The co catalyst is initially contacted with either of the transition metal catalyst or {HEAD ~ the electron donor} for {TAIL ~ a first contact time} of 5 120 seconds 
for
The co catalyst is initially contacted with either of the transition metal catalyst or { HEAD ~ the electron donor } for { TAIL ~ a first contact time } of 5 120 seconds
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH