Addition Of Microfibrillated Cellulose Research Articles

Preparation of Pulp, Microfibrillated Cellulose, and Paper Hand Sheets from Bakong (<i>Hanguana malayana</i> (Jack) Merr.)

Bakong (<i>Hanguana malayana</i> (Jack) Merr.) is a perennial herbaceous plant that grows abundantly in certain parts of the Philippines. This study investigates Bakong fibers' potential as a pulp source for papermaking. Furthermore, microfibrillated cellulose (MFC) produced from the fibers was used as an additive in the Bakong fiber-based hand sheets at 2%, 6%, and 10% w/w, and their effects on their strength properties were observed. The soda pulping method produced Bakong pulp with a total yield of 47.36%. Proximate chemical analysis showed that the method reduced the lignin content from 13.19% to 8.76%, and the resulting pulp was successfully formed into paper hand sheets. The strength properties of the hand sheets were tested, and the resulting burst index, tear index, tensile index, and folding endurance values were 5.98 kPa/m2∙g, 6.41 mN∙m2/g, 105.97 N∙m/g, and 626 double folds, respectively. Aside from the tear index, the Bakong hand sheets' strength properties were much higher than that of locally produced commercial printing paper. The addition of MFC on the hand sheets negatively affected the burst and tensile index values of the Bakong hand sheets but significantly improved the tear index up to 6% w/w. These results show that the pulp produced from the Bakong fibers can potentially be used as an alternative source of pulp for papermaking, but further optimization of the pulping process is recommended to increase the yield, lower lignin content, and improve compatibility with the MFC.

Preparation and characterization of green‐based anti‐ultraviolet and antidripping biodegradable film

AbstractThe biodegradable materials cannot meet the requirements as the agricultural film due to the poor UV resistance and antidripping performance. The work herein thus presented the development of the green‐based anti‐ultraviolet and antidripping multifunctional composite films using poly(butyleneadipate‐co‐terephthalate), microfibrillated cellulose (MFC), and soybean protein isolate (SPI) as the raw materials in the presence of other agents. The resulting composite films were systematically characterized using scanning electron microscope, thermogravimetry analysis (TG), UV, and rheometer measurements. The morphology changed obviously after introducing the MFC and SPI into the substrate film. In addition, the results indicated that the addition of MFC and SPI had a positive effect on the thermal stability and heat preservation of the film, respectively. The contact angle results indicated that SPI was an ideal antidripping agent and the MFC could be used as the release agent. The time of the first water drop of the film containing 2.5 g MFC and 2.0 g SPI was 6 min and 46 s, and the time of each 10 drops was less than 60 s, showing the advantages of using MFC as the release agent and SPI as the antidripping agent. The resulting multifunctional biodegradable films can be widely used in the agricultural and packaging fields.

Guar gum based flexible packaging material with an active surface reinforced by litchi shell derived micro fibrillated cellulose and halloysite nanotubes

In this study, authors investigated the potential of incorporating micro-fibrillated cellulose derived from litchi shells and halloysite nanotubes into guar gum films for active antioxidant food packaging applications. The films were prepared using a solvent casting method, and the concentration of micro-fibrillated cellulose was varied to determine its effect on the films' properties. Our results demonstrated that the guar gum and micro-fibrillated cellulose show covalent contact and hydrogen bonding, according to Fourier transform infrared. X-Ray diffraction analysis revealed that the addition of micro-fibrillated cellulose and Halloysite nanotube significantly increased the crystallinity of the films. However, Thermogravimetric analysis showed that the incorporation of both improved the thermal stability of the films. Scanning electron microscopy analysis depicted dense disorder network that would be responsible lower contact angle in the developed film with increased MFC concentration. The incorporation of micro-fibrillated cellulose and halloysite nanotube enhanced the films' antioxidant properties from 3.40 to 39.50%, with a higher radical scavenging activity observed at higher concentrations. In conclusion, our study suggests that incorporating micro-fibrillated cellulose and halloysite nanotube into antioxidant guar gum films can produce a promising active food packaging material with improved antioxidant properties. This study contributes to the development of sustainable and effective active food packaging solutions, with the potential to reduce food waste and improve food quality.

