Synthesis of Poly(ϵ-caprolactone-co-methacrylic acid) Copolymer via Phosphazene-Catalyzed Hybrid Copolymerization
Poly(ϵ-caprolactone-co-tert-butyl methacrylate) (CL-co-BMA) random copolymer is synthesized via hybrid copolymerization with 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5,4Λ5-catenadi(phosphazene) (t-BuP4) as the catalyst. The copolymer is hydrolyzed into poly(ϵ-caprolactone-co-methacrylic acid) (CL-co-MAA), a charged copolymer. Nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis measurements indicate that cyclic ester and vinyl monomer form a random copolymer. The degradation of the copolymers has also been studied by use of quartz crystal microbalance with dissipation.