Resin Binder Research Articles

Robustly Adherable Hierarchical Nanostructures via Self-Bonding and Self-Texturing of Aluminum Nitride for Applications in Highly Efficient Oil/Water Separation.

The release of wastewater containing oily contaminants into water bodies and soils severely threatens the environment and human health. Although several conventional techniques are used in treating oil/water mixtures and emulsions, these methods are often expensive, time-consuming, and inefficient. Porous membranes or sponges are widely used in filtration or absorption, but their use is limited by their low separation efficiencies and secondary contamination. Recently, a novel technology that is designed to selectively separate oil from oil/water mixtures or emulsions by using materials with special wetting surfaces was developed. Superwetting surfaces may be used to selectively separate oils from emulsions. This approach enables the use of materials with relatively large pores, resulting in high throughput properties and efficiencies. In this study, a facile method is proposed for use in preparing a superhydrophobic-superoleophilic felt fabric for utilization in separating oil/water mixtures and emulsions. By hydrolyzing aluminum nitride nanopowders, the desired micro-/nanostructures may be successfully fabricated and firmly attached to a fabric surface without using a binder resin. This results in various materials with special wetting properties, regardless of their sizes and shapes and the successful separation of oil and water from oil/water mixtures and emulsions in harsh environments. This approach exhibits promise as a low-cost, scalable, and efficient method of separating oily wastewater, with the potential for use in wider industrial applications.

MgO–C refractories based on refractory recyclates and environmentally friendly binders

This study focused on the development of an environmentally friendly binder system based on lignin and collagen for uniaxial pressed MgO–C refractories as an alternative to commonly used resin or pitch binders. Additionally, recycled MgO–C refractories from steel plants were partially utilized as raw material, investigating their influence on the resulting physical and mechanical properties. The binder system showed reliable binding properties, although the recyclate-containing MgO–C exhibited higher porosity, slightly lower density, and lower strength compared to the reference batches without recyclates. However, antioxidants significantly improved the properties of the recyclate-containing MgO–C samples. Scanning electron microscopy analysis with energy-dispersive X-ray spectroscopy revealed the formation of whiskers, as well as oxidation and nitridation of aluminum particles. This research highlights the potential of environmentally friendly binders and the utilization of recycled materials in MgO–C refractories to mitigate their environmental impact and enhances the environmental performance of carbon containing refractory materials.

Experimental study on flexural behavior of segmental precast large-cantilevered prestressed concrete cap beam

This study investigates the influence of epoxy joint configuration and longitudinal reinforcement continuity at the joints on the mechanical properties of segmental precast assembled large-cantilevered prestressed concrete (PC) cap beams under the co-action of flexural and shear internal forces. Accordingly, a practical project is considered, and five segmental precast-assembled large-cantilevered PC cap beam models as well as a comparative model of a monolithic precast large-cantilevered PC cap beam are designed and produced. The five segmental precast cap beam models were designed with a 1/5 scale ratio, and the joint interfaces were all connected using an epoxy resin binder. Three of these models whose longitudinal reinforcements at the joints were discontinuous utilized a large key tooth, a small key tooth, and corbel joint structures. The other two models whose longitudinal reinforcements at the joints were connected by grouted sleeves adopted large key-tooth and corbel joint configurations. Throughout the static loading test process of these six cap beam models, key results, such as the initial stiffness, cracking load, yield load, ultimate load capacity, concrete strain, deflection, and crack width, were obtained. The experimental results are as follows. The failure process and crack distribution patterns of each precast segmental cap beam model are fundamentally the same as those of the monolithic precast cap beam model. The crack distribution is sparse, cracks are wide, and the failure modes are all due to bending. Additionally, the mechanical properties of the three precast segmental cap beam models with discontinuous longitudinal reinforcement compared with those of the monolithic precast cap beam model were considerably degraded. The initial stiffness, yield load, ultimate load capacity, and ultimate deflection were only 81.4%, 80.4%, 81.1%, and 66.4%, respectively, of those of the monolithic precast cap beam model. Moreover, penetrating cracks formed in the concrete of the tensile zone on both sides of the epoxy joint interfaces during failure. Compared with the segmental precast cap beam models with discontinuous longitudinal reinforcement, the initial stiffness, yield load, ultimate load capacity, and ultimate deflection of the segmental precast cap beam models with continuous longitudinal reinforcement significantly improved. The mechanical properties of the latter were similar to those of the monolithic precast concrete cap beam model. Based on the experimental results, effective technical measures (such as grouted sleeves) were proposed to connect the longitudinal reinforcement at the joints. This ensured that the static performance of the segmental precast-assembled large-cantilevered PC cap beam was similar to that of the monolithic precast cap beam.