Development of Drying Energy Saving Technology of Paperboard by Applying Precipitated Calcium Carbonate Made from Oyster-Shell Byproducts

In this study, we aimed to identify the possibility of the internal application of a precipitated calcium carbonate made from oyster shell byproducts (O-shell PCC) for reducing the drying energy in paperboard mills. The micro-fibrillated cellulose (MFC) was also applied to improve the strength of the paperboard containing O-shell PCC. The O-shell PCC was classified through an 80 mesh screen and then its SEM image, particle size, and zeta potential were analyzed. After the MFC was prepared by micro-grinding hardwood bleached kraft pulp (Hw-BKP), its particle size, viscosity, and fiber width were also measured. The O-shell PCC and MFC were added to the Korean old corrugated container (KOCC) stock to prepare handsheets, and their physical properties and drying energy reduction were measured to determine the effect of the O-shell PCC and MFC on the drying energy saving. The O-shell PCC was effective to improve the bulk and drying energy reduction of handsheets, but the strengths decreased. The MFC was effective in improving the strength, but more drying energy was required as the addition of MFC increased due to its hydrophilic property. In addition, the application of the PCC and MFC, which had not been used in paperboard mills, could increase the production cost. However, the reduced cost of drying energy was estimated to be more than the increased cost of PCC and MFC at the optimum dosage (6% O-shell PCC and 0.2% MFC on o.d. fiber). Therefore, it was concluded that the combination of O-shell PCC and MFC could be effective in saving drying energy in paperboard mills.

A Comparative Investigation of the Surface Properties of Corn-Starch-Microfibrillated Cellulose Composite Films.

Starch-based materials seem to be an excellent alternative for conventional plastics used in various applications. Microfibralted cellulose can be used to improve the surface properties of starch-based materials. This study aims to analyze the surface properties of starch-microfibrillated cellulose materials. The surface properties of films were evaluated by ATR-FTIR, surface roughness, water wettability, and surface free energy. The surface homogeneity between corn starch and microfibrillated cellulose (MFC) fibers was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Microscopic analyses of the film surfaces confirm good compatibility of starch and MFC. The addition of MFC increased the surface roughness and polarity of developed starch/MFC materials. The surface roughness parameter has increased from 1.44 ± 0.59 to 2.32 ± 1.13 for pure starch-based materials and starch/MFC material with the highest MFC content. The WCA contact angle has decreased from 70.3 ± 2.4 to 39.1 ± 1.0°, while the surface free energy is 46.2 ± 3.4 to 66.2 ± 1.5 mJ·m-2, respectively. The findings of this study present that surface structure starch/MFC films exhibit homogeneity, which would be helpful in the application of MFC/starch materials for biodegradable packaging purposes.

High Performance of Paper Strength and Energy Savings in OCC Pulp Papermaking via MFC Addition

Fiber screen fractionation of recycled old corrugated container (OCC) pulp and subsequent targeted processing of each fraction can lead to higher fiber quality, more uniform pulp, and increased handsheet strength and surface smoothness. This pilot-scale study evaluates the benefits of fiber fractionation using a pressure screen prior to low consistency (LC) refining. A 0.81-mm smooth holed screen cylinder is utilized, and two refiner plate patterns are adopted (wide 0.99 km/rev BEL and interim 2.01 km/rev BEL). Here, LC-refined reject fractions are mixed with the created microfibrillated cellulose (MFC), and the mixed pulp and paper qualities are compared with no-MFC OCC pulps. The results indicate that the highest tensile strength of the handsheet is obtained by the addition of MFC to the fractionated refined OCC pulp compared to the unfractionated refined OCC and primary OCC pulps at a given specific energy. Furthermore, the experimental approach adopted in this study can be used to optimize recycled OCC pulping systems. Overall, the results indicate that fractionated LC refining plus MFC addition provides higher pulp and paper qualities and the potential for saving energy to reach the desired tensile strength of the OCC pulp.

