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In recent years, an increasing focus has been placed on the mitigation of carbon dioxide emissions, underscoring the significance of the sustainable energy-conservation industry as a prominent and consequential field of development. As an energy-intensive procedure within the papermaking sector, the process of pulp-fiber beating necessitates an imperative exploration of alternative approaches aimed at mitigating energy consumption. This study has synthesized renewable cationic cellulose nanoparticles (CCNPs) extracted from the parenchymal cells of maize stalk pith. The objective is to demonstrate their viability as a reinforcing additive for paper sheets, thereby reducing the reliance on conventional beating processes. The results showed that CCNPs were prone to augment the physical strength of bleached papers, compared with unbleached papers. The inclusion of 9% CCNPs led to a remarkable 163.5% and 140.0% increase in tear and tensile indexes for bleached Eucalyptus paper, respectively. Incorporating CCNPs into non-refined paper yields physical traits akin to wood pulp paper beaten over 40 °SR. The CCNP-strengthened handsheets exhibited superior tensile and tear index in comparison to commercial dry strength additives such as cationic starch (CS) and cationic polyacrylamide (CPAM). Additionally, at 80 μg/ml concentration, E-B-9 displayed significant bactericidal effectiveness, achieving an impressive 97% reduction in Escherichia coli. This notable outcome is attributed to the presence of quaternary ammonium salt moieties in the formulation. This investigation introduces a promising approach where in the utilization of CCNP as an innovative multifunctional agent for paper holds the potential to enhance paper performance and concurrently reduce production costs. [Display omitted] ● The agro-waste CCNP acted well as a paper multifunctional addictive. ● The CCNPs promoted physical strengths of the paper from non-refined wood pulps. ● 9% CCNP-added sheet has mechanical properties akin to that from the 40°SR paper. ● 80 μg/ml of the bleached hardwood showed 97% bactericidal efficacy against E. coli. ● The improvement of CCNPs applied to bleached pulps is superior to unbleached pulps. [ABSTRACT FROM AUTHOR]

Disordered wrinkles inevitably appear in the fluid assembly process of graphene and heavily depress performances of assembled graphene papers. Achieving high plasticity enables the post modulation to rearrange wrinkles by stretching. Here, we obtain an over 100% improved plasticity by intercalating oligomer into graphene oxide (GO) laminates and fabricate strong, stiff and conductive graphene papers (GPs) via post stretching. The intercalated oligomer activates the mobilization of GO sheets and achieves high plasticity of solid GO papers. The improved plasticity allows high stretching ratio and the post-stretched GP features regular orientation (0.95) of graphene sheets and aligned fine wrinkles. The crystalline GPs have a high tensile strength up to 1.3 GPa, Young's modulus of 92.9 GPa and highly electrical conductivity (1.05 × 105 S m−1). The greatly improved plasticity by oligomer extends the processing capability of graphene materials and the strong and conductive GP can be assembled in high performance nanocomposites with excellent electromagnetic interference shielding effectiveness (EMI SE). [Display omitted] • Intercalating oligomer greatly enhances plasticity of graphene oxide laminates for the improved interlayer friction. • The greatly enhanced plasticity enables to efficiently eliminate disordered wrinkles of assembled graphene sheets. • The crystalline graphene paper (GP) exhibits superior mechanical and electrical properties. • The (GP-based) laminated composite shows high tensile strength and electromagnetic interference shielding effectiveness. [ABSTRACT FROM AUTHOR]

High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains, exposing carbon residues resulting from electrical breakdown. These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds. This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90 % of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency. [Display omitted] • Electrically damaged meta-aramid paper can be recycled in a closed loop. • The DMAc/LiCl system completely dissolves waste aramid into PMIA molecular chains. • Carbon residues induced by electrical breakdown can be removed by purification. • The synergistic conservation of electrical and mechanical properties exceeds 90 %. • Closed loop recycling strategy is also viable for inorganic-aramid composite paper. [ABSTRACT FROM AUTHOR]

• Synthesis a new flame resistant coating for bagasse paper using 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, NaHCO 3. • Study the mechanical characteristics. • The thermal properties of the coated and uncoated specimens were measured. • The ignition properties as the flame chamber (UL/94), and limiting oxygen index (LOI) was measured according to standards • Those improvements are due to the synthesis of new flame retardant coatings based on commercially available chemicals. This manuscript aimed to enhance the mechanical, thermal, and ignition properties of bagasse paper when coated with different coatings synthesized from hydroxyethyl cellulose, 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, Talc powder, NaHCO 3 , cellulose nanocrystal. The effect of these coatings on the mechanical properties was studied by measuring elongation, tensile strength, and burst strength. The stages of degradation and ash residue of the measuring specimens were determined using thermal gravimetric analysis (TGA), behind that, the ignition properties as the flame chamber (UL/94), and limiting oxygen index (LOI) was measured according to standards. These tests proved that 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane has a direct effect on improving the mechanical characteristics and enhancing the ignition properties of the coated specimens compared to uncoated. In this study the physical, mechanical, thermal, and ignition properties of the bagasse paper sheets were enhanced by easy and low-cost method via synthesis of new coatings based on commercially available chemicals in a reasonable cost. [ABSTRACT FROM AUTHOR]

Wood is used as the major raw material in paper production around the world and this has resulted in severe deforestations having direct negative impact on our environment. This has led to the need of finding alternative raw materials for paper production. Mauritius has around 300 ha of land under pineapple cultivation resulting in agro-waste materials of the leaves. This paper aims at determining the feasibility of using pineapple leaf fibres for paper production. Samples of pineapple leaf fibre were mixed with cane-bagasse in different ratios namely, 20:80, 40:60, 60:40, 80:20,100:0. Pineapple leaf fibres were also mixed with wastepaper in the same ratios. Pulping of pineapple leaf was achieved through soda pulping at a concentration of 15%w/v for 90 min at 90 °C. The papers obtained were tested for their physical and mechanical properties. The average thickness of all the papers produced, ranged from 0.232 mm to 0.304 mm showing an increase in paper thickness with increasing grammage from 58.19 g/m 2 to 63.3 g/m 2 . The most absorbent paper(1.19 s) was found to be the 100% pineapple which also demonstrated the highest Tensile Index and Burst Index (6.5 Nm/g and 0.84 kPa m 2 /g respectively). The bagasse and pineapple composite of ratio 40:60 was found to be the most abrasion resistant paper with 21 turns and a weight loss of 0.86% with the use of emery paper of grade zero as abradant and 200 g load cells. The most crease resistant paper was the wastepaper and pineapple composite of ratio 80:20 with a crease recovery angle of 59.8°. [ABSTRACT FROM AUTHOR]

This article discusses the morphology and thermomechanical properties of graphene oxide (GO) paper sheets and GO paper composites reinforced with carbon fibers. GO paper was fabricated using GO paste obtained by the condensation of GO aqueous solution synthesized using the Hummers' method. Carbon fibers were implemented to improve the mechanical properties of the pristine GO paper. All the investigated papers were subjected to thermal treatment to check thermo-related morphological and mechanical properties. The results presented in this study allowed for the deeper insight into morphological, structural, and mechanical volume and surface-related properties of pristine GO and GO-based composite materials reinforced with carbon fibers. We showed that there are two important factors that should be taken into consideration for the design and fabrication of GO-based papers. These factors were the concentration of the reinforcing agent and the thermal reduction of the papers. Both factors have influenced the final properties of the resulting GO-based papers. For the first time, it was revealed how the addition of the reinforcing material affects the GO paper thermal expansion coefficient. [Display omitted] [ABSTRACT FROM AUTHOR]

