SOLID RESIDUE FORMATION OF RTV SILICONE-RUBBER DUE TO DRY-BAND ARCINGAND THERMAL-DECOMPOSITION

In this study, the solid residue of a RTVSR (room temperature vulcaniz ed silicone rubber) prepared in a tracking test are analyzed. By using the techniques of KBr pellet FTIR (Fourier transformed infra-red) spe ctroscopy and XRD (X-ray diffractometry), cristobalite SiO2, amorphous SiO2, amorphous SiO2.xH(2)O (namely, silica gel) and moissanite SiC a re identified in the solid residue. The TG (thermogravimetry) and TG-D TA (differential thermal analysis) are applied to study the thermal ch aracteristics of RTVSR and the concentration of carbon which contribut es to tracking of polymers is evaluated. By comparison of the solid re sidue of the tracking test to thermally decomposed RTVSR in air and ni trogen, models of chemical changes during the formation of the solid r esidue are proposed. Furthermore, it is found that RTVSR has a excelle nt property not to form conductive carbon.