Abstract
Investigation was carried out on the amorphous structure of melt blends of polyamides with relatively good compatibility such as 6 nylon - 66 nylon and 6 nylon -12 nylon.
In both systems, the component with higher melting temperature crystallizes preferentially, while the crystallization of the component with lower melting temperature was strongly prevented by the presence of the other component when quenched into ice-water after blending at the molten state. However, the more perfectly the lower melting temperature components were frozen at the amorphous state, the more rapidly they re-crystal-lized on annealing.
Investigating the variation of diffusion constants calculated from iodine sorption in the amorphous regions of the blends, it could be presumed that each component in both systems was dispersed very finely, and still more both components of 6 nylon - 66 nylon system were mixed to be packed more loosely than in the homopolymer.
The peaks of β and γ absorptions in the dynamic viscoelastic measurements of melt-quenched blends tended to shift about 10°C to higher temperature than those of homopolymers, while those peaks of blends annealed sufficiently tended to appear between those of both homopolymers. These phenomena were interpreted in terms of the weak interaction between free amide groups of both components dispersed very finely in the amorphous regions of melt-quenched blends.
