Analysis on copolymerization of dioxanone with lactide by ¹H-NMR

Bulk copolymerization of dioxanone (PDO) with lactide (LA) was achieved at different temperature. The copolymerization products were characterized by ¹H nuclear magnetic resonance spectrum(¹H-NMR). Based on the ¹H-NMR spectra, the conversions of the PDO and LA in copolymerization were obtained. Sequence structures of the PDO-co-LA copolymers were calculated through analysizing the copolymerization capabilities of the PDO and LA and the ¹H-NMR spectra. The experimental results indicate that the polymeric capability of LA is stronger than PDO's. With the feeding molar ratio of 2/3, the LA to PDO in the copolymer is near to 1/1 under the experimental conditions, and the average sequence length of the PDO and LA is 3.00 and 2.92 respectively. Meaning the PDO and LA segment in main dimer and trimer sequences in the copolymer chains. There is consistency between the calculated conversion of monomers and average sequence lengths.