MXene-based nanocomposites are highly desirable for electromagnetic interference (EMI) shielding applications. However, it is crucial but challenging to obtain an excellent trade-off between mechanical properties and EMI performances. Herein, inspired by Janus structure, flexible cellulose nanofiber-assisted MXene/silver nanowires (CNF-MXene/AgNWs) papers (CMAPs) are developed by a scalable sequential self-assembly plus a hot-pressing strategy. The ingenious introduction of highly conductive AgNWs into MXene forms a complementary leaf-like nanostructure, synergistically constructing highly effective conductive frameworks. Contributed by the designed Janus architecture, high-performance CNF substrate, and extensive hydrogen-bonding interactions, the resultant Janus CMAPs (J-CMAPs) with a low MXene/AgNWs addition of 30 wt% possess a high electrical conductivity (1066.85 S/cm), excellent mechanical strength (224.04 MPa) and modulus (9.98 GPa), exceptional EMI shielding effectiveness of 43.65 dB, and record-high EMI SE/t of 16788.51 dB cm−1 and SSE/t of 10543.18 dB cm2 g−1 with a reflection-dominant shielding mechanism, successfully achieving an outstanding balance between mechanical properties and EMI shielding performances. More importantly, high frequency structure simulator (HFSS) simulation in the frequency domain is further conducted to intuitively comprehend the attenuation process of electromagnetic waves and shield mechanism, verifying fascinating EMI shielding performances. Besides, the Janus paper also presents desirable Joule heating performances at low input voltage, short response time (<10 s), and superb heating stability and long-term steady reliability. We believe that the J-CMAPs demonstrate the great potential and advantage for advanced EMI shielding and portable thermal management applications. SynopsisIn this paper, inspired by Janus structure, flexible CNF-assisted MXene/AgNWs nanopapers with both excellent mechanical properties and impressive EMI shielding performance are developed. The nanopapers exhibit a high electrical conductivity, superior mechanical properties, impressive EMI shielding effectiveness of 43.65 dB, and record-high EMI SE/t of 16788.51 dB cm−1 and SSE/t of 10543.18 dB cm2 g−1, suggesting the great potential for advanced EMI shielding applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • Mechanical properties of waste papers are closely correlated with devolatilization. • Start of devolatilization caused a sudden decrease in relative storage modulus ( E ′ r). • Kinetics of storage modulus change is investigated referring to activation energy. • E ′ r can be predicted with mass loss ratio and CO 2 emission. Abstract This article details a correlation study on early devolatilization behaviors (drying & volatile emission at 25–240 °C) and the change in mechanical properties (expressed by viscoelasticity) of four types of waste papers. The early stage of devolatilization was investigated using the TG-FTIR and mechanical properties using the dynamic mechanical analysis (DMA) method. The results show that the elastic and viscous mechanical properties showed obvious correlations with free and bound water evaporation and volatile emission. The storage modulus (E ′) and loss modulus (E ″) of the papers decreased as temperature increased and at the two important temperatures, namely 100 °C, the start of bound water evaporation, and 150 °C, the start of devolatilization in TG & DTG curves, E ′ showed extrema. Especially the relative storage modulus ( E ′ r) exhibited a sudden decrease at around 150 °C, where the activation energy of thermochemical conversion jumps from low values to high values, indicating the start of devolatilization. CO 2 is the major compound of the volatiles and it is well correlated with E ′ r in exponential function model and can be used as an index for predicting the E ′ r of the waste papers in their early devolatilization stage; while during the drying stage, mass loss ratio can be used to predict E ′ r of the waste papers. [ABSTRACT FROM AUTHOR]

• Synthesis of new coating for bagasse paper. Studying mechanical, ignition properties. • Study the physical and mechanical properties of these bagasse papers compared to untreated. • The enhanced ignition properties was studied. This paper aimed to modify the ignitability of the bagasse paper by using talc powder, 1,3-di-aniline-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, and nanocellulose crystal. The formation of cellulose nanocrystals (CNCs) was detected using transmission electron microscopy (TEM), X-ray diffraction (XRD). Thermal analysis as thermal gravimetric analysis (TGA) of the specimens recorded the improvement of the highest % of ash residue at 750 °C compared to the untreated one. The shape of the flame spread was studied. The ignition properties were studied for the untreated and treated specimens by limiting oxygen index (LOI) and flame chamber (UL/94), which recorded enhancing compared to the untreated specimen. This improvement was recorded either by measuring the mechanical properties (tensile strength, burst strength, elongation, and elasticity) of the specimens. The current article showed that the treated specimen was recorded the highest values compared to the untreated one in all physical, mechanical, and ignition properties, so these treatment paper sheets may be used as fire-retardant packaging materials. [ABSTRACT FROM AUTHOR]

Bacterial infection has become one of the major threats to human health all over the world, and the development and application of antibacterial materials has drawn great attention. Based on the Schiff-base structure, ZnONPs@ACFs are obtained by loading zinc oxide nanoparticles (ZnONPs) on amino cellulose fibers (ACFs) in-situ through the coordination of amino groups with metal ions. The results of FT-IR, XRD and UV-vis demonstrate that ZnONPs are successfully loaded and uniformly dispersed on ACF surface, and the ACFs maintain intact morphology observed by SEM. Furthermore, the zero-span tensile strength of ZnONPs@ACFs is 66.48 N/cm (ROL: 24.98 N/cm/s) under the optimum conditions, which indicates that ZnONPs@ACFs have a certain strength and can be used to make antibacterial sheet materials via paper-making wet-forming process. Accordingly, the ZnONPs@ACF composites show inhibition zones of 4.95 mm and 1.10 mm against E. coli and S. aureus , respectively. The new cellulose-based antibacterial materials demonstrate potential applications in the field of food packaging and biological medicine etc. Abstract diagram of ZnONPs@ACF antibacterial composites [Display omitted] [ABSTRACT FROM AUTHOR]

The mechanical properties of paper coating layers are important in various converting processes such as printing and folding of the paper. A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these coating layers were characterized. Free-standing films with two types of binder formulations, pure latex or latex-starch combinations, with different binder content were prepared through an innovative film forming method that allows uniform drying of the coating layer while minimizing cracking. Tensile and flexural samples were cut out of these films. Tensile and flexural tests were carried out on samples and the results were compared. Tensile and flexural moduli were found to be similar. However, both stress at failure and strain at failure were higher in flexural tests compared to those in tensile tests. Three different types of paper were coated with these formulations and their failure during printing was evaluated through a standard ink picking test. Papers with different basis weights and porosities were found to have different picking resistance values. An interesting result was that the picking resistance did not correlate with the elastic modulus of the coating, but with the strain at failure behavior. This result indicates that the stiffness of the coating layer is not as critical during printing compared to its flexibility. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate some physical and mechanical properties of the paper mill (PMS) and spruce planer shaving added cement boards. Also the effect of sludge type in consequence of waste water treatment technique on properties of wood-cement boards (WCB) was investigated. The wood/cement ratios were used as 1/3, based on the oven dry weight for the WCB manufacture. PMS was used up to 20% wt of total composite based on organic (wood) and inorganic (cement) amounts. Black sludge has shown more improvement than grey sludge on properties of WCBs, which indicates the anaerobic waste treatment technique is more effective for additive in WCB. The modulus of rupture and elasticity values of the WCBs with 5% of grey sludge, 5% and 10% of mixture of grey and black sludge were acceptable limits according to EN 634-2 standard. The mechanical strengths of all WCBs with black sludge were found above the specified EN standard. This suggests that PMS depending on sludge type may be used up to 20% wt of total composite weight for the commercial production of WCBs, which could expand the raw material base for this panel product. [ABSTRACT FROM AUTHOR]

