scholarly journals Extraction and Characterization of Cellulose Nanowhiskers  from TEMPO Oxidized Sisal Fibers

2021 ◽  
Author(s):  
FANGWEI FAN ◽  
MENGTING ZHU ◽  
KAIYANG FANG ◽  
ENDI CAO ◽  
YINZHI YANG ◽  
...  
Keyword(s):  
Sodium Hydroxide ◽  
Sisal Fiber ◽  
Cellulose Ii ◽  
Cellulose Nanowhiskers ◽  
Cellulose I ◽  
Alkali Pretreatment ◽  
Sodium Hydroxide Concentration ◽  
Carboxylate Groups ◽  
Sisal Fibers

Abstract Cellulose nanowhiskers as one kind of renewable and biocompatible nanomaterials evoke much interest because of its versatility in various applications. Herein, the sisal cellulose nanowhiskers with length of 100–500 nm, ultrathin diameter of 6–61 nm, high crystallinity of 74.74 % and C6 carboxylate groups converted from C6 primary hydroxyls were prepared via a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/NaBr/NaClO system selective oxidization combined with mechanical homogenization. The effects of sodium hydroxide concentration in alkali pretreatment on the final sisal cellulose nanowhiskers were explored. It was found that with the increase of sodium hydroxide concentration, the sisal fiber crystalline type would change from cellulose I to cellulose II. The versatile sisal cellulose nanowhiskers would be particularly useful for applications in the nanocomposites as reinforcing phase, as well as in tissue engineering, filtration, pharmaceutical and optical industries as additives.

Effect of mercerization on the crystallite size and crystallinity index in cellulose from different sources

1987 ◽  
Vol 65 (8) ◽  
pp. 1724-1725 ◽  
Author(s):  
J. F. Revol ◽  
A. Dietrich ◽  
D. A. I. Goring
Keyword(s):  
Sodium Hydroxide ◽  
Crystallite Size ◽  
Narrow Range ◽  
Crystallinity Index ◽  
Cellulose Ii ◽  
Cellulose I ◽  
Native Cellulose ◽  
Wide Range ◽  
Different Sources ◽  
Low Crystallinity

Native cellulose samples having a wide range of crystallinity and crystallite size were mercerized by treatment with sodium hydroxide. The resultant cellulose II samples showed only a narrow range of crystallinity and an essentially constant crystallite size. For the low-crystallinity samples, crystallinity and crystallite size actually increased on mercerization. These results are in line with the proposal that mercerization involves the mingling of chains from adjacent and antiparallel cellulose I microfibrils to form cellulose II crystals of antiparallel chains.

Preparation and characterization of composites based on poly(lactic acid)/poly(methyl methacrylate) matrix and sisal fiber bundles: The effect of annealing process

2020 ◽  
pp. 089270572093078
Author(s):  
Ander Orue ◽  
Jon Anakabe ◽  
Ane Miren Zaldua-Huici ◽  
Arantxa Eceiza ◽  
Aitor Arbelaiz
Keyword(s):  
Lactic Acid ◽  
Methyl Methacrylate ◽  
Polymer System ◽  
Annealing Process ◽  
Sisal Fiber ◽  
Maximum Temperature ◽  
Poly Lactic Acid ◽  
Poly Methyl Methacrylate ◽  
Sisal Fibers

The interest on poly(lactic acid) (PLA)/poly(methyl methacrylate) (PMMA) blends has increased during the last years due to their promising properties. The novelty of the current work focuses on the preparation and characterization of biocomposites based on PLA/PMMA matrix and NaOH-treated sisal fibers. The effect of the addition of treated sisal fibers on the physico-mechanical properties of high polylactide content composites was studied. For this purpose, PLA/PMMA blend (80/20 wt%) was prepared by melt-blending and reinforced with different fiber contents. Although composites showed interesting specific tensile properties, the estimated heat deflection temperature (HDT), that is, the maximum temperature at which a polymer system can be used as a rigid material, barely increased 4°C respect to unreinforced system. After the annealing process, the HDT of the unreinforced polymer blend increased around 25°C, whereas the composites showed an increase of at least 38°C. Nonetheless, the specific tensile strength of composite decreased approximately 48% because the adhesion between fiber and polymer matrix was damaged and cracks were formed during annealing process.

