Polylactide/nano and microscale silica composite films. I. Preparation and characterization

Abstract

Polylactide (PLA)/silica composite films were prepared by two methods: blending nanoscale colloidal silica sol and sol-gel. The nano and microscale silica particles, respectively, were well dispersed in PLA when observed using scanning electron microscopy and transmission electron microscope. The mechanical and thermal stability of composite films were measured before and after hydrolysis by Instron and thermogravimetric analysis. The fillers increase tensile strength, Young's modulus, thermal stability, and hydrolysis resistance with increasing silica content. The nanoscale particles exhibit better effects than the microscale ones. The activation energy, E a , of thermal decomposition is also simulated by the Kissinger and Ozawa equation. The results also show that the thermal stability is increased by the incorporation of silica particles and is lowered by hydrolysis.

Preparation and characterization of nano‐SiO2 reinforced alginate‐based nanocomposite films (II)

“…The weight loss of SA was found to be 44.91% and 63.73% at 280 and 380 °C, respectively, whereas they are decreased to 21% and 23% for SASB‐6 film. The increase in thermal stability of SA/SiO 2 nanocomposite films under oxidative atmosphere can be ascribed to nano SiO 2 particles providing larger surface areas, which retard molecular mobility and thus enhance thermal stability of the nanocomposite films …”

New PLA/ZnO:Cu/Ag bionanocomposites for food packaging

“…The gas transmittance rate (of CO 2 and O 2 ) was conducted with a Lyssy L100-5000 (Systech Instruments Ltd, Illinois, UK) manometric gas permeability tester (~4 h to equilibrium for CO 2 and ~7 h to equilibrium for O 2 ). Specimens with (108×108×0.2) mm dimensions were used.…”

Evaluation of crystallinity and gas barrier properties of films obtained from PLA nanocomposites synthesized via “in situ” polymerization of l-lactide with silane-modified nanosilica and montmorillonite

“…Also nanosilica has been largely used to improve the properties of polymers such as PLA, to control rheological behavior or as a structural reinforcement [18][19][20]; as reported for clay particles, also with nanosilica it is important to obtain a very good dispersion of the mineral in the polymer matrix. Most of the scientific literature deals with nanocomposites prepared via blending or dissolving the polymer in a nanosilica suspension and re-precipitating the polymeric matrix, but these techniques sometimes could not be efficient enough to obtain materials with good properties [16,[21][22][23][24][25]. It is also necessary to add relatively high quantities of nanoparticles -between 4% and 10% on the total weight of the polymer -to have relevant effects on gas permeability reduction [26].…”