The molecular weight of the polymers was examined by using gel permeation chromatography (GPC) and the monomer ratio was characterized by NMR spectroscopy (Figures and). In the present work, PLVPs with MLA/2VP ratios of 5:1, 3:1, 1:1, 1:3, and 1:5 were prepared, termed as PLVP-1, PLVP-2, PLVP-3, PLVP-4, and PLVP-5, respectively (Table ). Also, PLVPs with similar monomer ratios (1:1) but different molecular weights were also prepared, i.e., PLVP-3L and PLVP-3M. The absence of vinyl protons in the 1 H NMR spectrum indicates that residual monomers were completely removed by precipitation (Figure ). Also, the intactness of cyclic lactide in the copolymers was confirmed by the presence of CH proton signals at 5.7-5.2 ppm. In addition, the chemical structures of PLVPs were confirmed by FTIR (Figure ). It is found that PLVPs can be dissolved in high polar solvents, for example, tetrahydrofuran (THF), dimethyl formamide (DMF), acetonitrile (ACN), and it is difficult to be dissolved in low polar solvents, such as dichloromethane (DCM). Scheme 1. Synthetic Route to PLVPs.