Melamine Acetate Preparation as a Urea-Formaldehyde Resin Additive for Particleboard Production

Urea-formaldehyde (UF) resin binders for wood-based panel production often use melamine as an additive to improve both mechanical properties and environmental compliance. Direct fortification for efficient use of melamine remains a problem due to low solubility. Pizzi & coworkers suggested the use of more soluble melamine salts and demonstrated success in terms of product performance. However, their preparation method showed low productivity and inefficient use of material and energy. In their scheme, a batch reactor fed with 1 kg of water and 75 g of a stoichiometric amount of melamine and acetic acid produced only around 25 g of solid melamine acetate crystal. In contrast, the remaining 50 g remained dissolved in 991 g of water, which requires high of energy to evaporate. This paper reports an attempt to increase batch productivity and work towards the more efficient use of material and energy. The experiment showed that the successive addition of melamine and acetic acid to the batch up to the solubility limit of melamine at the same reaction condition increased melamine and acetic acid fed from 75 g to 165 g. This was followed by a significant increase in dry crystal yield from 25 g to 117 - 132 g. Feeding the mother liquor to the next batch decreased the water use to only 8% of the original requirement. This resulted in a highly efficient process, eliminating the need for energy-intensive melamine acetate recovery from the mother liquor. The addition of 2% - 4% wt. of the product to UF resin resulted in particleboard with significantly lower thickness swelling, an increase in MOR & IB strength, and lower formaldehyde emission.

Comparison of conventional crushing and high-voltage pulsed power technology as techniques for disaggregating different types of spent magnesia-carbon refractory bricks during recycling

Three different types of spent magnesia-carbon (MgO–C) bricks were chosen to evaluate the liberation of magnesia particles through high-voltage pulsed power technology (HVPPT) and conventional comminution (jaw and cone crushing). The primary objective was to determine how the different types of MgO–C bricks comminute and whether magnesia particles could be restored to their original raw material particle size distribution (PSD).Analytical results revealed that the bricks contained varying amounts of graphite and resin binder, indicating differences in their compositions and therefore comminution properties. The HVPP technique demonstrated its ability to liberate magnesia particles within the +1700 μm fraction, whereas conventional crushing predominantly formed composite particles (containing MgO and carbon) within this size range, with over 63% particles falling in this category. This finding suggests that MgO particles were not adequately liberated during the conventional crushing process, indicating the need for an additional comminution step to achieve the desired liberation.

Preparation and performance analysis of high-viscosity asphalt containing high-content SBS and crumb rubber by oxygen-free high-temperature treatment

Styrene-butadiene-styrene (SBS) and crumbed rubber (CR) are widely used for asphalt binder modification in the field of road materials. Especially, the high-viscosity asphalt with high-content SBS/CR modifiers has been applied for constructing the porous pavement and ultra-thin overlay. However, the workability of the SBS/CR modified asphalt still needs to be improved due to many unswollen polymer particles in the blended system. This work aims to propose an oxygen-free high-temperature treatment method to reduce the viscosity of SBS/CR-modified asphalt at construction temperature for better workability. Viscosities at 60 °C and 180 °C were tested to obtain the content of SBS, CR, and tackifying resin for high-viscosity asphalt; multiple physical tests were conducted to obtain acceptable heating temperature, initial pressure, and reacting time; the two high-viscosity asphalt binders cured under various conditions were compared through physics, chemistry, and rheology properties. The results show that the 70# asphalt incorporating 10% SBS, 6% CR, and 9% (by weight of asphalt binder) resin can prepare ideal high-viscosity asphalt binders. After high-speed shearing, it was recommended that CR-SBS-asphalt blends be cured in the reactor at the initial pressure of 3 MPa and temperature of 200 °C for 45 mins. The improved reaction conditions increased light components in a homogeneous and formed a stable modified asphalt blended system. Hence, the low-temperature performance and workability were improved, despite weakening the rutting resistance, which was still excellent at the high temperature.

