Investigation of Structure-property Relationships of Polyisobutylene-based Biomaterials: Morphology, Thermal, Quasi-static Tensile and Long-term Dynamic Fatigue Behavior
This study examines the morphology, thermal, quasi-static and long-term dynamic creep properties of one linear and three arborescent polyisobutylene-based block copolymers (L_SIBS31, D_IBS16, D_IBS27 and D_IBS33). Silicone rubber, a common biopolymer, was considered as a benchmark material for comparison. A unique hysteretic testing methodology of Stepwise Increasing Load Test (SILT) and Single Load Test (SLT) was used in this study to evaluate the long-term dynamic fatigue performance of these materials. Our experimental findings revealed that the molecular weight of polyisobutylene (PIB) and polystyrene (PS) arms [MnPIB(arm) and MnPS(arm)], respectively had a profound influence on the nano-scaled phase separation, quasi-static tensile, thermal transition, and dynamic creep resistance behaviors of these PIB-based block copolymers. However, silicone rubber outperformed the PIB-based block copolymers in terms of dynamic creep properties due to its chemically crosslinked structure. This indicates a need for a material strategy to improve the dynamic fatigue and creep of this class of biopolymers to be considered as alternative to silicone rubber for biomedical devices.
Journal of the Mechanical Behavior of Biomedical Materials
Gotz, C.; Lim, G. T.; Puskas, Judit; and Altstadt, V., "Investigation of Structure-property Relationships of Polyisobutylene-based Biomaterials: Morphology, Thermal, Quasi-static Tensile and Long-term Dynamic Fatigue Behavior" (2012). Chemical and Biomolecular Engineering Faculty Research. 514.