Containing Cellulose Nanocrystals Research Articles

Adsorption of heavy metals on the surface of nanofiltration membranes: “A curse or blessing”?

Adsorptive membranes, formed by dispersing adsorbent particles in a the polymer matrix of ultrafiltration (UF) membranes, are among a number of promising technologies for removing heavy metal ions from water. They offer much higher water permeability compared to nanofiltration (NF) membranes. However, because of a limited adsorption capacity, adsorptive membranes require frequent regenerations to maintain their selective properties. In contrast, NF membranes rely on size/steric exclusion and electrostatic repulsion. Moreover, by incorporating adsorptive nanoparticles into, for example, the polyamide (PA) layer in thin film nanocomposite (TFN) membranes, NF membranes, in addition to size/steric exclusion and electrostatic repulsion, can also reject heavy metal ions by adsorption. Some TFN-NF membranes for processing feed solutions containing heavy metal ions require regeneration, implying a detrimental effect of heavy metal adsorption on their performance. Still, some do not, which leads to the question stated in the title of this article.In this study, we examined the role of heavy metal ions (Cu2+ and Pb2+) in feed solutions on their rejection and water permeability TFN membranes containing cellulose nanocrystals (CNCs), acetylated CNCs (ACNCs) and CysCNCs in the PA layer. We performed NF experiments of durations ranging from 1 to 16 h. At the end of each experiment, we measured the membranes' heavy metal adsorption, contact angle, and zeta potential and correlated them with time-dependent water permeability and heavy metal rejection. An increase in heavy metal adsorption with time was associated with a desirable simultaneous increase in water permeability and heavy metal rejection. The equilibrium adsorption was reached 8–12 h from the start of the experiments, while membrane performance remained constant. Therefore, membrane regeneration was not only unnecessary but would be undesirable because the adsorbed heavy metals improve membrane performance. In other words, the adsorption of heavy metals on the surface of NF membranes appears to be a “blessing” rather than a “curse."

Valorization of olive leaf waste as a new source of fractions containing cellulose nanomaterials

The olive oil activity generates annually a huge amount of biomass waste from the pruning action of the tree and fruit harvesting, including thin woody branches and leaves. In an effort toward more sustainability in the lignocellulosic biorefinery of olive waste activity, nanocelluloses (NCs) were produced from the solid residues remaining after the extraction of biological active compounds from the leaves. Fractions containing cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and lignin-containing cellulose nanofibrils (LCNFs) were prepared and characterized in terms of morphology, chemical composition, thermal stability, colloidal properties, and crystallinity. The reinforcing capability of the different fractions was evaluated in nanocomposite films made of an acrylic matrix incorporating different NC contents. Dynamic mechanical analysis (DMA) and tensile testing of the films were used to compare the reinforcing effect of the NCs. Although CNCs displayed the highest reinforcing effect based on the weight content, LCNFs and CNFs demonstrated also a reinforcing effect, which is higher when normalized with the cellulose content. Compared to CNFs and CNCs, LCNFs displayed a lower hydrophilic character confirmed by contact angle measurement, and had better thermal stability. This work demonstrated the potential use of the solid waste from olive leaves as a new source for biobased nanoparticles containing lignin, hemicellulose components, and cellulose nanofibrils. Beside the high content in bioactive polyphenol compounds that can be extracted from olive leaves, the conversion of the residual biomass can contribute to increasing the circularity and sustainability of olive oil activity.

Hydrophobization of aerogels based on chitosan, nanocellulose and tannic acid: Improvements on the aerogel features and the adsorption of contaminants in water

