 from about 75 mole percent to {HEAD ~ about 90 mole percent} of {TAIL ~ acrylonitrile}; and 
of
from about 75 mole percent to { HEAD ~ about 90 mole percent } of { TAIL ~ acrylonitrile } ; and
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH