Dynamic mechanical characterization of poly(glycerol sebacate)/poly(butylene succinate-butylene dilinoleate) blends for cardiac tissue engineering by flat punch nanoindentation

The viscoelastic properties of polymer blends of poly(glycerol sebacate) (PGS) and poly(butylene succinate-dilinoleate) (PBS-DLA) copolymer intended for cardiac tissue patches are investigated by dynamic flat punch nanoindentation at frequencies ranging from 1 to 45 Hz. The storage modulus is found to depend weakly on the testing frequency, the lowest value being for 1 Hz, which corresponds to the usual heart rate. More significantly, it is found that varying the PGS content between 40 and 70 wt% allows tuning the storage modulus of the blends between 11 and 39 MPa. The reliability of the nanoindentation method is validated by reference dynamic mechanical measurements on thicker PBS-DLA samples using a tensile testing machine.