Hydrophobic chitosan aerogels are promising adsorbents for immiscible contaminants such as oils and organic solvents. However, few studies have reported the application of hydrophobic aerogels as adsorbent for organic contaminants dissolved in water. Herein, novel highly hydrophobic chitosan (CS) beads containing cellulose nanocrystals (CNC) and hydrophobized tannic acid (HTA) composite were prepared with different CS and CNC−HTA content to achieve an optimized adsorbent to remove emerging contaminants from water in batch and fixed-bed assays. The CS@CNC−HTA beads properties were assessed by FTIR, XRD, SEM, XPS, Micro-CT, WCA, and zeta potential. Supramolecular interactions and physical interlacements between CS and CNC−HTA enabled the formation of CS@CNC−HTA beads with high porosity (98.6%), great volume of open pore space (10.16 mm3) and hydrophobicity (121.8°). The 1:1 CS@CNC−HTA beads showed the best performance for removing the pharmaceutical sildenafil citrate, the basic blue 26 dye, and the surfactant cetylpyridinium chloride, reaching adsorption capacities of 86 (73%), 375 (84%), and 390 (90%) mg.g−1, respectively. The 1:1 CS@CNC−HTA beads efficiently removed sildenafil citrate, basic blue 26 and cetylpyridinium chloride in fixed-bed experiments with exhaustion times of 890, 300, and 470 min, respectively. Theoretical calculations and adsorption assays indicate that the main attractive interactions are pyridinium−π, π−π, electrostatic and hydrophobic.

Synthesis of Cellulose Nanocrystals/HKUST-1 Composites and Their Applications: Crystal Violet Removal and Doxorubicin Loading.

This study developed a novel composite material containing cellulose nanocrystals (CNCs) and HKUST-1. Here, the addition of CNCs was used to enhance the characteristics of HKUST-1 in terms of surface area, adsorption ability, and functional groups. Here, the fabrication of CNCs@HKUST-1 composites was carried out by adding CNCs into the fabrication process of HKUST-1. The addition of CNCs provides additional functional groups on the surface of composite material which can be used to attach other organic compounds, such as in waste management and drug delivery systems. Here, CNCs@HKUST-1 composites were tested as a material for crystal violet (CV) removal and doxorubicin (DOX) loading. The removal capacity of CNCs@HKUST-1 composite towards CV molecules reached 1182.25 ± 27.74 mg/g, while the loading capacity for DOX drugs was around 1514.94 ± 11.67 mg/g. Both applications showed that CNCs@HKUST-1 composite had higher adsorption capacity and ability compared to its precursor materials, i.e., CNCs and HKUST-1.

Hybrid Graphenene Oxide/Cellulose Nanofillers to Enhance Mechanical and Barrier Properties of Chitosan-Based Composites.

Chitosan-based hybrid nanocomposites, containing cellulose nanocrystals (CNCs), graphene oxide (GO), and borate as crosslinking agents, were successfully prepared by solution-casting technique. The synergistic effect of the two fillers, and the role of the cross-linker, in enhancing the structural and functional properties of the chitosan polymer, was investigated. XPS results confirm the chemical interaction between borate ions and hydroxyl groups of chitosan, GO, and CNCs. The morphological characterization shows that the GO sheets are oriented along the casting surface, whereas the CNC particles are homogenously distributed in the sample. Results of tensile tests reveal that the presence of graphene oxide enhances the elastic modulus, tensile strength, elongation at break, and toughness of chitosan, while cellulose and borate induce an increase in the elastic modulus and stress at the yield point. In particular, the borate-crosslinked chitosan-based sample containing 0.5 wt% of GO and 0.5 wt% of CNCs shows an elongation at a break value of 30.2% and a toughness value of 988 J*m−3 which are improved by 124% and 216%, respectively, compared with the pristine chitosan. Moreover, the water permeability results show that the presence of graphene oxide slightly increases the water barrier properties, whereas the borate and cellulose nanocrystals significantly reduce the water vapor permeability of the polymer by about 50%. Thus, by modulating the content of the two reinforcing fillers, it is possible to obtain chitosan-based nanocomposites with enhanced mechanical and water barrier properties which can be potentially used in various applications such as food and electronic packaging.

Model development of aqueous diffusion softening transition in thermoplastic polyurethane cellulose nanocrystal composites

The mechanical adaptivity of polymer composites containing cellulose nanocrystals (CNCs) is of broad interest for the development of smart materials. The mechanism leading to diffusion-dependent mechanical softening in response to water uptake in these materials is well understood, however, the mass transport driving this phenomenon has not been completely resolved. Understanding such behavior would further enable the mechanism to be controlled and exploited for various applications. Here, we show that swelling of the bulk polymer composite during moisture uptake results in a decreased apparent diffusivity with increasing CNC concentration, despite the equilibrium water uptake increasing concurrently. Further, we demonstrate that a modification to the widely used percolation model predicts the full time-dependent evolution of storage modulus during the softening process by associating mass transport directly to the softening response. This model will be pertinent to studies of mechanical responses in CNC-polymer composites and is expected to be generally applicable to percolating networks which deactivate in response to a given stimulus.

