ABSTRACT
The accurate determination of molecular weight distributions (MWD) is nowadays an essential prerequisite for many polymer studies. GPC has, over the past 15 years, become a well established procedure for the fractionation and precise characterization of high polymers. Although significant progress has been made in the understanding of the mechanism of GPC, a general and rigorous model for the separation process has still not been achieved. Many systems have been studied and empirical relations were obtained for the dependence of the elution volume on the molecular weight (MW), but most theoretical work was limited to very simplified pore network geometries and to idealized polymer shapes.
In the present study, both MW calibration and the effect of experimental variables on the shape of the elution peak were thoroughly investigated. Controlled pore glass (CPG) was used as separation matrix because of its unsurpassed mechanical stability, chemical inertness to the system under investigation and constancy of pore structure. Dextran was selected as a polymer because of its well known conformational and solution properties, and the availability of fractions of extremely narrow MWD and precisely known MWs.
