Synthesis and characterization of poly(α-methyl β-alanine)-poly(ε-caprolactone) tri arm star polymer by hydrogen transfer polymerization, ring-opening polymerization and "click" chemistry

Synthesis of poly(α-methyl β-alanine)-poly(ε-caprolactone) [PmBA-(PCL)2] tri arm star polymer was accomplished by "click" chemistry. For this purpose, poly(α-methyl β-alanine) (PmBA) was synthesized from methacrylamide by hydrogen transfer polymerization (HTP). Terminally dibromo PmBA (PmBA-2Br) was obtained by using the end-group modification method. Terminally diazido poly(α-methyl β-alanine) [PmBA-2N3] was synthesized by the reaction of PmBA-2Br and sodium azide. Terminally propargyl poly(ε-caprolactone) [PCL-propargyl] was obtained using ε-caprolactone and propargyl alcohol by ring-opening polymerization. By the reaction of PCL-propargyl and PmBA-2N3, PmBA-(PCL)2 tri arm star polymer was synthesized via "click" chemistry. The characterizations of products were performed by using multi instruments including 1H-NMR, FT-IR, MALDI-MS, GPC, and SEM. Degradation features of the tri arm star polymer was investigated by using TGA technique. Water uptake measurement of the tri arm star polymer was performed. The multi instruments studies of the tri arm star polymer monitor that the polymer easily formed as a result of "click" chemistry.