Molecular Weight and Peak Broadening Calibration in Size Exclusion Chromatography

Molecular weight distribution of a branched epoxy polymer: 1,4-butanediol diglycidyl ether with cis-1,2-cyclohexanedicarboxylic anhydride

“…Near the gelation threshold, a macroscopic cluster as well as precursor units and clusters of all intermediate sizes are formed. Various statistical and kinetic models have been proposed to describe the evolution of the molecule weight distribution for different gelation processes.25-30 They all show that the molecular weight distribution of large clusters near the gelation threshold can be written in a scaling form31 N(M,e) « M~Tf(M/M*(e)) (21) where N(M,t) is the number of clusters with molecular weight M when the relative distance from the gel point is c. í = |p -pc|, where p is the extent of conversion and pc is the extent of conversion at the gelation threshold. Equation 21implies that the number of clusters decreases as a power law of molecular weight with a critical exponent t. Before the gelation threshold, a typical molecular weight M*(t) exists in the molecular weight distribution, which limits the spread of the distribution and which diverges when the gel threshold is approached: * ~e-1/<r, where l/ is a constant which is sometimes referred to as the gap exponent.…”

Simultaneous calibration of size exclusion chromatography and dynamic light scattering for the characterization of gelatin

“…After integrating both sides of eqs 3 and 4, we have <V>=A + B(log(D)> and Therefore, on the basis of eqs 19 and 20, we have (log2(D) > = JJfWiDMV) dV j;c<v)dv (10) On the one hand, since C( V) is a weight (or concentration) distribution of the elution volume, we have6 J0"C(V) dV = J07wm dM * j"fv(M)M d(log(M))…”