Dilute solution properties of epoxy resins

Number-average molecular weights of fractions of epoxy resins were estimated by vapor-pressure osmometry and size exclusion chromatography coupled with multiple-angle light scattering. Potential reasons for differences between the two sets of data are examined. The molecular weight dependences of the intrinsic viscosity in tetrahydrofuran and chloroform are discussed in terms of theories which take into account the low-molecular weight character of poly(hydroxy ether) chains. The polymer-solvent interaction parameter is estimated. The impact of the presence of branched chains on the results of size exclusion chromatography is examined. It is shown that the universal calibration of size exclusion chromatographic columns by polystyrene is reliable at molecular weights above 2000 only.