Tensile behavior analysis combined with digital image correlation and mechanical and thermal properties of microfibrillated cellulose fiber/ polylactic acid composites

Microfibrillated cellulose (MFC) employed as reinforcement of polymeric matrices can increase elastic modulus, stiffness and strength of a composite. In this work, the assessment of the mechanical, thermal properties and tensile tests assisted by digital image correlation (DIC) was performed for curaua fiber MFC-reinforced polylactic acid (PLA) composites as a function of MCF content. First, MFC was incorporated into PLA using a solvent exchange technique and subsequent polymer solubilization to produce master batch composites. Then, more PLA was added to obtain composites with 0.5 and 1.5 wt% MFC by using double screw extrusion and injection molding. As a result, the addition of MFC caused the flexural, tensile, indentation, impact and modulus strengths to increase compared to those of pure PLA. The deformation gradient obtained from DIC verified that the 0.5 wt% MFC/PLA composite presented greater homogeneity in relation to load dispersion, corroborating the higher rigidity, maximum stress, and Poisson's ratio.

A comparative study of the effects of pulp fractionation, refining, and microfibrillated cellulose addition on tissue paper properties

Environmental and economic concerns are driving tissue paper manufacturers to improve understanding of the relationships between fibres, the networks they form, the forming process, and the final tissue paper properties. This work investigated how pulp fractionation, refining, or addition of microfibrillated cellulose (MFC) affect the compromise between absorbency and strength of 33 ± 2 g/m² model papers made of bleached eucalyptus kraft pulp. The results showed that the compromise of properties was better when fibres were refined than when MFC was added. The absorbency capacity of 2%wt MFC-paper was almost 20% lower than the capacity of the refined paper at the same dry strength. The calculated additional storage capacity due to water-induced deformations of the fibre network was 40% lower in the same range of bulk. By forming a high viscosity gel at inter-fibre contacts, MFC could limit the occurrence of major fibre and network deformation mechanisms when water was imbibing the paper.

Effect of gelatin type on the structure and properties of microfibrillated cellulose reinforced gelatin edible films

AbstractThe physical and mechanical properties of gelatin edible films need to be significantly improved to meet the increasing requirements of food and pharmaceutical industry. This study investigates the effect of gelatin type on the structure and properties of glycerol plasticized gelatin films reinforced by microfibrillated cellulose (MFC). Results indicate that the tensile strength of type‐A and type‐B gelatin (GelA and GelB) films increases by 48% and 90% respectively at an optimum MFC content of 15 wt% in comparison to control gelatin films without MFC. The incorporation of MFC also has a more pronounced impact on optical properties and moisture absorption capability of GelB films than on those of GelA films. Scanning electron microscopy and polarized optical microscopy studies show that the MFC fibrils are uniformly distributed in both types of gelatin matrices. X‐ray diffraction and attenuated total reflectance‐Fourier transform infrared analyses reveal that the interactions between MFC and GelB are stronger than those of between the MFC and GelA. The mechanism behind the more significant mechanical performance improvement of GelB films by the addition of MFC is speculated to be that stronger hydrogen bonding interactions contribute to enhanced structural integrity and stability of the gelatin‐based films.

Dispersion of Micro Fibrillated Cellulose (MFC) in Poly(lactic acid) (PLA) from Lab-Scale to Semi-Industrial Processing Using Biobased Plasticizers as Dispersing Aids

In the present study, two commercial typologies of microfibrillated cellulose (MFC) (Exilva and Celish) with 2% wt % were firstly melt-compounded at the laboratory scale into polylactic acid (PLA) by a microcompounder. To reach an MFC proper dispersion and avoid the well-known aglomeration problems, the use of two kinds of biobased plasticisers (poly(ethylene glycol) (PEG) and lactic acid oligomer (OLA)) were investigated. The plasticizers had the dual effect of dispersing the MFC, and at the same time, they counterbalanced the excessive stiffness caused by the addition of MFC to the PLA matrix. Several preliminaries dilution tests, with different aqueous cellulose suspension/plasticizer weight ratios were carried out. These tests were accompanied by SEM observations and IR and mechanical tests on compression-molded films in order to select the best plasticizer content. The best formulation was then scaled up in a semi-industrial twin-screw extruder, feeding the solution by a peristaltic pump, to optimize the industrial-scale production of commercial MFC-based composites with a solvent-free method. From this study, it can be seen that the use of plasticisers as dispersing aids is a biobased and green solution that can be easily used in conventional extrusion techniques.

