Thiol-mediated chain transfer as a tool to improve the toughness of acrylate photo-crosslinked poly(ε-caprolactone)

Herein, a straightforward approach is reported to obtain photo-crosslinked, bioresorbable poly(epsilon-caprolactone) (PCL) based networks covering a range of mechanical properties (elongation at break from 203 +/- 53 up to 707 +/- 101% and ultimate strength from 6.8 +/- 2.2 to 13.9 +/- 1.5 MPa) via alteration of the network topology. Exploiting multifunctional thiols for crosslinking of acrylate-terminated PCL is an effective method to alter the mechanical properties of photo-crosslinked networks due to the chain transferring ability of the thiols. By controlling the thiol to acrylate ratio, the Young's modulus, elongation at break and ultimate strength can be significantly altered. The materials described in this work can be considered potential candidates for light-based 3D-printing and to serve tissue engineering applications