In the research, paper was successfully coated with curdlan and chitosan (CR/CH) coating solutions at different ratios (CR/CH ≈ 10:0, 8:2, 6:4, 5:5, 2:8, 4:6, 0:10% w/w). The novelty of this paper is in the use of combination of curdlan and chitosan, which led to a positive effect on the mechanical and water barrier properties. The tensile properties were improved when the ratio between polymers was 5:5. Coated papers were further investigated for their bursting strength, tear and bending resistance. Pure curdlan coating worsen the tensile and moisture properties and allowed to prepare the blend coatings with different amounts of chitosan. The equilibrium thickness of coatings as a function of curdlan content and tensile strength has shown a decrease in tensile strength. This has resulted in reduction of tensile strength especially at higher thickness. The resulting blend curdlan/chitosan coatings exhibited good water barrier and mechanical properties and could be used in many fields. [ABSTRACT FROM AUTHOR]

Cellulose-based paper is an alternative substitution for petroleum-based polymers for packaging applications, but its mechanical performance is poor when in contact with water. Herein, chitosan was applied on cellulose-based paper via a coating approach. The effects of chitosan coatings between none and five layers on the color properties, wettability, thermal properties, mechanical performance, and overall migration in food simulants of the paper were evaluated. After the application of chitosan, chitosan first filled cavities between cellulose fibers within a network, and the chitosan film was formed on the paper surface later. This resulted in a pronounced increase in wettability and mechanical properties associated with a loss of whiteness and an increase in yellowness of the coated paper. The chitosan-coated paper became hydrophobic with a water contact angle of 94.7 ± 2.8°, and a robust improvement of 156.4% for tensile strength and 114.8% for strain at break was observed for the paper coated with three layers of chitosan in wet conditions in comparison to the uncoated paper. A reduction in the migration of the low molecular residuals from the paper could be hindered by the chitosan coating. These enhanced features revealed that chitosan-coated paper could be used as a food-contact material. • Chitosan was applied on cellulose-based paper by a coating method. • Greater mechanical properties of chitosan coated paper were observed in wet conditions. • The hydrophilicity of the paper was transformed into the hydrophobic feature with incorporation of chitosan. • A reduction in the migration of the low molecular residuals from the paper could be hindered by the chitosan coating. • The chitosan-coated paper prepared could possibly be used for direct-contact packaging. [ABSTRACT FROM AUTHOR]

The article describes the compositions with red clay, as principal component, for utilization of paper production sludge and scrap glass to fabricate red ceramics at sintering temperatures of 700°, 800°, 850°, 900°, 1000°, 1050° and 1100 °C. The raw and final materials were analyzed by XRF, XRD, SEM, EDS and LAMMA methods. The flexural strength tests of obtained ceramics reached till 11.7 MPa, water absorption till 12.6%, bulk densities varied from 1.79 to 1.86 g/cm 3 , and shrinkage till 1.4%. These properties can be attributed to the sintering at 700° and 1100 °C of ceramics with glassy structures and small inclusions of new crystalline minerals, such as mullite, albite, orthoclase and nepheline. [ABSTRACT FROM AUTHOR]

In the present work, unshredded waste newspaper based composites have been prepared in polyester resin matrix. Reinforcing material, waste newspaper is characterized by chemically, X-ray diffraction (XRD) methods, Fourier transform infrared spectroscopy (FTIR) and tensile properties. Three different fibre content composite samples, namely 25%, 34%, and 50% (by weight) are prepared by hand lay-up techniques. Water absorption and thickness swelling tests are conducted by immersing composite samples in distilled water at room temperature. It is found that the percentage of moisture uptake and thickness swelling are increased as the fibre volume fraction is increased due to the high cellulose content. The tensile, flexural and interlaminar shear strength properties of water immersed samples are investigated and compared with dry composite samples. It is observed that after swelling the mechanical properties of composites are found to decrease with increase in percentage moisture uptake. [ABSTRACT FROM AUTHOR]

In this work, a robust and flexible bilayered MXene/cellulose paper sheet with superhigh electrical conductivity was prepared via vacuum-assisted filtration and a subsequent hot-pressing process for electromagnetic interference (EMI) shielding applications. By tightly assembling few-layered MXene (f-Ti 3 C 2 T x) on the cellulose substrate via hydrogen bonds, an effective and interconnected conductive network was constructed in the paper sheet, resulting in a high electrical conductivity of 774.6–5935.4 S m−1 at various f-Ti 3 C 2 T x loadings. The highly conductive MXene layer can promptly reflect a great amount of incident EM waves, a process which preceded the transmission of EM waves in the cellulose matrix. Owing to the highly efficient reflection-dominated EMI shielding mechanism, the resultant bilayered MXene/cellulose paper sheets exhibit excellent EMI shielding effectiveness of 34.9–60.1 dB and specific EMI shielding efficiency of 290.6–600.7 dB mm−1. Moreover, the MXene/cellulose paper sheets demonstrated improved mechanical strength (up to 25.7 MPa) and flexibility due to the mechanical frame effect acted by the cellulose substrate. Consequently, the robust and flexible bilayered MXene/cellulose paper sheet is a promising candidate for application in next-generation electric devices. [ABSTRACT FROM AUTHOR]

The paper describes the structure and properties of preceramic paper-derived Ti 3 Al(Si)C 2 -based composites fabricated by spark plasma sintering. The effect of sintering temperature and pressure on microstructure and mechanical properties of the composites was studied. The microstructure and phase composition were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. It was found that at 1150 °C the sintering of materials with the MAX-phase content above 84 vol% leads to nearly dense composites. The partial decomposition of the Ti 3 Al(Si)C 2 phase becomes stronger with the temperature increase from 1150 to 1350 °C. In this case, composite materials with more than 20 vol% of TiC were obtained. The paper-derived Ti 3 Al(Si)C 2 -based composites with the flexural strength > 900 MPa and fracture toughness of >5 MPa m1/2 were sintered at 1150 °C. The high values of flexural strength were attributed to fine microstructure and strengthening effect by secondary TiC and Al 2 O 3 phases. The flexural strength and fracture toughness decrease with increase of the sintering temperature that is caused by phase composition and porosity of the composites. The hardness of composites increases from ~9.7 GPa (at 1150 °C) to ~11.2 GPa (at 1350 °C) due to higher content of TiC and Al 2 O 3 phases. [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials possess broad applications because of their excellent multi-functional properties. In this work, a facile self-assembling method was presented for preparing one kind of graphene oxide-based paper/hollow microspheres hybrid. It was found that most of the hollow microspheres can strongly anchored on the surface of graphene oxide paper (GOP) by an in-situ scanning electron microscope peeling testing combining with molecular dynamics (MD) simulation. In addition, the uniform distribution of hollow microspheres on the surface of GOP cannot only provide a better surface wettability, but also can effectively improve the interfacial stress-transfer capability between such hybrid and polymer matrix. Our work provides a guidance for the structural designs of graphene-based nanomaterials and broaden their applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The damage to historical documents and books caused by the acidic character of paper is often manifested as a complete loss of their mechanical properties. Deacidification and restoration of archived paper objects require knowledge of the long-term behaviour of paper before and after repair actions. Our study was focused on the investigation of mechanical properties (tensile strength, stretch, tensile index, zero-span tensile strength, folding endurance) of original papers (one alkaline and three different acidic samples) exposed to five methods of dry-heat and moist-heat accelerated ageing. The degree of paper deterioration upon ageing was significantly influenced by the temperature and relative humidity, along with the intrinsic chemistry of the individual paper samples. The correlation matrix evaluated at a 95% confidence level for tensile strength, stretch, tensile index and zero-span showed linear correlations between these mechanical properties for all the paper samples. However, a linear dependence of folding endurance on zero-span tensile strength was found only for alkaline paper, which revealed the highest resistance to the accelerated ageing tests. In addition, the concentration of paramagnetic semiquinone species in the acidic lignin-containing paper samples was monitored by Electron paramagnetic resonance spectroscopy. [Copyright &y& Elsevier]

