During {HEAD ~ the polymerization} of {TAIL ~ the monomers} required to form the polyethylene terephthalate, a quantity of polyethylene glycol is copolymerized therewith to form a polymer which exhibits a substantial intrinsic viscosity  
of
During { HEAD ~ the polymerization } of { TAIL ~ the monomers } required to form the polyethylene terephthalate , a quantity of polyethylene glycol is copolymerized therewith to form a polymer which exhibits a substantial intrinsic viscosity
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH