Methylsiloxane cyclolinear polymers

The results of the thermal decomposition of branched chain methylsiloxane polymers and polycyclics indicate that the decomposition is similar to that observed with PDMS. The structures of the degradation products from (T2D6) and (T2D9) show that they originate from the cyclolinear polymers through the loop mechanism. Indeed, considering the bicyclic compounds of series I in Table 13 they can only be formed via a concerted intramolecular mechanism. Products in series II could result from three consecutive rearrangement steps which would explain the presence of the three-mem-bered cyclic siloxane... 

Thermal decomposition products [80] of two methylsiloxane polymers of strictly regular and known structure were examined to clarify the mentioned relations. The polymers studied include di- and tri-functional structural units (i.e. (CH3)2Si02/2 denoted as -D- and CFI3Si03/2 denoted as - / <) and involve cyclolinear chain structures, as follows ... 

Figure 12. Cyclolinear methylsiloxane polymers pyrolysis products separated in OV-1 gas chromatographic phase [80],...

Blazsd, M., T. Szekely, and N. Makarova, Thermal decomposition of cyclolinear and cyclic methylsiloxane polymer, J. Polym. Set, 23 2589-2599 (1985). 

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