Study of LCNF and CNF from pine and eucalyptus pulps

2020 ◽  
Vol 35 (4) ◽  
pp. 670-684
Author(s):  
Iara Fontes Demuner ◽  
Jorge Luiz Colodette ◽  
Fernando José Borges Gomes ◽  
Rubens Chaves de Oliveira
Keyword(s):  
Water Retention ◽  
Cellulose Nanofibrils ◽  
High Thermal Stability ◽  
Raw Material ◽  
Residual Lignin ◽  
Water Retention Value ◽  
Degradation Temperature ◽  
Great Relevance ◽  
Lignocellulose Nanofibrils ◽  
Cellulosic Fibres

AbstractNanocelluloses produced from wood pulp are widely studied for various economic applications. Most studies of cellulose nanofibrils (CNF) use lignin-free fibres obtained from bleached pulps; however, unbleached fibres with residual lignin may also be used to obtain lignocelluloses nanofibrils (LCNF). Research on lignocellulose nanofibrils is a recent subject in the field; thus, the aim of the present study was to determine the ultrastructure of lignocellulose nanofibrils compared to cellulose nanofibrils produced from the same raw material. Understanding of nanoparticle properties is of great relevance for their various applications; therefore, complete characterisation of the chemical, physical, and morphological structures of LCNF and CNF produced from pine and eucalyptus woods was performed. Unbleached cellulosic fibres are a viable alternative for LCNF production, which has properties comparable to that of traditional CNF production that uses lignin-free fibres. LCNF from pine and eucalyptus were obtained with 4.0 % and 1.8 % residual lignin, respectively. The nanofibrils had high thermal stability because LCNF had a higher maximum degradation temperature. Due to the low interaction of lignin with water, LCNF had a lower water retention value than CNF.

Modification of Cellulase to Different Bleached Softwood Pulp

2012 ◽  
Vol 550-553 ◽  
pp. 1186-1189
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Jin Wang ◽  
Peng Zhou Wang
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Retention ◽  
Raw Material ◽  
Enzymatic Modification ◽  
Water Retention Value ◽  
Wetting Properties ◽  
Before And After ◽  
Wetting Property

Cellulase named as Novozym 476 was used to modify three kinds of bleached softwood pulps respectively. By analyzing the changes of refining degree, water retention value, specific surface area, wetting properties of fiber before and after enzymatic treatment, studied the influence of characteristics of raw material to the effect of enzymatic modification. The results indicate that in the same conditions, the refining property, water retention value, specific surface area and wetting property of the three pulps all increase. Among these three pulps, the pulp of Kamloops Kraft has the best modification effect. Refining degree of Kamloops Kraft pulp increases 36.0 °SR when refining for 10,000 PFI revolutions, and the water retention value increases by 68.0%, the dye loading increases with 0.1 mg/g, the contact angle decreases by 4.5%. It illustrates that the fiber raw material with a thin cell wall would have a better effect of enzymatic modification and the wrapping way of microfibers would influence the effect of enzymatic modification.

Unbleached and bleached handsheet characteristics of Subabul heartwood and sapwood

2020 ◽  
Vol 35 (2) ◽  
pp. 161-171
Author(s):  
Madhuri Pydimalla ◽  
Ramesh Babu Adusumalli
Keyword(s):  
Modulus Of Elasticity ◽  
Water Retention ◽  
Wood Chips ◽  
Morphological Properties ◽  
Residual Lignin ◽  
Water Retention Value ◽  
Tensile Index ◽  
Kraft Cooking ◽  
Ecf Bleaching

AbstractThe objective of this study was to understand the influence of bleaching on % residual lignin, water retention value, brightness and morphological properties of Subabul heartwood and sapwood pulps. The second aim was to compare the properties of unbleached and bleached handsheets with respect to tensile index and fractography. Screened wood chips of Subabul were subjected to kraft cooking (165 °C, 3 hours) followed by ECF bleaching and refining. When unbleached handsheets were compared, higher tensile index was found for sapwood sheets (29.8 N.m/g) than heartwood sheets (12.8 N.m/g). Therefore, it is recommended to use unbleached sapwood sheets for packaging grade applications. The bleached pulps have exhibited negligible residual lignin (0.1 %), higher water retention value (∼21) and higher brightness (88 %) compared to unbleached pulps. Subsequently, the bleached heartwood sheets revealed higher tensile index (∼7 fold) and higher modulus of elasticity (∼2.7 fold) compared to unbleached heartwood sheets. For printing grade applications bleached sapwood and bleached heartwood pulps are equally recommended, because no differences were observed in their pulp and sheet characteristics.

Facile preparation of nanofiller-paper using mixed office paper without deinking

TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Cellulose Nanofibrils ◽  
Ash Content ◽  
Raw Material ◽  
Mechanical Grinding ◽  
Microscope Imaging ◽  
Facile Preparation ◽  
Electron Microscope Imaging ◽  
Thermal Stability Of ◽  
Scanning Electron ◽  
Office Paper

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.

