A feasible strategy to constructing hybrid conductive networks in PLA‐based composites modified by CNT‐d‐RGO particles and PEG for mechanical and electrical properties

Abstract

Carbon nanotubes (CNTs) and reduced graphene oxide (RGO) were successfully assembled by chemical reaction to obtain CNT‐d‐RGO particles. Then, a home‐made dynamic impregnating device was used to prepare hybrid CNT‐d‐RGO/polyethylene glycol (PEG). Next, the different modifiers, including CNTs, GO, CNT‐d‐RGO, PEG, and CNT‐d‐RGO/PEG, were, respectively, added into poly‐(lactic acid) (PLA) matrix via melt‐compounding. The dispersed morphology for these different modifiers within the PLA matrix was confirmed by SEM and TEM observations. Especially, compared with the identical weight ratio of CNT‐d‐RGO, the hybrid CNT‐d‐RGO/PEG within the PLA matrix exhibited an excellent exfoliated and interconnected networks morphology. Moreover, compared with pure PLA, not only the crystallinity of all PLA‐based composites notably improved, but half‐crystallization time was also shortened. Furthermore, despite the addition of different modifiers, the crystal form of PLA‐based composites remained unchanged. Noticeably, compared with those of pure PLA, the tensile stress, strain, and modulus of PLA composite added with CNT‐d‐RGO/PEG increased by 29.4%, 4.1%, and 56.1%, respectively, and the V‐notch impact strength slightly improved. In addition, compared with pure PLA, volume resistivity of the PLA composite added with 1 wt% CNT‐d‐RGO/PEG decreased by 93.1%, and its volume conductivity increased by five orders of magnitude.

Enhancement of 3D Printability by FDM and Electrical Conductivity of PLA/MWCNT Filaments Using Lignin as Bio-Dispersant

“…First, the glass transition temperature (Tg) of PLA remained constant with MWCNT addition. Second, PLA possesses a low crystallization rate during the cooling (due to its asymmetrical structure of chains [ 36 ]), but with the filler incorporation, PLA showed a notorious cold crystallization peak. These changes can be attributed to the nucleating effect provoked by MWCNT.…”

“…However, the improvement of the electrical conductivity of MWCNT/PLA compounds comes at the expense of viscosity increase and lower ductility, which makes the material useless in FDM. These problems can be solved using commercial plasticizers such as polyethylene glycol (PEG) [ 36 , 37 ], oligomeric PLA [ 38 ], Struktol [ 39 ], triethyl citrate (TEC) or acetyl tributyl citrate (ATCB). In addition, current studies are incorporating biomaterials as natural additives [ 40 ] are more environmentally friendly.…”

Graphene Derivatives in Biopolymer-Based Composites for Food Packaging Applications

“…In addition, the grafting of rGO with cellulose nanocrystals (rGO-CNC) potentiates the formation of hydrogen bonds between biopolymer/graphene derivative, and thus better mechanical results are achieved even when compared with the simultaneous incorporation of non-grafted rGO and CNC [ 145 ]. The combined use of rGO and CNT seems to potentiate the Young’s modulus and tensile strength increase [ 184 ]. Generally, the upper reinforcement degree of rGO or CNT and their chemically modified forms is usually reflected on the improvement of tensile strength and Young’s modulus.…”

A low seepage threshold and super‐toughness of polybutylene succinate‐based composites with double percolation structure: Synergy of multi‐wall carbon nanotubes and polyvinyl butyral

“…The dispersion capacity of the MWCNTs in polymer matrix can be improved by grafting carboxyl and/or hydroxyl on MWCNT surface. Meanwhile, to further improve the dispersed performance of MWCNTs, the carboxylated and/or hydroxylated MWCNTs are coated by organic molecules that have more suitable properties, such as silane coupling agent, 25,26 nonylphenol and PEG, and so on 27–29 …”

“…Meanwhile, to further improve the dispersed performance of MWCNTs, the carboxylated and/or hydroxylated MWCNTs are coated by organic molecules that have more suitable properties, such as silane coupling agent, 25,26 nonylphenol and PEG, and so on. [27][28][29] ; this method of enhancing dispersion in the polymer system is interesting.Unfortunately, the plasticity and flexibility of the conductive polymer clearly decreased with the addition of pristine MWCNTs and/or surface modified MWCNTs. Thus, blending of soft polymer with the polymer substrate is a feasible strategy in practice.…”