Poly(ε-caprolactone)-based hyperbranched polyurethanes prepared via A2 + B3 approach and its shape-memory behavior

Abstract Novel hyperbranched shape-memory polyurethanes based on e-caprolactone were prepared via A 2  + B 3 approach with different molecular weights ( M w ); the molecular weights ranged from 7.2 × 10 4 to 32.3 × 10 4  g/mol. The hard segment content was varied minimally and the B 3 monomer was also varied. The polymers were characterized by GPC, DSC, DMA, WAXD and shape-memory test. The crystallinity calculated from DSC and WAXD data indicated that the highly branched architecture does not affect the crystallization of these polymers. More interestingly the storage modulus ratios ( E ′ ratios) of hyperbranched polymers were found to be significantly high compared to the linear analogue. As a consequence, hyperbranched polymers show 100% more shape-recovery rate compared to their linear counterpart. Antimicrobial susceptibility tests confirmed that these polymers have good antimicrobial activity which is an essential requirement of medical implants.