Morphology and rheological behavior of polylactic acid/clay nanocomposites

Abstract

The investigated rheological properties of polylactic acid (PLA)/clay nanocomposite are important to understand the effect of organically modified layered silicates (OMLS) (clay) on processing as well as the change in viscoelastic properties due to polymer filler interaction. The time sweep result revealed that the thermal stability improved with addition of nanoclay due to the formation of percolating network structure. It was also supported by multi wave ramp test. The frequency sweep analysis showed that the dynamic moduli increased with addition of nanoclay. Viscoelastic spectra (DMTA) showed an increase of the storage and loss moduli with the increase in the clay content. Wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM) were used to determine the degree of intercalation, or exfoliation and nanostructure level of clay dispersion on PLA nanocomposites. XRD data demonstrated complete exfoliation at lower nanoclay content. On increasing the nanoclay content, exfoliated and partially intercalated structures were obtained. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

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

“…Thus, large-scale polymer relaxations in composites were effectively restrained by the presence of organoclays. Similar rheological behaviors were observed in polymer composites containing clay minerals (Pluta, 2006;Wang et al, 2011;Singh et al, 2012).…”

Synergy between fillers in organomontmorillonite/graphene–PLA nanocomposites

“…At 30°C, the PLA's modulus increased from 1.66 GPa to approximately 2.65 GPa in PLA filled with 3 phr of Cloisite® 15A, Cloisite® 30B, and graphene. A rapid drop of G′ values were observed around Tg of the PLA (Singh et al, 2012).…”

“…For organomontmorillonite-PLA nanocomposites, the Newtonian plateau viscosity was also observed for both of C30B-PLA/ and C15A-PLA systems. However, a slight increase of viscosity for nanocomposite prepared with Cloisite® 15A was observed with decreasing frequency indicating a pseudo-yield-stress behavior at low frequencies (Singh et al, 2012). Conversely to the Cloisite® 30B, the incorporation of the non-polar montmorillonite (C15A) into the PLA matrix reduced its viscosity in the high frequency domain, may be due to the absence of functional groups on C15A surfactant which can interact with carbonyl functions of PLA chains.…”

Organomodification of montmorillonite and its effects on the properties of poly(butylene succinate) nanocomposites

“…Then, polymer/organoclay nanocomposites based on Nylon 6 were firstly commercialized by Toyota Group [2]. To date, nanocomposites with various polymer matrices have been reported, such as polypropylene [3], polyethylene [4], poly(ethylene terephthalate) [5, 6], epoxy [7], polyurethane [8], polylactic acid [9, 10], etc. In recent years, much attention has been devoted to the nanocomposites based on biodegradable polymers and organoclay, due to their potential to minimize the environmental pollution associated with the disposal of synthetic, nonbiodegradable polymers.…”