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