Unsaturated polyesters are synthesized via ring-opening copolymerization of α-methylene-δ-valerolactone and δ-valerolactone. These polyesters 4a-c are mixed with ethyl methacrylate (EMA), 2-hydroxyethyl methacrylate (HEMA), and α-methylene-δ-valerolactone (α-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 α-MVL. These fi ndings indicate the formation of phase-separated polyester blocks crosslinked with the poly(meth)-acrylic-segments, respectively poly(α-methylene-δ-valerolactone) segments.

The preparation of AB 2 monomers via thiol-ene click reaction from six-and seven-membered unsaturated lactones is described. The hydroxyl-functionalized valerolactone was prepared by use of Michael thiol-ene-addition reaction starting from 2-mercaptoethanol and 3-methylenetetrahydro-2H-pyran-2-on. The hydroxyl-functionalized caprolactone was prepared radically from 2-mercaptoethanol and 7-allyloxepan-2-one. Both AB 2 monomers were polymerized via ring opening in the presence of tin(II)-2-ethylhexanoate (Sn(Oct) 2 ) as a catalyst yielding the hyperbranched polyesters. The new hyperbranched polyesters were analyzed by 13 C NMR spectra to determine the degree of branching.

A novel graft copolymer is synthesized from commercially available poly(vinyl alcohol) using ring‐opening polymerization. For the polymerization reaction of novel brush‐like poly(vinyl alcohol)‐graft‐poly(ϵ‐caprolactone‐co‐(3‐/7‐(prop‐2‐ynyl)oxepan‐2‐one) 5 Sn(Oct)2 is used as a catalyst. The formation of the graft copolymer is confirmed by 1H NMR, 13C NMR, and Fourier transform infrared (FTIR) spectroscopy. Furthermore, the modification of the novel synthesized graft copolymer via a “click” reaction to implement adamantane groups is described. The success of the “click” reaction is proven by 1H NMR spectroscopy and visualized by decomplexation of cyclodextrin with included phenolphthalein.