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A simple approach was developed to fabricate high‐performance MXene/cellulose (MC)‐based electromagnetic interference (EMI) shielding papers. The oriented MXene sheets located on one side of cellulose filter paper construct a continuous conductive layer, endowing the MC paper with high electrical conductivity (240.1 S/m) and excellent EMI shielding effectiveness (29.3 dB for 0.192‐mm thickness) at an MXene content of 0.72 vol%. Moreover, the EMI shielding effectiveness of four stacked MC papers reached 40.5 dB. This result means that 99.9911% of the microwave radiation is attenuated, and 0.0089% is transmitted, through the four‐piece MXene/cellulose filter papers. Therefore, MC paper has promising properties for excellent EMI shielding materials in current electronic devices. [ABSTRACT FROM AUTHOR]

The application of traditional cellulosic paper is limited because of its flammability, so it is necessary to explore new materials that can be used in the field of flame‐retardant paper. Based on the synergistic effect between fibers, flame‐retardant lyocell (FRL) and calcium alginate (FRL/Ca‐Alg) composite paper is prepared by a simple but efficient method. The thermal degradation process of the composite paper is analyzed by thermogravimetric (TG) and TG analysis coupled with Fourier transform infrared, the flame retardancy of the composite paper is analyzed by vertical flammability (VF) tests, limiting oxygen index test and cone calorimetry test, and the morphology of the residue after VF tests is observed by scanning electron microscopy. It is found that, the Ca‐Alg releases a large amount of CO2 before ignited, which delayed the ignited time of the composite paper; FRL reduces the effective combustion heat of composite paper during combustion, and the compact char formed by FRL effectively inhibits the smoldering of Ca‐Alg in the end stage of combustion. Based on these, the synergistic flame‐retardant effect of composite paper is proposed. [ABSTRACT FROM AUTHOR]

Reported herein is an economical, plastic‐ and fluorine‐free coating approach for oil and water repellent paper substrates using blends of poly(vinyl alcohol) and chitosan‐graft‐polydimethylsiloxane copolymer. The obtained coated paper showed good water‐resistance, as evidenced by its low Cobb60 values of ~20 ± 2.1 g/m2 and high water contact angles of 119 ± 6.3 °. The kit rating of the coated paper was 7.6/12, indicating decent grease‐resistant properties as compared to the kit value of 0/12 for the uncoated paper. The coated paper is also repulpable as demonstrated by the complete washing off the coating from the coated paper. Giving the cost‐effective nature of the coating materials and good water and oil‐resistant properties of the coated paper, the approach developed here is commercially viable, and will offer a multitude of environmental benefits such as the elimination of microplastic‐ and PFAS problems associated with existing paper coatings. [ABSTRACT FROM AUTHOR]

Although styrene acrylate emulsions (SAE) have demonstrated promising applications as surface sizing agents for paper, their strengthening effect on pulp fibers in papermaking is not clear. In this study, bagasse fibers, an agricultural waste, were treated with SAE to study the influences on the mechanical properties of the produced papers. SAE copolymers with hard chain (H‐PSA) and soft chain (S‐PSA) were prepared and added to bagasse pulp slurry at concentrations of 1%–4% by weight. The findings indicated that for the soft and hard copolymers, the glass transition temperatures were 19.5 and 26.8°C and their emulsion particle sizes were 166 and 182 nm, respectively. The copolymers strengthened the produced paper by wrapping around and forming a network of chemical and physical bonds with the pulp fibers. Papers treated with 3% H‐PSA exhibited the optimum improvement in tensile strength (38 MPa) and breaking length (67 m) by 13% and 64%, respectively. Treated papers were negatively affected by UV radiation due to phenyl groups spread along the chains. The copolymers demonstrated good wet‐strength properties achieved by self‐ and co‐crosslinked networks. The prepared paper sheets showed a preference for the mechanical properties of treated samples over the untreated ones. [ABSTRACT FROM AUTHOR]

Acid‐catalyzed hydrolysis of glycosidic bonds is the most important degradation mechanism affecting cellulose‐based materials. It results in the decrease of DP and in the loss of the original mechanical properties. The neutralization of acidity is therefore one of the most efficient ways to hamper the degradation of cellulosic artworks. However, in the case of acidic and strongly degraded artifacts, in addition to deacidification, a consolidation treatment must be performed. To this aim, a new class of biopolymers, obtained by a synthetic procedure that considers the principles of Sustainable Chemistry, was investigated. Three allyl saccharide/vinyl acetate copolymers, having different molar ratios between starting monomers, were prepared using α,α'‐trehalose, and used to synthesize the corresponding allyl saccharide/vinyl alcohol copolymers. The use of saccharide derivatives as monomers improves the affinity and compatibility of the biopolymer with the artifacts to be treated. After characterization, the efficacy of the copolymers in the strengthening of degraded paper was evaluated with mechanical tests. The most effective system was thus selected for further testing. Its performance was compared to that of Klucel G®, a commercial product belonging to the class of cellulose derivatives, which are largely used in conservation practice. [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]

ABSTRACT Waterborne UV-curable polyurethane (UWPU) dispersions with different hydrophilicity and functionalities were prepared by varying the content of dimethylol butanoic acid (DMBA) and pentaerythritol triacrylate (PETA). And linear and cyclic chain extenders with different functionalities were also incorporated into the UWPU backbone, including isophorone diamine (IPDA), diethylene triamine (DETA), and ethylene diamine (EDA). Effects of DMBA content, PETA content, photoinitiator content, UV curing time, chain extender on the properties of UWPU dispersions and films, as well as the properties of the unsized and sized paper were investigated. The water resistance and mechanical properties of sized paper were greatly relied on the particle size, the molecular weight, the croslinking density, and penetrability of UWPU. UWPU dispersion chain extended with IPDA (IPDA-UWPU) displayed smaller particle size than that of UWPU. The paper sized with IPDA-UWPU was endowed with best water resistance, tensile strength, folding strength and surface strength. XPS depth analysis revealed that IPDA-UWPU exhibited better penetrability into the paper substrate than UWPU. SEM and AFM demonstrated that the smoothness of sized paper was improved, and the bond strength between fibers was enhanced. The obtained UWPU could be directly used as an effective and fast drying surface sizing agent for cellulose fiber paper. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42354. [ABSTRACT FROM AUTHOR]

ABSTRACT Cationic polyacrylamide with different molecular weights were used to preflocculate the lime mud (LM) before it was added to the paper stock for handsheet preparation. The particle sizes, ζ potential, and morphology of the unpreflocculated and resulting preflocculated LM were studied. We found that high-molecular-weight cationic polyacrylamide (H-CPAM) led to larger LM flocs with a more positive ζ potential. The scanning electron microscopy images indicated that the morphological structure of the filler hardly changed during the preflocculation process. The effects of the preflocculation on the filler retention and paper properties were also investigated. The results show that the handsheets filled with preflocculated LM had better hydrophobicity and strength properties compared to handsheets filled with unpreflocculated LM, especially for H-CPAM-preflocculated LM. The paper formation was also improved, and the optical properties nearly remained the same. In addition, the LM preflocculated with H-CPAM had the highest filler retention. At a filler loading of 30%, the filler retention of the H-CPAM-preflocculated LM was higher than 86; it was less than 82.5% in other cases. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41640. [ABSTRACT FROM AUTHOR]