Long-Term Performance Analysis of Epoxy Resin Ultra-Thin Wearing Course Overlay on Cement Concrete Pavement

The overall rigidity of the cement concrete pavement is high, but there are defects such as easy cracking and insufficient anti-slip performance. The epoxy resin ultra-thin wearing course overlay can effectively solve these issues. However, there is still a lack of knowledge about the long-term performance of epoxy resin ultra-thin wearing course overlay on cement concrete pavement. Therefore, this article analyzed the interlayer adhesion and durability of epoxy resin ultra-thin wearing course overlay through the Hamburg rutting test and a series of shear tests under damp heat, thermal oxygen aging, and ultraviolet (UV) aging conditions. Shear test results indicated that the shear performance of epoxy resin overlay grew with the increase in epoxy resin content and was severely affected by high temperature, and the optimal content was set as 3.4 kg/m2. The Hamburg rutting test results showed that the epoxy resin overlay exhibited satisfactory high-temperature performance and water resistance. For the damp heat effect, it was revealed that damp heat led to more significant shear strength loss compared with the overlay specimens without damp heat. The water immersion caused the shear strength decline due to the water damage to the overlay interface. As for the thermal oxygen aging effect, it was reflected that the short-term thermal oxygen aging had a minor impact on the shear performance of the epoxy resin overlay. However, with the increase in thermal oxygen aging duration, the shear strength of the epoxy resin overlay significantly decreased due to the aging of epoxy resin binders. Regarding the UV aging impact, it was also found that the shear performance of the epoxy resin overlay rapidly decreased as the UV aging duration grew whether at 20 °C or 60 °C. Moreover, UV aging led to a more significant impact on the shear performance of the epoxy resin overlay than thermal oxygen aging.

Research on forming method of additive manufacturing of frozen sand mold

In order to promote the green and sustainable development of the foundry industry, it is necessary to further explore new methods and technologies for green foundry. This paper innovatively proposes a method of additive manufacturing of frozen sand mold, using water as the binder instead of resin binders for additive manufacturing in low-temperature environments, which effectively solves the problems of harmful gas emissions during the pouring process and the difficulty of direct recycling of molding sand, and realizes high-performance green casting of complex castings. In this paper, the liquid-solid phase transition mechanism of the binder for additive manufacturing of frozen sand mold and the change law of the normal temperature field and phase transition field of the pre-cooled powder bed porous medium at different temperatures are studied, and the process window of additive manufacturing of frozen sand mold is obtained, which provides a new green casting method for the foundry field.

Low voltage thick-film electroluminescent device with evaporated ZnS:Mn and spin coated BaTiO3 dielectric layer

In a thick-dielectric electroluminescent (TDEL) device, which is a variation of thin-film electroluminescent devices, one of the insulation layers is replaced by a thick-film dielectric layer. High brightness and reliability are the features of TDEL owing to a higher withstanding voltage of the thick-film dielectric layer. This paper presents a new type of TDEL with a bottom emission structure. The thick-film dielectric layer was manufactured by spin coating using an ink material, which is a mixture of BaTiO3 powder and a binder resin. The thicknesses of the phosphor and dielectric layers were minimized to reduce the operating voltage. A threshold voltage as low as 50 V and a maximum luminance of 1000 cd/m2 were obtained at 60 V.

Paste Development for an Optimized Filament Stretching Effect during Parallel Dispensing on Transparent Conductive Oxide Layers for Solar Cell Metallization

The availability of silver as an electrically conductive filler material in printing pastes for solar cell metallization is becoming a more crucial issue for multiterawatt‐scale production due to its global constraints. Therefore, the silver consumption for solar cell production needs to be reduced drastically by substituting silver with alternative conductive filler materials or utilizing process‐specific phenomena. The phenomenon of filament stretching during microextrusion allows significantly lower paste laydowns. The magnitude of filament stretching is paste‐dependent and therefore further knowledge of the pastes’ impact to the filament stretching is required. This study presents nine low‐temperature curing pastes differing in the particle system and binder resin. The rheological and thermal behavior of these suspensions are investigated and printing tests onto silicon heterojunction (SHJ) precursors are carried out. Additionally, scanning electron microscopy (SEM)‐based microstructure analyses of printed electrodes are performed. Based on these experimental results, the impact of paste compositions regarding the paste behavior during microextrusion and the SHJ solar cell performances are analyzed. The developed paste formulations exhibit a strong filament stretching, leading to a reduced silver laydown of down to ΔmAg = −60%rel. and an absolute efficiency gain of up to Δη = +0.75%abs. due to less shading losses.

