Oriented Poly(lactic acid)/Carbon Nanotube Composite Tapes with High Electrical Conductivity and Mechanical Properties

Abstract

Oriented poly(lactic acid) (PLA)/multiwall carbon nanotube (MWNT) tapes are prepared by solid‐state drawing. These tapes showed significant morphological, mechanical and electrical property changes after drawing, with polymer crystallinity, nanotube dispersion and alignment being improved. Interestingly, the presence of the MWNTs perturbed the orientation of the crystalline polymer chain domains. Drawing lowered the electrical conductivity and increased the percolation threshold of the nanocomposites, but micromechanical analysis showed that it greatly improved the reinforcing efficiency of the MWNTs. This resulted in an overall good balance with one of the best compromises in terms of high mechanical properties and electrical properties for conductive polymer composite tapes.

High-Strength, High-Toughness Aligned Polymer-Based Nanocomposite Reinforced with Ultralow Weight Fraction of Functionalized Nanocellulose

“…The ultimate strength of the aligned P0.1TOCNF-g-PEG is as high as 343 MPa, which is significantly higher than that of the aligned PLA-based nanocomposites reported previously in literature. 41,[44][45][46] Moreover, the ultimate strength and toughness of both aligned P0.1TOCNF/PEG and P0.1TOCNF-g-PEG are significantly higher than those of the aligned P0.1TOCNF, owing to the reduction of degree of aggregation of TOCNFs in PLA, corresponding to the microscope results shown in Figure 3 The effects of drawing process and TOCNF-g-PEG on the PLA-based nanocomposites are schematically illustrated in Figure 7. The undrawn semi-crystalline PLA as shown in Figure 7a consists of amorphous PLA chains and spherulites.…”

“…44 Mai et al confirmed that a high degree of alignment of CNTs was achieved in the oriented PLA/CNT composite tapes, and the reinforcing efficiency of CNT was enhanced owing to the alignment, resulting in a tensile strength of 156 MPa of the oriented composite with 2 wt% CNT at a draw ratio of 7.5. 45 In our previous work, 46 aligned nanocomposites consisting of plasticized PLA and 1 wt% of CNF were obtained via liquid-assisted extrusion followed by solid-state drawing. We investigated the effects of draw ratio, temperature, and speed on the properties of the nanocomposites, and determined that the strength and toughness of the nanocomposite drawn at 40 °C with a speed of 100 mm/min and a draw ratio of 2.5 reached 102 MPa and 70 MJ/m 3 , respectively, which were 2 and 47 times higher than those of the undrawn sample.…”

The Role of Multiwalled Carbon Nanotubes in the Mechanical, Thermal, Rheological, and Electrical Properties of PP/PLA/MWCNTs Nanocomposites

“…The loading of MWCNTs nanofiller increased the complex permittivity of the nanocomposites. When the MWCNTs content reached 2 wt% (percolation threshold), a significant rise in the electrical conductivity was found, which is attributed to the charge carried by the electric network within the PP/PLA40/MWCNTs nanocomposites [55][56][57][58][59]. Therefore, as seen in Figure 9b, the imaginary permittivity of the electric response was dominated by DC conductivity and led to an increase of nine orders of magnitude from 10 −10 for the PP/PLA blend to 10 −1 (S/m) for the PP/PLA40/MWCNTs 2% ( Figure 10).…”

Enhanced thermal and mechanical properties by cost-effective carboxylated nanodiamonds in poly (vinyl alcohol)

“…Recently, with the development of nanomaterials, the addition of nanofillers (e.g. carbon nanotube [1,2], carbon nanofiber [3,4], nanoclay [5], cellulose nanofiber [6], graphene [7][8][9][10][11]) in polymer matrix have been extensively studied in both academia and industry because nanofillers can achieve similar or superior reinforcing effects in polymer matrix to their microsized counterparts but at a much lower loading level. Thus, the advantages of polymer materials such as processability and lightweight can be substantially retained in these nanocomposites.…”