ULTRASONIC SOLUTION DEGRADATIONS OF POLY(ALKYL METHACRYLATES)

Ultrasonic (70 w, 20 kHz) solution (2%) degradations of poly(alkyl methacrylates) have been carried out in toluene at 27 degree C and in tetrahydrofuran (THF) at minus 20 degree C. M OVER BAR //w and M OVER BAR //n of all polymers (before and after sonification) were computed from GPC. Irrespective of the alkyl substituent, M OVER BAR //w decreased rapidly at first and then slowly approached limiting values. All M OVER BAR //w ROOT M//n ratios were in the vicinity of 1. 5 at the limiting chain lengths. For identical M OVER BAR //n, the rate constants k were (4. 2 plus or minus 2. 0) multiplied by 10** minus **6 min** minus **1 in toluene at 27 degree C and (5. 4 plus or minus 2. 0) multiplied by 10** minus **6 min** minus **1 in THF at minus 20 degree C.