Isolation and characterization of cellulose nanocrystals and synthesis of bioplastic cellulose acetate from the invasive weed Senna didymobotrya using acid hydrolysis and acylation methods.

Indonesia is the world’s largest palm oil producer and exporter, can produce 230 kg of OPEFB. The utilization of OPEFB is still at 10%, even though OPEFB is composed of 37.26% cellulose. This research aims to find out how to synthesize and characterize cellulose acetate from OPEFB cellulose into membrane material. The synthesis of cellulose acetate using the acetylation method is carried out in several processes. The activation process expands the surface of the cellulose fibers. The acetylation process is intended to substitute cellulose hydroxyl groups with acetyl groups. The hydrolysis removes some acetyl groups from trimester cellulose and reduces the combination of sulfate esters. In the results of FTIR analysis, carbonyl groups (C=O) and acetyl groups (C-O) have high peak depths in OPEFB cellulose acetate. Based on the calculation of acetyl content, OPEFB cellulose acetate has an acetyl content of 39.82% with a degree of substitution of 2.44. The results of XRD analysis show that OPEFB cellulose acetate has a crystallinity index of 34.5%. In TGA analysis, the thermal stability of cellulose acetate is up to a temperature of 210°C. Based on the research results, OPEFB cellulose can be synthesized into cellulose acetate using the acetylation method.

This study provides a novel value‐added utilization of the agroindustrial waste of royal palm tree leaf sheath to produce cellulose acetate. One of the motivations of this work was the fact that Brazil is one of the largest heart of palm producers in the world. However, as a result of extraction and processing, tons of waste are generated and discharged to the environment. Such waste is rich in lignocellulosic material, which could be reused to obtain derivatives of interest and commercial value. The synthesis of cellulose acetate was performed through a homogeneous acetylation reaction. Three different conditions were tested for delignification of the raw material, which resulted in a reduction in lignin content from 17.75 to 7.72%. The highest yield of cellulose acetate reached 99.5%, with degree of substitutions ranging between 2.08 and 2.82, which indicates satisfactory conversion. The Fourier transform infrared spectrum showed that practically all hydroxyl groups were replaced by acetate groups; this was also confirmed by nuclear magnetic resonance analysis. X‐ray diffraction analysis showed that the cellulose acetate crystallinity index was 8.9%. This demonstrates the viable potential of cellulose acetate production with low cost and use of highly available agroindustrial waste. POLYM. ENG. SCI., 59:891–898, 2019. © 2018 Society of Plastics Engineers

Cassava stem cellulose (CSC)Nanocrystal for optimal methylene BlueBio sorption with response surface design

Isolation and characterization of cellulose nanocrystals from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis)

Microstructural development and mechanical performance of poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) (80/20) blends containing single but geometrically different cellulose nanocrystals (CNCs) were investigated. The CNCs used in this study include cylindrical CNCs (ultrasonic treated), spherical CNCs (chemical treated) and rod-like CNCs (commercial), all characterized by particle size analyzer, atomic force microscopy (AFM) and X-ray diffraction. The melt viscoelastic results obtained for the melt compounded CNCs with PLA/TPU blend have implied a fine dispersion of both spherical and cylindrical CNCs which are preferentially localized in the PLA matrix and/or interface, while poorly dispersed rod-like CNCs were mostly accumulated in the TPU phase. These results were supported by AFM micrographs. More evidence was provided by scanning electron microscope micrographs which showed a decrease in TPU particle size in the blends filled with spherical and cylindrical CNCs, as a result of the nanoparticles’ localization in the PLA matrix and/or interface. The results of dynamic mechanical thermal analysis have revealed that the addition of spherical and cylindrical CNCs into the blends not only has compensated the reducing effect of TPU on the storage modulus but also has enhanced the modulus up to values even higher than that of PLA matrix. In contrast, the rod-like CNCs did not enhance the storage modulus of the blend significantly. More interestingly, the blend nanocomposite containing 3 wt% spherical CNCs exhibited a highly enhanced yield stress as well as significant elongation at break. This behavior could be explained by the induction of an interconnected type microstructure of spherical CNCs in which the nanoparticles are localized in PLA matrix, allowing the overlapping of stress counters around TPU particles and facilitating the stress transformation throughout the loaded sample. A similar enhancing effect but to a lesser extent, was obtained for those blend nanocomposites filled with cylindrical CNCs. In contrast to the other two types of CNCs, rod-like CNCs have weakened the mechanical performance of the blends. The results of fracture toughness obtained from single edge notch bending experiments have shown almost similar enhancing effect of the three types of CNCs on toughening. However, the sensitivity of the fracture test was not high enough to distinguish the effect of different CNCs on mechanical behavior of CNCs-filled blend nanocomposites.

