INVESTIGATION OF THE THERMAL-STABILITY OF NITROXIDE CAPPED POLYSTYRENE BY TGA AND PY-GC MS/

The thermal stability of nitroxide capped polystyrene is examined by T GA and pyrolysis-GC/ MS. As opposed to technical polystyrene, these po lymers (M-n < 30000 g mol(-1)) show a characteristic decomposition ste p at 230-250 degrees C. The volatile product of this step is mainly st yrene, which results from retropolymerization. For some PS-N adducts t erminator fragments can be identified. Prolonged isothermal treatment of PS-N adducts at their step temperature yields polystyrene without n itroxides. The loss of molecular weight is in the range of technical P S by the same treatment, but the polymers keep a narrow molecular weig ht distribution.