Polylactic Acid-Based Film Modified with Nano-Ag-Graphene-TiO₂: New Film versus Recycled Film

Table 3

Specific signals and description from the FTIR spectra.

Peak (cm^−1)	New film	Recycled film	Neat PLA	Description
2,973	√	√	√	Stretching vibration of aliphatic methyl groups from PLA [17]
1,750	√	√	√	Stretching vibration of the C═O bond from the ester group from PLA [17, 21]
1,451	√	√	√
1,395	–	√	–	Vibration of ─Ti─O─C bonds between recovered composite and PLA
1,382	√	–	√	─O─C─O─ stretching from PLA [22]
1,368	–	√	–	Vibration of ─Ti─O─C bonds between recovered composite and PLA
1,303	√ (small)	√	–	Stretching of ─Ti─O─C included in the PLA matrix
1,182–1,190	√	√	√	─C─O─ stretching from PLA [17]
1,127 and 1,044	√ (shoulder)	√	–	Presence of composite into the PLA matrix
1,081	√	√	√	Vibration of ─O─CH─CH3 from PLA [17]
952	√ (small)	√	√ (small)	Presence of composite into the PLA matrix
867	√	√	√	Vibration of C─C bond from the ─C─COO─ in PLA [21] Vibration of Ti─O─Ti and C─O─Ti [23]
751	√	√	√
689	√	√	√