Paper straws with environmental friendliness have been widely used to replace plastic straws, but their poor mechanical properties and uncontrollable deformation bring an unsatisfactory experience for users. Herein, we developed a polylactic acid/cellulose fiber (PLA/CF) ultrafine-fiber paper with a sandwich‐like structure via wet papermaking and laminated hot pressing, employing PLA ultrafine fiber and CF as raw materials. The PLA/CF ultrafine fiber paper has remarkable mechanical properties due to the tangling of the fibers and the strong hydrogen bonding that occurs between the PLA and CF during hot pressing. The test results demonstrate that the tensile strength of PLA/CFs ultrafine fiber paper can reach 60.32 N/cm, and it still retains great wet strength (27 N/cm) and stiffness (117.7 mN·cm) after long-time service in various clod and hot liquids. Besides, PLA/CF ultrafine fiber paper also displays high biodegradability, with a degradation rate of 70% after being buried in soil for 120 days. We believe that PLA/CF ultra-fine fiber paper with excellent comprehensive performance can be expected to completely replace plastic straws. [Display omitted] • The method of using environment-friendly degradable materials as raw materials. • Adopt self-assembly melt-blowing machine to raw material PLA superfine fiber. • A design combining PLA microfiber with cellulose was proposed and studied. • The straw has superior mechanical properties and thermal stability. [ABSTRACT FROM AUTHOR]

Micro- and nano-hybrid cellulose fiber (MNCF) stands out as a versatile cellulosic nanomaterial with promising applications in various fields owing to its excellent intrinsic nature and outstanding characteristics. However, the inefficiency in preparing MNCF, attributed to a complex multi-step processing, hinders its widespread adoption. In this study, a straightforward and highly efficient method for MNCF preparation was developed via a hot water soaking-assisted colloid grinding strategy. Active water molecules in hot water facilitating stronger transverse shrinkage and longitudinal expansion in fiber crystallized region, and thus improving the fibrillation degree of cellulose fibers. As a result, MNCFs with a mean diameter of 37.5 ± 22.2 nm and high concentration (2 wt%) were successfully achieved though pure mechanical method. The micro and nano-hybrid structure leads to the corresponding resulting cellulose paper with micro- and nano-hybrid structure possesses a compact stacking and fewer defects, leading to extraordinary mechanical properties including tensile strength of 204.5 MPa, Young's modulus of 6.3 GPa and elongation of 10.1 %. This work achieves significant progress towards straightforward and highly efficient production of MNCFs, offering an appreciable prospect for the development of multifunctional MNCF-based materials. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the effects of décor paper grammage (weight per unit area) and adhesive type on the tearing index, breaking length, and mechanical (modulus of rupture and modulus of elasticity) of the decorative papers, and surface quality (abrasion resistance) properties of the overlaid particleboard panels were investigated. As the raw décor paperweight was increased, the properties of the paper, and mechanical properties and abrasion resistance of the overlaid panels were significantly improved. It appears that the décor paper grammage is the parameter, other than scratch resistance, which determines the end use of the particleboard surfaces with décor paper. While the adhesive type was found to influence the abrasion resistance, it did not statistically affect the mechanical properties of particleboard. In addition, melamine formaldehyde caused better abrasion resistance than did the urea formaldehyde and melamine urea formaldehyde. [Copyright &y& Elsevier]

Highlights: [•] Wood–plastic composites were made with paper mill sludge produced by three different pulping processes. [•] The effects of primary and secondary sludge on composites properties were assessed. [•] Higher cellulose content improved the composite properties. [•] Secondary sludge had a negative impact on the composite properties. [•] The ash content in the sludge showed a positive impact on the WPC properties. [ABSTRACT FROM AUTHOR]

Nanofibrillated cellulose (NFC), a promising bio-based nanomaterial, has received much attention in the field of coating preparation due to its unique properties. Herein, NFC was prepared from microcrystalline cellulose (MCC) via high-pressure homogenization process and deliberately employed as coating agent to enhance the properties of paper coatings and coated paper. The results demonstrated that the obtained paper coatings exhibited strong NFC concentration dependence on rheological behavior and displayed decreased water retention value with the increased NFC addition. Meanwhile, NFC addition was found to lead to the reduced Cobb value, improved air resistance, and enhanced tensile strength of coated paper. Under an optimized NFC addition of 0.30–0.40%, the properties of coated paper generally reached the optimum state. Moreover, SEM observation further confirmed that NFC addition imparted a relatively uniform surface structure to coated paper. Hence, NFC could be defined as an effective coating agent for developing high-performance coated paper for food packaging applications. • Novel paper coating was designed and developed using NFC as coating agent. • Increased NFC addition resulted in increased viscosity and viscoelasticity of paper coatings. • Increased NFC addition led to decreased WRV of paper coatings. • NFC addition improved the barrier and mechanical properties of coated paper. [ABSTRACT FROM AUTHOR]