Effects of a PFI refiner’s operational parameters on the swellability of recycled fiber

TAPPI Journal ◽  
2020 ◽  
Vol 19 (5) ◽  
pp. 239-246
Author(s):  
XIAONING SHEN ◽  
BO LI ◽  
WENXUAN MO ◽  
XIN-SHENG CHAI
Keyword(s):  
Water Retention ◽  
Fiber Quality ◽  
Operational Parameters ◽  
Fiber Morphology ◽  
Water Retention Value ◽  
Electron Microscopic ◽  
Mathematical Relation ◽  
Scanning Electron Microscopic ◽  
Recycled Fiber ◽  
Scanning Electron

This paper presents data on the effects of operational parameters (number of revolutions, linear pressure, and gap) of the PFI refiner on the swellability of recycled fiber, which was characterized by water retention value (WRV). The results showed that the increase of recycled fiber’s WRV was proportional to the number of revolutions and the linear pressure, but inversely proportional to the gap. The mathematical relation between these parameters and the fiber WRV could be described by an empirical model for gaps greater than 0.1 mm. Scanning electron microscopic images of fiber morphology showed that the basic framework of fibers could be maintained with the gap greater than 0.1 mm, but was destroyed with smaller gaps. This model provides a technical reference for quantitative control of refining treatment and an effective method for improving recycled fiber quality.

scholarly journals Assessment of the Physicochemical and Thermal Characterization of Biofield Energy Treated Polylactic-co-glycolic acid (PLGA)

2019 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Alice Branton ◽  
Mahendra Kumar Trivedi ◽  
Dahryn Trivedi ◽  
Gopal Nayak ◽  
Snehasis Jana
Keyword(s):  
Glycolic Acid ◽  
Control Sample ◽  
Analytical Techniques ◽  
Thermal Characterization ◽  
Pharmaceutical Formulations ◽  
Plga Nanoparticles ◽  
Raw Material ◽  
Prosthetic Devices ◽  
Degradation Temperature ◽  
Energy Healing

Polylactic-co-glycolic acid (PLGA) is a biodegradable copolymer. It has many applications in the pharmaceuticals and biomedical industries, but its degradation and stability is a major concern. The objective of this study was to evaluate the influence of the Trivedi Effect® on the physicochemical and thermal properties of PLGA using modern analytical techniques. The PLGA sample was divided into control and Biofield Energy Treated parts. The control sample did not obtain the Biofield Energy Treatment, whereas the treated PLGA was received the Trivedi Effect®-Consciousness Energy Healing Treatment remotely by a renowned Biofield Energy Healer, Alice Branton. The particle size values of the treated PLGA were increased by 8.97%(d10), 8.79%(d50), 4.72%(d90), and 6.61%{D(4,3)}; thus, the surface area of treated PLGA was significantly decreased by 6.84% compared with the control sample. The latent heat of evaporation and fusion of the treated PLGA were significantly increased by 29.60% and 230.93%, respectively compared with the control sample. The residue amount was significantly increased by 21.99% in the treated PLGA compared to the control sample. The maximum thermal degradation temperature of the treated PLGA was increased by 2.30% compared with the control sample. It was concluded that the Trivedi Effect®-Consciousness Energy Healing Treatment might have generated a new form of PLGA which may show better powder flow ability, thermal stability, and minimize the hydrolysis of the ester linkages of PLGA. This improved quality of PLGA would be a better choice for the pharmaceutical formulations (i.e., the drug like simvastatin, amoxicillin, and minocycline loaded PLGA nanoparticles) and manufacturing of biomedical devices, i.e., grafts, sutures, implants, surgical sealant films, prosthetic devices, etc., in the industry using it as a raw material.

New model for predicting tensile strength and density of eucalyptus handsheets based on an activation parameter calculated from fiber distribution characteristics

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Juha Fiskari ◽  
Ville Alopaeus
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Wall Thickness ◽  
Water Retention ◽  
Activation Parameter ◽  
Water Retention Value ◽  
Data Set ◽  
Network Activation ◽  
Fiber Wall ◽  
Fiber Segment

Abstract The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper.

