Thermal degradation of some ferrocene-containing poly(aryleneethynylene)s

Abstract

This study reports the thermal degradation behaviour of two ferrocene-containing poly(aryleneethynylene)s. It reveals the influences of polymer structures and working atmospheres on the mechanism of thermal degradation by means of the gas analysis produced upon thermal decomposition in the mass spectrometer and FTIR spectrophotometer using the TG/MS/FTIR coupled technique. The cross-linked ferrocene-containing poly(aryleneethynylene) P1 contains terminal ferrocene groups. The initial thermal decomposition of this polymer, in an inert atmosphere, takes place at the terminal ferrocene groups, as evidenced by the presence of the m/z=186 ionic fragment. There is a mass increase in the air, which can be associated with the production of FeO or Fe2O3; at temperatures exceeding 170°C, the degradation of the cyclopentadienyl (C5H5+) ion also occurs. In the case of the polymer P2, the initial thermal decomposition in an inert atmosphere, but probably also in the air, takes place at the lateral hexadecyloxy chains due to the fact that ionic fragments resulting from the CC splitting are identified by the general formula CnH2n-1, CnH2n and CnH2n+1 in the MS spectra. The FTIR spectra further confirm this observation; CH aliphatic stretching is found in the range of 3000–2800cm−1.