Preferably {HEAD ~ the first synthetic material} is {TAIL ~ an aramide filament}, and preferably the second synthetic material is a pre oxidized filament 
is
Preferably { HEAD ~ the first synthetic material } is { TAIL ~ an aramide filament } , and preferably the second synthetic material is a pre oxidized filament
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH