Synthesis of Poly[(ethylene carbonate)-co-(ethylene oxide)] Copolymer by Phosphazene-Catalyzed ROP

Poly[(ethylene carbonate)-co-(ethylene oxide)] is synthesized by ROP of 1,3-dioxolan-2-one using 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phosphoranylidenamino]-2 Lambda 5,Lambda 5-catenadiphosphazene as the catalyst. NMR spectroscopy shows that the copolymer chain consists of EO-EC-EO-EO sequences. GPC measurements indicate a PDI of 1.43-1.66 and show that the molecular weight increases with monomer conversion. Thermal analysis demonstrates that the copolymer is amorphous with a glass transition temperature of about -42 degrees C and an onset decomposition temperature of about 200 degrees C.