scholarly journals Degumming of Hemp Fibers Using Combined Microwave Energy and Deep Eutectic Solvent Treatment

2021 ◽  
Author(s):  
Bulbul Ahmed ◽  
Qinglin Wu ◽  
Jaegyoung Gwon ◽  
Ioan Negulescu ◽  
Bruce Cameron
Keyword(s):  
Deep Eutectic Solvent ◽  
Fiber Surface ◽  
Cellulose Fibers ◽  
Microwave Energy ◽  
Composition Analysis ◽  
Cellulose Content ◽  
Protection Factor ◽  
Hemp Fiber ◽  
Amorphous Cellulose ◽  
Hemp Fibers

Abstract Hemp bast fibers were degummed using combined microwave energy (MWE) and deep eutectic solvent (DES) to generate pure hemp cellulose fibers for potential textile applications. The properties of the obtained fibers were investigated and compared with those from the traditional alkali-based process using several analytical techniques. Results revealed that hemp fiber surface underwent dramatic structural disruption during the pretreatment, due to the removal of “gummy” compounds (i.e., lignin, pectin, oil, and wax) and amorphous cellulose. Ultraviolet (UV) protection factor (UPF) of DES-treated fibers with 1:20 fiber-DES ratio (i.e., 183.67) were significantly higher than those from the traditional alkali-treated (140.75) and untreated raw hemp fibers (127.47). The treated fibers also had higher thermal stability. Chemical composition analysis showed that the cellulose content in the treated fiber samples increased to 49.95% which was comparable with the cellulose content of the alkali-treated fibers (49.49%). The study demonstrates a potentially effective, less time-consuming, and environmentally sustainable protocol for manufacturing purified hemp cellulose fibers using combined MWE-DES treatment.

scholarly journals Mechanical and Air Permeability Performance of Novel Biobased Materials from Fungal Hyphae and Cellulose Fibers

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 136
Author(s):  
Inese Filipova ◽  
Ilze Irbe ◽  
Martins Spade ◽  
Marite Skute ◽  
Inga Dāboliņa ◽  
...  
Keyword(s):  
Cellulose Fibers ◽  
Air Permeability ◽  
Composition Analysis ◽  
Elemental Distribution ◽  
Hemp Fibers ◽  
Biobased Materials ◽  
Fungal Hyphae ◽  
Production Techniques ◽  
Increasing Demand ◽  
Distribution Of Components

Novel biobased materials from fungal hyphae and cellulose fibers have been proposed to address the increasing demand for natural materials in personal protective equipment (PPE). Materials containing commercially available kraft fibers (KF), laboratory-made highly fibrillated hemp fibers (HF) and fungal fibers (FF) obtained from fruiting bodies of lignicolous basidiomycetes growing in nature were prepared using paper production techniques and evaluated for their mechanical and air permeability properties. SEM and microscopy revealed the network structure of materials. The tensile index of materials was in the range of 8–60 Nm/g and air permeability ranged from 32–23,990 mL/min, depending on the composition of materials. HF was the key component for strength; however, the addition of FF to compositions resulted in higher air permeability. Chemical composition analysis (Fourier-transform infrared spectroscopy) revealed the presence of natural polysaccharides, mainly cellulose and chitin, as well as the appropriate elemental distribution of components C, H and N. Biodegradation potential was proven by a 30-day-long composting in substrate, which resulted in an 8–62% drop in the C/N ratio. Conclusions were drawn about the appropriateness of fungal hyphae for use in papermaking-like technologies together with cellulose fibers. Developed materials can be considered as an alternative to synthetic melt and spun-blown materials for PPE.

Optimization and characterization of flavonoids extracted from Cannabis sativa fibers

2021 ◽  
pp. 004051752110277
Author(s):  
Qilu Cui ◽  
Jiawei Li ◽  
Chongwen Yu
Keyword(s):  
Chemical Structure ◽  
Cannabis Sativa ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Test Results ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Structure Surface ◽  
Degumming Process

In this paper, the extraction process of flavonoids from hemp fibers was studied. Response surface methodology (RSM) analysis of the extraction parameters indicated that optimized results would be ethanol concentration 76 vol.%, bath ratio 1:50, and reaction time 139 min; therefore, an optimal extraction rate of flavonoids of 0.2275% can be obtained. The chemical structure, surface morphology and element composition of flavonoid extracts were analyzed. The test results indicated that hemp extract contains flavonoids, which can be used to extract flavonoids from hemp fiber, so as to comprehensively develop hemp fiber and reduce the discharge of waste liquid in the traditional degumming process.

scholarly journals Influence of Alkali Treatment on the Microstructure and Mechanical Properties of Coir and Abaca Fibers

