]. It is obvious that for the 1,3-propanediol polyesters the variation of the melting points is small compared to those polyesters of the other two diols. 

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