Electron-Induced Alteration of PLA Chain Structure AITranslate

Basic Information:

DOI：https://doi.org/10.1021/acsapm.3c02111

Chinese Library Classification Number:

Citation Information:

Cross-linked polylactides (PLAs) were produced by electron beam (EB) irradiation at 80 °C using different preset crystallinities (0 to 13.3%), without using cross-linking-promoting additives. Based on functional group conversion detected by Fourier-transform infrared spectroscopy, molecular build-up mechanisms based on a two-stage chain recombination (from geometric T-type to H-type branching) were proposed for EB-induced cross-linking in additive-free PLA. Furthermore, EB-induced PLA crystallization has been discussed based on the combined evidence from morphology, crystallinity, and crystallization behaviors identified by polarized-light optical microscopy, X-ray diffraction, and differential scanning calorimeter (DSC). Several interpretations of the thermal property of EB-induced cross-linked PLA were presented from the point of view of chain scission and cross-linking in a coexisted system. The high irradiation dose obviously shifted the melting temperature (Tm) and cold crystallization temperature (Tcc) of irradiated PLA to a lower region than those of neat PLA. Moreover, the different preset crystallinities of the PLA starting materials did not lead to an obvious difference among irradiated PLAs with respect to Tg, Tm, Tcc, and cross-link density, according to DSC and equilibrium swelling measurements.