Search

As is well known, Laser print paper is usually produced with high‐quality chemical wood pulp. The laser print waste paper fiber (LPWF) is a high‐quality secondary fiber, and the research and development of high‐value utilization technology for laser print waste paper has attracted much attention in the field of renewable resource recycling. In this study, LPWF was used to reinforce poly(lactic acid) (PLA) composites in the field, and the composites were modified with bioenzyme, cationic polyacrylamide (CPAM), and nano‐silicon carbide (Nano‐SiC) to enhance the interfacial compatibility of LPWF/PLA composites. The study systematically investigated the effects of various modification methods on the characteristics and degradability of composites made from laser print waste paper fiber reinforced PLA resin matrix. The results showed that the mechanical properties of the composites treated with CPAM and Nano‐SiC were significantly improved, with tensile strengths of 54.3 and 59.5 MPa, and flexural strengths of 85.1 and 91.5 MPa, respectively, and the water absorption of the composites was reduced after the modification treatment, while the thermal stability was improved. The degradation performance of the composites in various water environments indicated that the inclusion of LPWF accelerated the water degradation rate of the composites, with the maximum degradation rate of the composite reaching 1.26% in 30 days. Highlights: Laser print waste paper is an excellent quality recyclable fiber resource.Four modifiers were used to modify LPWF/PLA composites.Characteristics and degradability of the composites were investigated.Significantly improved properties of CPAM and Nano‐SiC modified composites.The degradation rate of composites is increased by the addition of LPWF. [ABSTRACT FROM AUTHOR]

Cellulose is commonly acknowledged as a sustainable material owing to its abundance and renewability. However, the abundance of hydroxyl groups makes the paper material highly hydrophilic, and the hydrogen bonds between the fibers are easily broken by water, leading to the degradation of mechanical properties. This work details the fabrication of a composite paper comprising interwoven cellulose and polylactic acid (PLA) structures through hot‐pressing and PLA impregnation onto handwritten paper derived from conventional wood pulp fibers as the substrate. The investigation assessed how varying PLA concentrations influenced the overall characteristics of the composite paper, including its morphology, structure, mechanical properties, water absorption behavior, and water contact angle. Experimental results revealed that the composite paper fabricated through our approach exhibited an intertwined structure comprising both PLA and cellulose. With a tensile index reaching 33.24 kN·m/kg and a mere 31.1% loss in tensile index post‐water treatment, the mechanical properties of the composite paper were significantly enhanced due to the robust interfacial compatibility between cellulose and PLA, as well as the adhesive effect of PLA. Furthermore, the composite paper (CP) is easily processable and amenable to thermoforming into paper trays as required, indicative of its potential applications in the packaging industry. [ABSTRACT FROM AUTHOR]

The environmental challenges posed by plastic pollution have prompted the exploration of eco-friendly alternatives to disposable plastic packaging and utensils. Paper-based materials, derived from renewable resources such as wood pulp, non-wood pulp (bamboo pulp, straw pulp, reed pulp, etc.), and recycled paper fibers, are distinguished by their recyclability and biodegradability, making them promising substitutes in the field of plastic food packaging. Despite their merits, challenges like porosity, hydrophilicity, limited barrier properties, and a lack of functionality have restricted their packaging potential. To address these constraints, researchers have introduced antimicrobial agents, hydrophobic substances, and other functional components to improve both physical and functional properties. This enhancement has resulted in notable improvements in food preservation outcomes in real-world scenarios. This paper offers a comprehensive review of recent progress in hydrophobic antimicrobial paper-based materials. In addition to outlining the characteristics and functions of commonly used antimicrobial substances in food packaging, it consolidates the current research landscape and preparation techniques for hydrophobic paper. Furthermore, the paper explores the practical applications of hydrophobic antimicrobial paper-based materials in agricultural produce, meat, and seafood, as well as ready-to-eat food packaging. Finally, challenges in production, application, and recycling processes are outlined to ensure safety and efficacy, and prospects for the future development of antimicrobial hydrophobic paper-based materials are discussed. Overall, the emergence of hydrophobic antimicrobial paper-based materials stands out as a robust alternative to plastic food packaging, offering a compelling solution with superior food preservation capabilities. In the future, paper-based materials with antimicrobial and hydrophobic functionalities are expected to further enhance food safety as promising packaging materials. [ABSTRACT FROM AUTHOR]

The research presented in this paper introduces a novel environmental energy‐harvesting technology that harnesses electricity from the evaporation of water using porous structural materials. Specifically, a strategy employing paper‐based hydroelectric generators (p‐HEGs) is proposed to capture the energy produced during water evaporation and convert it into usable electricity. The p‐HEGs offer several advantages, including simplicity in fabrication, low cost, and reusability. To evaluate their effectiveness, the water evaporation‐induced electrical output performance of four different p‐HEGs are compared. Among the variants tested, the p‐HEG combining wood pulp and polyester fiber exhibits the best output performance. At room temperature, this particular p‐HEG generates a short‐circuit current and open‐circuit voltage of ≈0.4 µA and 0.3 V, respectively, thereby demonstrating excellent electrical stability. Furthermore, the electrical current and voltage generated by the p‐HEG through water evaporation are able to power an LED light, both individually and in series and parallel connections. This study delves into the potential of electricity harvesting from water evaporation and establishes it as a viable method for renewable energy applications. [ABSTRACT FROM AUTHOR]

