Differential scanning calorimetry (d.s.c.) has been applied to characterize the miscibility of blends of a high T~ polyester, synthesized by condensation polymerization from 4,4'-(2-norbornylidene)diphenol and terephthalic acid/azelaic acid in a 60/40 molar ratio (this polyester will be denoted T(40)C-GJ), with bisphenol-A polycarbonate. The theoretical development to determine the Flory-Huggins interaction parameter (Z) of phase-separated polymer blends from their phase compositions is described. The glass transition temperature (Tg) of a miscible blend of T(40)C-GJ and a low molecular weight polycarbonate (Lexan) can be accurately described by both the Gordon-Taylor equation with k = 1.7 and the Couchman equation. These equations were used to determine the phase compositions of a phase-separated blend of T(40)C-GJ and a high molecular weight polycarbonate (Makrolon) from the Tg data. The Z values for these blends are in the range (8.4-9.9) x 10-3 and are slightly composition dependent. The miscibility of these blends can be quantitatively understood in terms of the X results from the d.s.c, measurements. The morphology observed by transmission electron microscopy for 50/50wt% blends of T(40)C-GJ and polycarbonate is consistent with the d.s.c, results.
Посилання на статтю:
Miscibility studies of high Tg polyester and polycarbonate blends / H. Yang and W. Yetter // Polymer. – 1994. – Vol 35. – P. 2417-2421.