All‐cellulose composites (ACCs) were prepared by partially dissolving cellulose in the filter paper using NaOH/thiourea aqueous solution. The effects of dissolution time, thiourea ratio, and temperature on the properties of ACCs were investigated. ACCs were characterized by scanning electron microscope, attenuated total reflectance Fourier transform infrared spectroscopy, Raman spectroscopy, X‐ray diffraction, and tensile tests. The results revealed that the fibers in ACCs were tightly intertwined. The crystalline form of cellulose in ACCs was transformed from type I to type I/II mixture, and the crystallinity decreased from 77.32 to 51.40%. The tensile strength of ACCs was remarkably improved to 23.16 MPa. The results confirmed ACCs had a high potential for practical applications in the packaging field. [ABSTRACT FROM AUTHOR]

ABSTRACT Antimicrobial polyethylene wax (PEW) emulsions, prepared by emulsifying polyethylene wax grafted with polyhexamethylene guanidine hydrochloride (PEW-g-PHGH), were used as wet-end additives or coating materials for fabricating hydrophobic and anti-mold hand-sheets or paper. To obtain PEW-g-PHGH, maleic anhydride (MAH) was adopted as a bridging agent. The melt or solution grafting of MAH to PEW was performed to achieve the appropriate grafting degree and grafting efficiency. The resulting PEW-g-PHGH was emulsified using a homogenizer by means of surfactants, and the resulted emulsions were characterized in terms of particle size, zeta potential, charge density, minimal inhibitory concentration (MIC), and adsorption capacity. After that the hydrophobicity of emulsion treated hand-sheets was determined by measuring water contact angle (WCA). The morphology of the hand-sheets treated by the emulsion was revealed using scanning electron microscope (SEM) and atom force microscope (AFM). Finally, the antimicrobial properties of the emulsion treated hand-sheets were investigated by anti-mold tests against Aspergillus niger and Chaetomium globosum. Results indicated that the PEW-g-PHGH emulsions exhibited good stability, high fiber adsorption capacity, and antimicrobial activity. The WCAs of the treated hand-sheets reached 82°-140° with 80%∼99.9% growth inhibition against fungi. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42214. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for characterizing heat sealing processes in packaging machines, which identifies all appropriate and optimum sealing parameters subject to given quality criteria. The presented approach is distinct from established methods, such as heat seal curves or response surface plots, in three aspects: It provides an easy‐to‐read chart indicating optimum and appropriate settings of sealing temperature and dwell time, as well as process robustness for each parameter set. The data points of the charts are generated directly from experiments without using any regression model. The design of experiments features a determinate sequence of tests and no iterative loops are necessary. The approach stems from a 'trade‐off' model of heat sealing and a specific multi‐objective optimization method. This trade‐off model states that improving seam quality, reducing sealing temperature, reducing dwell time, and increasing process robustness are conflicting objectives. This hypothesis is deduced from a literature review and verified by experiments. The optimization method claims that all optimum sealing parameters are part of the solution of a multi‐objective optimization problem, the Pareto‐frontier. This hypothesis is elaborated into a design of experiments using the normal‐boundary‐intersection method, and is verified using a peelable seam and tear seam scenario. [ABSTRACT FROM AUTHOR]

Cement is known to be brittle and usually reinforced with fibers. However, there is a lack of effective chemical bonding between organic fibers and inorganic cement, resulting in a weaker interfacial bonding strength. In this paper, amino hyperbranched polymer (HBP) was used to modify the surface of polyacrylonitrile (PAN) fibers, and then silica nanoparticles (SiO2 NPs) were grafted on the surface of modified PAN fibers to realize the inorganic treatment of organic fibers. The modified PAN fibers applied to cement concrete can significantly enhance the interfacial strength between the fibers and cement. The morphology and chemical composition of the modified PAN fibers were characterized by scanning electron microscope, atomic force microscope, electron energy dispersive spectroscopy, and Fourier transform infrared spectroscopy, and the influence of grafting conditions on grafting effect was analyzed. The results show that SiO2 NPs were evenly distributed on the surface of PAN fiber. When SiO2 NPs concentration was 4%, grafting temperature was 50°C, and grafting time was 4 h, the grafting degree of SiO2 NPs grafted PAN fiber can reach to 1.4%. After coating with SiO2 NPs, the pullout bonding strength of the PAN fiber was increased from 5.5 to 6.5 cN. [ABSTRACT FROM AUTHOR]

The proposed paper presents the design of a leaky‐wave antenna inspired by holographic metasurfaces employing thin film. Leveraging the holographic principle, this metasurface showcases its transformative capacity by converting an omnidirectionally radiating monopole into a highly directional antenna emitting leaky waves. The holographic metasurface is constructed using a thin film of polyimide (PI) (Df = 0.008; Dk = 3.5), measuring 50 μm in thickness. The antenna structure comprises multiple layers, commencing with the top PI layer, succeeded by a 40 μm thick adhesive layer (Df = 0.004; Dk = 6). Subsequent layer includes the Rogers RT/duroid 5880 substrate (Df = 0.0009; Dk = 2.20), grounded at the bottom and has a thickness of 1.6 mm. The meticulously tailored design of the proposed antenna ensures optimal performance at 15 GHz, facilitating directional radiation and precise beam steering at 10 degrees (ϴ = 10°). This innovative design, incorporating the holographic metasurface on thin film, significantly enhances the antenna's performance, increasing gain from 1.5 dBi to 13.8 dBi. [ABSTRACT FROM AUTHOR]

This paper delves to improve the upper‐limit temperature of hydrogenated nitrile rubber (HNBR) through regulation of the vulcanization process, filler system and cross‐linking additive. The tensile test and scanning electron microscope images showed that the aging at 180°C significantly accelerated the deterioration in the property of HNBR compared with 150°C aging. The results showed that a higher dosage of bis(1‐(tert‐butylperoxy)‐1‐methylethyl)‐benzene curing agent reduced the compression set of HNBR without sacrificing its tensile strength. Carbon black N539‐filled HNBR exhibited high tensile strength, while carbon black N774‐filled HNBR showed high heat resistance and low compression set. When the HNBR sample was reinforced with 20 phr of N539 and 20 phr of N774 carbon black, it achieved low compression set, high tensile strength, and heat resistance simultaneously. Then, N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI) was introduced into the HNBR composite as a cross‐linking assistant agent. The residual strength of BMI‐modified HNBR was 20.3 MPa (the retention rate of 92.3%), and its compression set was as low as 19.2% after aging at 180°C for 72 h. Even after aging the composite at 180°C for 168 h, its strength retention rate remained at 83.2% (18.3 MPa). The approach provided here increased the upper‐limit temperature range of HNBR to 180°C. [ABSTRACT FROM AUTHOR]

