Molecular design of photocurable liquid biodegradable copolymers. 1. Synthesis and photocuring characteristics

Photocurable liquid biodegradable copolymers were prepared by ring-opening copolymerization of epsilon-caprolactone (CL) and trimethylene carbonate (TMC) at an equimolar monomer feed ratio in the presence of a polyol as an initiator and tin(II) 2-ethylhexanoate as a catalyst, followed by subsequent coumarin derivatization at their hydroxyl terminus. These liquid copolymers (molecular weight range from approximately 2500 to 12 000), tri- and tetracoumarinated copolymers, were cross-linked by ultraviolet (UV) light irradiation. Photocuring was enhanced by higher coumarin functionality, higher UV intensity, and reducing the thickness of the liquid film precursor. Stereolithographically prepared microarchitectured surfaces were demonstrated for potential applications in biomedical fields.