Developing 3D printable waste paper based biocomposites is a potentially greener alternative to traditional waste paper recycling methods. In this paper, waste office paper (WOP) filled polylactide acid (PLA) biocomposites were prepared as filaments for Fused Filament Fabrication (FFF). The morphology, rheology, thermal properties, and physical properties of PLA-WOP composites were investigated. Results revealed that the addition of WOP improved the composites' melt flow abilities. The T g and T m of composites remained similar to the neat PLA. However, tensile strengths of the prints decreased with the increase of WOP content, which could be attributed to the heterogeneous dispersion and aggregation caused by the abundance of WOP in the system. When 5% WOP was used, the elongation at break increased in comparison with pure PLA specimens. Nonetheless, when the WOP content was increased to 15%, the elongation at break decreased. To improve the mechanical properties of the prints, a silane coupling agent (γ-methacryloxypropyltrimethoxylsilane, KH570) was used to modify WOP granules. The mechanical properties were clearly enhanced post KH570 treatment. Furthermore, FTIR analyses demonstrated that the hydrogen bonding improved interfacial adhesion between WOP fillers and the PLA matrix. Thermal decomposition showed that the PLA-WOP composites had virtually no degradation below 260 °C, indicating that the composite filaments are safe for indoor 3D printing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plastic pollution contributed mostly from packaging industry seeks a solution in eco-friendly alternatives. • Natural fiber composites could cater to versatile demands posed by carry bags. • Indigenous fibers like coir, cotton are used as hybrid reinforcement dispersed in recycled paper matrix. • Mechanical tests reveal better tensile, impact and water repellent properties over standard packaging paper. • Thermal analysis was carried out to shimmer light on thermal stability of the novel material. Increasing concern about environmental pollution has led researchers to find sustainable alternatives to synthetic counterparts. With the packaging industry accounting for 42 percent of plastics entering our marine systems, governments have also passed legislation banning single-use plastics. This paper essays the fabrication and experimental validation of hybrid bio composite with coir and cotton fiber reinforcement dispersed in paper matrix. Specimen with varying concentration of coir and different fiber length was validated against 150 GSM standard packaging paper material. The specimen constituted by 20 wt% coir was observed to have better tensile strength of 2.678 N/mm2, Izod higher impact value of 0.15 J compared to the standard sample which had tensile strength of 1.875 N/mm2 and lower Izod impact value of 0.10 J. Increasing coir content led to 142.4% higher water absorption and was not appreciable for making carry bags. The thermal stability characteristics of composite specimens were comparable to conventional packaging materials. [ABSTRACT FROM AUTHOR]

The aim of this work is to evaluate of the effect of incorporating nanofibrillated cellulose (NFC) and chitosan (CH) in a dual system as dry additives during papermaking for unbleached bamboo alkaline sulfite anthraquinone methanol (ASAM) under different beating revolutions. Pulp beating at 4000 and 6000 revolutions has comparable properties with varying dosages of NFC (5% and 10%) and different chitosan concentrations (0.5%, 1, 1.5%, and 2%). Hand sheets of a basis weight (60 g/cm2) were produced and measured for thickness, tear, tensile, burst index, and resistance to folding under TAPPI standard methods. Results revealed that with an increase in the number of beating revolutions, there was a decrease in the value of freeness. All analyzed pulp had freeness values within the permissible amount of 300–500 mL in papermaking, except 10% NFC, which was 244–190 mL at 6000 revolutions. Furthermore, the addition of chitosan to 1.5% with 5% NFC at 6000 beating revolutions enhanced the tensile index (85.16 Nm/g) and burst index (7.69 kPa. m2/g) in comparison to the sample control. The incorporation of nanofibrillated cellulose and chitosan significantly altered the physical and mechanical strength. Optimal alkaline sulfite anthraquinone methanol ASAM-enhanced paper properties are displayed with 5% NFC and 1.5% chitosan at 6000 beating revolutions. [Display omitted] • Nanofibrillated cellulose/chitosan potential as a dry strength additive in pulp. • Nanofibrillated cellulose acted as an adhesion promoter by bridging adjacent fibers • Larger fibers contribute to boost the load-bearing capacity of the paper. • Chitosan is structurally like cellulose and contain active hydroxyl and amino group. • The incorporation of Nanofibrillated cellulose/Chitosan enhanced paper properties [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials have found significant interest in the development of embedded sensors to monitor the fracture behavior in composite structures. In this work, in-situ crack propagation and fracture behavior within a glass fiber reinforced polymer composite (GFRP) was monitored using embedded reduced graphene oxide (rGO) coated fabrics and highly conductive graphene nanoplatelet (GnP) paper. All laminates were fabricated using the resin infusion process. The piezoresistive performance of both types of laminates was evaluated using in-plane and out-of-plane mechanical tests. The effect of GnP paper thickness (50/150/240 µm) and loading rate was also evaluated using tensile and Mode-I fracture loadings. Piezoresistivity of the sensors was reduced by increasing loading rate during tensile tests. All laminates with GnP paper exhibited poor mechanical performance under tensile loading. The laminates with 50 µm GnP paper showed highest sensitivity under Mode-I loading. In comparison to pristine laminates, the interlaminar fracture toughness of laminates with 50 µm GnP paper was reduced by 70%. Furthermore, laminates with rGO coated fabrics demonstrated stable crack propagation under Mode-I loading as compared to GnP based laminates. The fractured surfaces were analyzed using scanning electron microscopy to investigate the underlying fracture mechanisms of the sensors in the composite laminates. [Display omitted] • Composites with embedded GnP paper and rGO coated fabric sensors were manufactured. • Sensor based on thin GnP paper was found more sensitive than the thick GnP sensors. • Loading rate and thickness effects on the sensing behavior were characterized. • Increasing the load rate during in-plane tensile tests decreases the sensitivity. • rGO based sensor exhibited high mechanical properties than the GnP based sensors. [ABSTRACT FROM AUTHOR]

Inspired by the excellent mechanical reinforcement effect of carbon nanotubes (CNTs) and the strong interactions between metal ions and graphene oxide (GO), ultra-robust, and high-toughness GO papers were fabricated via the synergistic reinforcement of CNTs and copper ions (Cu2+). The freestanding and flexible CNT/GO nanocomposite papers with a layered structure were readily fabricated by the vacuum-assisted filtration. After being cross-linked by a trace amount of copper ions (Cu2+), the tensile strength, elastic modulus and toughness of the modified GO papers increase 409.7%, 81.5% and 188.2%, respectively, when compared with the pure GO papers. It is revealed by scanning electron microscope and in situ Raman spectroscopy analysis that the CNTs and Cu2+ hindered the interlayer slippage between the GO sheets and promoted the stress transfer during the tensile loading. Considering the tunable and versatile properties of this hybrid carbon nanomaterial, this study will open an avenue for integrating rGO or GO papers to various applications. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • The simulation results successfully guided the preparation of the insulating paper. • Nano-SiO 2 enhances the interfacial binding and compatibility of composite fiber. • Nano-SiO 2 improved the mechanical and insulating properties of the insulating paper. • Nano-SiO 2 reduced the energy barrier of composite fiber and reduce polarization loss. Following the surge in power loads and continuous improvement in the voltage level, insulating papers' mechanical and electrical properties face new challenges. However, traditional inefficient "tentative" trial and error experiments are formidable to rapidly and efficiently prepare cellulose composite insulating paper because the direct scientific theory or simulation guidance is insufficient. To solve this problem, the nano-silica(nano-SiO 2)/polyimide(PI)/cellulose composite models were designed and their mechanical, and dielectric properties were predicted by molecular dynamics (MD) simulation. The preparation of corresponding nano-SiO 2 /PI/cellulose insulating paper was guided by the MD simulation results and their surface morphology, mechanical properties, and electrical properties were investigated. The experimental results are in good agreement with the MD simulation results and confirmed that P3 insulating paper possesses the best comprehensive performance, and its tensile strength, relative permittivity, dielectric loss, volume resistivity, and breakdown strength are 71.44 MPa, 2.39, 0.2%, 5.16 × 1015 Ω∙m, and 75.8 kV∙mm−1, respectively. This work proves the feasibility and effectiveness of using MD simulation to guide the development of new insulating papers, and compared with the existing traditional preparation methods, this method is expected to be applied to study various new materials in the future and promote the vigorous development of new materials. [ABSTRACT FROM AUTHOR]

