Effect of Nanoclay Hydrophilicity on the Poly(lactic acid)/Clay Nanocomposites Properties

Abstract

In order to improve poly(lactic acid) (PLA) mechanical, thermal, and barrier properties, different layered silicate nanoclays are added. This work deals with the study of the effect of the type of nanoclays with different hydrophilicity on the preparation procedure and properties of PLA nanocomposites. Six kinds of clays have been loaded in PLA whose hydrophilicity varies in the following order of increased hydrophilicity: modified Dellite 67G (67G) < Cloisite 15A (C15A) < C20A < C93A < C30B < hydrophilic smectite clay (HPS). Resultant nanocomposites have been characterized both with respect to bulk and surface properties by mechanical, rheological, thermal analyses, X-ray diffraction study, Fourier transform infrared spectroscopy, gas permeability tests, contact angle measurements, scanning electron microscopy, and atomic force microscopy. Antimicrobial properties have been also tested. Evidenced was the dependence of most properties on the hydrophilicity/hydrophobicity of the clays. The nanocomposites containing the most hydrophilic clays such as Cloisite 93A, Cloisite 30B, and HPS show satisfactory antimicrobial activity against both Gram-positive and Gram-negative bacteria, excepting fungus Candida albicans.

In situ poly(sodium acrylate)‐based nanocomposite formation by redox‐initiated solution polymerization

“…The addition of nanosilver to the poly(sodium acrylate) had little if any effect on the polymer's hydrophilicity as noted by an unchanging contact angle. On the other hand, the addition of nanoclay showed a significant increase in hydrophilicity due to the hydrophilic nature of the nanoclay .…”

Effect of the montmorillonite intercalant and anhydride maleic grafting on polylactic acid structure and properties

“…For the pure PLA, the G′ increased constantly with a frequency and tended to level off at high frequencies (Darie et al, 2014). PLA containing C20A and C30B shows a gradual deviation of the G′ slope at low frequencies indicating a "pseudo solid-like behavior."…”

Effect of Modified Clay on the Morphological and Thermal Properties of PLA/PBAT Nanocomposites.

“…Addition of OMMT additions increased the initial decomposition temperature compared with the pristine PLA/PBAT due to the reduced permeability oxygen and volatile biodegradation product resulting from the homogenous distribution of the OMMT particle barrier effect of these high aspect ratios and char formation 14 .…”