Modification Of Nanocrystalline Cellulose Research Articles

The effect of urea-formaldehyde adhesive modification with diisocyanate-functionalized nanocellulose on the properties of particleboard

In this paper, a nanocrystalline cellulose (NCC) functionalized with 4,4′-diphenylmethane diisocyanate (MDI) was used as a modifier for urea-formaldehyde (UF) adhesive in particleboard production. The applied method of NCC functionalization with diisocyanate has not been previously studied in research on wood-based materials. Chemical structure of MDI-NCC evaluated with Fourier transform infrared spectroscopy (FTIR) demonstrated some significant changes indicating that the functionalization was effective. No change in crystallinity caused by the modification was noted based on the lateral order index and total crystallinity index. Hydrophilicity of NCC was reduced due to the functionalization with MDI. Based on the differential scanning calorimetry (DSC) results, it was found that the reactivity of the resin was improved by the addition of NCC, and moreover, the effect was even more noticeable when the MDI-NCC was introduced. Properties of manufactured particleboards such as density, water absorption and formaldehyde content were not affected by the resin reinforcement. In turn, the modification of NCC with MDI allowed to increase the strength and reduce swelling of the particleboards more significantly than in the case of a neat NCC. It indicates that application of diisocyanate-functionalized NCC has great potential for the use as the UF resin modifier in particleboard production.

PGlu-Modified Nanocrystalline Cellulose Improves Mechanical Properties, Biocompatibility, and Mineralization of Polyester-Based Composites.

The development of biocompatible composite materials is in high demand in many fields such as biomedicine, bioengineering, and biotechnology. In this study, two series of poly (D,L-lactide) and poly (ε-caprolactone)-based films filled with neat and modified with poly (glutamic acid) (PGlu) nanocrystalline cellulose (NCC) were prepared. An analysis of scanning electron and atomic force microscopies’ results shows that the modification of NCC with poly (glutamic acid) favored the better distribution of the nanofiller in the polymer matrix. Investigating the ability of the developed materials to attract and retain calcium ions led to the conclusion that composites containing NCC modified with PGlu induced better mineralization from model solutions than composites containing neat NCC. Moreover, compared to unmodified NCC, functionalization with PGlu improved the mechanical properties of composite films. The subcutaneous implantation of these composite materials into the backs of rats and the further histological investigation of neighboring tissues revealed the better biocompatibility of polyester materials filled with NCC–PGlu.

Poly(ε-caprolactone)-based biocomposites reinforced with nanocrystalline cellulose grafted with poly(L-lactic acid)

The modification of nanocrystalline cellulose with poly(L-lactic acid) was carried out using the “grafting from” approach based on the ring-opening polymerization of L-lactide initiated with cellulose hydroxyls. The modification was proved by FTIR spectroscopy, thermogravimetric analysis and dynamic light scattering. Samples of native and modified cellulose were applied as fillers for poly(ε-caprolactone) films that were studied for their mechanical properties. A significant increase of Young’s modulus was observed for composite material based on PCL containing nanocrystalline cellulose modified with poly(L-lactic acid).

The effect of surfactants modification on nanocrystalline cellulose for paclitaxel loading and release study

The Nanocrystalline cellulose (NCC) was prepared from filter paper by acid hydrolysis process. The modification of NCC with cationic, anionic, and nonionic surfactant did not have a tremendous effect on the chemical structure of material based on the characterization of XRD and FTIR. The modified NCCs were employed as a drug carrier for paclitaxel (PTX). Increasing concentration of ionic surfactants can enhance the loading of the hydrophobic drug, while the opposite trend was observed for nonionic surfactant modified nanocrystals. The attachment of surfactant toward the particle was a more likely physical aggregation of micelle on the surface of nanocrystals. Larger particle size was observed after the modification of nanocrystal cellulose. The fitting of Higuchi and sigmoidal models were applied in the release profile to investigate the kinetic release mechanism of paclitaxel at pH 5.8 and 7.4. Cell viability was determined to check the biocompatibility of the materials toward mouse osteoblast cells 7F2 using MTT assay. Toxic behavior was not observed for NCC, while CTAB was completely not compatible with cells.

Effect of Unmodified and Modified Nanocrystalline Cellulose Reinforced Polylactic Acid (PLA) Polymer Prepared by Solvent Casting Method Morphology, mechanical and thermal properties

The positive attributes of excellent biocompatibility and biodegradability of biocomposites with the addition of versatile nanocellulose from agriculture wastes have provided plenty opportunities for further development of functional biocomposite in various fields. Therefore, solvent casting was selected as a reinforcement method in order to produce biocomposite comprise of nanocrystalline cellulose and PLA polymer. Modification of nanocrystalline cellulose through acetylation reaction was conducted upon reinforcement to reduce its surface polarity and hidrophilicity. Biocomposite films prepared at various unmodified (uNC) and acetylated nanocrytalline cellulose (aNC) loading were exposed to morphological (FESEM), tensile test and thermal analysis (TGA). Reinforcement of aNC shows a better dispersion in PLA polymer due to the decreasing of surface polarity, thus increasing inter-facial interaction between both materials. This is proven by greater performance of biocomposite films in tensile strength, Young�s modulus and thermal stability of aNC reinforced PLA as compared to uNC reinforced PLA. Overall, it can be concluded that these research findings can widen the scope of biocomposites research area and have significant implications for the commercial application of biomass products.

Effect of Aminosilane Modification on Nanocrystalline Cellulose Properties

The application of renewable nanomaterials, like nanocrystalline cellulose (NCC), has recently been widely studied by many researchers. NCC has many benefits such as high aspect ratio, biodegradability, and high number of hydroxyl groups which offer great opportunities for modification. In this study, the NCC derived from empty fruit bunches (EFB) was modified with aminosilane, 3-(2-aminoethylamino)propyl-dimethoxymethylsilane (AEAPDMS), and the characterization was performed to investigate the potential as carbon dioxide (CO2) capture. Modification of NCC with AEAPDMS was carried out in water/ethanol solvent (80/20) (v/v) with a ratio of NCC to aminosilane of 1 : 1, 1 : 2, 1 : 3, and 1 : 4 w/w%. The effects of AEAPDMS on NCC were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, elemental analysis (CHNS), and transmission electron microscopy (TEM). The existence of AEAPDMS onto NCC was confirmed by ATR-FTIR spectroscopy as the new peaks of NH2were bending and wagging, and Si-CH3appeared. The thermal stability of NCC increased after modification due to the interaction with AEAPDMS. The elemental analysis result showed that the nitrogen content increased with an enhancement ratio of the modifiers. The XRD indicated that the crystallinity decreased while the rod-like geometry of NCC was maintained after amorphous AEAPDMS grafted on the NCC. Since AEAPDMS can be grafted on the NCC, the sample is applicable as CO2capture.

Modification of NCC for Improving the Wetting Property with Polyurethane

In this study, different lipophilic groups from 3-aminpropyltriethoxysilane (APTES) and 3-glycidoxypropyltrimethoxysilane (GPTMS) were used to alter the surface structure of nanocrystalline cellulose (NCC). The diversifications of NCC surface resulted from modifiers improved the wetting property between NCC and polyurethane significantly. The modified NCC was characterized by X-ray powder diffraction (XRD). And the wetting property was indicated by contact angle (CA). Epoxy groups from 6% GPTMS led to a 47.6% decline of CA, while the improvement of wetting property from APTES was inconspicuous.