Abstract
Bulk polymer-polymer, and block copolymer, phase behaviors have traditionally been interpreted using mean-field theories. Recent small-angle neutron scattering (SANS) studies of critical phenomena in model binary polymer mixtures confirm that non-mean-field behavior is restricted to a narrow range of temperatures near the critical point, in close agreement with the Ginzburg criterion. In contrast, strong derivations from mean-field behavior are evident in SANS and rheological measurements on model block copolymers more than 50°C above the order-disorder transition, which can be attributed to sizeable composition fluctuations. Such fluctuation effects undermine the mean-field assumption, conventionally applied to bulk polymers, and result in qualitative changes in phase behavior, such as the elimination of a thermodynamic stability limit in these materials. The influence of fluctuation effects on block copolymer and binary mixture phase behavior is compared and contrasted in this presentation.
| Original language | English (US) |
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| Title of host publication | American Chemical Society, Polymer Preprints, Division of Polymer Chemistry |
| Publisher | Publ by ACS |
| Pages | 128 |
| Number of pages | 1 |
| Volume | 31 |
| Edition | 2 |
| State | Published - Aug 1990 |
| Event | Papers presented at the Washington, DC Meeting 1990 of the ACS, Division of Polymer Chemistry - Washington, DC, USA Duration: Aug 26 1990 → Aug 31 1990 |
Other
| Other | Papers presented at the Washington, DC Meeting 1990 of the ACS, Division of Polymer Chemistry |
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| City | Washington, DC, USA |
| Period | 8/26/90 → 8/31/90 |