Recycled fiber treated with NaOH/urea aqueous solution: effects on physical properties of paper sheets and on hornification

2018 ◽  
Vol 33 (4) ◽  
pp. 651-660 ◽  
Author(s):  
Yingju Miao ◽  
Yunfei Zhi ◽  
Heng Zhang ◽  
Ying Chen ◽  
Shaoyun Shan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Physical Properties ◽  
Water Retention ◽  
Crystalline Region ◽  
Cellulose Film ◽  
Reinforced Concrete Structure ◽  
Water Retention Value ◽  
Fiber Network ◽  
Urea Aqueous Solution ◽  
Intramolecular Hydrogen

Abstract Hydrogen bonding among fiber microfibrils is the primary cause of fiber hornification, wherein NaOH/urea aqueous solution precooled to −13 °C can disassemble inter- and intramolecular hydrogen bonds. Whether hornified fibers treated with this process can significantly improve fiber swelling ability and physical properties of the resulting paper sheets remains a problem. In this investigation, the 6th cycle fiber was pretreated with this procedure, and the water retention value of the fiber before and after treatment and the physical properties of the resulting paper sheets were studied. The results indicate that the lignin decline, complete swelling of flat fiber, filling of cellulose film between the interfiber network, and decreasing crystalline region all contribute to the increase in water retention value. The water retention value of repaired fiber is equivalent to that of virgin pulp, and hornification reverses by 89 %. In addition, the cellulose film filling among the fiber network constructs a similar reinforced concrete structure, which causes the tear, burst, and tensile index of the resulting paper sheets to increase by 145 %, 98 %, and 43 %, respectively.

scholarly journals Evaluation of Nanocomposite Made of Polylactic Acid and Nanocellulose from Carrot Pomace Modified with Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 812 ◽  
Author(s):  
Monika Szymańska-Chargot ◽  
Monika Chylińska ◽  
Piotr M. Pieczywek ◽  
Anna Walkiewicz ◽  
Giorgia Pertile ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Antibacterial Properties ◽  
Young Modulus ◽  
Transmission Rates ◽  
Degradation Temperature

In this research, it was proposed to use carrot cellulose nanofibrils (CCNF) isolated from carrot pomace modified with silver nanoparticles (AgNPs) as a filler of polylactic acid (PLA) composites matrix. The new procedure was based on two steps: first, the preparation of nanocellulose modified with metal nanoparticles, and then the combination with PLA. Two concentrations—0.25 mM and 2 mM—of AgNO3 were used to modify CCNF. Then, PLA was mixed with the filler (CCNF/AgNPs) in two proportions 99:1 and 96:4. The influence of CCNF/AgNPs on mechanical, hydrophilic, thermal, and antibacterial properties of obtained nanocomposites was evaluated. The greatest improvement of mechanical properties was observed for composite containing CCNF with 2 mM of AgNPs, which obtained the lowest Young modulus and highest strain at break. The degradation temperature was lower for PLA with CCNF/AgNPs, but crystallization temperature wasn’t influenced. The addition of CCNF/AgNPs also increased hydrophilicity. The transmission rates of oxygen, nitrogen, and carbon dioxide also increased after the addition of CCNF/AgNPs to PLA. The antibacterial function against Escherichia coli and Bacillus cereus was obtained after the addition of AgNPs but only at the contact surface with the material made, suggesting the lack of migration of nanoparticles from the composite.

scholarly journals Structure and Properties of Polylactic Acid Biocomposite Films Reinforced with Cellulose Nanofibrils

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3306
Author(s):  
Qianqian Wang ◽  
Chencheng Ji ◽  
Jianzhong Sun ◽  
Qianqian Zhu ◽  
Jun Liu
Keyword(s):  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Nitrogen Atmosphere ◽  
Scanning Calorimetry ◽  
Enzymatic Pretreatment ◽  
Thermogravimetric Analyzer ◽  
Degradation Temperature ◽  
Biocomposite Films ◽  
Renewable Feedstock ◽  
Vis Spectroscopy

Polylactic acid (PLA) is one of the most promising biodegradable and recyclable thermoplastic biopolymer derived from renewable feedstock. Nanocellulose reinforced PLA biocomposites have received increasing attention in academic and industrial communities. In the present study, cellulose nanofibrils (CNFs) was liberated by combined enzymatic pretreatment and high-pressure homogenization, and then subsequently incorporated into the PLA matrix to synthesize PLA/CNF biocomposite films via solution casting and melt compression. The prepared PLA/CNF biocomposite films were characterized in terms of transparency (UV-Vis spectroscopy), chemical structure (attenuated total reflectance-Fourier transform infrared, ATR-FTIR; X-ray powder diffraction, XRD), thermal (thermogravimetric analyzer, TGA; differential scanning calorimetry, DSC), and tensile properties. With 1.0–5.0 wt % additions of CNF to the PLA matrix, noticeable improvements in thermal and physical properties were observed for the resulting PLA/CNF biocomposites. The 2.5 wt % addition of CNF increased the tensile strength by 8.8%. The Tonset (initial degradation temperature) and Tmax (maximum degradation temperature) after adding 5.0 wt % CNF was increased by 20 °C, and 10 °C, respectively in the nitrogen atmosphere. These improvements were attributed to the good dispersibility and improved interfacial interaction of CNF in the PLA matrix.

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