One-Pot Synthesis of Cellulose/MXene/PVA Foam for Efficient Methylene Blue Removal

Ti3C2Tx MXene has attracted considerable interest as a new emerging two-dimensional material for environmental remediation due to its high adsorption capacity. However, its use is greatly limited by its poor mechanical properties, low processability and recyclability, and the low dispersity of such powder materials. In this work, a porous adsorbent (C–CMP) containing cellulose nanocrystals (CNC), Ti3C2Tx MXene and polyvinyl alcohol (PVA) was prepared by a simple and environmentally-friendly foaming method. Glutaraldehyde was used as crosslinker to improve the mechanical properties and boost the adsorption efficiency of methylene blue (MB) molecules. Fourier transform infrared (FT–IR), elemental analysis (EDX) and thermogravimetric analysis (TGA) further confirmed that the preparation of the C–CMP foam and cross-linking reaction were successful. Scanning electron microscope (SEM) indicated that the macropores were distributed homogeneously. The adsorption experiment showed that maximum adsorption capacity of MB can reach 239.92 mg·g−1 which was much higher than anionic dye (methyl orange, 45.25 mg·g−1). The adsorption behavior fitted well with the Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. Based on FT–IR, EDX and X-ray photoelectron spectroscopy (XPS) analysis, the adsorption mechanism between C–CMP and MB molecules was attributed to electrostatic interaction.

DRYING BEHAVIOR OF 3D PRINTED CEMENTITIOUS PASTES CONTAINING CELLULOSE NANOCRYSTALS

This study uses neutron radiography to evaluate the drying of printed cement paste samples containing cellulose nanocrystals (CNCs). CNCs have previously been used in printed cement paste to decrease the extrusion pressure and increase the degree of hydration (DOH) of the samples. Three different mixtures were prepared consisting of a plain mixture and mixtures containing two different types of CNCs. The influence of the sample surface to volume ratio (S/V) on the drying of cement paste samples and their DOH was examined. Exposing 3D printed samples to drying immediately after preparation can lead to high levels of water evaporation, which can limit the hydration evolution in the system and increase the porosity. The DOH and the drying behavior of cement paste are found to be dependent on the S/V of the element. The DOH decreased with an increase in the S/V of the sample. The addition of the CNCs to the mixture design did not substantially alter the DOH of poorly cured 3D printed samples. Previous work has shown that CNCs addition to the mixture design can lead to an increase in DOH only if water remains in the sample.

Thermochromic Cholesteric Liquid Crystal Microcapsules with Cellulose Nanocrystals and a Melamine Resin Hybrid Shell.

Thermochromic coatings that can change their color in response to variations in ambient temperature have various potential applications. Cholesteric liquid crystals (CLCs) are promising thermochromic materials due to their selective light reflection and wide regulation range. However, it remains a challenge to fabricate thermochromic coatings that combine good responsivity, mechanical strength, fabrication feasibility, and flexibility. In this study, CLC microcapsules containing cellulose nanocrystals (CNCs) and a melamine-formaldehyde (MF) resin hybrid shell were fabricated via in situ polymerization using CNC-stabilized Pickering emulsions as templates. The CNCs were employed as both Pickering emulsifiers and alignment agents of CLCs to prepare CLC Pickering emulsions. The CLC microcapsules were mixed with curable binders to obtain coating slurries, and thermochromic coatings were prepared by painting the slurries on substrates and drying. The thermochromic coatings could adjust their color in the visible wavelength range in a temperature range of 12 to 42 °C. Moreover, the obtained thermochromic coatings displayed a relatively high reflectance of up to 30-40% and can even be applied to flexible substrates. The CLC microcapsules with CNCs and an MF hybrid shell are promising in the field of smart decorative paints, anti-counterfeit labels, and artificial skins.

