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