The manufacture of sustainable functional fibers with low environmental footprint and superior properties is a pressing research issue under the auspices of more sustainable industrial textile processes. In the present study, regenerated cellulose fibers (CellReg) with flame retardancy properties are manufactured by functionalizing regenerated wood pulp fibers (obtained through the dissolution of paper‐grade pulp in an ionic liquid followed by regeneration in water) with a natural derived phosphorus compound, namely phytic acid ammonium (PAA). The pale‐yellow modified fibers present a phosphorus content up to 1.80% and a uniform and smooth surface morphology. Furthermore, the functional cellulose fibers exhibit moderate antioxidant activity (ca. 18.4% of maximum radical scavenging), water contact angles below 92°, as well as good thermal‐oxidative stability up to 200°C. The flame‐retardant performance of the CellReg/PAA fibers was investigated by the vertical burning test, and as anticipated, the results show a higher flame retardancy with the increasing content of phosphorus, meaning that the fibers ceased to burn before flaming or glowing, even after several flame applications. The accomplished properties validate the potential of these functional fibers of regenerated wood pulp cellulose and PAA for application as textile fibers with flame retardancy properties. [ABSTRACT FROM AUTHOR]

Comb polymers were prepared by reacting a poly(ethylene‐alt‐maleic anhydride) with alkyl amines or poly(ethylene glycol) (PEG) amines. The resulting polymers were used to modify bleached softwood kraft pulp fibre surfaces by catalyst‐free grafting in a process suitable for pulp mill implementation. Pulp fibres were impregnated with a polymer solution and cured above 100°C. High grafting yields were obtained despite having up to 88% of the anhydride groups consumed by amine derivatization. Grafting yields were more than 90% when the polymer dosage was <13 g/kg (dry polymer/dry fibre) for alkyl derivatives and < 38 g/kg for PEG derivatives. We propose that the upper dosage limit for efficient grafting reflects the need for direct contact between cellulose and every polymer chain for ester linkage formation. For a given polymer dosage, the cured pulp sheets had a maximum wet tensile index, TImax, when either curing time or temperature was increased. Both the alkyl and PEG derivatives fit the power law for the wet TImax~βΓru0.54–0.62 where β values were the estimated conversion of succinic acid moieties to anhydrides when the pulp sheets were cured, and Γru is the dimensionless polymer content that is numerically equal to the amount of applied polymer in mmol repeat units/g dry fibre. However, high polymer dosages give experimental TImax values that fall below the power law, irrespective of curing intensity, because the pulp sheets contain unfixed polymer chains that lubricate fibre/fibre joints, lowering wet strength. [ABSTRACT FROM AUTHOR]

The quality loss and shelf life of cherry tomatoes stored in different types of commercially available bio‐based packaging trays were analysed and compared with the reference materials, corrugated cardboard and recycled polyethylene terephthalate (rPET). During storage under conditions reflecting points in a regional German supply chain, typical quality parameters were investigated. Surface bacterial counts of the packaging materials were investigated before and after storage, and material parameters were determined for selected packaging. The results showed that groundwood pulp and sugar cane trays showed higher preserving characteristics of tomatoes in comparison with the references. During storage, weight loss was highest for tomatoes stored in polylactic acid (PLA). The highest increase in microbial count with 3.5 log10 units was observed after 20 days for tomatoes stored in packaging trays of bamboo. The lowest increase with 0.5 log10 units and 0.6 log10 units was recorded for tomatoes stored in packaging trays of groundwood pulp and grass paper, respectively. The results of the packaging parameters show the highest (411.0 N) and lowest (79.0 N) tensile strength for cellulose and groundwood pulp. The water absorption capacity ranged from <10 g/m2 (bamboo, cellulose) up to 211.2 g/m2 (corrugated cardboard). [ABSTRACT FROM AUTHOR]

Nanocellulose is an exceptional biomaterial whose industrial applications in widely different sectors and technologies so far have been limited by the high cost of its multi‐step extraction routes. Extraction methods of cellulose nanocrystals or nanofibers, indeed, generally involve the energy‐intensive mechanical treatment of wood pulp, treatment with concentrated H2SO4 to obtain cellulose nanocrystals or chemical oxidation followed by mechanical fibrillation of the partly oxidized fibers. In the last decade (2011–2021) a number of green routes to cellulose nanofibers and nanocrystals have been developed. This study provides a critical outlook of said emerging new green routes to this versatile and safe bionanomaterial that, once sustainably produced, preferably from low cost cellulosic biowaste, will become ubiquitous in a number of different industrial products. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Air pollution caused by particulate matter (PM) poses an imminent threat to the global environment and public health. However, balancing the removal efficiency and pressure drop of most filter materials is difficult. Moreover, filter materials are non‐degradable and non‐recyclable, causing serious harm to the environment. Herein, a strategy to create fully degradable branched poly (lactic acid) (PLA) nanofibers based on electrospinning by adjusting the spinning solution properties was reported and branched PLA nanofibers were applied as nanofiber filter paper for air filtration materials. When the PLA and tetrabutylammonium chloride concentrations were 8 and 5 wt%, respectively, PLA nanofibers with branched structures were obtained. The obtained nanofibers possessed a small pore size (0.70 μm), high porosity (92.3%), appropriate mechanical properties, resulting in high PM0.3 removal efficiency (99.95%), low air resistance (79.67 Pa), and promising long‐term PM2.5 purification. Notably, branched T‐PLA‐5 nanofibers exhibited excellent filtration performance when applied to cellulose wood pulp paper. The filtration efficiency of the nanofiber filter paper remained stable above 85% for PM0.3 (32 L min−1) after 5000 backflushings. Thus, the preparation of such nanomaterials may provide new insights into the design and development of high‐performance degradable filtration materials for various applications. [ABSTRACT FROM AUTHOR]