Influence of microfibrillated cellulose and soft biocomponent on the morphology and thermal properties of thermoplastic polyurethanes

AbstractComposite materials from thermoplastic polyurethanes (TPUs) with biodegradable segments and microfibrillated cellulose (MFC) were developed as alternatives to traditional materials used in packaging or biomedical applications. Two TPUs were synthesized by the prepolymer method starting from different soft segments, poly(ε‐caprolactone)/poly(butylene adipate) (PUBA) or poly(ε‐caprolactone)/poly(ethylene oxide) (PUEO), and isophorone diisocyanate/aliphatic chain extender. Proton nuclear magnetic resonance (1H NMR) confirmed the structure and Fourier transform infrared spectroscopy (FTIR) along with scanning electron microscopy showed that the soft segments with different hydrophobicity led to a higher phase mixing in PUBA and improved microphase separation in PUEO. MFC was added in the TPUs with different soft segments to increase biocompatibility, strength, and degradation rate. A better thermal stability, a gradual increase of crystallinity and a better dispersion of MFC were noticed in PUEO composites compared to PUBA ones. The crystallinity increased with 78% and 50% in PUBA and PUEO composites with 5 wt% MFC compared to the neat polyurethanes showing the nucleating ability of MFC. In addition, the enhanced storage modulus, with 75% and 25% in PUEO and PUBA composites, highlighted the reinforcing efficiency of MFC. Therefore, the addition of MFC to the already synthesized TPUs allows tailoring the morphology and thermal properties of TPUs for industrial application.

Comparison between cellulose nanocrystal and microfibrillated cellulose as reinforcement of poly(vinyl acetate) composites obtained by either in situ emulsion polymerization or a simple mixing technique

Nanocellulose is abundant, renewable, biocompatible, and a good candidate as reinforcement agent in nanocomposites; however, its hydrophilicity leads to poor dispersion in hydrophobic polymers. Recently, both in situ polymerization and cellulose surface modification have been used to improve dispersion, but emulsion polymerization is rarely adopted, and when it is, the reinforcement agent is usually cellulose nanocrystal (CNC), with gain in mechanical properties being the main focus of the research. Therefore, this work aims to explore the influence of adding either CNC or microfibrillated cellulose (MFC), both without surface modification, on the mechanical resistance, thermal degradation, and water vapor permeability of poly(vinyl acetate) composites obtained by either in situ emulsion polymerization or mixing. The results showed that despite having similar impacts on thermal and barrier properties, MFC and CNC affect the mechanical properties of their composites differently. Both cause decrease of the thermal degradation rate and do not have a significant impact on water vapor permeability. However, the addition of CNC during synthesis increased composite mechanical resistance significantly while the addition of MFC did not show improvement. Mechanical resistance is also strongly dependent on the procedure used to produce the composites.

Mechanical and Rheological Properties of 3D Printable Cement Composites

Additive manufacturing is a recent revolution in the construction field since cementitious materials became printable. This extrusion technique has enabled the construction of very complex geometry with a reduction in costs, time and labour interventions. This study aims to evaluate the possibility of reinforcing 3D printable cementitious composites with the use of nano and micro materials, particularly nano silica, micro silica and microfibrillated cellulose (MFC) which are known for their ability to enhance the fresh and hardened properties of cement-based composites. Rheology property test, flowability and mechanical properties are the types of tests performed to evaluate the fresh and hardened properties of mortar modified with the rested additives. The results show the addition of MFC of 0.4% (of total solid matter) can significantly enhance the mechanical property. In addition, the presence of MFC (at 0.4% of total solid matter) can reduce the pressure required to extrude the mortar, enabling a steady state extrusion. It was also found that 1% nano silica addition significantly improves the mechanical properties and minimizes segregation in the failure surface.

Additive Manufacturing of Prostheses Using Forest-Based Composites.

