Multiscale Characterization by Equibiaxial Tensile Testing and Time-Domain 1H Solid State NMR for PTMC-Based Networks for Tissue Growth

Abstract

Poly(trimethylene carbonate) (PTMC) is a biodegradable and biocompatible elastomer suitable for tissue growth in biomedical applications, due to its tunable mechanical properties and safe degradation behavior. While PTMC-based photo-cross-linked networks have demonstrated promising performance for such applications, their mechanical behavior under multiaxial loading remains seldom investigated. In this study, PTMC networks with macromer molecular weights ranging from 3 to 25 kg/mol were investigated to elucidate the relationship between network structure and biaxial tensile properties. A multiscale experimental approach combining biaxial tensile testing, Dynamic Mechanical Analysis (DMA), and Time-domain ${}^{1}H$ Solid State NMR measurements were employed. Magic Sandwich Echo experiments were used to probe molecular mobility, while Double-Quantum ${}^{1}H$ NMR measurements provided insight into the networks' cross-link densities. Obtained results reveal a direct correlation between network architecture, cross-link density and distribution, and macroscopic thermomechanical behavior. These findings highlight the importance of a deepened multiscale characterization for understanding and tailoring the mechanical performance of PTMC networks for biomedical applications.