In this paper, wound dressing materials made of silk fibroin (SF) and transgenic SF with Arg-Gly-Asp motifs (TG-RGD SF) were developed. Initially, an animal evaluation experiment with mice to demonstrate the usefulness of SF film as a wound dressing was performed. The amorphous SF film was shown to promote the formation of granulation tissue and neovessels in the dermis, leading to skin regeneration. As a result, amorphous SF film is suitable for use as a wound dressing materials. Then, the SF- Human umbilical vein endothelial cells signaling pathway was determined by cell proliferation assay with pharmacological inhibitors. Subsequently, a mice evaluation experiment to assess the promotion of healing effects using TG-RGD SF was conducted and the results were compared with those obtained using SF. In the wound area evaluation and the quantitative evaluation of granulation tissue formation, the TG-RGD SF film promoted dermis regeneration more than the SF film. [ABSTRACT FROM AUTHOR]

The conventional filtration loss reducers, which help reduce the invasion into the formation, often make the rheology of the oil‐based drilling fluid difficult to control. In this paper, the new type of porous deformable polymeric particle was synthesized as filtration loss reducer (FLR), through dispersion polymerization using acrylamide and stearyl methacrylate. Fourier transform infrared spectroscopy, differential scanning calorimeter, thermogravimetric analysis, contact angle apparatus, nitrogen adsorption/desorption techniques and scanning electron microscope have been carried out to confirm the chemical structure of the FLR. The results illustrated that FLR is a hydrophobic porous solid particle with deformability. The oil‐based drilling fluid loaded with FLR retains high temperature resistance up to 180°C and the density of 2.2 g/cm3. The FLR help reduced the filtration loss to 3.2 mL, smaller than their counterparts, and synthesized FLR has small impact on the rheology of drilling fluids. [ABSTRACT FROM AUTHOR]

In recent years, the packaging industry has utilized electronic packaging materials with epoxy resin (EP) and high‐performance fillers, exhibiting superior mechanical properties and thermal conductivity. Spherical silica micro‐powder (SSP) is a critical thermal conductive filler but faces challenges due to its inorganic nature. Surface modification is essential to improve SSP's compatibility and dispersion in organic matrices for effective use in EP‐based composites. In this paper, the effects of the following four modification methods on SSP/EP composites were studied: (1) the processes include co‐modification with dimethyldimethoxysilane (DMDMS) and trimethylethoxysilane (MTES), (2) modification with NaOH, (3) co‐modification with DMDMS and MTES in an alkaline environment after NaOH modification, and (4) co‐modification with methyltrimethoxysilane (MTMS) and propyltrimethoxysilane (PTMOS). Through comprehensive characterization and evaluation, it is evident that modification schemes 1, 3, and 4 significantly enhance SSP's hydrophobicity, dispersibility, and compatibility with EP. This led to the improvement of thermal conductivity and stability of the composite, and modification scheme 4 showed the highest enhancement, with a 42.6% increase in thermal conductivity. Moreover, the mechanical properties of modified composite materials, such as bending strength, impact resistance, and tensile strength, surpass those of unmodified SSP/EP composite materials. The study provides valuable insights for reducing manufacturing costs and enhancing productivity in the electronic packaging sector. [ABSTRACT FROM AUTHOR]

Shrinking resources of fossil oil prompt search for other biosphere‐present substrates to obtain polyols, which in turn are basic components to synthesize polyurethane foams (PUF). Widely available examples are biopolymers like starch, cellulose, and chitosan. It has been shown that oligomeric chitosan as well as water soluble chitosan can be applied to obtain polyols and rigid PUF of good performance properties. In this paper, the higher molecular mass chitosans, insoluble in organic solvents and water, were converted to polyols and ultimately into foamed polyurethane plastics. The polyols were characterized by the infrared spectra (IR), 1H‐NMR, and MALDI‐ToF methods. Their properties, such as density, viscosity, surface tension and hydroxyl numbers, were determined. The PUF were obtained from these polyols of various molecular mass. The biodegradable, rigid PUF of enhanced thermal resistance were obtained. Their physical parameters like apparent density, water volume absorption, dimension stability, heat conductance, compressive strength, and heat resistance at 150 and 175°C were studied and compared with those synthesized previously from oligomeric chitosan and water soluble chitosan. [ABSTRACT FROM AUTHOR]

The "all in one" multifunctional and concentrated daily chemical products are required by the market, such as the long‐term release of anti‐bacterial, medical, or perfume agents. These functions mainly rely on the microcapsules, which could encapsulate these functional and unstable molecules, and then release them in the long term. To stabilize these functional solid particles in a high‐content surfactant, it is necessary to add a suspending rheological modifier. The poly(acrylic acid) (PAA)‐based rheology modifier is one of the most common additives in the industry of daily chemicals, for thickening or suspending. In this paper, linear PAA, and branched PAA polymers (Carbomer 941 and Carbomer 940) were selected to study the suspending ability of PAA‐based rheology modifier in high‐content surfactant and to investigate the effect of PAA polymer structure and Mw on the complex solution's rheological properties. The yield and viscosity test of the complex solutions of linear PAA and high‐content surfactant revealed that the addition of linear PAA could lead to lower yield stress and viscosity, and failed to suspend the polystyrene (PS) model microspheres due to its smaller mean square radius of gyration. The branched PAA polymer, Carbomer 940 and Carbomer 941 were more stable than the linear PAA in these two kinds of surfactant. More specifically, Carbomer 940 with a higher Mw, would exhibit higher yield stress and viscosity than Carbomer 941 with a lower Mw in nonionic surfactant alcohol polyoxyethylene ether (AEO) solvent with content less than 5 wt%. When the content was higher than 5 wt%, Carbomer 941 presented higher yield stress and viscosity than Carbomer 940, and successfully suspended PS microspheres in the 20 wt% AEO solution. This could depend on the polymer chain's elongation state of these two PAA‐based branched rheology modifiers. The same trend happened in the appearance of Carbomer 940 and Carbomer 941 in alcohol ether sulphate (AES) solution. However, the electrostatic repulsive force between the AES and PAA‐based rheology modifier could further make the polymer chain curl up and restrain the suspending ability in a lower content surfactant solution. Therefore, this fundamental research could guide the application of the anionic polyelectrolytes in the concentrated daily chemical product for stable suspending particles. [ABSTRACT FROM AUTHOR]