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2636
Author(s):  
Petr Valášek ◽  
Miroslav Müller ◽  
Vladimír Šleger ◽  
Viktor Kolář ◽  
Monika Hromasová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Alkali Treatment ◽  
Fiber Surface ◽  
Cellulose Fibers ◽  
Sem Analysis ◽  
Experimental Program ◽  
Time Interval ◽  
The European Union ◽  
Vegetable Fibers

Composite materials with natural fillers have been increasingly used as an alternative to synthetically produced materials. This trend is visible from a representation of polymeric composites with natural cellulose fibers in the automotive industry of the European Union. This trend is entirely logical, owing to a preference for renewable resources. The experimental program itself follows pronounced hypotheses and focuses on a description of the mechanical properties of untreated and alkali-treated natural vegetable fibers, coconut and abaca fibers. These fibers have great potential for use in composite materials. The results and discussion sections contribute to an introduction of an individual methodology for mechanical property assessment of cellulose fibers, and allows for a clear definition of an optimal process of alkalization dependent on the content of hemicellulose and lignin in vegetable fibers. The aim of this research was to investigate the influence of alkali treatment on the surface microstructure and tensile properties of coir and abaca fibers. These fibers were immersed into a 5% solution of NaOH at laboratory temperature for a time interval of 30 min, 1 h, 2 h, 3 h, 6 h, 12 h, 24 h, and 48 h, rinsed and dried. The fiber surface microstructures before and after the alkali treatment were evaluated by SEM (scanning electron microscopy). SEM analysis showed that the alkali treatment in the NaOH solution led to a gradual connective material removal from the fiber surface. The effect of the alkali is evident from the visible changes on the surface of the fibers.

scholarly journals Two β-glucuronosyltransferases involved in the biosynthesis of type II arabinogalactans function in mucilage polysaccharide matrix organization in Arabidopsis thaliana

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oyeyemi O. Ajayi ◽  
Michael A. Held ◽  
Allan M. Showalter
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Size ◽  
Seed Coat ◽  
Glucuronic Acid ◽  
Industrial Applications ◽  
Crystalline Cellulose ◽  
Sugar Residue ◽  
Composition Analysis ◽  
Cellulose Content ◽  
Type Ii

Abstract Background Arabinogalactan-proteins (AGPs) are heavily glycosylated with type II arabinogalactan (AG) polysaccharides attached to hydroxyproline residues in their protein backbone. Type II AGs are necessary for plant growth and critically important for the establishment of normal cellular functions. Despite the importance of type II AGs in plant development, our understanding of the underlying role of these glycans/sugar residues in mucilage formation and seed coat epidermal cell development is poorly understood and far from complete. One such sugar residue is the glucuronic acid residues of AGPs that are transferred onto AGP glycans by the action of β-glucuronosyltransferase genes/enzymes. Results Here, we have characterized two β-glucuronosyltransferase genes, GLCAT14A and GLCAT14C, that are involved in the transfer of β-glucuronic acid (GlcA) to type II AGs. Using a reverse genetics approach, we observed that glcat14a-1 mutants displayed subtle alterations in mucilage pectin homogalacturonan (HG) compared to wild type (WT), while glcat14a-1glcat14c-1 mutants displayed much more severe mucilage phenotypes, including loss of adherent mucilage and significant alterations in cellulose ray formation and seed coat morphology. Monosaccharide composition analysis showed significant alterations in the sugar amounts of glcat14a-1glcat14c-1 mutants relative to WT in the adherent and non-adherent seed mucilage. Also, a reduction in total mucilage content was observed in glcat14a-1glcat14c-1 mutants relative to WT. In addition, glcat14a-1glcat14c-1 mutants showed defects in pectin formation, calcium content and the degree of pectin methyl-esterification (DM) as well as reductions in crystalline cellulose content and seed size. Conclusions These results raise important questions regarding cell wall polymer interactions and organization during mucilage formation. We propose that the enzymatic activities of GLCAT14A and GLCAT14C play partially redundant roles and are required for the organization of the mucilage matrix and seed size in Arabidopsis thaliana. This work brings us a step closer towards identifying potential gene targets for engineering plant cell walls for industrial applications.

scholarly journals Hemp Fiber Reinforced Red Mud/Fly Ash Geopolymer Composite Materials: Effect of Fiber Content on Mechanical Strength

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 511 ◽  
Author(s):  
Eyerusalem A. Taye ◽  
Judith A. Roether ◽  
Dirk W. Schubert ◽  
Daniel T. Redda ◽  
Aldo R. Boccaccini
Keyword(s):  
Fly Ash ◽  
Mechanical Strength ◽  
Red Mud ◽  
Fiber Reinforced ◽  
Brazilian Tensile Strength ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Geopolymer Composites ◽  
Scanning Electron