To unlock nature's potential for functional biomaterials, many efforts have been devoted to isolating the nanocrystalline domains within the supramolecular structure of polysaccharides. Yet, low reactivity and yield in aqueous systems along with excessive solvent usage hinders its development. In this report, the first solvent‐free pathway to access carboxylated chitin and cellulose nanocrystals with excellent mass balance is described, relying on a new method coined high‐humidity shaker aging (HHSA). The method involves a mild grinding of the polysaccharide with ammonium persulfate followed by an aging phase under high‐humidity and on a shaker plate. Insights into the mechanism were uncovered, which highlighted the unique role of high humidity to afford a gradual uptake of water by the material up to deliquescence when the reaction is complete. This process was then validated for direct synthesis of nanocrystals from biomass sources including crab and soft wood pulp. [ABSTRACT FROM AUTHOR]

Wood apple (Limonia acidissima) is monsoonal fruit comprising of pulp with an exterior hard shell. The investigation of mechanical and textural properties according to maturity stages (unripe, semi‐ripe, and ripe) and rheological modeling of ripe fruits is beneficial for post‐harvest maturity grader and processing equipment development. The compression mechanical properties of whole fruit at maturity stages along the x‐axis, y‐axis, and z‐axis orientations recorded minimum rupture force (962.73 N) for ripe fruits followed by semi‐ripe and unripe along z‐axis and maximum force (2,256.2 N) for unripe fruits along y‐axis. The pulp puncture test at maturity stages for textural properties recorded reduced hardness value with maturity having 12.84, 4.30, and 3.88 N for unripe, semi‐ripe, and ripe fruits, respectively. The rheological properties for ripe fruits pulp validated cross and Carreau‐Yasuda best‐fit models (R2 = 0.9) for steady shear indicating non‐Newtonian, shear‐thinning behavior as viscosity (η) reduced from 1,508.45 Pa s while dynamic shear for frequency sweep test indicated elastic behavior as storage modulus G′ > loss modulus G″ and tan δ < 1 for power model (R2 = 0.9). The mechanical and textural properties of wood apple exhibited significant variance according to the maturity of the fruit. Practical Applications: Wood apple, despite being underutilized in the global fruit trade, has vast application in nutraceuticals industries. The steady shear flow properties of wood apple pulp can be used in engineering design applications such as manufacturing, packaging, and storage; they can be utilized to determine flow parameters and predict the degree of structural breakdown with shear. Because of the numerous processing systems in use, it is essential to precisely forecast rheological behavior. Oscillatory experiments of wood apple pulp can be used to study pulp structure, the strength of pulp and dependency on the shear rate of pulp. The findings of this study will substantially assist food processing industries in producing wood apple pulp‐based products. [ABSTRACT FROM AUTHOR]

An experimental study of the dewatering of wood‐pulp fiber suspensions by uniaxial compression is presented, to rationalize their dewatering dynamics within a two‐phase framework. Twenty‐seven pulp suspensions are examined, encompassing materials with different origins, preparation methodologies, and secondary treatments. For each suspension in this library, the network permeability and compressive yield stress are calibrated at low rates of dewatering. Faster compressions are then used to verify that a solid bulk viscosity is essential to match two‐phase model predictions with experimental observations, and to parameterize its magnitude. By comparing the results with a suspension of nylon fibers, we demonstrate that none of the wood‐pulp suspensions behave like an idealized fibrous porous medium. Nevertheless, the properties of pulp fiber networks can be reconciled within a two‐phase framework, and comparisons made between different wood‐pulp suspensions and between wood‐pulp and nylon fibers, by appealing to potential microstructural origins of their macroscopic behavior. [ABSTRACT FROM AUTHOR]

The lignosulfonates are water‐soluble anionic polymers, which are considered as byproducts from the production of wood pulp using sulfite pulping. Calcium lignosulfonate is chosen as a filler according to previous research due to its effect on the properties of the blends. It is added in the concentration range from 10 to 60 phr to the blends with NBR, SBR, and EPDM. It is found out that the increasing concentration of filler has a favorable effect on the values of physical—mechanical properties of vulcanizates. [ABSTRACT FROM AUTHOR]

In this study, 1‐ethyl‐3‐methylimidazolium diethyl phosphate, having the advantages of regulating the performance of cellulose dissolution and degradation, simplicity in synthesis, is chosen as solvent to dissolve wood pulp cellulose for regenerated cellulose fibers (RCFs) manufacture using dry‐jet wet spinning equipment. The effect of draw ratios on RCFs' mechanical properties in three bathes, including coagulation bath, stretch bath, and washing bath is investigated and a series of RCFs with high strength are obtained. The morphology, crystallinity, thermal stability, and dyeing behavior of the prepared RCFs are analyzed and discussed. More importantly, the biocompatibility of the RCFs, which is first performed, demonstrated that the toxicity of RCFs is as low as the viscose fibers. These RCFs could be easily dyed by natural turmeric and antibacterial fibers are obtained finally. In conclusion, this work provides tools for achievement of RCFs with good strength and environmental friendliness by changing the draw ratios, and also further develops a new green process for fabricating RCFs based on ionic liquids. [ABSTRACT FROM AUTHOR]