The recycling of petroleum‐based polymers such as polypropylene (PP) and polyethylene (PE) is an effective means of reducing environmental pollution. However, the incompatible PP and PE blended waste is difficult to separate accurately, which reduces the quality of the recycled material. In this paper, the trifunctional acrylate monomer (trimethylolpropane triacrylate), peroxide (2,5‐dimethyl‐92,5‐di[tert‐butylperoxy] hexane) and free radical activity modifier (zinc dimethyldithiocarbamate) were applied to in situ generate the copolymer of isotactic polypropylene and high‐density polyethylene (iPP‐co‐HDPE) with a long‐chain co‐branched structure via a melt blending method. The co‐crystallization of the branched copolymer chain segments with the chemical identical homopolymers vastly improved the compatibility of iPP and HDPE components. This in situ co‐branching compatibility strategy resulted in a significant improvement in the mechanical properties of PE and PP mixed wastes. The temperature gradient extraction method was used to separate the co‐branching modified iPP/HDPE blends. The results confirm that the separated iPP‐co‐HDPE components have a highly co‐branched structure. The significant improvement in compatibility resulted in a large increase in elongation at break and impact strength of the iPP/HDPE blends, which provides an economic and effective method for the recycling of mixed PE and PP wastes. [ABSTRACT FROM AUTHOR]

The bottleneck problem of the development of high‐voltage motors to a larger capacity can be solved if the thermal conductivity is improved without sacrificing the insulation characteristics of the main insulation material. In this paper, a spraying technology based on electrospinning is proposed that can evenly spray boron nitride (BN) with high thermal conductivity onto the surface of mica tape. With the increase in BN content, the insulation and thermal conductivity of mica tape are optimized to varying degrees. When the BN content reaches 2.25 wt%, the in‐plane conductivity increases from 1.6 to 2.7 w/(m K), while the out‐of‐plane conductivity increases from 0.17 to 0.26 w/(m K). Additionally, the direct‐current (DC) breakdown strength has increased from 90.6 to 96.9 kV/mm and the dielectric constant and dielectric loss are almost unchanged. Finally, through simulation verification, if the modified mica tape is applied to the main insulation of a synchronous motor, the operating temperature of the motor insulation will be reduced from 73.5 to 66.1°C. This study provides a new research idea for the preparation of high thermal conductivity insulating materials. [ABSTRACT FROM AUTHOR]

A novel nanocomposite leather‐finishing agent (denoted as H‐TiO2@SDS‐rGO/F‐PBMA) composed of fluorinated copolymer (denoted as F‐PBMA) matrix using methyl methacrylate (abbreviated as MMA), butyl acrylate (abbreviated as BA) as well as acrylic acid (abbreviated as AA) as monomers and H‐TiO2@SDS‐rGO composite nanoparticles as nano‐additives were successfully fabricated by aqueous emulsion polymerization in this paper. The hollow TiO2 nanoparticles (denoted as H‐TiO2) were firstly prepared with tetrabutyl titanate as titanium source wall and tetraethyl silicate as silicon source core through an alkali etching method, and then they were compounded with reduced graphene oxide (rGO) modified by sodium dodecyl sulfate (denoted as SDS‐rGO) for obtaining H‐TiO2@SDS‐rGO composite nanoparticles. Fourier transform infrared spectra, X‐ray diffraction, Raman spectra, scanning electron microscopy, and nuclear magnetic resonance spectra were used to characterize the structure and morphology of different samples. The experimental results reveal that the nanocomposite leather‐finishing agent not only has excellent transparency, but also endows sheepskin better weather resistance, thermal stability, hydrophobicity and mechanical properties compared with traditional leather finishing agents. [ABSTRACT FROM AUTHOR]

Polyoxymethylene (POM), as an energy‐saving material, is widely applied in the manufacturing field. Yet, research on the rectangular clinching process between metal and POM sheets is still lacking. In this paper, the rectangular clinching process for POM and Al5052‐H32 plates was investigated. The feasibility of the metal–polymer hybrid component had been analyzed in terms of diverse forming forces and diverse joint layout angles, respectively. The mechanical characteristics were appraised by the lap‐shear test. The failure modes of rectangular clinched joints produced under diverse forming conditions had also been analyzed. The results showed that the optimal forming force of rectangular clinched joints was 14 kN, in which the lap‐shear strength was 1090 N. Furthermore, the rectangular clinched joints produced under the joint layout angle of 90° could withstand the maximum lap‐shear load (1415 N) under the optimal forming force. The failure mode was the separation of two plates and the fracture of the bridge structures. [ABSTRACT FROM AUTHOR]

According to the infrared stealth mechanism, controlling the surface temperature of objects can effectively hide the infrared radiation and resist the infrared detection. In this paper, a high infrared transparent polymer ultrahigh molecular weight polyethylene (UHMWPE) is selected as the matrix of a thermal insulation material. UHMWPE porous films with high porosity and hybrid pore structure are obtained through the thermal induced phase separation combining with particle leaching method. The film structures with micropores and macropores are adjusted through the variation of the mass ratio of UHMWPE/liquid paraffin, the dosage and the particle size of NaCl. The thermal conductivity of the UHMWPE film is as low as 0.034 W/(m K), while the density is only 54.4 mg/cm3. The classical Maxwell‐Eucken model is used to discuss the relationship between the pore structure and the thermal conductivity of the films. It is determined that the hybrid porous structure can reduce heat conduction and gas–solid coupling effect simultaneously, thus the thermal conductivity is significantly reduced. Moreover, the porous films exhibited remarkable flexibility and hydrophobicity. Based on these properties, the porous films are highly promising in the field of thermal insulation protection and infrared stealth. [ABSTRACT FROM AUTHOR]

Poly(l‐lactic acid) (PLLA) has been widely used in constructing biodegradable braided stents due to high biocompatibility and biodegradability. However, poor mechanical properties of this stent are main weaknesses. In this paper, the mechanical properties of PLLA braided stents containing axial stiffeners were evaluated. The stents with stiffener diameters of 0.11, 0.19 and 0.28 mm are named SS11, SS19 and SS28, respectively, and the stent without stiffener is named SS00 as control. The results show that compared with SS00, the bending stiffness of SS11, SS19 and SS28 is increased by 0.77, 1.76, and 2.70 times, respectively. Meanwhile, chronic outward force at an indicated use diameter of 5 mm is increased by 0.83, 0.50, and 0.21 times, but elastic recovery rate is decreased by 5.6%, 14.6%, 22.5%. In addition, radial stiffness of SS11, SS19, and SS28 are increased by 2.81, 2.08 and 1.62 times, respectively. Therefore, the radial support performance is improved and the bending flexibility is weakened by adding stiffeners. Taken together, SS11 can provide sufficient radial support force and low axial force in clinical applications. This study may provide a reference for optimizing the mechanical properties of the biodegradable braided stents. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane (TPU) has become the focus of attention in the green and sustainable materials field because of its superior processability and recyclability. In this paper, a series of polylactic acid (PLA) and polycaprolactone (PCL)‐based TPUs were successfully prepared by selecting PLA glycol, PCL glycol, isophorone diisocyanate (IPDI) and 1,4‐butanediol (BDO) through a one‐step polymerization method. The properties of the PLA and PCL‐based TPUs are comprehensively characterized by Fourier transform infrared spectroscopy, 1H NMR spectra, gel permeation chromatography, differential scanning calorimetry, thermalgravimetric analyzer, tensile test, dynamic mechanical analysis, scanning electron microscope, and so forth. The effect of hard segments content and PLA glycol molecular weight on the properties of PLA and PCL‐based TPUs was systematically studied. Notably, their performance shows a certain degree of regularity and can be controlled by adjusting the hard segments content or the molecular weight of the PLA glycol. The prepared PLA and PCL‐based TPUs have a tensile strength of 24.71 MPa, excellent thermal stability and out‐standing damping performance. Its tan δ max of 1.40 and an effective damping temperature range of 50°C also make it a green damping material with great potential. [ABSTRACT FROM AUTHOR]