Abstract Al 2 O 3 /Cu-O composites were fabricated from the paper-derived alumina matrix infiltrated with a Cu-3.2 wt% O alloy. Paper-derived alumina preforms with an open porosity ranging from ∼ 14 to ∼ 25 vol% were prepared by sintering of alumina-loaded preceramic papers at 1600 °C for 4 h. Pressureless infiltration at 1320 °C for 4 h of the preforms with Cu–O alloy resulted in the nearly dense materials with good mechanical and electrical properties, e.g. fracture toughness up to 6 MPa m0.5, four-point-bending strength up to 342 MPa, Young's modulus up to 281 GPa and electrical conductivity up to 2 MS/m depending on the volume fraction of copper alloy in the composites. The technological capability of this approach was demonstrated using prototypes in various engineering fields fabricated by lamination, corrugating and Laminated Object Manufacturing (LOM) methods. [ABSTRACT FROM AUTHOR]

Highlights • Cellulose nanofibrils(CNF)/graphene nanoplatelets(GnP) hybrid papers were prepared with a simple water-based method. • CNF and hot-pressing efficiently enhance the mechanical properties of the GnP paper. • The CNF reinforced GnP paper demonstrates high electrical conductivity. • Mechanical flexibility and electrical conductivity of the papers are controllable. Abstract Mechanically flexible and high electrically conductive multilayered graphene nanoplatelets (GnP)/cellulose nanofibrils (CNF) composite papers were successfully fabricated through a vacuum-assisted self-assembly technique. The morphology observation showed that highly disassembled CNF were achieved by high-pressure homogenization of water-based cellulose slurry, and the homogenized CNF uniformly interpenetrated within the microporous GnP paper network. The analyses of mechanical properties and morphology suggest that the CNF effectively bridged the adjacent GnP sheets and efficiently strengthened the GnP papers by producing strong GnP/CNF interfacial interactions resulting from mechanical interlocking, van der Waals forces and hydrogen bonds between the GnP and the CNF. Moreover, it was noticed that hot-pressing pressure is necessary to be applied on samples to produce stronger papers with higher electrical conductivity. As the CNF loading reached 60 wt%, the Young's modulus and tensile strength of the hot-pressed GnP/CNF hybrid paper were significantly increased to 9.1 GPa and 57.7 MPa, respectively. In addition, a high electrical conductivity of 26.8 S/cm was retained for the paper with 30 wt% CNF. Our approach provides a facial and eco-friendly fabrication route to produce strong and highly conductive GnP/CNF papers which are of great practical appeal as a new type of nanomaterials in various fields. [ABSTRACT FROM AUTHOR]

Abstract: Fumigants, including methyl bromide and ethylene oxide, are generally used for the preservation of the Korean cultural heritage, especially paper products like letters and books. However, the use of fumigants is banned because of their harmful effects on humans and the environment. Gamma irradiation is being considered as an alternative for the sterilization of insects and fungi in organic products. Therefore, the purpose of this study was to investigate the sterilization effects of radiation and its effect on the mechanical properties of the Korean traditional paper—Hanji. Treatment doses of 9kGy and 8kGy of gamma irradiation inactivated 5 log units of Aspergillus niger and Bacillus cereus spores inoculated on Hanji, respectively. The gamma irradiations up to an absorbed dose of 50kGy resulted in no significant changes in the tensile strength, bursting strength, and appearance of Hanji. These results confirmed that radiation treatment disinfects the Korean traditional paper efficiently without changing its properties and that this treatment could be used to prevent the damage of Korean ancient archives by molds and fungi. [Copyright &y& Elsevier]

Abstract We developed a paper-type electrode for the next-generation wearable devices by complementary hybridization of methyl cellulose and carbon nanotubes (CNTs). The large-scale hybrid paper was fabricated using an incomparably simple and low-cost solution process. Structural features, surface hydrophobicity, and chemical interaction between CNTs and cellulose of the hybrid papers were systematically explored by adjusting the concentration of CNTs. The hybrid papers demonstrated superb mechanical durability even under highly strained conditions such as folding, crumpling and re-flattening regardless of the concentration of CNTs. The electrical properties of the CNTs/methyl cellulose were well-preserved even when folded as origami or submerged in water. [ABSTRACT FROM AUTHOR]

Highlights • LbL technique was conducted to assemble starch PEMs on recycled fibers. • Recycled fibers was also treated by refining as commonly industrial method. • RSM optimized PEMs-treated fibers as mixed with refined pulp on paper properties. • The model predicted acceptable paper strengths at lower-refined fibers loading. Abstract Layer-by-layer (LbL) treated recycled fibers were investigated in mixtures with refined pulp relative to the mechanical properties of paper. The LbL treatments were conducted to assemble consecutive cationic and anionic starch layers on the fibers of old corrugated container (OCC) pulp. Fibers zeta potential was measured to examine the success of LbL treatment. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to reveal the differences between treated and untreated fibers surface and network. Subsequently, the LbL-treated fibers were added to the refined OCC pulps. Optimization of paper (60 ± 3 g m-2 basis weight) strength properties including: tensile index, Scott bond (internal bonding), and ring crush test (RCT) was carried out by response surface methodology (RSM). The meaningful change of zeta potential substantiated cationic/anionic starch layers construction. The AFM results showed that the surface of fibers were covered with starch, which was consistent with deposition of polyelectrolyte multi-layers (PEMs). The surfaces of the LbL-treated fibers were rough in comparison with untreated fibers. The optimization of mechanical parameters using RSM indicated that refining time significantly affected the paper’s mechanical properties. The property values of 44.5 N.m/g tensile index, 149 J/m2 Scott bond, 32 mN RCT, and 245% strain at break were achieved at optimal conditions of 16 min refining time and the addition ratio of 17.6% LbL treated pulp respectively. [ABSTRACT FROM AUTHOR]

The pulp and paper industry growingly paid attention to the recycling and maintenance of waste paper products. Each paper-making cycle would lead to a sharp drop in the mechanical properties of the cellulosic paper, which was related to the hornification effect. Here, the recycling performance of the holocellulose paper was studied, compared with that of the cellulosic paper. Holocellulose fibers from sisal were fabricated by a gentle delignification method, and the well-preserved cellulose and hemicellulose components hindered the cocrystallization and aggregation of cellulose fibril. Holocellulose paper exhibited much more favorable recycling properties, compared with cellulosic paper. After 5 runs of recycling, holocellulose paper still shown an ultimate strength as high as 25 MPa (reduced from 35 MPa), a decrease of 28.6%. However, cellulosic paper experienced a substantial loss in ultimate strength from 35 MPa to 9 MPa, a decrease of about 74.3%. This can be attributed to the core-shell structure from cellulose and hemicellulose to weaken the hornification effect. [Display omitted] • Sisal-based holocellulose paper possessed excellent recycling performance. • After 5 runs of recycling, the ultimate strength of holocellulose paper only showed a decrease of 28.6%. • Hemicellulose acted as a protective shell to weaken the hornification effect of cellulose. [ABSTRACT FROM AUTHOR]