Summary: In the present work, flame‐retardant wood pulp paper (WPP) with high water resistance was fabricated through in‐situ synthesis and adhesion of flame retardant on the lignocellulose fibers. Through a simple solution spraying method, melamine (Me) and polyphosphoric acid solution were adequately permeated into interior lignocellulose fibers of WPP in turn and then reacted to produce water‐insoluble phosphorous–nitrogen melamine polyphosphate (MPP). The finally sprayed melamine formaldehyde prepolymer played the roles of flame‐retardant coating, adhesive agent, and water‐proofing layer, thus bonding MPP particles to the lignocellulose fibers firmly. This low‐cost and efficient treatment endowed WPP with excellent flame retardance and satisfactory durability. It showed that the modified WPP had a high limiting oxygen index value of 37.3%, and achieved B‐0 rating in vertical burning test, as well as greatly lowered the peak heat release rate and the total heat release. The flame‐retardant mechanisms of the modified WPP were analyzed and discussed. Moreover, the flame retardance kept well after 72 hours of water resistance test, showing good combination between the flame‐retardant particles and the lignocellulose fibers. [ABSTRACT FROM AUTHOR]

We investigated the effects of wood kraft pulp (KP) feeding on feed digestibility and rumen fermentation of Japanese Black (JB) steer in the middle fattening stage. The feeding experiment was carried out a replicated 3 ± 3 Latin square design using six JB steers (16.2 ± 0.8 months of age). Steers were fed rice straw and three concentrated feeds: commercial formula feed (control), formula feed containing 7.5% KP on a dry matter (DM) basis (7.5% KP), and formula feed containing 15% KP on a DM basis (15% KP). Feed digestibility and rumen fermentation parameters were recorded for 3 days during the measurement period, after an adaptation phase of 11 days. There was no significant difference in DM intake per day among diets. A slightly higher digestibility of neutral detergent fiber was observed in steers fed 15% KP, compared with those fed other diets (P = 0.059). The butyric acid ratio in rumen fluid was higher in steers fed KP diets than in steers fed control (P = 0.083). The average ruminal pH was unaffected by KP diets. This study suggests that replacing 15% of concentrated feed with KP has little effect on feed digestibility and rumen fermentation in JB fattening steer. [ABSTRACT FROM AUTHOR]

Within the scope of this research work, an efficient membrane‐based process with ceramic ultrafiltration membranes was developed for the recovery of purified lignosulfonates from the spent sulfite liquor of chemical wood pulping. The aim was to separate the lignosulfonates from low‐molecular organic impurities (sugar, carboxylic acids, etc.) and process chemicals, to concentrate them, and to make them available for a targeted further use. One further aspect of the project was the separation of the products (target molecules) of lignosulfonate degradation using ceramic membrane technology. [ABSTRACT FROM AUTHOR]

A model was developed to describe the nitration of cellulose in mixed acids used in the production of military grade nitrocellulose. Acid dissociation, swelling, diffusion, and chemical reaction were considered to model the nitration of industrially important cellulose materials for given reaction times and conditions. This model is supported by experimental work conducted to measure the dynamics of swelling and diffusion in wood pulp slivers, and the model was validated using the results of lab‐scale nitration reactions. Microcomputed tomography was also used to perform a structural analysis of wood pulp slivers that were cut on industrial, rotary cutting machines to evaluate features that may influence the reactivity of these materials. [ABSTRACT FROM AUTHOR]

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP. [ABSTRACT FROM AUTHOR]

Continuous-flow nanocatalysis based on metal nanoparticle catalyst-anchored flow reactors has recently provided an excellent platform for effective chemical manufacturing. However, there has been limited progress in porous structure design and recycling systems for metal nanoparticle-anchored flow reactors to create more efficient and sustainable catalytic processes. In this study, traditional paper is used for a highly efficient, recyclable, and even renewable flow reactor by tailoring the ultrastructures of wood pulp. The 'paper reactor' offers hierarchically interconnected micro- and nanoscale pores, which can act as convective-flow and rapid-diffusion channels, respectively, for efficient access of reactants to metal nanoparticle catalysts. In continuous-flow, aqueous, room-temperature catalytic reduction of 4-nitrophenol to 4-aminophenol, a gold nanoparticle (AuNP)-anchored paper reactor with hierarchical micro/nanopores provided higher reaction efficiency than state-of-the-art AuNP-anchored flow reactors. Inspired by traditional paper materials, successful recycling and renewal of AuNP-anchored paper reactors were also demonstrated while high reaction efficiency was maintained. [ABSTRACT FROM AUTHOR]

ABSTRACT An environmentally friendly bleached extruder chemi-mechanical pulp fiber or wood flour was melt compounded with poly(lactic acid) (PLA) into a biocomposite and hot compression molded. The mechanical, thermal, and rheological properties were determined. The chemical composition, scanning electron microscopy, and Fourier transform infrared spectroscopy results showed that the hemicellulose in the pulp fiber raw material was almost completely removed after the pulp treatment. The mechanical tests indicated that the pulp fiber increased the tensile and flexural moduli and decreased the tensile, flexural, and impact strengths of the biocomposites. However, pulp fiber strongly reinforced the PLA matrix because the mechanical properties of pulp fiber-PLA composites (especially the tensile and flexural strengths) were better than those of wood flour-PLA composites. Differential scanning calorimetry analysis confirmed that both pulp fiber and wood flour accelerated the cold crystallization rate and increased the degree of crystallinity of PLA, and that this effect was greater with 40% pulp fiber. The addition of pulp fiber and wood flour modified the rheological behavior because the composite viscosity increased in the presence of fibers and decreased as the test frequency increased. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44241. [ABSTRACT FROM AUTHOR]