Supramolecular Structure Characterization of Cellulose II Nanowhiskers Produced by Acid Hydrolysis of Cellulose I Substrates

2012 ◽  
Vol 13 (2) ◽  
pp. 570-578 ◽  
Author(s):  
Gilles Sèbe ◽  
Frédérique Ham-Pichavant ◽  
Emmanuel Ibarboure ◽  
Akissi Lydie Chantal Koffi ◽  
Philippe Tingaut
Keyword(s):  
Acid Hydrolysis ◽  
Supramolecular Structure ◽  
Structure Characterization ◽  
Cellulose Ii ◽  
Cellulose I ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

scholarly journals Study and Characterization of Sisal Fiber/Zein Resin Interface

2020 ◽  
Vol 8 (2) ◽  
pp. S1-S19
Author(s):  
Hamid Souzandeh ◽  
Anil N. Netravali
Keyword(s):  
Interfacial Shear Strength ◽  
Fiber Surface ◽  
Microfibrillated Cellulose ◽  
Sisal Fiber ◽  
X Ray ◽  
Before And After ◽  
Microbond Test ◽  
Zein Protein ◽  
Sisal Fibers

The interfacial shear strength (IFSS) between natural sisal fiber and zein protein resin was explored using the microbond test. Commercially available zein protein was processed into resins and their IFSS with sisal fiber was measured. Effects of sorbitol plasticizer content and microfibrillated cellulose (MFC) reinforcement loading on the IFSS with the resin were studied. Scanning electron microscopy (SEM) was used to characterize the fracture surfaces before and after the microbond test. Energy dispersive X-ray spectroscopy (EDX) was utilized to map the residual resin on the sisal fiber surface after the microbond test. The results showed that sisal fiber/ zein IFSS decreased with sorbitol content. At 20 wt% sorbitol content 53% decrease in IFSS was observed. IFSS increased with MFC loading from 1.32 MPa (control) to 2.40 MPa for resin containing 15 wt% MFC. Physical entanglements between sisal fibers and MFC are believed to be responsible for this enhancement in the IFSS.

scholarly journals Extraction and characterization of cellulose nanowhiskers from TEMPO oxidized sisal fibers

Cellulose ◽  
2021 ◽  
Author(s):  
Fangwei Fan ◽  
Mengting Zhu ◽  
Kaiyang Fang ◽  
Endi Cao ◽  
Yinzhi Yang ◽  
...  
Keyword(s):  
Cellulose Nanowhiskers ◽  
Sisal Fibers

Synergistic Effect of Mixed Bases in the Conversion of Cotton Cellulose I to Cellulose II

1969 ◽  
Vol 39 (4) ◽  
pp. 305-316 ◽  
Author(s):  
Tyrone L. Vigo ◽  
Ricardo H. Wade ◽  
Donald Mitcham ◽  
Clark M. Welch
Keyword(s):  
Synergistic Effect ◽  
Sodium Hydroxide ◽  
Lithium Hydroxide ◽  
Cellulose Ii ◽  
Organic Base ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
Quaternary Base ◽  
Cation Size ◽  
High Degree

Several aqueous bases were found which swell cotton yarn greatly, but, after their removal from the cotton, leave the x-ray diffraction pattern unchanged from that of native cellulose I. Such bases include 9.5% lithium hydroxide and 35% benzyltrimethylammonium hydroxide. However, the addition of as little as 1.5% lithium hydroxide or 5% sodium hydroxide, to the benzyltrimethylammonium hydroxide causes substantial conversion of cellulose I to cellulose II. This synergistic effect is attributed to the decrystallizing action of the organic base which, by breaking down the cellulose I lattice, facilitates the action of lithium, sodium, and potassium hydroxides in forming alkali cellulose lattices leading to cellulose II. Rubidium and cesium hydroxides failed to produce this effect when added to the organic base. Cellulose swelling, decrystallization, and recrystallization appear to be distinct steps in lattice conversion. These steps may present greatly different requirements as to optimum cation size and coordination, such requirements being more readily met by mixtures of cations than by any one species. In the absence of the quaternary base, but at alkali concentrations giving maximum fiber swelling, no lattice conversion was produced by lithium or cesium hydroxides, a high degree of conversion occurred with sodium hydroxide, and the other alkalies were intermediate in effect. The strength, elongation, energy-to-rupture, and tenacity of treated yarns varied greatly with the cations present in the alkali. In contrast to yarn, fiber bundles underwent slow and partial conversion to cellulose II by the quaternary base.

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