Hydrolysis of green nanocomposites of poly(lactic acid) (PLA), chitosan (CS) and polyethylene glycol (PEG) in acid solution

Abstract

Green nanocomposites based on poly(lactic acid), chitosan, and polyethylene glycol (PLA/CS/PEG) were prepared by the solution method. The content of PEG was 2–10 wt.% compared with the weight of PLA. The characterization and morphology of the nanocomposites before and after hydrolysis in acid solution were determined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and scanning electron microscopy (SEM). The hydrolysis of PLA/CS/PEG nanocomposites in acid solution for different times was also investigated. The shift of C=O, CH3 groups in FTIR spectra of PLA/CS/PEG nanocomposites before and after hydrolysis was clearly observed. The SEM images of the nanocomposites indicate that PEG plays a role in improving the interaction between PLA and CS, resulting in limiting the permeability of acid solution into the structure of the nanocomposites in the presence of PEG. The obtained results after 28 days of testing in the acid solution show that the PLA/CS/PEG8 nanocomposite (containing 8 wt.% of PEG) had the lowest weight loss with the highest regression coefficient (R2=0.9614).

Keywords

• chitosan
• hydrolysis
• nanocomposite
• poly(lactic acid)
• weight loss