Preparation, mechanical properties and thermal stability of poly(l-lactide)/γ-polyglutamate-modified layered double hydroxide nanocomposites

This study reports the preparation and physical properties of biodegradable nanocomposites fabricated using poly(l-lactide) (PLLA) and γ-polyglutamate-modified magnesium/aluminum layered double hydroxide (γ-LDH) by solution mixing process. Both X-ray diffraction data and transmission electron microscopy images of PLLA/γ-LDH nanocomposites indicate that most of the swellable γ-LDHs were disorderedly distributed into the PLLA matrix. Mechanical properties of the fabricated 5 wt% PLLA/γ-LDH nanocomposites show significant enhancements in the storage modulus when compared to neat PLLA. Adding more γ-LDH into PLLA matrix induced a slight decrease in the storage modulus of PLLA/γ-LDH nanocomposites, probably due to the excessive content of γ-PGA moleculars with low mechanical properties. The effect of γ-LDH on thermal degradability of PLLA was also investigated.