TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Rizzarelli, Paola A1 - Piredda, Giovanni A1 - La Carta, Stefania A1 - Mirabella, Emanuele Francesco A1 - Valenti, Graziella A1 - Bernet, Ramona A1 - Impallomeni, Giuseppe T1 - Characterization and laser-induced degradation of a medical grade polylactide JF - Polymer Degradation and Stability N2 - In this study, we carried out the structural and thermal characterization of a medical-grade poly (lactide) (PLA) by SEC, TGA, DSC, NMR, ICP-MS and Py-GC/MS. Moreover, we investigated the laser-induced degradation occurring when ultrashort laser pulses (ULP) were employed to cut extremely thin polymer films prepared by solvent-casting. ULP polymer cutting technology is an interesting manufacturing process for its advantages in potential medical applications. In fact, heat transmission to the region surrounding the cuts is limited, so that the incisions are precise and the effects on the regions around them are small. In this way, the need for post-processing is reduced and ULP cutting becomes interesting for industrial applications. However, degradation induced by ULP may occur and compromise the properties of the polymer samples. To investigate this possibility, portions of PLA films, ultrashort laser cut (ULC) and uncut, were analysed by SEC, DSC, NMR and FTIR. Furthermore, PLA oligomers were studied by ESI-MS. Both SEC and NMR showed a decrease in the molecular weight. FTIR, ESI-MS and NMR spectra revealed the presence of olefin end groups originated from a \beta-H transfer mechanism, induced by heat and/or light (Norrish II mechanism). Additionally, the inspection of the ESI mass spectra highlighted the cleavage of ester bonds related to the Norrish I type mechanism, undetected by the other techniques. KW - Biodegradable polymers KW - Ultrashort pulses microfabrication Y1 - 2019 U6 - https://doi.org/10.1016/j.polymdegradstab.2019.108991 DO - https://doi.org/10.1016/j.polymdegradstab.2019.108991 VL - o.Jg. IS - Bd. 169 SP - 13 S1 - 13 ER -