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
Ch. Bergstrom et Jv. Seppala, 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, Journal of applied polymer science, 63(8), 1997, pp. 1063-1070
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.