| Abstract: | Poly(urethane/vinyl) block copolymers (PU-PV) were obtained in high yields by the polymerization of vinyl monomers (butyl methacrylate (BMA), ethyl acrylate (EA), and methyl methacrylate (MMA)) in the presence of polyurethane-type macroazo initiators (PUMAI). PUMAI was prepared via addition reaction of azodialcohol, dipropylene glycol and hexamethylene diisocyanate. The PU-PBMA's, as typical examples of PU-PV's were purified by solvent extraction. Characterization of the purified PU-PBMA's by 1H NMR, IR, together with extraction behavior, supported the block nature of PU-PBMA. Film tensile strength and elongation measurements in comparison with the corresponding blend samples also supported the block nature of PU-PV. |
