Synthesis of -S—CH₂CH₂—OH telechelic polyisobutylenes and their use for the preparation of biostable polyurethanes

摘要

Sulfur containing, hydroxyl-telechelic PIBs, hydrolytically and oxidatively resistant, biocompatible and biostable polyurethanes (PUs) made therefrom, and methods for making both are disclosed. Well-defined hydroxyl telechelic PIBs are synthesized by a thiol-ene click photochemical reaction between PIBs carrying unsaturated end groups and 2-mercaptoethanol (HS—CH₂CH₂—OH). This regioselective process affords HO—CH₂CH₂—S-PIB-S—CH₂CH₂—OH (abbreviated herein as HO—S-PIB-S—OH) in high yield. In some embodiments, these HO—S-PIB-S—OH polymers may be reacted with diisocyanates and a chain extender to form sulfur containing PIB-based PUs. These sulfur containing PIB-based PUs have been found to have properties and chemical stability that are very similar to that of PUs made from di-hydroxyl terminated PIBs (OH-PIB-OHs) without sulfur, but have surprisingly increased creep resistance and are easier and less expensive to make.