• The waste paper is transformed into Aggregates of Waste Paper (AWP). • New biocomposite based on the Aggregates of Waste Paper and Lime (AWPL) is formulated and characterized. • The microstructure of the new composite AWPL is characterized by high open porosity. • The thermal conductivity of the material AWPL are ranging between 0.097 and 0.012 W/mK. • The compressive strength of the material AWPL is ranging between 4.2 and 10.95 MPa. • The new material AWPL can be used as structural material and thermal insulation. In the aim of the valorisation of waste paper, an experimental study of a new biocomposite (AWPL) dedicated to building based on Aggregates of Waste Paper and Lime is performed. The waste paper used in this work is transformed to Aggregates of Waste Paper (AWP), the physical, thermal and morphological properties were carried out. Five combinations of (AWP – Lime) have been prepared and the weight ratios of lime used are 20, 30, 40, 50, and 60 wt% correspond. Experimental investigations of physical, mechanical, thermal and morphological characterizations of AWPL were carried out in order to determine: the apparent density, the open porosity, the water absorption, the ultrasound pulse velocity, the flexural and compressive strengths and the thermal conductivity. Furthermore, a characterization by Scanning Electron Microscopy (SEM) was realized to observe the AWP/lime bond. The results of characterization of AWPL show good mechanical properties as flexural and as compressive, these results are confirmed by the analysis SEM, that shown good adhesion of the AWP/Lime interface. The thermal characterization tests of AWPL have shown an important thermal insulation capacity linked to the low values of the thermal conductivity, these low values can be explained by the high porosity of AWPL. As a result, the AWPL could be classified as a structural and thermal insulation material for buildings according to the RILEM classification. [ABSTRACT FROM AUTHOR]

In this research, an environmentally friendly and biodegradable cationic starch (CS)/nanocrystalline cellulose (NCC) nanocomposite coating was produced and it was applied to improve the mechanical, barrier and physical properties of packaging kraft paper via surface coating. The mechanical and barrier properties of the paper were affected by the CS/NCC nanocomposite coating and it was the subject of investigation. CS/NCC nanocomposites were prepared by the solvent method. Structural and morphological properties of the nanocomposite were studied by FESEM and TEM observation. Results showed that the increased NCC nanoparticles loading, increased the tensile strength, oil resistance and air resistance of the coated paper. Also, the water absorption of the coated paper decreased 50% at 5 wt% NCC concentration. In our study it was concluded that the optimized amount for the NCC nanoparticles (among, 3 wt%, 5 wt%, and 7 wt%), is 5 wt%. The CS/NCC nanocomposite coatings are then proposed as a favorable booster which intensifies the mechanical and barrier properties of the paper in the food packaging application. • Environmentally friendly and biodegradable cationic starch (CS)/nanocrystalline cellulose (NCC) nanocomposite was produced. • Paper surface coating with CS/NCC nanobiocomposite improved its strength and barrier properties. • Increasing of NCC concentration improved paper sheet properties. • Optimum concentration of NCC to achieving the best properties in paper sheet was 5 wt%. • FESEM images showed the filled pores on the paper surface after nanocomposite coating. [ABSTRACT FROM AUTHOR]

Incorporation of nanofillers into a polymeric matrix has received much attention as a route to reinforced polymer nanocomposites. In the present work, an environmentally friendly chitosan (CTS)/titanium dioxide (TiO 2 ) nanocomposite coating was designed/prepared and subsequently employed for imparting antibacterium and improved mechanical properties to cellulosic paper via surface coating. Effect of TiO 2 nanoparticle loadings on the rheological behavior of nanocomposite coatings was investigated. Surface application of CTS/TiO 2 nanocomposite coatings to cellulosic paper was performed, and the antibacterial activity and mechanical properties of surface-coated cellulosic paper were examined. Results showed that the increased TiO 2 nanoparticle loadings decreased the viscosity and dynamic viscoelasticity of the as-prepared coatings, and improved the antibacterial activity and mechanical properties of surface-coated cellulosic paper. The optimum loading of TiO 2 nanoparticles was identified at 10%. This work suggested that CTS/TiO 2 nanocomposite coatings may have the potential to be used as a promising antibacterial protective coating for paper packaging. [ABSTRACT FROM AUTHOR]

This study focusses on the in-situ production of bacterial cellulose in recycled pulps to increase the quality of fibers in the suspension. The effect of different dosages of the upgraded pulp on the mechanical, physical and optical properties of handsheets was assessed. Papers produced with pulps cultivated in agitation exhibited increments in both tensile and tear indexes of 12.2% and 14.2%, respectively. Thus, flexibility of the paper was also improved. On the other hand, pulps enhanced with static culture fail to improve tensile index of paper, while tear index was increased by 12.4%. The production mechanism for both types of culture was proposed. In agitated culture, bacteria were found to coat the primary fibers, improving their quality. In the case of static culture, heterogeneous systems were observed since recycled fibers tended to sediment while bacteria moved to the surface of the culture broth in search of oxygen. Hence, the in situ production of BC with recycled fibers can, therefore, be an alternative to replace conventional paper strengthening agents. The results attained indicate that the in-situ production of upgraded pulps can be implemented in paper mills cultivating pulp streams sterilized through low cost, non-exhaustive operations, such as ozone or ultraviolet radiation. [ABSTRACT FROM AUTHOR]

The integrity of materials containing packaging (natural or synthetic polymers) is essential to keep the aseptic condition of commercialized products (health care products, food and pharmaceuticals). The objective of this paper was to study gamma radiation effects (25 kGy, 40 kGy and 50 kGy) on the main properties of paper and multilayer films (polyester and polyethylene). Paper and multilayer films are components of packaging (pouches) for radiation sterilization containing medical equipment or products. Paper was the more radiation sensitive among the studied materials and radiation effects were more pronounced at brightness, pH, tearing resistance, bursting strength and tensile strength. Concerning plastic film, no pinholes were induced by radiation and the effects on the tensile strength were not significant. Although the seal strength packaging (pouches) decreased according to increasing dose, the sealing integrity was preserved. [ABSTRACT FROM AUTHOR]

Abstract: Biopolymers have the potential to serve as coating materials for paper to improve its performance properties. The objectives of this study were to determine the effect of hydroxypropyl methylcellulose (HPMC), glycerol (Gly) and beeswax (BW) coatings on the physical properties and water vapor permeability (WVP) of coated papers. It was found that HPMC coated paper showed significant differences on physical properties, compared with uncoated (p ⩽0.05). Folding endurance of HPMC-based coated papers greatly increased which indicated improved durability of coated paper. Moreover, HPMC-based coated papers increased in stretch and decreased in tensile index. HPMC-based coatings reduced WVP and further reduction was obtained when beeswax was incorporated in the HPMC-lipid composite coated paper. Paper coated with hydrocolloid and lipid can be used to produce packages with the potential to be used to maintain agricultural produce quality for the food industry, and may have other applications (i.e., medical packaging). [Copyright &y& Elsevier]

