(250d) Polymer Dynamics and Rheology in Designing and Understanding Polymeric Biomaterials for Tissue Engineering Applications

In this study, the importance of understanding chain structure and physical properties in designing novel polymeric biomaterials has been shown on one promising bone-tissue-engineering materials poly(propylene fumarate) (PPF) with 38 molecular weights and a multiblock copolymer polypropylene-co-polycaprolactone (PPF-co-PCL) with 15 compositions. For PPF, a variety of microscopic chain dimensions and macroscopic physical properties for both melts and solutions have been given and correlated, which are informative for practical and theoretical purposes in both fields of biomaterials and polymer dynamics. For PPF-co-PCL, rheological measurements have been performed on copolymers and their parent homopolymers at various temperatures to obtain zero-shear viscosity η₀, storage and loss moduli G' and G". The relaxation times decrease dramatically as much as 4-5 decades through changing chain friction coefficient and flexibility after introducing PCL segments into PPF backbone. Therefore, the objective of this work is not only to supply an extensive library of important chain parameters and physical properties of both groups of polymers, but also to further examine the validity of state-of-art theoretical work on chain dynamics on unsaturated polyesters and reveal the necessity of using rheology to advance the development of new biomaterials.