PBAT/PLA/cellulose nanocrystals biocomposites compatibilized with polyethylene grafted maleic anhydride (PE‐g‐MA)

AbstractThe use of biodegradable polymers has grown exponentially due to their lower environmental impact when compared to conventional polymers. In this sense, biocomposites are an alternative due to their promising properties, maintaining biodegradability. For this purpose, in the present study, a biodegradable biocomposite of PBAT (poly [butylene adipate co‐terephthalate]) and PLA (polylactide) blend containing cellulose nanocrystals (CNC) were obtained, using polyethylene grafted with maleic anhydride (PE‐g‐MA) as a coupling agent. Seven formulations were produced by extrusion and had their structure, morphology, thermal, and rheological properties analyzed. The results showed a significant improvement of adhesion among the components using PE‐g‐MA as a coupling agent. Moreover, CNC and PE‐g‐MA increased the PLA crystallinity degree and reduced the complex viscosity. These results are unprecedented in the literature using these compositions and extrusion processing conditions. Therefore, these new insights provide a vast horizon for the use of biodegradable mixtures using PBAT/PLA and CNC.

All-cellulose functional membranes for water treatment: Adsorption of metal ions and catalytic decolorization of dyes

In this study, we present a facile, one-step method for the manufacturing of all-cellulose, layered membranes containing cellulose nanocrystals (CNC), TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidized cellulose nanofibers (TO-CNF), or zwitterionic polymer grafted cellulose nanocrystals (CNC-g-PCysMA) as functional entities in combination with cellulose fibers and commercial grade microfibrillated cellulose. The presence of active sites such as hydroxyl, carbonyl, thioethers, and amines, gave the membranes high adsorption capacities for the metal ions Au (III), Co (II), and Fe (III), as well as the cationic organic dye methylene blue (MB). Furthermore, the membranes served as excellent metal-free catalysts for the decolorization of dyes via hydrogenation. A 3-fold increase of the hydrogenation efficiency for cationic dyes such as rhodamine B (RhB) and methylene blue was obtained in the presence of membranes compared to NaBH4 alone. Water-based processing, the abundance of the component materials, and the multifunctional characteristics of the membranes ensure their potential as excellent candidates for water purification systems.

Effect of Cellulose Nanocrystals and Lignin Nanoparticles on Mechanical, Antioxidant and Water Vapour Barrier Properties of Glutaraldehyde Crosslinked PVA Films.

In this work, PVA nanocomposite films containing cellulose nanocrystals (CNC) and different amounts of lignin nanoparticles (LNP), prepared via a facile solvent cast method, were crosslinked by adding glutaraldehyde (GD). The primary objective was to investigate the effects of crosslinker and bio-based nanofillers loading on thermal, mechanical, antioxidant and water barrier behaviour of PVA nanocomposite films for active food packaging. Thermogravimetric analysis showed improved thermal stability, due to the strong interactions between LNP, CNC and PVA in the presence of GD, while Wide-angle X-ray diffraction results confirmed a negative effect on crystallinity, due to enhanced crosslinking interactions between the nanofillers and PVA matrix. Meanwhile, the tensile strength of PVA-2CNC-1LNP increased from 26 for neat PVA to 35.4 MPa, without sacrificing the ductility, which could be explained by a sacrificial hydrogen bond reinforcing mechanism induced by spherical-like LNP. UV irradiation shielding effect was detected for LNP containing PVA films, also migrating ingredients from PVA nanocomposite films induced radical scavenging activity (RSA) in the produced films in presence of LNP. Furthermore, PVA-CNC-LNP films crosslinked by GD showed marked barrier ability to water vapour.

Light- and Humidity-Responsive Chiral Nematic Photonic Crystal Films Based on Cellulose Nanocrystals.

Light- and humidity-responsive chiral nematic photonic crystal (PC) films containing cellulose nanocrystals (CNCs) were fabricated. A photoactive polymer with hydrophilic groups, poly-(3,3'-benzophenone-4,4'-dicarboxylic acid dicarboxylate polyethylene glycol) ester, was coassembled with CNCs to form flexible iridescent films with a tunable chiral nematic order. In the coassembly process, the intermolecular hydrogen bonds of CNCs were weakened, which facilitated the fine regulation of the chiral PC nanostructure. The PC films displayed sensitive responses to both light and humidity. With increasing humidity from 30 to 100%, the chiral nematic helix pitch increased from 328 to 422 nm. The color of the PC films changed from blue to green, yellow, orange, and dark red with increasing relative humidity. Over 15 min of light irradiation, the absorption intensity of the films increased gradually. The light and humidity responses of the films were reversible. The films maintained their variable cholesteric liquid crystal texture and helical lamellar structure after light irradiation at different humidities. These PC films are expected to be useful in intelligent coatings and 3D printing.

