A Caltech Library Service

Thermodynamics of Mixing for Blends of Model Ethylene-Butene Copolymers

Graessley, W. W. and Krishnamoorti, R. and Balsara, N. P. and Butera, R. J. and Fetters, L. J. and Lohse, D. J. and Schulz, D. N. and Sissano, J. A. (1994) Thermodynamics of Mixing for Blends of Model Ethylene-Butene Copolymers. Macromolecules, 27 (14). pp. 3896-3901. ISSN 0024-9297.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


This paper describes a study of thermodynamic interactions in binary blends of A_yB_(1-y), copolymers. The blend components are hydrogenated polybutadienes, consisting of chains with branched C_4 and linear C_4 units and corresponding to model ethylene-butene copolymers. Overall compositions range from nearly polyethylene (y = 0) to nearly poly(butene-1) (y = 1) through a series of nearly random branched C_4-linear C_4 copolymers. Values of the Flory-Huggins interaction parameter χ were determined by small-angle neutron scattering (SANS) from binary blends (one component deuterated) and then corrected for the effect of isotopic substitution. The reduced interaction parameter χ(y_2 - y_1)^2 was found to be a strong function of the average blend composition, contrary to classical copolymer theory. Higher order theories, based on diad or triad interactions, could be made to fit, but the physical significance of the fits was unclear. The same results were also expressed in terms of a relative solubility parameter, δ - δ_(ref), for each copolymer. These values were found to agree well with calculations based on PVT properties of the pure components. Thus, it seems clear that, for this system at least, departures from the copolymer equation are foretold in the pure component properties and have nothing to do with anomalies associated with mixing. More generally, inferences about the mixing process that are based on the temperature dependence of χ alone must be viewed with great caution.

Item Type:Article
Related URLs:
URLURL TypeDescription
Balsara, N. P.0000-0002-0106-5565
Additional Information:© 1994 American Chemical Society. Received October 21, 1993; Revised Manuscript Received April 15, 1994. We thank Dr. Gregory T. Dee, DuPont Central Research and Development Department, for the PVT measurements and Dr. Charles Han of NIST for many fruitful discussions on this and other topics. Financial support by a grant from the National Science Foundation to Princeton University (DMR89-05187) is acknowledged with gratitude by W.W.G. and R.K.
Funding AgencyGrant Number
Issue or Number:14
Record Number:CaltechAUTHORS:20180530-151224778
Persistent URL:
Official Citation:Thermodynamics of Mixing for Blends of Model Ethylene-Butene Copolymers W. W. Graessley, R. Krishnamoorti, N. P. Balsara, R. J. Butera, L. J. Fetters, D. J. Lohse, D. N. Schulz, and J. A. Sissano Macromolecules 1994 27 (14), 3896-3901 DOI: 10.1021/ma00092a033
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86726
Deposited By: George Porter
Deposited On:30 May 2018 23:23
Last Modified:03 Oct 2019 19:47

Repository Staff Only: item control page