Thereafter, {HEAD ~ the reactor} is charged with the polymerization medium and {TAIL ~ ingredients} in the usual manner and the polymerization reaction commenced 
is charged with
Thereafter , { HEAD ~ the reactor } is charged with the polymerization medium and { TAIL ~ ingredients } in the usual manner and the polymerization reaction commenced
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH