Side chain melting

On treatment with bromine in carbon tetrachloride solution, it yields a dibromide in which two atoms of bromine have been fixed in the pro-penyl side chain, melting at 85° to 86°. 

A film of the branched chain 5-methylhexyl polymer absorbed at 315 nm and the position of this maximum was relatively insensitive to temperature. Likewise, no thermal transition was observed in the region where the side chain melting transition was seen for PDHS and its higher homologs. 

Figure 1. Side-chain melting point (Tm) versus the number of side-chain carbon atoms (Nc). Key O, PDM-PMAS and A, PMAS. The data for PMAS were obtained from reference 7.

First endotherm at 118 °C (28.1 kJ mol ), attributed to side-chain melting. 

Hsu et al. [87] performed DSC, IR and x-ray diffraction studies of POT, PDoDT, PTeDT and PHexDT Their conclusions are in accordance with those of Tashiro et al. and Prosa et al. In fact they enforced the conclusions of side chain melting by noting that uptake of vaporous hexane by PTeDT increases discontinuously at the temperature of the first specific heat anomaly. 

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