ABSTRACT Acetylation is one of the most interesting chemical treatments to improve the affinity of lignocellulosic fibers with polymeric matrices for the elaboration of several types of composites. In this paper, the acetylation of flax and wood pulp (bleached softwood Kraft pulp and thermomechanical pulp) fibers was carried out at room temperature in a solvent-free system with acetic anhydride in the presence of sulfuric acid as catalyst. The effect of acetylation on the fine structure of fibers was investigated by spectroscopic methods, while the extent of acetylation was quantified by weight percent gain. The effect of reaction time on fiber morphology was studied at macro- and microscale using scanning electron microscopy, optical microscopy, and fiber quality analysis. The evolution of the hydrophobic/hydrophilic character of fibers was determined by contact angle measurements. The wettability of fibers by liquid epoxy resin was also evaluated to confirm the improvement of the affinity of acetylated fibers with the epoxy matrix. It was found that the hydrophilic character of fibers decrease with increasing reaction time, whereas the trend was less pronounced beyond specific reaction times. Acetylated fibers can therefore be potential candidates for replacing nonbiodegradable reinforcing materials in composite applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42247. [ABSTRACT FROM AUTHOR]

ABSTRACT Triacetyl cellulose (TAC) films, which are currently produced mainly from cotton linter, are widely used for liquid crystalline display (LCD) applications. However, cotton linter is an expensive source of cellulose and the environmental load related with cotton cultivation is notoriously heavy. Herein, the replacement of cotton linter by wood pulp was systematically investigated to explore the possibility of TAC production using a less expensive source. The mechanical and thermal properties of TAC films made from wood (wTAC) were outstanding compared to those of TAC films made from cotton (cTAC). The optical transparency of wTAC was also excellent. While Tinuvin (a UV stabilizer) produced more isotropic structures in cTAC films, it produced more anisotropic structures in wTAC films. Overall, the optical films of wTAC showed good performance for LCD applications, comparable to that of cTAC. These results could be used to develop more environmentally friendly production methods for optical TAC films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42146. [ABSTRACT FROM AUTHOR]

ABSTRACT Kraft pulp fibers were used as substrates for the grafting of poly(ε-caprolactone) (PCL) from available hydroxyl groups through ring-opening polymerization, targeting three different chain lengths (degree of polymerization): 120, 240, and 480. In a paper-making process, paper-sheet biocomposites composed of grafted fibers and neat pulp fibers were prepared. The paper sheets possessed both the appearance and the tactility of ordinary paper sheets. Additionally, the sheets were homogenous, suggesting that PCL-grafted fibers and neat fibers were compatible, as demonstrated by both Fourier transform infrared spectroscopy microscopy and through dye-labeling of the PCL-grafted fibers. Finally, it was shown that the paper-sheet biocomposites could be hot-pressed into laminate structures without the addition of any matrix polymer; the adhesive joint produced could even be stronger than the papers themselves. This apparent and sufficient adhesion between the layers was thought to be due to chain entanglements and/or co-crystallization of adjacent grafted PCL chains within the different paper sheets. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42039. [ABSTRACT FROM AUTHOR]

Turbulent flow over a rough wall with suction or blowing is an industrially important fluid mechanics problem. In the screening of wood pulp fibre suspensions, for example, turbulent flow is induced by a rotor adjacent to a slotted screen cylinder. To better understand the complex hydrodynamics in the critical region between the pulp screen rotor and the slotted screen wall, the stream-wise velocity and aperture velocities were measured using particle image velocimetry. The vortex generated above the aperture is shown to be strongly dependent on aperture velocity and wall roughness. The vortex diminishes in size at higher aperture velocities and increased exit layer height. The experiments also show that the reversal flow in the slot decreases with lower rotor speeds and increased mean slot velocities. This observation challenges the existing models of apertures being cleared by flow reversal driven by a Bernoulli-type suction pulse. In its place, this paper identifies elements of a more sophisticated flow model that considers the depletion of the zone below the rotor as well as the flow in the wake of the foil. [ABSTRACT FROM AUTHOR]

The impact of lignin-derived inhibition on enzymatic hydrolysis is investigated by using lignins isolated from untreated woods and pretreated wood pulps. A new method, biomass reconstruction, for which isolated lignins are precipitated onto bleached pulps to mimic lignocellulosic biomass, is introduced, for the first time, to decouple the lignin distribution issue from lignin chemistry. Isolated lignins are physically mixed and reconstructed with bleached pulps. Lignins obtained from pretreated woods adsorb two to six times more cellulase than lignins obtained from untreated woods. The higher adsorption of enzymes on lignin correlates with decreased carbohydrate conversion in enzymatic hydrolysis. In addition, the reconstructed softwood substrate has a lower carbohydrate conversion than the reconstructed hardwood substrate. The degree of condensation of lignin increases significantly after pretreatment, especially with softwood lignins. In this study, the degree of condensation of lignin (0.02 to 0.64) and total OH groups in lignin (1.7 to 1.1) have a critical impact on cellulase adsorption (9 to 70 %) and enzymatic hydrolysis (83.2 to 58.2 %); this may provide insights into the more recalcitrant nature of softwood substrates. [ABSTRACT FROM AUTHOR]

