Table 1 Poly[(R)-3-hydroxybutyric acid] vibrational modes and spectral assignments

979

C=C [31]

1045

C–CH₃ stretching [32]

1056

C–O stretching [32]

1101

C–O–C stretching [32]

1131

CH₃ rocking [32]

1182

C–O–C stretching [32, 33]

1228

C–O–C stretching [32, 33], CH₂ wagging [31]

1262

C–O–C stretching + CH deformation [32, 33]

1271

C–O–C stretching (amorphous) [32]

1280

C–O–C stretching (crystalline) [32, 33]

1290

CH deformation [32]

1356

CH deformation and CH₃ symmetric deformation [32]

1378

CH₃ symmetric deformation [32]

1456

CH₂ scissoring, CH₃ asymmetric deformation [32]

1720

C=O stretch (crystalline) [32–34]

1747

C=O stretch (amorphous) [32, 34]