SELECTIVE PYROLYSIS OF POLYSTYRENE TO THAT WITH A DESIRED LOW POLYMERIC DEGREE

To obtain low polymeric polystyrene (PS), pyrolysis of high polymeric PS in solution was studied in the temperature range from 290 to 400 de grees C by using additives or acid catalysts. The low polymeric PS tar geted here was that with average molecular weight of 10(4). When the f eed PS was pyrolyzed in tetralin by adding sulfur or diphenyl disulfid e, the molecular weight of PS decreased greatly, even at lower tempera tures, and the desired low polymeric PS was formed in a relatively lar ge amount at the temperatures below 350 degrees C. The degradation beh avior was able to be explained in terms of a random polymer chain scis sion mechanism initiated by sulfur radicals formed from the additives. (C) 1998 John Wiley & Sons, Inc.