Nanocellulose Polymer Composites as Innovative Pool for (Bio)Material Development

Abstract

Using a ''never-dried'' procedure (according to Figure 4) shaped bacterial nanocellulose (BC, 1% cellulose, 99% water) has been modified by the formation of BC-polymer composites. For this purpose, acrylate and methacrylate monomers and methacrylate crosslinkers were photopolymerized inside an ethanol-swollen nanofiber network. Using the ethanol as solvent and as confirmed by model reactions the synthetic polymer (SP) part of the composites is constructed of crosslinked polymers (number of repeating units in the range of 500). As part of ongoing work on the development of (bio)materials from the innovative pool of BC composites these investigations are recently directed towards the creation of collagen-like materials. Thus, for these purposes, mainly water absorption capacity, strength, and elasticity have to be controlled, whilst still retaining essential features of BC like shape, nanofiber network, pore system, and proved biocompatibility. Using acrylic acid, 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate, N-vinyl pyrrolidone as acrylate monomers and triethylene glycol dimethacrylate and 1,4-butandiol dimethacrylate as crosslinkers of different concentrations either a filling of the pores or a coating of the fibers in the BC nanocomposites could be achieved. The small cellulose content of the composites significantly increases the water absorption value and the strength of the material as well as the ability of re-swelling in the case of fiber coated composites. Sample 12 is an optimized BC-SP composite regarding important properties of hyaline cartilage like Young's modulus in the range of 5-20 MPa using the well-known Simplex-method.

Surface Modification of Natural Fibers Using Bacteria: Depositing Bacterial Cellulose onto Natural Fibers To Create Hierarchical Fiber Reinforced Nanocomposites

“…[19][20][21][22][23][24] Cellulose microfibrils can be extracted from wood or many other plant-based materials, but pulping and bleaching processes are not environmentally friendly. 25 Cellulose whiskers can also be extracted from tunicate, a sea animal.…”

Embedding of Bacterial Cellulose Nanofibers within PHEMA Hydrogel Matrices: Tunable Stiffness Composites with Potential for Biomedical Applications

“…BC composites have been prepared by addition of reinforcing agents during the BC biosynthesis (e.g., using silica [12], titania [13], or silver [14] nanoparticles as fillers), by blending of BC with various polymers (e.g., with chitosan [15], polyvinyl alcohol [16,17], or acrylic resin [18]) or by in situ polymerization of monomers within the BC network (e.g., (meth)acrylates [19][20][21][22][23] or (meth)acrylamides [24][25][26]). …”

“…The properties of such composites were controlled by the chemical composition of the hydrogel matrix (i.e., by monomer ratio, crosslink density, or diluent concentration) while keeping the BC content at the level of 1 wt%. Other authors [19,27,28] studied BC composites of different BC content and showed that mechanical improvement can be achieved, so that these densified BC scaffolds almost approached the mechanical requirements of the native tissue.…”

Viscoelasticity and water plasticization of polymer-cellulose composite films and paper sheets

“…renewability, biodegradability, biocompatibility, abundance, high specific strength, and non-abrasive nature in processing. The use of different cellulosic materials as reinforcing phase in the bio/nano composite field (Samir et al 2005;Kramer et al 2006), or as the continuous phase in all cellulose composites (Nishino et al 2004), as well as in very special applications e.g. in biomedicine (Klemm et al 2001) have conceived new ways to isolate cellulosic materials and to tailor cellulose to desired applications.…”

“…Cellulose reinforced (bio)composites have high promises in future and the materials have been an object of significant amount of scientific research. The research field have been extensively reviewed recently by several experts (Samir et al 2005;Berglund 2005;Dufresne 2006;Eichhorn et al 2001;Hubbe et al 2008;Kramer et al 2006). Moreover, the traditional industrial consumers of cellulose, paper and textile industries, are looking for additional value and new markets to their products by increasing R&D contributions to materials science.…”