Synthesis of 1,3‐bis(2‐trimethylsilyloxyhexafluoro‐2‐propyl)‐5‐allylbenzene and its introduction into polysiloxane chains

The synthesis of 1,3‐bis(2‐trimethylsilyloxyhexafluoro‐2‐propyl)‐5‐allylbenzene ( IV ) is described, starting from commercially available 1,3‐bis(2‐hydroxyhexafluoro‐2‐propyl)benzene. After the first step of iodination was optimized, a series of metallating agents were tested, before allylation, so that the best reagent could be selected. The allyl compound IV was then added to two different copoly(dimethyl‐methylhydro)siloxanes, PS 122.5 and PS 123 from Gelest/ABCR, via platinum‐catalyzed hydrosilylation, for the preparation of new polysiloxanes bearing specifically designed pendant aryl moieties. The different synthesized products were characterized by spectroscopic methods (IR and ¹H, ¹³C, ¹⁹F, and ²⁹Si NMR), and the glass‐transition temperatures of copolymers VI‐2 , VI‐3 , and VI‐4 were measured. It was shown that the higher the amount was of grafted fluoroaryl groups, the higher the glass‐transition temperature was. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1400–1410, 2003