Bis-HEMA Poly(Glycol/TMP Adipate)/IPDI Copolymer is a urethane polymer formed by a multi-step process. First, a polyester is made by condensing Glycol, Trimethylolpropane and Adipic Acid, which is subsequently reacted with Isophorone Diisocyanate. The resulting polymer is end-capped with HEMA.