Thermal behavior, mechanical and rheological properties, and hydrolytic degradation of novel branched biodegradable poly(ethylene succinate) copolymers

The thermal behavior, mechanical and rheological properties, and hydrolytic degradation of novel branched biodegradable poly(ethylene succinate) (PES) copolymers were studied in detail and compared with those of linear PES. The branched copolymers displayed the same crystal structure as the linear homopolymer. The glass transition temperature, melting point and heat of fusion of branched PES copolymers were lower than those of linear PES and further decreased gradually with an increase of side chain content. The dynamic storage modulus values of branched PES copolymers were less than that of linear PES, and also decreased with increasing side chain content. All samples behaved as non-Newtonian fluids. Furthermore, the dynamic complex viscosity, loss modulus and storage modulus exhibited a decreasing tendency with increasing side chain content at all frequency ranges studied. In addition, the hydrolytic degradation rates were slower in branched PES copolymers than in linear PES.