Calculation of the [η] (M) relationship for ethylene/propylene copolymers
from the relations for homopolymers
Polimery 2001, No 11-12, 817
Intrinsic viscosity [η]-weight-average molecular weight (Mw) relations were calculated for ethylene/propylene copolymers at varying copolymer compositions by using the principle of the two-parameter theory of dilute polymer solutions and by taking the conformational and interaction parameters for PE and PP. The interaction parameter between chemically dissimilar monomer units was assumed to be zero. For high-temperature solvents [tetralin, trichlorobenzene (TCB), α-chloronaphthalene (α-CN)], the relation was found to be sensitive to copolymer composition. The calculated data proved to be consistent with the reported experimental data. The results were used for a theoretical examination of the effect of copolymer composition on the calibration of SEC columns.
Keywords: ethylene/propylene copolymers, calculation of [η](M) function, calibration of SEC column