The modification of plastics to generate germ‐reducing surface materials is a promising strategy to decrease nosocomial infections in hygiene‐sensitive areas. In this paper, photocatalytically active nanoparticles were incorporated as additives, not as a coating, into silicone rubber matrix material to produce elastic antibacterial bulk materials. Samples with 5 wt% and 10 wt% of two different types of TiO2 and ZnO were prepared and investigated. The thermal analysis of the developed materials showed a complete vulcanization of the developed materials and slight modifications of mechanical properties were found. Investigations of the surface of the materials indicated no changes in the wettability of the surfaces or in their fourier transform infrared spectrometer (FT‐IR) spectra, suggesting no degradation of the developed material. The photocatalytic activity on the surface of the test samples was investigated by microbial tests with Escherichia coli, Pseudomonas fluorescens, and Staphylococcus aureus bacteria. Depending on the additive type and the test germs, the samples showed different intensities of a germ‐reducing effect (up to >99,999%). [ABSTRACT FROM AUTHOR]

Succinic acid is an important synthetic monomer but it is difficult to use it as a precursor for synthesizing high molecular weight polyamide, due to its tendency to perform intra‐cyclization reaction at high temperature. In order to solve this problem, in this paper, the direct solid‐state polymerization (DSSP) method with the initial reactant, nylon salt which was composed of 1, 5‐diaminopentane, succinic acid, and terephthalic acid, was applied to synthesize the bio‐based copolyamide PA 5T/54. In comparison with the conventional melting polymerization method, the DSSP method can prevent the cyclization reaction of succinic acid effectively due to the lower reacting temperature as well as the restriction effect of the nylon salt. As a result, the product fabricated by DSSP method has higher molecular weight and much lighter color from red to white. Therefore, the DSSP method is advantageous for the synthesis of the polymers or copolymers composed of the succinic acid as the monomer. Furthermore, the polymerization mechanism proposed in this work can serve as a guidance for the design of the molecular structure and control of the polymerization process. [ABSTRACT FROM AUTHOR]

Fluororubber (FKM) materials have excellent mechanical properties, and are widely used in automotive and aerospace fields. As fluorine rubber is a typical representative of new special rubber, the formula and mechanical test method of fluorine rubber have become one of the important issues at present. Multi‐factor optimization of fluororubber compound plays an important role in the mechanical properties of FKM. Based on the introduction of new materials in FKM compounding agents (reinforcing agent, softening plasticizer, anti‐aging agent, accelerator, vulcanizing agent, auxiliary agent and filler), this paper focuses on the research progress of characterization methods and mechanical properties of the composite materials combined with FKM. [ABSTRACT FROM AUTHOR]

Developing 3D printing high‐performance biodegradable materials is important to protect the environment and deal with emergencies such as COVID‐19. Fused deposition modeling (FDM), one of the 3D printing methods, has many advantages, such as low cost and wide range of materials. However, the weak interlayer adhesion is an important factor restricting the development of FDM. In addition to the influence of material properties, the optimization of 3D printing parameters is also an important means to give full play to the inherent properties of materials. The optimal 3D printing parameters are conducive to the diffusion and entanglement of molecular chains between adjacent layers. PLA/PBAT/PLA‐g‐GMA (70/30/10 wt%, PLA‐g‐GMA was a compatibilizer synthesized in our lab) was used as the research object. This work aims to analyze the mechanical properties response of biodegradable polymers products manufactured through FDM. Herein, the effect of 3D printing parameters including layer thickness, nozzle temperature, printing speed and platform temperature have been systematically investigated by orthogonal experimental design. The result showed that the excellent performance of 3D printing specimen was obtained when the layer thickness was 0.15 mm, the printing speed was 50 mm·s−1, the nozzle temperature was 200°C and the platform temperature was 50°C. The SEM images showed that the optimal 3D printing products had the best interlayer adhesion and the lowest porosity. Undergoing optimization of 3D printing processing, the yield strength and elongation at break of specimen increased by 115% and 229%, respectively. In this paper, the interlayer adhesion and mechanical properties of 3D printing products can be significantly improved by simply optimizing the 3D printing parameters without complex material modification. This work provided a new method for improving the interlayer adhesion of FDM and the mechanical properties of FDM products. [ABSTRACT FROM AUTHOR]

High water material, a kind of filling and supporting material, is widely used in underground engineering, whose creep mechanical properties are directly related to the underground engineering stability. In this paper, creep tests of different types of high water material are carried out. The results show that: for the complete specimen and the single and double crack specimens with crack inclination angles of 0°, 30°, and 60°, the curves present initial elastic, creep attenuation and creep stabilization in the first four stages, and the creep acceleration appears in the fifth stage, leading to the final failure of the specimen; for the single and double crack specimens with a crack inclination angle of 90°, no creep acceleration appears. According to the test results, a new nonlinear viscoplastic body is proposed, and connected with the traditional Nishihara model, forming the nonlinear Nishihara model. The new model can clearly describe the creep characteristics of complete and cracked specimens at different stages. Finally, according to the new creep model, crack parameters are discussed with the creep rate index and the starting time of accelerated failure. [ABSTRACT FROM AUTHOR]

ABSTRACT In a paper mill's water circuit, normal runnability of the paper machine is often disturbed due to the buildup of dissolved and colloidal substances (DCS). Contaminant adsorption on a solid adsorbent in a fluidized bed reactor has been applied for white water treatment. In the present study, polystyrene (PS) spheres were firstly acylated by acryloyl chloride, then poly(methacryloxyethyltrimethyl ammonium chloride) (PMAC) was grafted onto the acylated PS spheres, induced by surface-initiated free-radical polymerization. Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy were used to characterize the changes of PS spheres in chemical structures and surface morphology. The results showed that acylated PS spheres could be easily grafted with PMAC in 53.83% weight increase. Polyelectrolyte loading of PS spheres reached up to 1.72 mmol/g. The resulted cationic modified PS spheres could effectively decrease the cationic demand in white water and it still maintained high performance after operating repeatedly for 10 batches. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 10.1002/app.41379. [ABSTRACT FROM AUTHOR]