Isolation of cellulose nanocrystals from grain straws and their use for the preparation of carboxymethyl cellulose-based nanocomposite films

Two different types of cellulose nanocrystals, derived from water hyacinth fibers and microfibrillated cellulose (MFC), were prepared using an acid hydrolysis treatment. These cellulose nanocrystals (CNCs) were further used as barrier enhancing fillers for polyurethane (PU) blended with 25 wt% of poly(vinylidene dichloride) (PVDC). The aim of this study was to investigate the effects of types and concentration of CNCs on mechanical, optical and barrier properties of polymer composite films. The feasibility of applying the obtained composite films as an encapsulating material for enhancing the lifetime of dye sensitized solar cells (DSSC) was also of interest. The acid hydrolysis of the MFC-yielded rod-shaped cellulose nanocrystals (CNCm) while the acid-hydrolyzed water hyacinth led to a formation of spherical-shaped cellulose nanocrystals (CNCw). Regardless of the types of CNCs, the optical transparency of the composite films was maintained well above 60%. According to results in this study, the most efficient film with the lowest water vapor transmission rate of 0.0517 g m−2 day−1 was the PU/PVDC film reinforced with 0.1 wt% of CNCm. The encapsulants made from this composite could prolong the lifetime of the DSSC devices for up to 14 days, with the normalized PCE value of 0.78. Overall, this work showed that the considerations of the barrier properties of the polymer encapsulants alone are insufficient to ensure that the system would be effective. An interfacial adhesion between the encapsulants and the electrodes, as well as some side reactions between polymers and chemicals inside the fabricated cell, should also be taken into account.

Cellulose nanocrystals (CNCs) is synthesized from alpha-cellulose by acid hydrolysis method, and formation of nanocrystallization is comprised by using various microscopic and spectroscopic techniques like PXRD, XPS, Raman, FTIR, PL, UV-Vis, DSC, TGA, DLS, SEM, TEM. Nanocrystalline cellulose shows a notably higher photoluminescence (PL) intensity than cellulose, which enhances its ability to absorb and emit visible light. This increase in PL intensity is attributed to a smaller particle size of CNCs, greater surface area, and quantum confinement effects. The higher intensity of the XPS spectrum further supports the larger surface area of CNCs. PXRD and Raman spectroscopy results show that CNCs has a higher crystallinity index than cellulose. Through deconvolution of the 13C CP-MAS SSNMR spectrum, we confirmed a significant reduction in the relative abundance of the amorphous region of cellulose (43.61%) to just 4.97% in CNCs. The 13C CP-MAS SSNMR spectrum of CNCs, at the C4, C6, C2C3C5 nuclei sites, can be fitted by two distinct lines for both amorphous and crystalline region, indicating the formation of a co-crystal from two nanocrystallites. Despite this, the principal components of the CSA (chemical shift anisotropy) tensor remain unchanged, suggesting similar electronic environments for these two nanocrystallites. The spin-lattice relaxation time and local correlation time of cellulose and CNCs are determined for chemically distinct carbon nuclei residing on D-glucopyranose units. It is noteworthy that the 13C spin-lattice relaxation time and 13C local correlation time are longer for each chemically distinct nucleus in CNCs compared to cellulose. It can be predicted by observing the NMR relaxometry data that the longer relaxation time in CNCs is due to the enhancement of crystallinity index. Hence, a correlation between the crystallinity index and nuclear spin dynamics can be established by NMR relaxometry measurements. These findings offer significant insights into the intricate structure and dynamic behavior of cellulose and nanocrystalline cellulose (CNCs), crucial for advancing biomimetic material design, which has huge applications across the pharmaceutical, textile, and cosmetics industries.

Synthesis of cellulose acetate from cotton byproducts

Rechargeable lithium-ion batteries (LIBs) have gained popularity and the attention of numerous researchers in recent times because of their benefits. The separator membrane is one of the most important parts of the LIB. Separator membranes are made of polymeric materials, one of which is cellulose acetate (CA). In this study, we synthesize CA from corn husk. There are 2 methodological ways in this study, namely the synthesis of CA which consists of delignification and acetylation, and fabrication of PVDF/ CA/ Nanoclay electrolyte membrane with variation of CA PVDF (0%:100, 10%: 90%, 20%: 80%, 30%: 70%, 50%: 50%). The synthesis of CA from corn husk exhibits XRD results which were comparable to the peak of commercial CA. Meanwhile, the PVDF/ CA-Nanoclay-based separator membrane with the composition of 50% PVDF and 50% CA had the best characterization results with an electrolyte uptake value of 139.649% and a porosity value of 79.11%. Based on the attained results, the CA extracted from corn husk in this study is applicable to use for the fabrication of electrolyte membrane.

In this study, Artemisia annua stem waste was identified, for the first time, as a potential natural source to produce cellulose microfibers (CMF), as well as cellulose nanocrystals (CNC) with unique functionalities by using various organic acids. The CMF extraction was carried out using alkali and bleaching treatments, while the CNC were isolated under acid hydrolysis by using sulfuric acid (S-CNC), phosphoric acid (P-CNC), and hydrochloric acid / citric acid mixture (C-CNC). The CMF and CNC physicochemical, structural, morphological, dimensional, and thermal properties were characterized. CMF with a yield of 53%, diameter of 5 to 30 µm and crystallinity of 57% were successfully obtained. In contrast, CNC showed a rod-like shape with an aspect ratio of 53, 95, and 64 and a crystallinity index of 84, 79, and 72% for S-CNC, P-CNC, and C-CNC, respectively. Results suggested that the type of acid significantly influenced the structure, morphology, and thermal stability of CNCs. Based on these results, Artemisia annua stem waste is a great candidate source for cellulose derivatives with excellent characteristics.Graphical

Influence of mechanical pretreatment to isolate cellulose nanocrystals by sulfuric acid hydrolysis

Sono-chemical synthesis of cellulose nanocrystals from wood sawdust using Acid hydrolysis

Synthesis of cellulose acetate using as raw material textile wastes

Synthesis of cellulose acetate and carboxymethylcellulose from sugarcane straw