abstract |
A polyisobutylene polyurethane (PIBU) copolymer comprising a polyisobutylene (PIB) having a molecular weight of about 400 to about 5,000 daltons; a hard segment (PU) formed from reacting the PIB with diisocyanates and from reacting one of the diisocyanate linked to the PIB with a chain extender. The chain extender has a length based on a number of carbon atoms in the chain extender. A shore hardness of the PIBU copolymer is determined, in part, by either one or more of a PIB:PU ratio, the length of PIB, the type of diisocyanate, and the type and length of the chain extender. |