Water contamination by heavy metals is a serious environmental problem. Several adsorbents with high adsorption capacity have been reported by researchers. In this paper we report the application of a new crosslinker allyl sorbitol (AS), and two other crosslinkers viz. allyl mannitol (AM) and allyl pentaerythritol (AP), toward the synthesis of polymer hydrogels. These hydrogels have been utilized for the removal of heavy metal ions from water. Chemically crosslinked polyacrylic acid hydrogels have been prepared using these crosslinkers viz. AS or AM or AP. The synthesized crosslinked hydrogels have been utilized for the removal of heavy metal ions from water. The maximum copper (Cu) metal ion removal of 81.8, 81.6, 86.8% and adsorption capacity of 409, 408, 434 mg/g were found with AS, AM and AP crosslinker based hydrogels respectively. While the maximum nickel (Ni) metal ion removal of 96.8, 96.6, 99.0% and adsorption capacity of 484, 483, 495 mg/g were found with AS, AM and AP crosslinkers based hydrogels respectively. The maximum chemical oxygen demand (COD) reduction of 72, 74, 78% and total dissolved solids reduction of 86%, 83%, 95% were found with AS, AM, AP based polymer gel respectively. Approximately, 439.2, 451.4, and 475.8 (mg COD removed/g polymer gel) of pollutants reduction capacity was achieved during their treatment. [ABSTRACT FROM AUTHOR]

To fabricate the low‐cost transparent polyamide with high heat resistance and good melt flowing property simultaneously is a huge challenge in many high‐end fields due to the contradiction between these two properties. In order to balance this contradiction, in this paper, by using isophthalic acid (IPA, aromatic monomer), 4,4′‐methylenebis(cyclohexylamine) (PACM, alicyclic monomer) as rigid stereoscopic monomers, 1,6‐hexanediamine (HMD, aliphatic monomer) as the flexible monomer, a series of transparent poly(hexamethylene isophthalamide/poly(m‐benzoyl4,4′‐methylenebis(cyclohexylamine)) (PA6I/PACMI) with rigid and stereoscopic structure (corresponding to the large distance between adjacent molecular chains) were successfully synthesized. The results indicated that the newly synthesized PA6I/PACMI copolymer has an intrinsically amorphous structure and high optical transparency, which could reach as high as 90%. Furthermore, the highest glass transition temperature (Tg) of the copolymer is over 153.9°C, at the same time, the copolymer also possesses excellent melt flowing property, which can be melt processed easily. Therefore, the newly synthesized copolymer has great advantages in many fields, and it can also shed light on the design and fabrication of high‐performance materials. [ABSTRACT FROM AUTHOR]

Polyhedral oligomeric silsesquioxane (POSS) as an organic–inorganic hybrid at a molecular level, has excellent mechanical properties, thermodynamic properties, dielectric properties and so on. In recent decades, POSS has been extensively used in modification of various polymers to prepare nanocomposites with enhanced comprehensive performances. Biomass materials such as chitosan, cellulose, silk protein, collagen fibers and gelatin have excellent biocompatibility and biodegradability, which have been widely used in the fields such as biomedical, innovative environmental protection and so on. However, deficiencies including insufficient mechanical properties and rapid rate of biodegradation hampered their application. This paper briefly introduced the principal methods to synthesize POSS nanoparticles, and then focused on technologies for preparing biomass‐based composites utilizing diverse functional POSSs. Finally, put forward the prospects of POSS modification technology and its future application direction. This article will have a positive guiding role for the further research and development of biomass/POSS nanocomposites. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, a hydrophobic monomer (HM) that has a cationic double alkyl-substituted group bonded to the nitrogen atom was first synthesized. Then a hydrophobic poly(vinyl alcohol) (PVA) was prepared by a radical solution copolymerization of vinyl acetate (VAc) with the HM followed by an alcoholysis reaction in alkaline conditions. The structures of HM and hydrophobically modified PVA (H-PVA) were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The effect of hydrophobic cationic segments on crystallization behaviors, mechanical properties, morphology, solution viscosity, and hydrophobic property were investigated. The results indicated that the crystallinity decreased from 37.2% of pure PVA to the minimum 23.2% of H-PVA with the incorporation of 1.15 mol % HM. The thermal decomposition temperature of H-PVA increased by about 50 °C compared with that of pure PVA. The viscosity of the H-PVA solution was several times higher than that of the corresponding unmodified PVA solution over the whole shear rate range, which demonstrated that the H-PVA had good shear-resistance ability. Furthermore, the contact angle was significantly increased from 55.1° to 115° with the incorporation of only 0.83% HM, which illustrated that the H-PVA had high hydrophobicity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43888. [ABSTRACT FROM AUTHOR]

High processing viscosity and poor solubility limit the application of heterocyclic polymers for fabricating organic wavetransparent composites for aerospace applications. In this paper, a novel resin, poly(phthalazinone ether bisphenol fluorene) encapped with phthalonitrile (PPEBF-Ph), was synthesized and used as the matrix. Biphenol-based phthalonitrile monomer BP-Ph was also synthesized and blended with PPEBF-Ph to further lower the processing viscosity. Solubility tests showed that the resin was soluble in dimethylformamide, N,N-dimethyl acetamide, N-methylpyrrolidone, dimethyl sulfoxide, chloroform, and other solvents. Differential scanning calorimetry and rheological studies revealed that the mixed resins exhibited low processing viscosity and a wide processing window below the gel temperature. Thermogravimetric analysis indicated that the cured resins were stable below 510-530 8C under nitrogen atmosphere after 6 h of curing (decreased by 40-60% compared with previous reports on phthalonitrile resin). In air, the char yields of the resins reached 20-30% when heated at 800 °C. The composites were reinforced by a quartz fiber cloth and exhibited a dielectric constant of 2.94-3.27 in an electromagnetic field with frequency ranging from 8 to 18 GHz. Retention of the bending modulus exceeded 70% at 400 °C according to dynamic mechanical analysis, indicating excellent mechanical stability was obtained. [ABSTRACT FROM AUTHOR]

The past few decades have seen extraordinary gain in interest for bio-based products, driven by the intensifying call of the society for petrochemical material replacement and developing materials with next-to-no environmental impact. Cellulose, which is an abundantly available "green" material, can be derived from plant fibers and tailored for a plethora of possible uses where it can be used as a substrate or as a filler material. However, emerging technologies and product advancements necessitate the search for materials that are small, biodegradable, lightweight, and strong. Nanocellulose, which can be obtained through as mechanical and chemical production methods with tensile strength and Young's modulus of up to 0.5 and 130 GPa, respectively, proves to be the answer that they were looking for. However, the inherent hydrophilic nature of nanocellulose limited its potential widespread application. Surface modifications of nanocellulose to alter and diminish its hydrophilicity were done to address the aforementioned issues. In this article, we had reviewed on different types of surface modifications and their resulting impact on the properties of nanocellulose and their effect on polymer composites. The importance of nanocellulose in emerging applications such as biosensor, nanoremediation, papermaking, and automotive as well as the current state of the industry and the commercialization progress of nanocellulose were also discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT High-vinyl polybutadiene rubber (HVBR) and solution-polymerized styrene-butadiene rubber (SSBR) can meet the requirements of high-performance tires due to their excellent wet skid resistance and lower rolling resistance. In this paper, the effects of the vinyl and phenyl groups and their contents on the vulcanization behavior, mechanical strength, fatigue resistance, heat resistance, and wear resistance of HVBR and SSBR were investigated, and the dynamic viscoelasticities of HVBR and SSBR vulcanizates with or without carbon black were explored by dynamic mechanical analysis (DMA). The experimental results showed that the vinyl groups contributed more to the wear resistance and fatigue resistance of vulcanizates than the phenyl groups, but the phenyl groups contributed more to the mechanical strength of the vulcanizates than the vinyl groups. The DMA results showed that the vinyl and phenyl groups could significantly improve the road-gripping capability and wet skid resistance of HVBR and SSBR vulcanizates, but carbon black could slightly weaken the effect of vinyl and phenyl groups on the wet skid resistance of vulcanizates, and the effect of carbon black on vinyl groups was more significant. Despite the presence of carbon black, the phenyl groups contributed more heat buildup to the vulcanizates than the vinyl groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45975. [ABSTRACT FROM AUTHOR]

