Networks Based on Poly(α-methylene-δ-valerolactone-co-δ-valerolactone): Crosslinking Through Free-Radical Vinyl Copolymerization

Unsaturated polyesters are synthesized via ring-opening copolymerization of -methylene--valerolactone and -valerolactone. These polyesters 4a-c are mixed with ethyl methacrylate (EMA), 2-hydroxyethyl methacrylate (HEMA), and -methylene--valerolactone (-MVL), respectively. Then, crosslinking is carried out by free radical polymerization initiated by an azo-initiator. A second glass transition is found with incorporation of HEMA and -MVL. These findings indicate the formation of phase-separated polyester blocks crosslinked with the poly(meth)-acrylic-segments, respectively poly(-methylene--valerolactone) segments.