Polyoxide aliphatic

In Table 6.10 the influence of functional groups on the Ym(CH2) increments are given m = 0 means no functional goups in aliphatic carbon chains and m = 1 means with one functional group, like in polycaprolactams, polyoxides, etc.(see Fig. 6.7a). 

Figure 1.15 shows polyisobutylene, a vinylidene polymer with symmetric substitution, and thus without stereoisomers. Cis and trans isomers are possible in butenylene polymers. Two examples are at the bottom of Fig. 1.15. They are not interconvertable by rotating of the molecule. Shown in the figures are the trans isomers (). In the cis isomers the backbone chain continues on the same side of the double bond ( /). In Figs. 1.16 and 1.17 a series of vinyl and vinylidene polymers are shown. The above-mentioned PTFE, poly(vinyl butyral), and poly (methyl methacrylate) are given, starting in Fig. 1.17. Polyoxides are drawn at the bottom of Fig. 1.17, and the top of Fig. 1.18. Poly(ethylene terephthalate) and two aliphatic polyamides (nylon 6,6 and nylon 6) round out Fig. 1.18. The 20 polymers just looked at should serve as an initial list that must be extended many-fold during the course of study of thermal analysis of polymeric materials.

The table of group vibration frequencies with their -temperatures and the number of skeletal vibrators, with their two -temperatures permits us now to calculate the total and, with help of the expressions for Cp - C, also Cp. Figure 2.55 shows the results of such calculations, not only for POM and PE in the bottom two curves, but also for a larger series of homologous, aliphatic polyoxides. The calculations are based on the proper number of group vibrations for the number of O- and CH2- in the repeating unit from Fig. 2.54 ... 

The more detailed analysis of the heat capacities of the solid, aliphatic polyoxides is summarized in the next two figures. Figiu-e 2.56 displays the deviations of the calculations from the experiment. Although the agreement is close to the accuracy of the experiment (+3%), some systematic deviation is visible. It is, however, too little to interpret as long as no compressibility and expansivity data are available for... 

Change of Theta-temperatures of Solid Aliphatic Polyoxides with Composition... 

Data on the supercooling of aliphatic polyoxides in Fig. 3.91 can be compared to the paraffin and polyethylene data used for the illusdation of the limits of molecular nucleation in Fig. 3.75. In the same range of chain length all three polymers, polyethylene, PE, poly(oxyethylene), POE, and POTM, decrease in amount of supercooling due to molecular nucleation. The polyoxides, however, show a second... 

Since group vibrations are not affected much by their chemical environment, it becomes possible from the table in Fig. 5.19 to compute the heat capacity not only of polyoxymethylene, but also of all other aliphatic polyoxides, as shown in the bottom figure. The abbreviations are to be translated as follows ... 

Compulation of Heal Capacities of Solid Polyethylene and Aliphatic Polyoxides... 

---