Polyetherimide/poly(ether ether ketone)/liquid crystalline polymer ternary blends—II. Approximated interaction parameters and phase diagrams

✍ Scribed by A.R. Morales; R.E.S. Bretas

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 615 KB
• Volume: 32
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(95)00127-1

✦ Synopsis

A Flory-Huggins equation for the spinodal curve of a ternary system was used to simulate the theoretical phase behavior of polyetherimide (PEI)/poly(ether ether ketone) (PEEK)/liquid crystalline polymer (LCP) ternary blends. The resulting theoretical phase diagram was compared with experimental phase diagrams of these compositions just after injection molding, obtained from data of differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The agreement with the DSC data was found to be relatively good. Two other experimental phase diagrams after annealing at 200 and 260°C were also obtained; at this last temperature, all binary blends were shown to be miscible. However, a new theoretical phase diagram, assuming miscibility of all the binary compositions, could not be obtained because the binary blends PEEK/HX4000 showed miscibility of the amorphous phases, but separation of the crystalline ones.