Hybrid nanocellulose/carbon nanotube/natural rubber nanocomposites with a continuous three‐dimensional conductive network

Abstract

In this study, the hybrid effect of nanocellulose/carbon nanotube (NCC/CNT) reinforcement on natural rubber (NR) nanocomposites was investigated. To this end, three series of NR nanocomposites were prepared: NCC/NR, CNT/NR and NCC/CNT/NR. First, the nanocomposites morphology and the filler–rubber interactions were studied using scanning electron microscopy (SEM) and the swelling behavior in toluene, respectively. The results showed that the presence of NCC improved the NCC/CNT hybrid filler dispersion forming a 3D network, while the presence of CNT increased the filler–matrix interaction. The curing results also confirmed that the degree of crosslinking increased when hybrid fillers were used, but the curing time was not modified. In addition, it was observed that using a NCC/CNT hybrid system led to superior mechanical properties, dynamic mechanical properties and thermal conductivity than each material used separately. When 10 phr hybrid filler (with a filler ratio of 1) was added to NR, the tensile strength, modulus at 300% elongation (M300), storage modulus at 10% strain and thermal conductivity were all increased by 57%, 137%, 120%, and 30%, respectively. The results also showed that the NR nanocomposites properties can be controlled by tuning the NCC/CNT filler ratio.

A Review of Rubber Biocomposites Reinforced with Lignocellulosic Fillers

“…They reported that cellulose can form complexes with zinc (II) to produce a 3D network (cellulose/cellulose network and Zn/cellulose network) in the NR matrix, which was the origin of significant improvements in mechanical properties. However, other studies showed that the tensile strength decreased when more than 10 wt.% of nanocellulose was added [116,134,135]. This was associated with the presence of a high number of hydroxyl groups in the nanocellulose, causing agglomerations in the rubber matrix.…”

“…The results showed that in addition to increased sustainability, nanocellulose/CB hybrid fillers can produce an optimal balance between different properties of NR composites and generate a better reinforcing effect than using CB alone [140,[161][162][163]. Hybridization of nanocellulose with conductive fillers, such as carbon nanotube (CNT) [135,164,165], graphene [166,167] and conductive carbon black [168,169], is also interesting for some applications, such as flexible strain sensors and energy storage. These hybrid fillers can produce a 3D conductive network inside a rubber matrix (Figure 15), leading to improved conductivity (thermal and electrical) as well as mechanical and dynamic mechanical properties (Figure 16).…”

Cellulose and lignin as carbon black replacement in natural rubber

“…1,2 On the other hand, lignocellulosic fillers are readily available, renewable, biodegradable, lightweight and inexpensive making them promising candidates to replace conventional fillers in NR composites. [3][4][5][6][7][8][9][10][11] Since lignocellulosic fillers are extracted from plants, their main components are similar (cellulose, lignin and hemicellulose), but their ratios depend on the type of plant (wood, bast, leaf, seed, grass, etc.) These differences in chemical compositions lead to different mechanical properties.…”

“…However, CB is a petroleum‐based material and requires high amounts of energy for its production, leading to environmental issues and higher production costs 1,2 . On the other hand, lignocellulosic fillers are readily available, renewable, biodegradable, lightweight and inexpensive making them promising candidates to replace conventional fillers in NR composites 3–11 . Since lignocellulosic fillers are extracted from plants, their main components are similar (cellulose, lignin and hemicellulose), but their ratios depend on the type of plant (wood, bast, leaf, seed, grass, etc.)…”

Flexible and thermal conductive poly (vinylidene fluoride) composites with silver decorated hexagonal boron nitride/silicon carbide hybrid filler

“…Polymers have been considered as a choice for thermal management of electronic devices due to their inherent advantages, such as diverse functionality, lightweight, easy processing, low cost, and excellent environmental stability, [7] but their thermal conductivity is extremely poor, greatly limiting their practical application. It is widely accepted that the addition of highly thermally conductive fillers, such as boron nitride (BN), [8][9][10][11] aluminum oxide (Al 2 O 3 ), [12][13][14] silicon carbide (SiC), [15,16] silver (Ag), [17,18] graphene, [19,20] and carbon nanotubes (CNTs), [21][22][23] can enhance the thermal conductivity of polymer composites. The heat conduction path will be formed after adding a large content of fillers, further improving the thermal conductivity.…”