Cellulose-based eco-friendly wafer-cleaning reagent

As the semiconductor industry has advanced, precisely patterned wafers of the sub-nanometer scale have been produced; hence, the development of cleaning reagents to remove contaminants from such wafers has received increasing attention. However, conventional cleaning solutions have significant drawbacks, including high cost and toxicity to both humans and the environment. In this work, we developed an eco-friendly cleaning reagent containing cellulose nanocrystals (CNCs) and a biodegradable amphoteric surfactant, cocamidopropyl betaine (CAPB), at optimal concentrations. The proposed system was applicable to both bare and patterned wafers, achieving a contaminant removal efficiency of ca. 100% without wafer damage. After investigating the cleaning mechanism utilizing different analytical techniques, we determined that the synergistic effect of the CNC/CAPB and free CAPB that includes the physical bombardment, electrostatic repulsion, and the adsorption inhibition of contaminants, contribute to the effective cleaning process. We expect this eco-friendly and cost-effective cleaning reagent to be readily adopted in the production of semiconductor products, as it could reduce the overall cost of producing electronics.

Preparation and characterization of polyhydroxybutyrate-co-valerate (PHBV) as green composites using nano reinforcements

This article presents the preparation and characterization of polyhydroxybutyrate-co-valerate (PHBV) nanocomposite films containing cellulose nanocrystals (CNC) and aluminum oxide nanoparticles (Al2O3) as reinforcements. The effects of adding nanoparticles on the mechanical properties, such as tensile strength and elongation, were studied using dynamic-mechanical analysis (DMA) such as modulus and tan δ. Also, morphology and thermal features were investigated by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), respectively. For this purpose, first, CNC and Al2O3 with a ratio of 0, 1, 3 and 5 wt% was added to a biopolymer, then a combination of these two with the ratio of 3:3 and 5:5 was added to the PHBV matrix, separately; and finally, the various nanocomposite films were prepared by the solvent casting method. After adding nanoparticles, the tensile strength and thermal stability of the PHBV/CNC films increased and the elongation decreased. SEM observations showed that large amounts of nanoparticles (3 wt%) are strongly agglomerated in the biopolymer matrix. This led to a decrease of mechanical properties in the composites with nanoparticles of more than 3% by weight. DSC results showed that the glass transition temperature (Tg) increased slightly with the incorporation of nano participles to PHBV. The enthalpy of fusion (ΔHfus) increased from 33.8 J/g for neat PHBV film to 48.1, 50 and 45.8 J/g for PHBV films containing 1, 3, and 5 wt% CNC, respectively. These results are consistent with the conclusions of DMA. The improvement of physical and mechanical properties of the composites confirmed that CNC has a better effect than aluminum oxide nanoparticles as a nano reinforcement.

Effect of cellulose nanocrystals on thyme essential oil release from alginate beads: study of antimicrobial activity against Listeria innocua and ground meat shelf life in combination with gamma irradiation

Thyme essential oil (EO) loaded alginate beads (1–3%) containing cellulose nanocrystals (CNCs) (0–40% polymer dry basis) were prepared in order to study EO release profile in simulating solvent and the antimicrobial effect against Listeria innocua via in vitro and in situ tests. Introduction of CNCs from 0 to 30% in alginate beads exhibited an increase of EO loading capacity from 0.12 to 0.17% and a kinetic release constant (k) decrease from 9.85 to 6.77 when beads were prepared with 3% thyme EO, respectively. These optimal concentrations were selected in order to assess the antimicrobial efficiency to eliminate L. innocua and to reduce the mesophilic total flora (MTF) on ground meat during storage. Results showed that ground meat containing active alginate beads showed a 2 log reduction of L. innocua during more than 10 days as compared to the control. The influence of gamma-irradiation treatment was studied on MTF of ground meat, allowing a 4 log reduction during 14 days when alginate beads containing 3% thyme EO were added. A synergy between thyme EO and irradiation was observed in terms of L. innocua elimination and shelf-life extension.

Design and Characterization of PLA Bilayer Films Containing Lignin and Cellulose Nanostructures in Combination With Umbelliferone as Active Ingredient.

