Atomic force microscopic and encrustation studies of novel prospective polyisobutylene‐based thermoplastic elastomeric biomaterials

Abstract

Abstract This paper investigates the surface morphology of polyisobutylene–polystyrene (PIB–PS) block‐type thermoplastic elastomers, emerging new biomaterials, by atomic force microscopy (AFM). A novel aborescent PIB–PS block polymer (AR15) was synthesized through inimer ‐type living carbocationic polymerization and characterized in comparison with a semi‐commercial PIB–PS thermoplastic elastomer (TPE) (TS30). Tapping‐mode AFM revealed that PS spheres with a domain size of 45–60 nm were very irregularly distributed in the continuous PIB phase of the aborescent AR15 polymer, whereas ordered and mixed cylindrical/lamellar morphology with 25–31 nm hard phase appeared in a linear TS30 triblock polymer. Moreover, AFM revealed rough surface features of a 1 mm thick compression molded TS30 polymer disk coated with a probiotic protein. AR15 disks were used for in vivo urinary tract encrustation study. Encrustation of the PIB–PS disks was comparable or better than that of medical‐grade silicone rubber. The preliminary results imply the prospect of PIB–PS thermoplastic elastomers as emerging soft biomaterials. Copyright © 2003 John Wiley & Sons, Ltd.