Table 2.
Groove characteristics and 3D texture parameters obtained for polyimides PI-HMDA and PI-ODA after stretching (STR), rubbing (RUB), rubbing after stretching (STR RUB), and stretching after rubbing (RUB STR).
| Sample | Groove Characteristics | 3D Texture Parameters | ||||
|---|---|---|---|---|---|---|
| A | Λ | Sq | Sdr | Stdi | Sbi | |
| PI-HMDA STR | 211 ± 24 | 3686 ± 555 | 41 | 0.556 | 0.298 | 0.497 |
| PI-HMDA RUB | 39 ± 16 | 706 ± 129 | 17 | 0.424 | 0.137 | 0.170 |
| PI-HMDA STR RUB | 22 ± 5 | 953 ± 256 | 11 | 0.286 | 0.385 | 0.102 |
| PI-HMDA RUB STR | 74 ± 15 | 1422 ± 567 | 50 | 0.700 | 0.157 | 0.670 |
| PI-ODA STR | 54 ± 12 | 1923 ± 297 | 16 | 0.382 | 0.480 | 0.0568 |
| PI-ODA RUB | 20 ± 6 | 657 ± 191 | 15 | 0.328 | 0.214 | 0.168 |
| PI-ODA STR RUB | 33 ± 15 | 1026 ± 190 | 14 | 0.374 | 0.448 | 0.124 |
| PI-ODA RUB STR | 65 ± 17 | 1112 ± 142 | 25 | 0.737 | 0.179 | 0.187 |
A: depth of the groove (nm); Λ: frequency of the grooves (nm); Sq: root mean square roughness of the surface (nm); Sdr: surface area ratio (%); Stdi: surface texture direction index; Sbi: surface bearing index.