Light-scattering study of poly(hydroxy ester ether) in N,N-dimethylacetamide solution

Static and dynamic light-scattering techniques were used to study biodegradable thermoplastic poly(hydroxy ester ether) in N,N-dimethylacetamide (DMAc). A weight average molecular weight M-w = 6.4 x 10(4) g/mol, radius of gyration R-G = 9.4 nm, second-virial coefficient A(2) = 1.05 x 10(-3) mol mL/g(2), translational diffusion coefficient D = 1.34 x 10(-7) cm(2)/s, and hydrodynamic radius R-H = 8.3 nm are reported. In addition, the effect of H2O on the polymer chain's conformation and architecture in a DMAc/H2O solution is evaluated. Results suggest that H2O makes the mixed solvent poorer as well as promotes polymer chain branching via intramolecular transesterification. (C) 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1737-1745, 2001.