ABSTRACT To improve the paper properties of the poly(1,3,4-oxadiazoles) (POD), the POD pulps were prepared by prechemical and mechanical methods to increase their polarity, contact area, and interaction. The fibrillated degree of the staple fibers was evaluated by the Canadian Standard Freeness and the specific surface area, while the surface free energy was calculated by the Micro-wilhelmy method. Meanwhile, the functional groups and compositions on the surface of the POD fibers were confirmed by the FTIR-ATR and the X-ray photoelectron spectroscopy, and the surface morphological structure and the crystalline structure of the POD fibers were observed by the fiber analyzer, scanning electron microscope, and Wide-angle X-ray diffraction, respectively. It was found that the pronounced abrasive and distinctive grooves were formed on the surface of the POD fibers after prechemical and mechanical treatment. The surface free energy of POD fibers increased 8.41%, and the polar part increased by 32.10% after treatment. It was confirmed that the polar functional groups and fibril were formed after chemical and mechanical treatment, so the interaction of the POD fibers was highly enhanced, and as a result the apparent density, tensile strength, fold endurance, and tear strength of the paper formed by those treated fibers were all improved apparently. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39818. [ABSTRACT FROM AUTHOR]

Stiffness is one of the most relevant properties of composite materials. Although fiberglass has been traditionally used as reinforcement, natural fibers are seen as possible replacements due to concerns for environmental protection. In this work fibers from orange tree prunings were prepared and converted into mechanical, thermomechanical and chemi-thermomechanical pulps, to be used as reinforcement for polypropylene. Polypropylene composite materials with 20-50% of reinforcing fibers were prepared and mechanically characterized. The intrinsic Young's modulus of the fibers was back calculated by means of the Hirsch model. The moduli were also obtained by Halpin-Tsai equations with Tsai-Pagano methods and then compared to establish the influence of the aspect ratio. Finally, a fiber tensile modulus factor was defined in order to characterize the contribution of the fibers to the Young's moduli of the composites. POLYM. COMPOS., 34:1840-1846, 2013. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this study, we determined the effects of Ceratocystis fimbriata wilt on volumetric growth and cellulose pulp yield of eucalyptus. Seven-year-old healthy and infected trees were separated into different classes of severity, and the individual volume of each whole tree with bark was determined. Volumetric losses were found regardless of the class of disease severity, resulting in reduction in volumetric growth of the trees from 65% to 87%, depending on the infection level. Two approaches were used for evaluating the effects of the disease on cellulose pulp yield: (i) evaluation of wood basic density and chemical composition, contents of ethanol/toluene extractives and Klason lignin, and the alkaline load and screen yield across Kraft pulping to kappa number 18 ± 0.5 for both healthy and discoloured materials; (ii) determination of the alkaline load and yield across Kraft pulping to kappa number 18 ± 0.5 of woods with different levels of discoloration (0, 25, 50, 75 and 100% of discoloured wood). Discoloured wood presented lower basic density, higher ethanol/toluene extractives and Klason lignin, higher alkaline load and lower pulp screened yield at kappa number 18 ± 0.5 compared with the healthy ones. Increasing the fraction of infected wood in chip furnishes resulted in proportionally increased alkaline load demand and decreased screen yields. Adding 50% of infected wood in the chip furnish resulted in 23.8% increase in the alkali load and 13.7% reduction in the pulp screen yield at kappa number 18 ± 0.5. The results obtained have proved that the disease reduces volumetric growth, increases wood consumption and reduces yield in eucalyptus pulp production. [ABSTRACT FROM AUTHOR]

Herzberg staining, a quick and convenient tool for distinguishing non-wood fibers from wood pulp, and Raman spectroscopy were employed to investigate three paper currencies issued under the reign of the Chinese Ming and Qing Emperors between 15th and 19th centuries - da ming bao chao (AMS C-14 Date: 1410-1435 AD, ±1σ) from the Early Ming Dynasty (1405-1433 AD) and da qing bao chao (1859 AD) and hu bu guan piao (1854-1858 AD) from the Late Qing Dynasty (1840-1911 AD). Fiber staining and microscopic examination revealed a predominance of bast fiber from probably mulberry trees and very few cotton fibers (supposed to be environment contamination) in da ming bao chao; fibers in da qing bao chao and hu bu guan piao turned out to be quite pure, which are also bast fibers but very likely came from ramie and paper mulberry trees, respectively. Raman analysis of red, blue, and black pigments on the investigated paper currencies showed that: (1) The reddish seal on da ming bao chao is not a vermilion (HgS) paste, as it is traditionally assumed, but instead a red lead (or minium, Pb3O4) one. The red pigments on both da qing bao chao and hu bu guan piao are vermilion (HgS). (2) Prussian blue (Fe7(CN)18⋅14-16H2O), a Western pigment, was identified as blue on both da qing bao chao and hu bu guan piao. (3) The black pigment on all these three paper currencies is amorphous carbon from soot. (4) Raman analysis of evenly distributed white pigment particles among the fibers in da qing bao chao confirmed the use of calcium carbonate (CaCO3) as coating pigment or fillers. Both microscopic examination of stained fibers and Raman analysis allowed, for the first time, the understanding of fiber and pigment use in producing ancient Chinese paper currencies. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Wood is an important biological resource which contributes to nutrient and hydrology cycles through ecosystems, and provides structural support at the plant level. Thousands of genes are involved in wood development, yet their effects on phenotype are not well understood. We have exploited the low genomic linkage disequilibrium (LD) and abundant phenotypic variation of forest trees to explore allelic diversity underlying wood traits in an association study., Candidate gene allelic diversity was modelled against quantitative variation to identify SNPs influencing wood properties, growth and disease resistance across three populations of Corymbia citriodora subsp. variegata, a forest tree of eastern Australia., Nine single nucleotide polymorphism (SNP) associations from six genes were identified in a discovery population (833 individuals). Associations were subsequently tested in two smaller populations (130-160 individuals), 'validating' our findings in three cases for actin 7 (ACT7) and COP1 interacting protein 7 (CIP7)., The results imply a functional role for these genes in mediating wood chemical composition and growth, respectively. A flip in the effect of ACT7 on pulp yield between populations suggests gene by environment interactions are at play. Existing evidence of gene function lends strength to the observed associations, and in the case of CIP7 supports a role in cortical photosynthesis. [ABSTRACT FROM AUTHOR]