PREPARATION AND PERFORMANCE OF CEMENTING MATERIALS FOR RAPID MAINTENANCE OF PAVEMENT POTHOLES

At present, China has entered the peak stage of large-scale maintenance, but repair materials for asphalt pavement potholes are subjected to problems, such as low construction efficiency and poor durability. Polyurethane modified epoxy acrylic resin was selected in this study to repair pavement potholes rapidly and improve durability further. Meanwhile, the cementing material and aggregate were formed into a mixture for rapid repair. A four-factor and four-level orthogonal experiment was designed, and the optimal mass ratio of each component of the cementing material (EPMY) was determined according to three indexes: tensile strength, elongation at break, and viscosity. The basic properties of the material were evaluated using viscosity, glass transition temperature, thermal stability, and elastic recovery rate tests. Finally, the mechanical properties of EPMY immersed in water, salt, acid, and oil solutions were tested under different environmental stimuli. Results showed that the optimal mass ratio of epoxy resin binder is 100% epoxy acrylic resin:15% diluent:30% toughening agent:60% curing agent:6% accelerant, with a tensile strength of 21.48 MPa and an elongation at break of 48.3% at ?10 °C. Elastic recovery rate is 51.3% at room temperature, glass transition temperature is ?13.6 °C, and mass residual rate of EPMY is 10.06% when the temperature rises to 500 °C. The mechanical properties of EPMY are maximally affected by the acidic solution; and the elongation at break, bending strength, and bending deformation are reduced by 11.63%, 7.52%, and 9.58%, respectively. Moreover, and the elongation at break of EPMY can be maintained above 89%. The cementing material can be used for the rapid repair of pavement potholes, thereby increasing the convenience of maintenance work and improving the maintenance level. Keywords: pavement materials, epoxy resin, polyurethane, material design, mechanical properties

Si–Ni-alloy-assisted very high-areal-capacity silicon-based anode on Ni foam for lithium ion battery

Silicon is investigated as an active material for the anode of lithium-ion battery (LIB) because of the 10 times higher specific capacity of silicon than graphite. In order to achieve a low internal resistance and high areal capacity of a silicon-based anode, metal foams are used as three-dimensional current collectors. However, unless the foam is densely compressed, active materials adhere loosely to the foam and suffer from loss of electrical contacts with the current collector. A densely compressed anode suffers from poor physical integrity without spare room for large volume expansion of silicon. By means of pyrolysis at 800 °C in argon of a mixture of silicon nanoparticles, phenolic resin binder, and Super P conductivity agent on the nickel foam, silicon reacts with nickel to form nickel silicide while the specially selected binder is graphitized to form a conductive and porous anode with a nickel foam current collector. We report 80-nm-silicon-based anode with a nickel foam, exhibiting excellent cycling performance and a high retained areal capacity of 6.5 mAh/cm2 after 50 cycles under a discharge/charge current density of 4 mA/cm2. For anode area of 1 cm2, it stores 23.4 C of charges at a current rate of 4 mA.

Improved Oxidation Resistance of Graphite Block by Introducing Curing Process of Phenolic Resin.

The purpose of this study is to improve the oxidation resistance of graphite blocks after graphitization at 2800 °C by introducing a curing process of phenolic resin, used as a binder to control the pore size. Using the methylene index obtained from FTIR, the curing temperature was set to 150 °C, the temperature at which cross-linking most highly occurs. Graphite blocks that had undergone curing, and were carbonized with a slow heating rate, showed increased mechanical and electrical properties. Microstructural observation confirmed that the curing process inhibited the formation of large pores in the graphite block. Therefore, the cured graphite block showed better oxidation resistance in air than a non-cured graphite block. Oxidation of the graphite block was caused by pores created by pyrolysis of the phenolic resin binder, which acted as active sites.

Influence of Heterogeneous Ion-Exchange Membranes Composition on Their Structure and Transport Properties

The physicochemical properties of experimental heterogeneous MK-40 and MA-41 membranes with different ratios of ion-exchange resin and polyethylene binder in their composition are studied. It is shown that the specific electrical conductivity in 0.01–1 M NaCl solution decreases by more than 3 times for cation-exchange membranes and by 2 times for anion-exchange ones with a decrease in the content of ion-exchange resin in the membranes from 69 to 55%. It has been established that the diffusion permeability of anion-exchange membranes is more sensitive to their composition and naturally increases with an increase in the ion-exchange resin proportion in the composition. Information on the influence of the heterogeneous membrane composition on its structure, obtained by method of standard contact porosimetry, is supplemented by the calculation of transport-structural parameters of the microheterogeneous and extended three-wire models of the ion-exchange membrane.

