One example of such a material is urethane, including polyurethane resin, {TAIL ~ polyurethane rubber}, and {HEAD ~ combinations} thereof 
One example of such a material is urethane , including polyurethane resin , { TAIL ~ polyurethane rubber } , and { HEAD ~ combinations } thereof
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH