Nanosized cellulose derivatives as green reinforcing agents at higher loadings in natural rubber

Abstract

Cellulose nanoparticles (CelNPs) prepared by an acid hydrolysis process were acetylated under ambient conditions to retain the nanosize and to obtain hydrophobic nanosized derivatives. Green nanocomposites of natural rubber (NR) with more than 50 phr of cellulosic fillers were successfully developed by a commercial dry mixing process. The incorporation of cellulose acetate nanofiller up to 40 phr led to an almost linear increase in both the tensile and elongation properties, which were higher than even those of a composite with the conventional filler carbon black (CB). This was further supported by the almost uniform single‐phase morphology of the nanobiocomposite revealed by scanning electron microscopy and the high thermal stability. The results indicate the high degree of compatibility between the hydrophobic nanosized filler and the NR matrix. Although a drop in the mechanical strength was observed above 50 phr, the cellulose derivatives were expected to prove to be promising substitutes for the hazardous filler CB even at higher loadings. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40632.

Synergistic Cross-linking and Reinforcing Enhancement of Rubber Latex with Cellulose Nanocrystals for Glove Applications

“…17−21 Because of the large surface area and their tendency to form hydrogen bond mediated aggregation, an efficient dispersion of CNCs in nonpolar matrices including natural rubber via conventional mixing methods such as batch mixing, mastication and extrusion compounding is challenging. 22 Hence, blending in an aqueous colloidal suspension medium is employed to achieve proper dispersion with the aid of high shear mixing such as ultrasonication to deconstruct agglomerates of the nanoparticles. 23,24 Typically, CNCs are dispersed in natural latex without any modification specifically because of their excellent dispersibility in aqueous mediums, stemming from the abundant hydroxyl groups on the surface.…”

“…One promising filler, which has caught a lot of attention recently due to its high stiffness and reinforcing ability is cellulose nanocrystals (CNCs). − CNCs are obtained from renewable resources typically via the acid hydrolysis of cellulose. A review of the literature has shown it to exhibit excellent reinforcing abilities in polymers, such as NR. − Because of the large surface area and their tendency to form hydrogen bond mediated aggregation, an efficient dispersion of CNCs in nonpolar matrices including natural rubber via conventional mixing methods such as batch mixing, mastication and extrusion compounding is challenging . Hence, blending in an aqueous colloidal suspension medium is employed to achieve proper dispersion with the aid of high shear mixing such as ultrasonication to deconstruct agglomerates of the nanoparticles. , Typically, CNCs are dispersed in natural latex without any modification specifically because of their excellent dispersibility in aqueous mediums, stemming from the abundant hydroxyl groups on the surface. , Nonetheless, improving the interfacial adhesion between the hydrophobic rubber chains and hydrophilic CNC can lead to improvement in properties.…”

Cellulose/Cellulose-Based Nanospheres: Perspectives and Prospective

“…[51][52][53] Ibrahim et al report plant species-dependent differences in nanosphere diameter, while Thakore, using only sulfuric acid without sonication, reports the formation of fibrous cellulose, which upon acetylation formed cellulose triacetate nanospheres (d = 25-30 nm). 51,52 Xiong and coworkers prepared SCNs with a mean diameter of 35 nm (range 10-65 nm), which was obtained by converting cotton fabric to microcrystalline cellulose via additional acid hydrolysis with mixed sulfuric and nitric acids to form the spherical product. 53 Degree of polymerization (DP) of their product was 144, while that of the starting cotton was 1,200.…”

A Review of Rubber Biocomposites Reinforced with Lignocellulosic Fillers

“…This modification improved by 1530% the Young's modulus of NR nanocomposites containing 5 wt.% of CNF compared to the neat NR, and by 530% compared to the nanocomposite without treatment. In another study, Thakore et al [143] used the acetylation method to produce hydrophobic cellulose acetate nanofiller for NR nanocomposites. The authors claimed that adding this filler (up to 40 phr) to NR linearly increased the tensile strength by 300%.…”