First example of an unsymmetrical difunctional monomer polymerizable by two living/controlled methods

In this paper the synthesis and (co)polymerizations of 4-(acryloyloxy)-e-caprolactone are reported. This new monomer can be polymerized in a living/ controlled way by two different polymerization mechanisms; atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP). ATRP, which was carried out at 90°C using NiBr 2 (PPh 3 ) 2 , leads to new polyacrylates containing pendant caprolactone functionalities with controlled molecular weights and narrow polydispersities (M w /M n ∼1.1). Alternatively, ROP of this functional e-caprolactone bearing a pendant acrylate functionality leads to new poly(4-(acryloyloxy) caprolactone) as well as random copolymers when e-caprolactone and L,L-lactide are added as comonomers. The (co)polymerizations were carried out using either Al(O i Pr) 3 in toluene at 25°C or Sn(Oct) 2 as a catalyst at 110°C producing (co)polymers with controlled molecular weights and narrow polydispersities (M w /M n ∼ 1.2). As a potential application, the introduction of acrylate pendant groups into the polyesters facilitated the preparation of cross-linked biodegradable materials either thermally or by irradiation with ultraviolet light radical curing.