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.

scholarly journals Adsorption Performance of Human-like Collagen by Alkali-modified Kapok Fiber: A Kinetic, Equilibrium, and Mechanistic Investigation

2021 ◽  
Author(s):  
Liyao Cao ◽  
Hongchang Wang ◽  
Hua Shen ◽  
ruiliu Wang ◽  
Fumei Wang ◽  
...  
Keyword(s):  
Fiber Surface ◽  
Alkali Concentration ◽  
Composition Analysis ◽  
Order Kinetic ◽  
Water Contact ◽  
Kapok Fiber ◽  
Mechanistic Investigation ◽  
Cavity Structure ◽  
Hollow Cavity ◽  
Adsorption Amount

Abstract Collagen-based dressings achieve excellent repair of the skin during metical cosmetology, which has received a lot of attention recently. Although great progress has been made on using biomass fiber as dressing carrier, more research is required on developing novel biomass fibers because of the limitations of (i.e., high cost and complex processing) of existing materials. In this study, the adsorption behaviors of two human-like collagen were studied by examining the Kapok fiber that was modified using alkali consisting of various amounts of the mass fraction. Results show that the alkali-modified Kapok fiber surface becomes rough with vertically arranged grooves, and the cross-section depicts the hollow cavity structure. The composition analysis of alkali modified Kapok shows that alkali dissolves part of the hemicellulose and lignin. Additionally, the surface energy rises sharply and the water contact angle changed from hydrophobic to hydrophilic. The adsorption amount of raw Kapok fiber is around 0.6g/g, which accounts for only one twenty-first of the adsorption amount of alkali-treated Kapok (around 12.6g/g), while the equilibrium adsorption amount was not sensitive to alkali concentration. The kinetics of human-like collagen followed both Quasi first and Quasi second order kinetic model, implying that the adsorption process where characterized by both physisorption and chemisorption. Finally, characterization of the AKF-2 coupled with the studies based on the inter-particle diffusion model showed a three-step of human-like collagen diffusion consisting of surface diffusion, inter-fiber diffusion and fiber' hollow cavity diffusion. Our results demonstrate a perfect high absorption performance of Kapok fiber providing a potential for application of collagen-base dressings.

Anti-ultraviolet and anti-static modification of polyethylene terephthalate fabrics with graphene nanoplatelets by a high-temperature and high-pressure inlaying method

2018 ◽  
Vol 89 (8) ◽  
pp. 1488-1499 ◽  
Author(s):  
Cheng Zhang ◽  
Ling Zhong ◽  
Dingfei Wang ◽  
Fengxiu Zhang ◽  
Guangxian Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Polyethylene Terephthalate ◽  
Fiber Surface ◽  
Graphene Nanoplatelets ◽  
X Ray Diffraction ◽  
Static Properties ◽  
Protection Factor ◽  
X Ray ◽  
Pet Fabric

Grafting graphene on polyethylene terephthalate (PET) fibers requires a large number of environmentally harmful chemicals. In this study, a facile high-temperature and high-pressure method of inlaying graphene nanoplatelets was applied to fabricate anti-ultraviolet (UV) and anti-static graphene/PET composites. The resulting graphene-inlaid (GI) PET fabric, which showed excellent anti-ultraviolet and anti-static properties, was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform–infrared spectroscopy and X-ray diffraction. Results suggested that graphene had been inlaid into the PET fiber surface, and that the optimal inlaying conditions were as follows: inlaying temperature 200℃, inlaying pressure 15 MPa, and inlaying time 15 s. The UV protection factor of the GI PET fabric under optimal conditions could reach 50+ and was maintained at 50+ after 50 laundering cycles. The peak values of the static voltage and its half-time in the GI PET fabric could be reduced from 500.0 V to 10.0 V and from 7.39 s to 0.53 s, respectively, and the electrical resistivity of the GI PET fabric was 36.04 ± 0.14 kΩ.cm. The breaking strengths of the GI PET fabrics could be retained over 70.0% that of the pure PET fabric. The facile high-temperature and high-pressure inlaying method is an eco-friendly technique that requires very few chemicals, except for ethyl alcohol.