ABSTRACT Construction of a highly hydrophilic polymer surface with excellent long-term stability underwater is a great challenge. In this paper, a facile ultraviolet (UV) curing technique was employed to realize the three-dimensional (3D) grafting of poly(ethylene glycol) diacrylate (PEGDA, molecular weight: 400, 600, and 1000 g/mol) on a bisphenol A epoxy acrylate (BEA) sheet. The cross section morphology, surface chemical composition, and wettability of the sheets were monitored using an optical microscope, an attenuated total reflectance Fourier transform infrared spectroscope, and a water contact angle analyzer, respectively. The PEGDA-grafted epoxy sheets displayed a highly hydrophilic surface and meanwhile possessed excellent stability underwater, despite the molecular weight of PEGDA. In contrast, the PEGDA/BEA blend sheets are easily damaged underwater, due to strong swelling. In addition, the PEGDA1000-grafted BEA sheet demonstrated good antifouling performance in a natural marine environment. Nevertheless, its long-term antifouling is not satisfactory, being presumably due to hydrolysis or biodegradation of the PEG segments. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43972. [ABSTRACT FROM AUTHOR]

ABSTRACT Development of structure-properties relationships between the fillers/rubber matrix interface chemistry and the dispersion and interfacial adhesion properties of the rubber composites is critical to predict their bulk mechanical and tribological properties. In this paper, three solution styrene butadiene rubber (SSBR) composites containing various fillers with tailored interfacial chemistry were prepared via conventional mixing technique. Subsequently, thermal and structural features of filled SSBR composites were monitored by TG, DSC, XRD, XPS, FESEM and TEM, respectively. Sliding contact experiments were conducted to study tribological properties of styrene butadiene rubber composites under dry and wet conditions. It was shown that the SSBR filled with silicon dioxide nanoparticles significantly reduced both the friction coefficient and the wear against marble block. On the contrary, it exhibited an increased friction coefficient and wear under wet friction conditions due to the specific superior wet-skid resistance of silicon dioxide nanopartilce filled rubber composites, a good dispersion of silicon dioxide nanopartilce in the rubber matrix and strong interfacial adhesion between nanoparticles and rubber matrix. In addition, the influence of fillers dispersion and interfacial adhesion on friction and wear of styrene butadiene rubber composites was evaluated employing theoretical calculation, and the predicted results were in agreement with the experimental observations. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43589. [ABSTRACT FROM AUTHOR]

ABSTRACT Hemp fibre-reinforced polycaprolactone (HFRP) composite has inherent good mechanical properties and benefits which include remarkably high specific strength and modulus, low density, and renewability. No doubt, these properties have attracted wider applications of HFRP composite in engineering applications. This paper presents an investigation on the influence of drilling parameters and fibre aspect ratios, AR (0, 19, 26, 30, and 38) on delamination damage factor and surface roughness of HFRP composite laminates utilising high speed steel twist drills under dry machining condition. Taguchi's technique was used in the design of experiment. The results obtained show that increase in cutting speed reduces delamination factor and surface roughness of drilled holes, whereas increase in feed rate causes increase in both delamination factor and surface roughness. Feed rate and cutting speed had the greatest influence on delamination and surface roughness respectively when compared with aspect ratio, while an increase in fibre aspect ratios leads to a significant increase in both delamination factor and surface roughness. The optimum results occurred at cutting speed and feed rate (drilling parameters) of 20 mm/min and 0.10 mm/rev, respectively, when drilling sample of AR 19. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42879. [ABSTRACT FROM AUTHOR]

ABSTRACT Recently, efforts have been devoted to find ways in utilizing biomass as feedstocks for the production of organic chemicals. This is because of its abundance, renewability and worldwide distribution. Lignocellulosic agricultural waste materials are regarded as abundant, inexpensive, and readily available natural resources for both chemical and paper industries. Hydrogels are polymeric materials that vary in their origin and composition and can absorb large amount of water without dissolving. In our study, cellulose-based acrylic acid hydrogel was synthesized starting from rice straw as a source for the lignocellulosic material, where cellulose was first isolated after alkaline-acid pulping treatment followed by bleaching step with sodium hypochlorite resulting of 90.8% holocellulose. The cellulose-based acrylic acid hydrogel was synthesized applying heterogeneous reaction and shows a swelling ratio more than 3000%. The resulting hydrogel was further characterized with FT-IR and SEM. On the other hand, comparison between the rice straw-based hydrogel and the commercially available acrylamide hydrogel was studied for improving maize production in salt affected soil as well as in the growth promoters of maize under water stress. The experimental results demonstrated that the yield parameters were increased with increasing irrigation rates. Both types of hydrogels introduce positive and significant effect compared to the one without adding hydrogels. Also, acrylamide hydrogel was effective for improving almost yield parameters more than applying rice straw-based hydrogel. Generally, the addition of hydrogel increases the nutrient concentration, uptake, and both of water and nutrients use efficiency. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42652. [ABSTRACT FROM AUTHOR]

Synthetic dyes are commonly used in textile, paper, leather, food, plastic and cosmetic industries. In this study, a series of novel graphite oxide/polyurethane (GO/PU) polymeric foam materials were prepared by foaming technique. The GO/PU was applied to remove malachite green (MG) from aqueous solution. When static adsorption experiment was carried out with a GO content of 3.0%, a GO/PU dosage of 40 mg/mL, a temperature of 50°C, and a time of 3 h, the highest adsorption efficiency can reach 99.7%. The kinetics, equilibrium and thermodynamics of MG adsorption onto GO/PU polymeric foam material were investigated. The results indicated that adsorption behavior was found to follow closely the pseudo-second order kinetics, equilibrium data were well fitted by Langmuir adsorption model and the adsorption process was spontaneous and endothermic. Prepared GO/PU foam material has potential application for the wastewater treatment containing MG dye. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40988. [ABSTRACT FROM AUTHOR]

