Influence of silanized low‐dimensional carbon nanofillers on mechanical, thermomechanical, and crystallization behaviors of poly(L‐lactic acid) composites—A comparative study

Abstract

Composites were investigated regarding the comparison of multi-walled carbon nanotubes (MWCNTs) with exfoliated graphene(EG) in poly(L-lactic acid) (PLLA) and the effect of silane-treated carbon nanofillers on properties of PLLA composites. Solution blending method was used to prepare PLLA composites at a filler content of 0.5 wt %. Fourier transform infrared spectroscopy and X-ray photoelectron spectra results indicated the attachment of silane molecules on the surface of these nanofillers. It was found that the addition of these nanofillers greatly enhanced the mechanical, thermomechanical, and crystallization behaviors of PLLA due to the heterogeneous nucleation effect. Moreover, the silane-treated fillers further enhanced the breaking elongation moderately (although the materials are still brittle), modulus and thermal property of the nanocomposites, without sacrificing the tensile strength, compared with the pristine nanocomposites. On the other hand, composites reinforced with MWCNTs and EG perform almost the same mechanical property. And EG outperformed MWCNTs in thermomechanical properties of composites when being used as the reinforcement of PLLA. Conversely, composites reinforced with MWCNTs showed better crystallization properties than those reinforced with EG. Interestingly, no significant changes were observed for the crystallization properties of PLLA composites when MWCNTs and EG had been treated by silane coupling agent.

Poly(lactic acid)/graphene oxide-ZnO nanocomposite films with good mechanical, dynamic mechanical, anti-UV and antibacterial properties

“…(b) and Table , T g values increase from 65.45 °C for pure PLA to 70.90 °C for PLA/0.5 wt% GO–ZnO composites. Because of the large specific surface area of GO sheets and the reinforcing effect of ZnO nanoparticles loaded on the GO sheets, a strong interfacial action is formed and reduces the mobility of the PLA chains …”

Preparation and properties of poly(lactic acid)/lipophilized graphene oxide nanohybrids

“…Recently, some efforts have been made in the preparation of PLA/GO nanohybrid films for various applications . Chen et al .…”

“…Well‐dispersed PLA/graphene nanocomposite films were prepared by master batch‐based melt‐blending of PLA and uniform dispersion of graphene nanolayers in the PLA matrix . The PLA/graphene nanocomposites showed improved mechanical, electrical conductive and fire resistance properties, rate of crystallization and crystallinity and reduced thermal degradation temperatures, whereas a hybrid film prepared by mixing of PLA and silane‐functionalized multi‐walled carbon nanotubes in a solution blending method also showed better tensile strength, Young's modulus, storage modulus and elongation at break . A membrane prepared by the use of poly(vinylidene fluoride) (PVDF) and 3‐aminopropyltriethoxysilane‐functionalized GO showed improved performance and anti‐fouling property.…”

“…In the work presented here, GO was prepared using a modified Hummers method and then lipophilized (LGO) through functionalization with octylamine (OA), dodecylamine (DA) and octadecylamine (ODA); the alkylamines possess different carbon contents in the linear alkyl chain (C 8 , C 12 and C 18 , respectively). This one‐step process can enable both reduction and modification simultaneously, which should be more desirable from the viewpoint of economics and energy savings compared to other methods . To examine the effects of the alkyl chains grafted on GO, wide‐angle X‐ray diffraction (WAXD) was performed and a dispersion test was conducted in an organic solvent.…”

Investigation on polyimide/silica hybrid foams and their erosion resistance to atomic oxygen

“…Recently, combining the advantages of organic materials and inorganic polymers, organic–inorganic hybrid materials have been intensively studied. Moreover, compared with traditional materials and composites, they usually exhibit unique properties, such as the anti‐AO erosion properties, thermal, and dielectric properties . Duo et al prepared PI/silica (SiO 2 ) hybrid films by the sol–gel process to improve the erosion resistance in AO environments.…”