Poly (lactic acid) (PLA) bilayer films, containing cellulose nanocrystals (CNC) or lignin nanoparticles (LNP) and Umbelliferone (UMB) were extruded and successfully layered by thermo-compression starting from monolayer films. Lignocellulosic nanostructures were used in PLA based film as nanofillers at 3 wt.%, while UMB was used as active ingredient (AI) at 15 wt.%. The effects of processing techniques, presence, typology and content of lignocellulosic nanoparticles have been analyzed and thermal, morphological, mechanical and optical characterization of PLA nanocomposites have been made. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) studies evaluated the presence of nanofillers and AI at chemical level. Bilayer formulations showed a good interfacial adhesion and improved stress at break with respect of PLA monolayers, although they were less stretchable and transparent. Data obtained from thermal, colorimetric and transparency investigations underlined that the presence of lignocellulosic nanofillers and AI in PLA monolayer and bilayer films induced relevant alterations in terms of overall color properties and thermal stability, while antioxidant activity of umbelliferone was enhanced by the addition of lignin in produced materials.

Solvent Regulation Approach for Preparing Cellulose-Nanocrystal-Reinforced Regenerated Cellulose Fibers and Their Properties.

An electrolyte and aprotic solvent mixture were used to prepare cellulose solutions containing cellulose nanocrystals (CNCs). All-cellulose composite fibers were then produced by dry–wet spinning these solutions. The presence of CNC in the all-cellulose fibers was demonstrated, and the effects of the CNC on the fiber properties were investigated. The all-cellulose fibers were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and electronic tensile measurements. These results showed that CNCs were present in the mixture and that their structure was maintained in the all-cellulose fibers. No compatibility problems between the CNC and cellulose II matrix were observed. Introducing CNC enhanced the crystallinity, thermal stability, and mechanical properties of the composite fibers.

2.5D Hierarchical Structuring of Nanocomposite Hydrogel Films Containing Cellulose Nanocrystals.

Although two-dimensional hydrogel thin films have been applied across many biomedical applications, creating higher dimensionality structured hydrogel interfaces would enable potentially improved and more biomimetic hydrogel performance in biosensing, bioseparations, tissue engineering, drug delivery, and wound healing applications. Herein, we present a new and simple approach to control the structure of hydrogel thin films in 2.5D. Hybrid suspensions containing cellulose nanocrystals (CNCs) and aldehyde- or hydrazide-functionalized poly(oligoethylene glycol methacrylate) (POEGMA) were spin-coated onto prestressed polystyrene substrates to form cross-linked hydrogel thin films. The films were then structured via thermal shrinking, with control over the direction of shrinking leading to the formation of biaxial, uniaxial, or hierarchical wrinkles. Notably, POEGMA-only hydrogel thin films (without CNCs) did not form uniform wrinkles due to partial dewetting from the substrate during shrinking. Topographical feature sizes of CNC-POEGMA films could be tuned across 2 orders of magnitude (from ∼300 nm to 20 μm) by varying the POEGMA concentration, the length of poly(ethylene glycol) side chains in the polymer, and/or the overall film thickness. Furthermore, by employing adhesive masks during the spin-coating process, structured films with gradient wrinkle sizes can be fabricated. This precise control over both wrinkle size and wrinkle topography adds a level of functionality that to date has been lacking in conventional hydrogel networks.

Cellulose Nanocrystals and Jute Fiber-reinforced Natural Rubber Composites: Cure Characteristics and Mechanical Properties

A comparative study was conducted for three natural rubber (NR) composites: one containing raw jute fibers, one containing bleached jute fibers, and one containing cellulose nanocrystals (CNCs). The composites were prepared by adding each filler at 5 or 10 phr to the latex before chemical coagulation, and the composites were processed in a two-roll mixing mill. The mechanical, thermal, and vulcanization properties of the prepared composites were then determined. The NR stiffness increased with increasing fiber content, particularly when bleached fibers were added, as evidenced by the increased elastic moduli, maximum torques, glass transition temperature, and crosslinking density. Scanning electron microscopy showed agglomerates in the composite with 10 phr CNCs, which led to poorer mechanical performance compared to that of the bleached fiber-reinforced composite (10 phr). On the other hand, the addition of CNCs to the NR increased the cure rate index, thereby significantly advancing the optimum vulcanization time.