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