EFFECT OF CELLULOSE FIBER SURFACE TREATMENT TO REPLACE CARBON BLACK IN NATURAL RUBBER HYBRID COMPOSITES

2021 ◽  
Author(s):  
Hossein Kazemi ◽  
Frej Mighri ◽  
Keun Wan Park ◽  
Slim Frikha ◽  
Denis Rodrigue
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Treatment ◽  
Hybrid Composites ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Cellulose Fiber ◽  
Cellulose Fibers ◽  
Infrared Spectrometry ◽  
Hybrid Filler

ABSTRACT In recent years, cellulose fibers have attracted considerable attention as biofillers for natural rubber (NR) composites. However, neat cellulose cannot be used as a substitute for conventional fillers due to its poor compatibility with NR. Therefore, a new surface treatment via maleic anhydride grafted to polyisoprene (MAPI) in solution was developed to improve the filler–matrix interaction. Different contents of carbon black (CB) and cellulose fibers (before and after modification) were used as a hybrid filler system to investigate the possibility of CB substitution in NR composites. First, contact angle, Fourier transformed infrared spectrometry (FTIR), and scanning electron microscopy (SEM) techniques were used to confirm the successful cellulose surface treatment. Second, morphological analysis, Payne effect, and swelling behavior of the rubber compounds in toluene confirmed the effect of cellulose treatment on improving the interfacial filler–matrix adhesion. Finally, the results showed that the composite filled with 20 phr modified cellulose and 20 phr CB (50% replacement of CB) exhibited even better results than the composite filled with 40 phr of CB, since the tensile strength was only 7% lower, but the elongation at break, tensile modulus at 100%, and storage modulus at 25 °C were respectively 35%, 24%, and 22% higher.

Investigation of the Mechanical Behavior of Natural Vegetable Fibers Used in Composite Materials for Structural Strengthening

2021 ◽  
Vol 888 ◽  
pp. 15-21
Author(s):  
Ivelina Ivanova ◽  
Jules Assih ◽  
Dimitar Dontchev
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Fiber Composite ◽  
Low Cost ◽  
Weight Ratio ◽  
Synthetic Fiber ◽  
Engineering Structures ◽  
Hemp Fiber ◽  
Plant Fibers ◽  
Hemp Fibers

This research aims at studying the mechanical properties of industrial hemp fibers and promoting their use as a reinforcing composite material for strengthening of civil engineering structures. Natural hemp fibers are of great interest due to the following advantages they have: low cost, high strength-to-weight ratio, low density and non-corrosive properties. The use of plant fiber composite materials has increased significantly in recent years because of the negative reduction impact on the environment. For example, the tendency to use renewable resources and their possibility for recycling. They cause fewer health and environmental problems than synthetic fibers. Natural fibers, in addition to environmental aspects, have advantages such as low densities, i.e. have low weight, interesting mechanical properties comparable to those of synthetic fiber materials, and last but not least, low cost. Composites based on natural plant fibers can be used to reinforce or repair reinforced concrete structures, as shown by research on flax fiber composites. These concretes specimens strengthened with biocomposite materials have very good resistance to bending and significantly increase the rigidity of the structure. The results show that the hemp fiber reinforcement has significant effects on the strengthening and increase in flexural strength from 8% to 35 %.

Hemp Fiber Reinforced Geopolymer Composites: Effects of NaOH Concentration on Fiber Pre-Treatment Process

2020 ◽  
Vol 841 ◽  
pp. 166-170
Author(s):  
Phattharachai Maichin ◽  
Teewara Suwan ◽  
Peerapong Jitsangiam ◽  
Prinya Chindaprasirt
Keyword(s):  
Treatment Process ◽  
Solution Concentration ◽  
Alkaline Treatment ◽  
The Self ◽  
Hemp Fiber ◽  
Natural Materials ◽  
Hemp Fibers ◽  
Naoh Solution ◽  
Pre Treatment ◽  
Geopolymer Composites

High demand for using parts of natural materials, e.g., cores, fibers or leaves, as alternative additives are being increased. The main reasons are that natural materials can be served as renewable and eco-friendly choices such a sustainable development. Nevertheless, some limitations of applying those natural products, such as biodegradation, UV degradation, or weak bonding, are raised and need to be modified before further handling. One of the modification techniques for bio-based materials is chemical treatment by using alkaline solution (alkalization). Treatment process allows the plant's fiber to have fewer impurities as well as to increase the bonding on its contacting surface area. This research focuses on (i) effects of NaOH solution concentration on the pre-treatment properties of hemp fibers and (ii) self-treatment behavior of hemp fiber in geopolymer composites. The results show that the concentration of NaOH solution directly affected the pre-treatment process of hemp fiber as higher concentration from 1, 3, 5, 8, 10 to 12 Molar provided more vanishing level of fiber impurities, indicated by Contact Angle (CA) measurement and Fourier Transform Infrared (FT-IR) Spectroscopy analysis. With the concept of alkaline treatment, the self-treatment process was therefore applied for hemp fiber incorporated in alkaline-activated geopolymer matrix. The results illustrate the self-treatment behavior of hemp fiber in geopolymer composites, which could improve the final performances of the hardened products without conventional pre-treatment process.

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