By using natural softwood pulp with higher degree of polymerization (DP = 1460) as cellulose source, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid as solvent and glycerol as plasticizer, a novel cellulose packaging film was prepared. The effects of plasticization conditions on the structures, mechanical properties, permeability for oxygen and water vapor were measured by Wide-angle X-ray scattering, thermogravimetric analysis, scanning electron microscopy (SEM), and other techniques. The investigations suggested that the glycerol concentration and plasticizing time had great effect on the properties of the regenerated cellulose films. The crystal transformation of cellulose I to cellulose II occurred during the dissolution and regeneration process, combining with the decrease of thermal stability. The tensile strength decreased rapidly with the addition of glycerol and prolongation of plasticizing time. However, elongation at break of the regenerated cellulose films increased at first and then decreased with increasing of glycerol concentration and plasticizing time. The morphologies for the fracture surface obtained from SEM images showed transformation of typical brittle fracture to plastic deformation with increasing of glycerol concentrations. It was also found that both water vapor permeability and oxygen permeability of the regenerated cellulose films decreased slowly with increasing of glycerol concentrations and plasticizing time, but water vapor permeability and oxygen permeability presented an almost opposite trend. The films prepared by using ionic liquid technology would be used in food packaging or other fields as a kind of green packaging material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

This paper presents a new automated method for analyzing compression wood fibers in fluorescence microscopy. Abnormal wood known as compression wood is present in almost every softwood tree harvested. Compression wood fibers show a different cell wall morphology and chemistry compared to normal wood fibers, and their mechanical and physical characteristics are considered detrimental for both construction wood and pulp and paper purposes. Currently there is the need for improved methodologies for characterization of lignin distribution in wood cell walls, such as from compression wood fibers, that will allow for a better understanding of fiber mechanical properties. Traditionally, analysis of fluorescence microscopy images of fiber cross-sections has been done manually, which is time consuming and subjective. Here, we present an automatic method, using digital image analysis, that detects and delineates softwood fibers in fluorescence microscopy images, dividing them into cell lumen, normal and highly lignified areas. It also quantifies the different areas, as well as measures cell wall thickness. The method is evaluated by comparing the automatic with a manual delineation. While the boundaries between the various fiber wall regions are detected using the automatic method with precision similar to inter and intra expert variability, the position of the boundary between lumen and the cell wall has a systematic shift that can be corrected. Our method allows for transverse structural characterization of compression wood fibers, which may allow for improved understanding of the micro-mechanical modeling of wood and pulp fibers. [ABSTRACT FROM AUTHOR]

Kinetic models applied to oxygen bleaching of paper pulp focus on the degradation of polymers, either lignin or carbohydrates. Traditionally, they separately model different moieties that degrade at three different rates: rapid, medium, and slow. These models were successfully applied to lignin and carbohydrate degradation of poplar wood submitted to oxidative pretreatment with lime at the following conditions: temperature 110-180°C, total pressure 7.9-21.7 bar, and excess lime loading of 0.5 g Ca(OH)2 per gram dry biomass. These conditions were held constant for 1-6 h. The models properly fit experimental data and were used to determine pretreatment selectivity in two fashions: differential and integral. By assessing selectivity, the detrimental effect of pretreatment on carbohydrates at high temperatures and at low lignin content was determined. The models can be used to identify pretreatment conditions that selectively remove lignin while preserving carbohydrates. Lignin removal ≥50% with glucan preservation ≥90% was observed for differential glucan selectivities between ∼10 and ∼30 g lignin degraded per gram glucan degraded. Pretreatment conditions complying with these reference values were preferably observed at 140°C, total pressure ≥14.7 bars, and for pretreatment times between 2 and 6 h depending on the total pressure (the higher the pressure, the less time). They were also observed at 160°C, total pressure of 14.7 and 21.7 bars, and pretreatment time of 2 h. Generally, at 110°C lignin removal is insufficient and at 180°C carbohydrates do not preserve well. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the properties of cellulose pulp and paper from different lignocellulosic materials and the heating value and chemical composition of their autohydrolysis liquor. An integral fractionation method was used to assess their potential for the obtainment of energy, sugars and other chemical products. Raw materials included Eucalyptus globulus, Arundo donax, Leucaena diversifolia, Paulownia fortunei, sunflower stalks and Chamaecytisus proliferus. Results showed that the lignocellulosic materials seem to be effective choices for obtaining biomass fuel and cellulose pulp. In addition, the hemicellulose contents of all raw materials were higher than those for eucalyptus.

