EFFECTS OF POLYMERIZATION CONDITIONS WHEN MAKING NORBORNENE-ETHYLENE COPOLYMERS USING THE METALLOCENE CATALYST ETHYLENE BIS(INDENYL) ZIRCONIUM DICHLORIDE AND MAO TO OBTAIN HIGH-CLASS TRANSITION-TEMPERATURES

Using 70 mol % norbornene in the monomer mixture before polymerization , the influences of different polymerization conditions were studied. It was found that by increasing the temperature from 10 to 70 degrees C, the yield increased and the molecular weight decreased; and when in creasing the ethylene pressure from 2 to 6 atm, yield and molecular we ight increased. The highest glass transition temperatures, however, we re achieved at 30 degrees C and 4 atm. Further improvements could be o btained by increasing the amount of catalyst or Al/Zr ratio. Using the conditions of 30 degrees C, 4 atm, 4 mg catalyst, 3000 Al/Zr, 250 mL toluene solution, and 30 min, the amount of norbornene was increased f rom 31.1 to 90 g, resulting in an increase in the glass transition tem perature from 98 to 155 degrees C. (C) 1997 John Wiley & Sons, Inc.