Abstract
We report measurements of chain diffusion in macroscopically oriented, well-entangled lamellar block copolymers. Diffusion in the lamellar plane is proposed to occur by an activated reptation mechanism when the composition profile is roughly sinusoidal. At higher degrees of segregation a crossover to an entropically limited block retraction mechanism is apparent. Diffusion through the layers reflects a thermodynamic barrier determined by the combination of temperature and molecular weight.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 657-660 |
| Number of pages | 4 |
| Journal | Physical review letters |
| Volume | 75 |
| Issue number | 4 |
| DOIs | |
| State | Published - 1995 |