Sandospace R and five multi-functional reactive dyes have been applied to lyocell fibre, by exhaust methods. A comparison has been made of the number of mmoles of each species covalently bonded to the fibre, with cross-linking efficiency (NSF values). None of the dyes studied was able to achieve levels of cross-linking found in non-fibrillating grades of lyocell, unless unrealistically high levels were applied. Sandospace R readily matched the NSF values found in commercially produced non-fibrillating fibres. An explanatory mechanism based on differences in size between Sandospace R and the reactive dyes has been proposed. Fitting the experimental NSF data to an Arrhenius model confirmed the increasing gradient of the NSF curves with increasing millimolar concentration of species fixed. The chroma of the agent-plus-dye fibre samples remained relatively constant being either at the same level or above that of those fibre samples treated only with dye. Co-application of Sandospace R with the reactive dyes has achieved levels of cross-linking found in commercial non-fibrillating lyocell fibres. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogen peroxide is a potent, relatively inexpensive oxidant that chemically degrades chromophoric components in pulps and textiles. Oxidation of cellulose is a byproduct of this process step that decreases the tensile strength of individual fibres. The residence time of pulp in the bleaching reactor must be optimized to achieve the desired brightness and minimizing fibre degradation. To evaluate the impact of peroxide bleaching at the microfibrillar level, a single black spruce tree was chosen and kraft pulped. Peroxide bleaching was conducted via benchtop polyethylene bag bleaching in a temperature-controlled waterbath. Atomic force microscopy (AFM) topographical images acquired before and after the bleaching step show dramatic changes in fibre structure consistent with delignification and defects in the surface topography. This was further verified by X-ray work at Brookhaven National Laboratory, NY, U.S.A. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Chemical Engineering is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dermatitis is reported from slimicides added to wood pulp slurry in a paper mill. The active constituents of the slimicides involved were bis-l, 4-bromoacetoxy-2-butene and 2, 3-dichloro-4-bromotetrahydrothiophene-1, 1-dioxide. Wood pulp slimicides include many chemicals which are highly irritant and potentially sensitizing to the skin. [ABSTRACT FROM AUTHOR]

A worker in the rubber tyre industry is described with occupational asthma from exposure to a solution of tall oil, a pine resin, confirmed by specific inhalation challenge. This supports studies of contact dermatitis which have suggested abietic and dehydroabietic acid oxidants to be the cause of colophony induced allergic reactions. [ABSTRACT FROM AUTHOR]

The quality of carboxymethyl cellulose (CMC) prepared from different wood‐derived market pulps is examined. The pulps represent kraft and sulfite qualities with different levels of hemicellulose (1.5–22.8 wt %), intrinsic viscosity (391–780 mL g−1), and content of extractives (0.04–0.13 wt %). The pulps are carboxymethylated in aqueous medium at three different levels of sodium hydroxide concentration, resulting in three levels of degree of substitution (DS), 0.3, 0.7–0.8, and 1.3–1.4 (according to nuclear magnetic resonance spectroscopy and high‐performance liquid chromatography). CMC with DS 0.7–0.8 is found to be near the limit for water solubility and the resulting ranking for that solubility is shown to be correlated to DS. The DS is found to be impaired by a high content of impurities and high degree of Cellulose II in the pulp. The sulfite pulps yield CMC with the best solubility in water. A high level of extractives does not interfere with reactivity. Moreover, it is found that impurities, such as lignin and xylan, inhibit thickening behavior even at high DS, and that the ratio of substitution on Position 3 is a measure of the xylan content, which suggests that this position in xylan has extremely high reactivity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47862. [ABSTRACT FROM AUTHOR]

When using a combination of pre‐extraction and chemical pulping, a high yield of sugar recovery and minimal negative effect on the subsequent pulping step are expected. In this work, the P factor was utilized to investigate the effect of auto‐hydrolysis severity on sugar recovery, removal of the main component, and impact on the kraft pulping of acacia wood chips. Using a P factor of 235, 84.34% of the polysaccharides in 14.05 g L−1 of dissolved sugars could be obtained. In addition, the soluble sugars were easily separated with a recovery yield of 3.54 g ·L−1 and Mw of 4,690 g mol−1 by direct precipitation using organic solvents. However, a maximum of 22.14 g L−1 of dissolved sugars was obtained with approximately 72.53% polysaccharides and Mw of 2,198 g mol−1 for a P factor of 601. Moreover, nearly 50% of the degraded carbohydrates remained in the auto‐hydrolyzed wood chips. The decrease in the mass of pentosan, holocellulose, and klason lignin was 62, 30, and 8.76%, respectively. With intensifying severity, the screened yield and viscosity of pulps decreased markedly, whileas the Kappa number increased. No significant differences were observed in the morphology of the resultant fibers. Moreover, there was a decrease in the physical strength of the pulps due to the loss of the intrinsic strength of the pulp fibers, which in turn resulted from the cellulose damage. The combustion performance of the resultant pulping black liquor is improved due to the higher lignin content. [ABSTRACT FROM AUTHOR]

The Back Cover picture shows a renewable wood pulp paper reactor for highly efficient, green, and sustainable chemical manufacturing. This “paper reactor” contains hierarchical micro/nanoscale pores tailored from wood pulp fibers, which can act as both convective‐flow and rapid‐diffusion channels for efficient access of reactants to metal nanoparticle catalysts anchored within the paper reactor, leading to dramatically improved reaction efficiency. More details can be found in the Communication by Koga et al. on page 2560 in Issue 12, 2017 (DOI: 10.1002/cssc.201700576). [ABSTRACT FROM AUTHOR]