ABSTRACT The electrochromic (EC) and optical properties of three new viologen compounds containing 1,1′-di- n-heptyl-4,4′-bipyridinum dibromide (DHBPDB; C24H38Br2N2), 1-heptyl-4-(4-pyridyl)pyridinium bromide (HPPB; C17H23BrN2), and 1,1′-dis( p-cyanophenyl)-4,4′-bipyridinium chloride (DCBPC; C12H8N2OBr2) for potential use in electrochromism applications were investigated. The repetitive stability of all of the EC cells could be improved through the addition of ferrocene as an electron donor (a counter redox material) to the electrolyte solution under several redox cycles. The experimental results demonstrate that the EC cell showed a reversible color change from clear (tintless) to three different colors with the application of electrochemical stimuli at specific potentials. The color of the EC cells turned red, green, or blue upon electrochemical reduction for DHBPDB, HPPB, and DCBPC in indium tin oxide sandwich-type cells. Because of the different viologen molecules competing to capture electrons and affecting the EC efficiency and life of the multiviologen cells, they could be improved by the optimization of the working voltage in the multiviologen cells from the modification of an operative potential based on the cyclic voltammetry measurements. In this article, we propose a prototype device of multicolor electrochromic display, which provides potential application for multicolor electronic displays or EC paper. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40485. [ABSTRACT FROM AUTHOR]

ABSTRACT Cellulose nanofibers were prepared using TEMPO/NaBr/NaClO oxidation of kraft pulp and successive ultrasonic treatment, and the properties were characterized by conductimetric titration, X-ray diffraction, and atomic force microscopy. The resulting product was then applied as an anionic microparticle to constitute a microparticulate system with cationic polyacrylamide (CPAM), to induce the flocculation of the kaolin clay suspension. The flocculation effect was evaluated by determining the relative turbidity of clay suspension. The results showed that the obtained cellulose nanofibers had cellulose I structure with higher crystallinity than that of the kraft pulp, and their cross-sectional dimension was in the range of 3-5 nm. They had more negative zeta potential at neutral and alkaline conditions. It was found that the microparticulate system showed high flocculation effect on kaolin clay at a very low level of nanofiber addition, and a high shear level after CPAM addition was helpful for the flocculation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40450. [ABSTRACT FROM AUTHOR]

The paper presents a simple and effective approach to fabricating a poly(vinylidene fluoride) (PVDF) film with excellent ultraviolet (UV) shielding performance. Carbon quantum dots (CQDs) with a highly UV absorbing property were made via a hydrothermal reaction and were then added to a poly(vinyl alcohol) (PVA) solution. The PVDF membrane pretreated with an alkaline solution was immersed in the prepared CQD/PVA solution to coat a UV‐shielding layer on the film surface. Fourier transform infrared spectroscopy, X‐ray photoelectron spectrometry, X‐ray diffraction, transmission electron microscopy, and UV–visible spectrophotometry were applied to study the structure, morphology, and optical performance of the CQD particles. The stability and UV‐shielding performance of the obtained PVDF‐OH@CQDs/PVA composite film were further investigated. The results showed that the CQD particles with diameter of 18 nm could be well dispersed in solution. Additionally, the CQDs had fairly high UV absorbance, and the PVDF‐OH@CQDs/PVA composite film could shield the UV light completely. The method described in this paper is a promising one for fabricating UV‐shielding composite films. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47555. [ABSTRACT FROM AUTHOR]

Samples of ethylene vinyl acetate (EVA) co‐polymer foams in form of plates and industrial outsoles of prototyped sport shoes containing 0% (reference), 2.5%, and 5.0 weight % (wt%) of hollow glass microspheres (HGM) were made. The goal was to study the influence of HGM on properties of EVA foam in laboratory conditions followed by the industrial trial, where the most promising laboratory result was applied. The physical properties of samples and behavior of material under dynamic load were examined. EVA foams with HGM filler demonstrated that they have better ability to reduce impact peak force and increase absorb impact impulse compared to the reference foam without HGM. Addition of 5.0 wt% of HGM in laboratory foam increased its absorbed impact pulse by two‐fold. Meanwhile for industrial prototype outsoles, the impact peak force was reduced by 5%–7% in walking simulated conditions and by 11% in case of simulated running. It is also observed that, addition of 5.0 wt% of HGM in EVA foam increased its abrasion resistance by three times, which generally helps to increase the lifetime of sport footwear. Under dynamic load, samples with the addition of HGM behave interestingly and result shows a small decrease in energy return (7%) which is logical, because this composite tends to absorb energy and not return it. Samples with 2.5 wt% HGM are stiffer than reference until 40% compression deformation, but beyond that point it becomes softer, and better absorbs impact energy than reference. Outsole with 2.5% of HGM in EVA outsole increased resistance of shoe at lateral bending of 50% and 20% rise of resistance was found at medial twist. Impact absorption and flexibility resistance are useful for protection against impact which are also helpful to prevent sport injuries. The obtained results show the addition of HGMs which are cheap by‐products in several technologies brings improvement to properties of EVA foams which is the most common materials for the sport footwear industry. [ABSTRACT FROM AUTHOR]

Through cross‐linking modification of poly(o‐phenylenediamine) (PoPD) to increase the adsorption active sites, the Cu2+ adsorption capacity of PoPD was improved significantly. According to FT‐IR, XRD, SEM and BET results, both PoPD and the cross‐linked PoPD had porous or surface‐adhesive porous morphology with a typical mesoporous character, the specific surface area of the latter was increased obviously from the former. Both of them showed excellent Cu2+ adsorption capabilities with the maximum adsorption qexpmax of 76.51 and 85.49 mg·g−1, and the corresponding removal ratios of 60.21% and 68.39%, respectively. The adsorption capacity was increased to its 1.54 times with pentaerythritol tris[3‐(1‐aziridinyl)propionate] (cross‐linking agent‐III) as cross‐linking agent at pH = 5 and 25°C. Because temperature could affect the adsorption behavior of materials and the adsorption process is endothermic with ΔG < 0, the process should be accompanied by spontaneous chemical changes. The XRD, SEM–EDX mapping and XPS results showed that Cu2+ was successfully removed from the aqueous solution. Additionally, the adsorption was mainly based on the cation‐π interaction and the formation of Cu‐N bonds. [ABSTRACT FROM AUTHOR]

Large amounts of chromium‐containing leather solid waste (CLSW) generated in conventional leather making industry. The high value‐added transformation of CLSW has attracted lots of attention from scientists and technologists. Herein, gelatin was extracted from CLSW through alkaline hydrolysis dechroming and decalcification process. Then, form‐stable phase change material composites (GMPCMs) based on gelatin, n‐docosane, and melanin were designed and fabricated through impregnating n‐docosane into gelatin/melanin hybrid aerogels (GMAs). The three‐dimensional (3D) honeycombed aerogels GMAs with ultralow density and extremely high surface area can perfectly support n‐docosane and prevent liquid leakage. As expected, the solar‐thermal conversion efficiency of GMPCMs (up to 84.8%) was significantly increased with the introduction of melanin in PCM composites. DSC analysis indicated that GMPCMs possessed relatively large thermal energy storage density and the melting enthalpy of GMPCMs ranged from 207.1 to 228.0 J/g. Furthermore, GMPCMs showed admirable shape stability, excellent encapsulation capacity, and satisfactory thermal reversibility. [ABSTRACT FROM AUTHOR]