A custom-made prosthetic product is unique for each patient. Fossil-based thermoplastics are the dominant raw materials in both prosthetic and industrial applications; there is a general demand for reducing their use and replacing them with renewable, biobased materials. A transtibial prosthesis sets strict demands on mechanical strength, durability, reliability, etc., which depend on the biocomposite used and also the additive manufacturing (AM) process. The aim of this project was to develop systematic solutions for prosthetic products and services by combining biocomposites using forestry-based derivatives with AM techniques. Composite materials made of polypropylene (PP) reinforced with microfibrillated cellulose (MFC) were developed. The MFC contents (20, 30 and 40 wt%) were uniformly dispersed in the polymer PP matrix, and the MFC addition significantly enhanced the mechanical performance of the materials. With 30 wt% MFC, the tensile strength and Young´s modulus was about twice that of the PP when injection molding was performed. The composite material was successfully applied with an AM process, i.e., fused deposition modeling (FDM), and a transtibial prosthesis was created based on the end-user’s data. A clinical trial of the prosthesis was conducted with successful outcomes in terms of wearing experience, appearance (color), and acceptance towards the materials and the technique. Given the layer-by-layer nature of AM processes, structural and process optimizations are needed to maximize the reinforcement effects of MFC to eliminate variations in the binding area between adjacent layers and to improve the adhesion between layers.

Effect of microfibrillated cellulose (MFC) on the properties of gelatin based composite films

Properties of gelatin composite films（with 4% glycerol as plasticizer）with different mass concentrations of microfibrillated cellulose (MFC) (0.2-1.0%) were investigated. The prepared composite films with 1.0 % MFC showed the highest tensile strength (12.32 MPa) with the lowest water absorption rate (391.1 %). The composite films can be dissolved in hot water of 95°C in less than 5 minutes. However, the addition of MFC had insignificant effect on the heat shrinkage and light transmittance of the resultant composite films.

Morphological, chemical, and thermal characteristics of chitosan nanocomposite films reinforced with steam-exploded microfibrillated cellulose

The objective of the study was to investigate and analyze the morphological, chemical, and thermal properties of chitosan nanocomposite films reinforced with microfibrillated cellulose (MFC). MFC, which was isolated via steam explosion assited with alkaline treatment, produced a diameter size average of about 50 nm with self-aggregated ball-like shapes. Obtained chitosan/MFC nanocomposite films had a varied thickness average and moisture content in the range from 3.70 to 13.34%. Chitosan films had a good UV prevention without sacrificing transparency nature. The reinforcement of MFC 0.5–2.5% and MFC 5–10% in the films induced irreversible self-aggregation with a size average of about 0.5 and 10 µm, respectively. Carbon and oxygen elementals varied whereas nitrogen slightly decreased along with MFC incorporation. The addition of MFC into chitosan films noticeably shifted FT-IR wavenumber and intensity because of chemical interaction between chitosan and MFC functional groups. MFC enhanced the thermal stabilities of chitosan films due to high remnant weight of the films after thermal decomposition although MFC accelerated the decomposition and degradation of the films. The inclusion of MFC into chitosan polymer did not show anti-bacterial properties against Escherichia coli due to no clear zone of inhibition and no zone of inhibition indices around the tested films.

Microfibrillated cellulose addition improved the physicochemical and bioactive properties of biodegradable films based on soy protein and clove essential oil

Active nanocomposite films based on soy protein isolates (SPI), microfibrillated cellulose (MFC) and clove essential oil (CEO) were developed, and the contribution of each component to the functionality of ensuing films was intended to elucidate. MFC with diameters of 50–60 nm, an average length of 485 ± 2 μm, a high aspect ratio of 8800 and 35.5% of cristalinity, was prepared from Phormium tenax fibers by mechanical treatment. Films were processed by casting from aqueous dispersions containing SPI, glycerol (as plasticizer), different MFC contents and the optional addition of CEO. All filmogenic dispersions exhibited a pseudoplastic flow behavior and formed homogeneous films. The addition of MFC reinforced the protein matrix, increasing the mechanical strength and Young's modulus of the films and improving their barrier properties to water vapor and oxygen. On the other hand, the addition of CEO caused some plastification effect of protein and nanocomposite matrix (mainly observed in the mechanical properties, solubility and water content) and a differential modification in the barrier properties, as the oxygen permeability increased and WVP decreased. Furthermore, it conferred important antioxidant properties and antimicrobial activity against bacteria related to foodborne diseases that increased with increasing MFC content in the formulation. Nanofibers seemed to favor the release of the active compounds of CEO probably due to the improved dispersion of CEO in nanocomposites through a higher amount of smaller droplets. These active nanocomposite films with antimicrobial and antioxidant properties are promising for the development of active food packaging.

