Miscibility and Crystallization Behavior of Poly(ether ether ketone ketone)/poly(ether imide) Blends

摘要

The niiscibility and ~stalUzation behavior of poly(ether ether ketone ;.1 ketone) (PEEKK)lpoly(ether imide) (PEl) blends prepared by melt-mixing were inves- tigated by differential scanning calorimetry. The blends showed a single glass transi- tion temperature. which increased with increasing PEl content. indicating that PEEKK , and PEl are completely miscible in the amorphous phase over the studied composition range (weight ratio: 90110-60/40). The cold crystallization ofPEEKK blended with PEl was retarded by the presence of PEl, as is apparent from the increase of the cold crystallization temperature and decrease of the normalized crystallinity for the sam- ples anealed at 300°C with increasing PEl content. Although the depression of the apparent melting temperature ofPEEKK blended with PEl was observed. there was no evidence of depression in the equilibrium melting temperature. The analysis of the isothermal crystallization at 313-321°C from the melt ofPEEKK/PEI (100/0, 90/10. and 80120) blends suggested that the retardation of crystallization of PEEKK is caused by the increase of the crystal surface free energy in addition to the decrease of the mobility by blending PEl with a high glass trimsition temperature.