• Waste tissue paper was successfully utilized for the preparation of WTP-PVA CAs. • The WTP-PVA CAs displayed low density and superior mechanical properties with specific Young's modulus 1246.8 MPa cm3 g−1. • The WTP-PVA CAs showed good electrical and thermal properties. • The average EMI shielding effectiveness of WTP-PVA is ~40.8 dB with an absorption-dominant shielding feature. • WTP-PVA CAs showed considerable capacity to CO 2 adsorption with excellent selectivity and recyclability. Carbon aerogels (CAs) have always shown great potential for multifunctional applications. However, simultaneous improvement of mechanical, electrical and thermal properties of CAs with low density is still a big challenge due to their structural defects, disordered microstructure, and colossal oxygen containing functional groups. Herein, a subtle approach is developed to prepare CAs from waste tissue paper (WTP) and poly(vinyl alcohol) (PVA) as the basic ingredients. The WTP-PVA CAs possessed a highly interconnected three-dimensional porous structure with low density (0.057 g cm−3), high porosity (~97%) and specific surface area (1384 m2 g−1). Albeit with low density, the resultant CA displayed superior mechanical properties (specific Young's modulus up to 1246.8 MPa cm3 g−1) and thermal stability. Besides, they also featured high electrical conductivity (1.35 S cm−1) and low thermal conductivity (0.087 W m−1 K−1). These properties provided an opportunity for some advanced applications such as electromagnetic interference (EMI) shielding and CO 2 gas capture. The highest shielding effectiveness (SE), specific SE and thickness-averaged specific SE of WTP-PVA in the X-band are 40 dB, 700 dB cm3 g−1 and 1818 dB cm2 g−1 respectively, with an absorption-dominant shielding mechanism. More importantly, the WTP-PVA CA with abundant ultramicropores showed great potential for CO 2 adsorption (5.14 mmol g−1 at 0 °C) with good selectivity and regeneration capability even without the aid of any chemical activation, functionalization or heteroatom doping. [ABSTRACT FROM AUTHOR]

To obtain high dispersion and good mechanical properties, the incorporation of cellulose in non-polar polymeric matrices is usually carried out with chemical modification of precursors or addition of compatibilizers. Despite the great advances in increasing stiffness, the resulting composites generally have their deformation compromised (dramatic decrease in ductility in comparison with neat polymer). Here, from polyethylene films and thin paper sheets, composites that combine high rigidity and high ductility were obtained by hot pressing, without additional steps or compatibilizers. The use of a structured reinforcement (low grammage paper) to prepare the composites allowed: (a) obtaining a good fiber distribution in the matrix; (b) achieve an architecture for composites that enables high deformation; (c) use of mild processing conditions; (d) obtaining via continuous processing by a heated cylinder system. The low grammage paper – PE composites exhibited a considerable increase in modulus (up to 90%) and high ductility. Therefore, as a consequence of the (i) rigidity and ductility, (ii) low price of precursors and (iii) possibility of processing by a simple and practical method, these composite films have potential industrial application (as in tarpaulins and geomembranes). [Display omitted] • Ductile composite films of cellulose fibers well distributed in the polyethylene matrix. • Microstructure containing thin sheets of paper separated by matrix portions. • Matrix presents between the fibers of the sheet prevents pores from coalescing. • Matrix layers between paper sheets prevent pores from growing towards the surface. • Processing on a system of heated rolls. [ABSTRACT FROM AUTHOR]

In this study, the multifunctionality of structural dielectric capacitor made by integrating graphene oxide paper into carbon fibre reinforced composite has been investigated. The study is based on an earlier work on the use of graphene oxide for dielectric material in the structural dielectric capacitor, in which electrical properties have been characterized. In this work, an in-depth study on electrical and mechanical properties of this kind of structural dielectric capacitor have been carried out. In addition, the multifunctional efficiency of structural dielectric capacitors were evaluated and compared with existing structural dielectric capacitors. Through experiments, it is revealed that both electrical and mechanical properties of the structural dielectric capacitors were significantly enhanced by interleaving a graphene oxide paper in the middle of composite. Therefore, the multifunctional efficiency of this kind of structural dielectric capacitors has been ultimately improved, indicating the excellent potential of graphene oxide paper in the development of multifunctional materials for energy storage, potentially for high-strength required applications, such as electric vehicles and unmanned aerial vehicles. [ABSTRACT FROM AUTHOR]

On being exposed to water, cellulose paper swells and its mechanical properties become weak. In this study, natural wax with an average particle size of 12.3 μm extracted from banana leaves was mixed with chitosan to prepare coatings applied on paper surfaces. Chitosan efficiently dispersed banana leaf-extracted wax on paper surfaces. The mixed chitosan and wax coatings considerably influenced paper properties, including yellowness, whiteness, thickness, wettability, water absorption, oil sorption, and mechanical properties. The coating induced hydrophobicity in the paper, resulting in a significant increase in the water contact angle from 65.1 ± 7.7° (uncoated paper) to 123.2 ± 2.1°, and a decrease in water absorption by ⁓64 % to 52.6 ± 1.9 %. The coated paper demonstrated an oil sorption capacity of 212.2 ± 2.8 %, which was ⁓43 % greater than that of the uncoated paper (148.2 ± 5.5 %), and the tensile strength of the coated paper improved under wet conditions compared to the uncoated paper. Additionally, a separation of oil in water was observed for the chitosan/wax coated paper. Based on these promising results, the paper coated with chitosan and wax could be used for direct-contact packaging applications. [Display omitted] • Wax was successfully extracted from banana leaves. • Chitosan efficiently dispersed banana leaf-extracted wax on paper surfaces. • Water-resistant paper was developed by application of the chitosan and wax coatings. • The hydrophobic and oleophilic paper potentially separated oil from water. • The paper coated with chitosan and wax could be used for direct-contact packaging. [ABSTRACT FROM AUTHOR]

Bio-based materials offer tremendous contributions by replacing conventional fossil-based products for a more sustainable society. The aim of the current study was to study the effect of crosslinked starch (CST) and poly (vinyl alcohol) (PVA) on the properties of cellulose foam papers prepared by compression molding. Several experimental techniques were applied to characterize prepared foam materials, including SEM, contact angle, thermogravimetric, mechanical, and barrier analysis. The chemical structure of the foam papers were analyzed using FTIR and XRD spectroscopy. The crystallinity of the foam papers increased from 75.8% for cellulose foam papers to 79.3% for CST/PVA reinforced cellulose foam papers. The tensile test results indicated that the addition of CST/PVA improved the mechanical properties of the foam papers. The tensile strength increased from 0.9 MPa for neat cellulose foam to 9.9 MPa for the CST/PVA reinforced cellulose foam papers. Therefore, the materials developed in this work can be a viable ecological alternative to replace the non-biodegradable polystyrene foam trays used in single-used food packaging containers. [Display omitted] • Foam papers based on cellulose and CST/PVA were produced using compression molding. • The addition of CST/PVA improved the mechanical performance of the cellulose matrix by reducing the pore sizes. • The dispersed CST/PVA addition cooperated to improve the cellulose matrix's crystallinity, thermal, and barrier properties. • Developed foam papers could be used for packaging dry foods in supermarkets. [ABSTRACT FROM AUTHOR]

A series of hydroxypropyl cellulose (HPC)/oxidized cellulose nanocrystals (OXCNC) nanocomposites films was prepared via casting and evaporation. OXCNC was used in ratios from 2.5 to 20% in HPC matrix. The prepared nanocomposites films were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic mechanical thermal analysis (DMTA), tensile strength properties (TS) and water vapor permeability (WVP). Significant increase in the crystallinity and tensile strength accompanied by an increase in WVP of HPC films occurred as a result of adding OXCNC. HPC/10% OXCNC film was found to possess the maximum tensile strength properties and that composition was chosen for coating bagasse paper sheets. Coating of paper sheets increased TS, WVP and decreased porosity of the paper sheets. The slight increase in WVP of the films and the coated paper sheets was attributed to the hydrophilic nature of OXCNC. [ABSTRACT FROM AUTHOR]