Table 1: Vibrational Combination Bands of Polylactic Acid (PLA).
Calculated position (cm-1) | Observed position (cm-1) | Assignment |
---|---|---|
4725 | 4770 | νasCH3 + νC = O (1780) |
4725 | 4725 | νasCH3 + νC = O (1740) |
4635 | νsCH3 + νC = O | |
4420 | 4438 | νasCH3 + δasCH3 |
4351 | 4372 | νasCH3 + δasCH3 |
4330 | 4307 | νsCH3 + δasCH3 |
4330 | νasCH3 + δ(CH) wagging | |
4260 | 4255 | νsCH3 + δsCH3 |
4240 | νsCH3 + δ(CH) wagging | |
4233 | 4217 | νasCH3 + (νCOC + δCH) |
4180 | 4175 | νasCH3 + (νCOC + ρ asCH3) |
νCH3 + δCH | ||
4143 | 4135 | νsCH3 + (νCOC + δCH) |
4098 | 4086 | νasCH3 + ρasCH3 |
4090 | νsCH3 + (νCOC + ρasCH3) | |
4065 | 4051 | νasCH2 + νCOC |