Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Study of Ethylene-Propylene Copolymer Thermoreversible Gels



C Daniel, T C. Jao, Barry J. Bauer, Eric J. Amis


Molecular structure and rheological properties of ethylene-propylene (EP) random copolymer gels formed in toluene and methylcyclohexane, respectively, have been investigated by small angle neutron scattering (SANS) and oscillatory shear. In both solvents, SANS results are analyzed by considering a fiber-like structure with a radius cross-section distribution function expressed by w (r) - r -. It is shown that a small change in the EP copolymer ethylene content has a large effect on the density of network connecting fibers, but a much smaller effect on the diameter of the fibers. Oscillatory shear experiments reveal that the relaxation rate of the elastic modulus increases with decreasing EP copolymer ethylene content. This behavior indicates a decrease in the density of connections between fibers with decreasing ethylene content. The relationship between the elastic modulus and polymer concentration has also been examined. The results suggest, in light of the theory developed by Jones and Marques for rigid networks, that the rigidity of fibers formed in the gel is achieved only locally.
No. 26


copolymer, ethylene, gel, network, propylene, rheology, SANS


Daniel, C. , Jao, T. , Bauer, B. and Amis, E. (1999), Study of Ethylene-Propylene Copolymer Thermoreversible Gels, Macromolecules, [online], (Accessed July 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created November 30, 1999, Updated October 12, 2021