The characterization of linear polyethylene SRM 1475. VII. Differential refractive index of polyethylene solutions

The value of dn/dc for polyethylene in 1-chloronaphthalene at 135 °C, required for the determination of molecular weight by light scattering, was found to vary with molecular weight. Similar changes were found in 1,2,4-trichlorobenzene, the gel permeation chromatograph solvent. The absolute value of dn/dc decreases by about 2 percent as the polymer molecular weight increases from 12,000 to 110,000.