Reinforcement Effects of Microfibrillated Cellulose on Chitosan–Polyvinyl Alcohol Nanocomposite Film Properties

Abstract The objective of this research was to analyze the reinforcement effect of microfibrillated cellulose (MFC) on chitosan–polyvinyl alcohol (chitosan-PVA) nanocomposite films in terms of their morphological, physical, chemical, thermal, biological, and mechanical properties. Chitosan-PVA blend films reinforced with MFC filler loadings at 0.5 to 5 percent had smoother, more regular, and more uniform external surface morphology compared with chitosan-PVA reinforced with MFC filler loaded at 7.5 percent. With regard to the physical properties, incorporation of MFC into chitosan-PVA polymer blends reduced nanocomposite film transparency. Furthermore, the films had three different diffraction peaks: crystalline peak, amorphous peak, and small ancillary peak. Compared with the neat chitosan-PVA blend, the addition of MFC to chitosan-PVA polymer blends shifted Fourier-transform infrared spectroscopy peaks at 3,500 to 3,000, 2,918, 1,440, 1,101, and 850 cm−1, indicating a chemical interaction between chitosan-PVA polymer blends and MFC. According to differential scanning calorimetry, thermogravimetric analysis, and differential thermal analysis, the addition of MFC enhanced the thermal stability of chitosan-PVA compared with neat chitosan-PVA composite films. Most nanocomposite films reinforced with MFC had a higher tensile strength than films made from neat chitosan-PVA and chitosan-PVA-MFC 7.5 percent because of percolation formation. However, neither neat chitosan-PVA composite film nor chitosan-PVA-MFC nanocomposite films showed a zone of inhibition or had a zone of inhibition index against Escherichia coli, Staphylococcus aureus, Candida albicans, and Ganoderma sp.

Comparative study of ultra-lightweight pulp foams obtained from various fibers and reinforced by MFC

A range of cellulose-based, ultra-lightweight pulp foams with different morphologies were prepared and reinforced with microfibrillated cellulose (MFC). By careful design of the pulp foam forming process, free-standing ultra-lightweight pulp foams were obtained through high velocity mixing and air/oven drying from cellulose fiber in the presence of surfactant, MFC, and retention aid. The effects of different types of fibers and surfactants on the air uptake volumes and mechanical properties of the foam were systematically investigated. The structures characterized using an optical microscope and scanning electron microscope (SEM) showed that the foam was composed of wood fibers into two- or three-dimensional microstructures within random orientations surrounding gas bubbles. The results indicated that in spite of the strength of the foam could be manipulated by varying the surfactants and processing parameters, the addition of MFC indeed improved strength of pulp foams further. The process developed in this work provides a cost effective approach to fabricate the strong and ultra-lightweight pulp foam, with a density lower than 0.02g/cm3, using a standard handsheet former.

Propolis and chitosan as antimicrobial and polyphenols retainer for the development of paper based active packaging materials

Abstract The research investigates the potential combination of propolis and chitosan to develop a completely bio-based active food packaging material. Propolis glycolic extract was used as antioxidant and antimicrobial, due to its polyphenols content. Two commercial chitosans with different molecular weights were comparatively used as antimicrobial, wet strength additive substitute and polyphenols retainer. The effects of the addition of carboxymethyl- (CMC) or microfibrillated cellulose (MFC) and two pH values in paper production were investigated for polyphenols retention and paper strength. Chitosan, in replacement of the most commonly used wet strength resin (PAAE), increased polyphenols retention more than 10 times. Paper sheets produced with the highest molecular weight chitosan, at pH 7 and with MFC addition showed the best wet strength (7.4 ± 0.5 Nm/g) and wet resistance (13.3 ± 1.2%). Paper antimicrobial activity was confirmed on thinly sliced raw veal meat, where a decrease of intentionally inoculated L. innocua of around 1 log cycle was achieved in 48 h at 4 °C.