Nanocellulose mechanical properties

Nanocellulose, such as that produced by the bacteria Gluconacetobacter xylinus (bacterial cellulose, BC), is an emerging biomaterial with great potential in several applications. The performance of bacterial cellulose stems from its high purity, ultra-fine network structure and high mechanical properties in the dry state [114]. These features allow its applications in scaffold for tissue regeneration, medical applications and nanocomposites. A few researchers have used bacterial cellulose mats to reinforce polymeric matrices and scaffolds with wound healing properties [115-121]. BC is pure cellulose made by bacterial fabrication via biochemical... 

However, thermal stability and mechanical properties of ANP are poor. Young s modulus and tensile strength of this kind of nanocellulose are 10—20 times lower than those of cellulose nanocrystals (loelovich, 2012a,b). Therefore, ANP of cellulose cannot be suitable as a reinforcing nanofiller. 

Mckee JR, Hietala S, Seitsonen J, Laine J, Kontturi E, Ikkala O (2014) Thermoresponsive nanocellulose hydrogels with tunable mechanical properties. ACS Macro Lett 3 266-270... 

Mechanical Properties of Various Nanocelluloses Obtained from Different Sources Elastic Modulus in Axial Direction (GPa) Elastic Modulus in Transverse Direction (GPa) Tensile Strength (Tensile Testing) (GPa)... 

Various properties of polymers like mechanical properties, barrier properties and adhesion properties have been modified when reinforced with nanocellulosics. The changes observed by different workers are discussed below. 

These impressive mechanical properties make nanocellulose substrates ideal candidates for reinforcing polymer-based composites. Incorporating these nanoparticles in a synthetic or natural polymeric matrix consists in mimicking nature. 

Recent advances in the field of biomaterials and their medical applications indicate the significance and potential of various nanoceUulose in the development of novel classes of medical devices and applications in healthcare and veterinary medicine. The physical and mechanical properties of nanocellulose are attributes that enable nanocellulose membranes to function as effective temporary wound dressings. On the other hand, because implantable biomaterials (i.e., scaffolds) are also needed, a new approach has been undertaken to apply cellulose as a material entirely integrated into the body, either as a bone or skin graft. 

The mechanical properties of PLA/nanocellulose biocomposites are also strongly affected by the processing strategy and surface chemical modification of nanocellulose. Table 9.2 provides an overview of modulus, tensile... 

The conclusion to be drawn is that nanocellulose, with its characteristics— nanofibers size and distribution, mechanical properties, compatibility, and ability to regenerate—, has been considered an indispensable biomaterial in health area. Also, the nanocellulose composite scaffolds are biocompatible, appearing as a promising biomaterial, suitable for cell adhesion/attachment, which recommends them for wound-dressing or tissue engineering scaffolds (Kalia et al. 2011). 

Similar improvements in mechanical properties of nanocellulose/NR and nanolignin/NR composites have been reported by Favier et al. (1995), Hajji et al. (1996), Abraham et al. (2007) and Thakur et al. (2014b). Due to the uniform dispersion of the nanocellulose in mbber latex, the composites showed improved stiffness and strength without any loss of its elastomeric nature, as shown in SEM micrograph of Fig. 8. The research on nanocellulose/NR composites is an emerging field and more work needs to be done in this area. 

On the other hand, native cellulose is an abundant and inexpensive macromolecular compound that reinforces most plant cell walls. During recent years, attention has been devoted to the use of cellulose (nanocellulose or nanofibrillated cellulose), and important studies have been published [13-22]. The outstanding mechanical properties of nanocellulose or nanofibrillated cellulose, linked to its wide availability, biodegradability, and extensive number of alternatives for chemical modification, have been the driving force for its utilization as reinforcement in polymers. These cellulosic materials are composed of nanosized cellulose fibrils with a high aspect ratio (length-to-width... 

Keywords Polymers, nanocellulose, nano composites, surface modification, in-situ polymerization, mechanical properties, biodegradation, scanning electron microscopy (SEM)... 

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