Reinforcing Poly(ethylene) with Cellulose Nanocrystals

Abstract

The fabrication of nanocomposites of low-density polyethylene (LDPE), one of the world's most widely used polymers, and cellulose nanocrystals (CNCs), which represent the world's most abundant bio-based nanofiller, is reported. While the hydrophobic polymer and the hydrophilic filler seem to be intrinsically incompatible, this article shows that it is possible to kinetically trap homogeneous nanocomposites by a templating approach. An organogel is first prepared by exchanging the solvent of an aqueous CNC dispersion against acetone, impregnating the resulting organogel, in which the CNCs form a percolating network with a hot LDPE solution in toluene, and compression-molding the resulting materials into thin films. At a filler content of 7.6% v/v, the resulting materials display a three- to four-fold increase in strength and stiffness compared with the neat LDPE, which confirms that the CNC network could be largely maintained. It is also possible to reprocess these nanocomposites and dilute them with LDPE using conventional melt-processing techniques.

Compostable composites of wheat stalk micro‐ and nanocrystalline cellulose and poly(butylene adipate‐co‐terephthalate): Surface properties and degradation behavior

“…Many researchers have proposed using biodegradable copolyesters, 11 which are easily attacked by microbes in the environment to disintegrate into smaller fragments by hydrolyzing their ester bonds. [17][18][19][20] Many studies have proved that the degradation behavior of such polymers can be tuned preciously on mixing with biofillers of animals or plant origins such as chitosan, hydroxyapatite, microcrystalline cellulose (MCC), and nanocrystalline cellulose (NCC). [14][15][16] The composites of these materials with natural fibers are more environment-friendly and have good mechanical, thermal and other functional properties similar to the tough synthetic polymers.…”

“…12,13 In this context, several "biodegradable" and biobased plastics have been commercialized. 19,21,22 Turning towards the renewable flora-based resource of the nature, either from agriculture or from the forest products, it can be observed that major part of the plant bodies are made up of macromolecular cellulosic materials. [17][18][19][20] Many studies have proved that the degradation behavior of such polymers can be tuned preciously on mixing with biofillers of animals or plant origins such as chitosan, hydroxyapatite, microcrystalline cellulose (MCC), and nanocrystalline cellulose (NCC).…”

A critical review of the current knowledge regarding the biological impact of nanocellulose

“…CNCs can further form lyotropic phases, display a high surface area, and the abundance of surface hydroxyl groups makes the chemical modification of the surface readily possible. All these features make CNCs and other nanocellulose types interesting for a broad range of new applications including, use as a reinforcing filler in polymer nanocomposites [35, 36], the basis for stimuli responsive materials [9, 37, 38], as a nucleating agent [39, 40], a carrier for the controlled delivery of molecules [41], biosensors [42], and a component of tissue engineering scaffolds [43, 44]. In addition, the substitution of microcrystalline cellulose, which has long been used as rheology modifier in food products and cosmetic formulations, and as an excipient in tablets, with nanocellulose types can be envisioned to bring significant benefits beyond those described above.…”

Enhanced homogeneity and interfacial compatibility in melt-extruded cellulose nano-fibers reinforced polyethylene via surface adsorption of poly(ethylene glycol)- block -poly(ethylene) amphiphiles

“…The results were attributed to the high shear rates experienced during extrusion which would prevent the formation of the strong percolated hydrogen bonded network and to the possible lack of physical interaction between PEO surface saturated CNC's. Another recent approach was proposed recently by Sapkota [45] using a templating approach consisting in impregnating using hot LDPE solution in toluene a CNC based organogel prepared by solvent exchange methodology. The resulting percolated CNC/LDPE nano-composite network were compression-molded and subsequently mixed with LDPE via extrusion to produce nano-composites containing 0.6 and 1.3 vol.% of CNC.…”