Additive manufacturing and performance tuning of functionally graded Al/AP with continuous change of content

As a typical energetic composite, aluminum (Al)/ammonium perchlorate (AP) has been widely applied in propellants, explosives, and pyrotechnics. To regulate its energy output, a functionally graded Al/AP composite with continuously changing component content was fabricated by 3D printing through a self-designed "partition". The printed functionally graded Al/AP composite was characterized by different techniques. The research showed that the overall structure of functionally graded Al/AP is complete, the internal particles are densely packed and the porosity is small, the phenolic resin binder had good compatibility with powders (Al, AP), and the content of Al and AP in the functional gradient Al/AP strip has achieved continuous gradient change (Al content from 50 wt% to 20 wt%, AP content from 50 wt% to 80 wt%) along a certain direction. Because of the continuous change of the content of different components, functionally graded Al/AP realizes the effective regulation of flame shape, combustion rate, pressure output, and energy release on the macro level. That is, with the increase of Al content, the combustion temperature and heat release gradually increase, and the combustion flame shows the morphological changes of horizontal uniform injection, downward tilt, bright spot injection, and attenuation in turn. With the increase of AP content, the pressure output gradually increases, and the combustion rate first increases and then decreases. These results indicate that functional gradient provides a new strategy for controlling the combustion reaction and energy output of energetic materials. In addition, 3D printing technology provides a feasible method for the preparation of functionally graded materials.

Low Dielectric Constant Characteristics of Styrene and Maleimide Anhydride Copolymer with Modification for High Frequency Application of Printed Circuit Board.

Recently, due to the intensive and fast progress of the high frequency wireless communication environment, including 5th generation (5G) wireless communication, more robust substrate for printed circuit board (PCB) application, especially with less power consumption, is required. In this study, modified resins based on styrene-maleic anhydride (SMA) copolymer were prepared and evaluated as binder resin to accomplish a low dielectric constant or relative permittivity (εr: <3.0) substrate for the PCB application under ultrahigh frequencies (UHF; 1 GHz~9.4 GHz). The low εr dielectric characteristics of the modified SMA copolymer could be correlated with effects from the stereo-structure of carbon chains or conformational orientation, where the degree of crystallization was analyzed by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) spectroscopies. Prepreg films of the low εr modified SMA copolymers and their compounds with epoxy resins were also characterized in terms of dielectric loss or dissipation factor (Df), which have shown more noticeable relation with their stereo-structures as well.

Transient radiative transfer in two graded – index slab adhered by an infinitely thin vacuum via the lattice Boltzmann method

The lattice Boltzmann method is presented to solve the radiative transport of both diffuse and collimated problems in inhomogeneous and semitransparent two – layered slab with graded refractive indices. The two layers are bounded by Fresnel's walls and separated by an infinitely thin vacuum interlayer with negligible thickness to represent the case with surface roughness or assembling of two layers using a transparent binder or intumescent resin. The high – order discrete ordinates is used to simulate the angular redistribution due to variable refractive indices and multiple reflections at the boundaries and interface. The accuracy and efficiency of the methodology is firstly tested for transient and steady state solution in two – layered slab with constant or variable refractive indices. Effects of the distributions of refractive indices and surrounding, scattering albedos, and the optical thicknesses on the transient radiative signals are examined. Calculation results show that, these parameters have a significant influence on radiative transfer and the angular intensities at different few times levels are presented to illustrate the effects of the interface characteristics, and the discontinuous nature of the intensity at the interface is discussed. The developed LBM is a promising, efficient and simple solver to perform the radiative transport in inhomogeneous layered media with graded – index functions.

Comparative Assessment of Compression Strength of Solid Biobriquette using Different Binding Materials

Charcoal and firewood are the most common cooking fuels, despite the fact that they represent a variety of social and economic environmental difficulties in many affluent countries. Apart from the environmental implications of deforestation and resource loss, indoor air pollution caused by cooking with solid fuels causes 2 million fatalities each year. Biobriquettes are then utilized as a substitute for oils. Briquettes are also employed as carbon sources for cooking in various industries such as power plants, brick factories, and bakeries. Five specific binding materials were tested in this study for manual densification of cabbage waste, including beef tallow oil, starch, cassava binder, sodium silicate, and vinyl ester resin. The briquettes are made from a combination of 80% densified biological waste and 20% binder material. The sample density ranges from 545.564 to 591.278 kg/m3. The samples with the highest calorific value were beef tallow oil and vinyl ester resin, which had 5,357.26 and 5,800.79 kcal/kg respectively. The content of the samples were ashes, fixed carbon content, volatile material, and total humidity is 6.47% ± 1.13%, 18.43% ± 6%, 70.68% ± 6%, and 4.42% ± 4%, respectively. The sample with the most calorific value and densification is the one with the inorganic binder mixture.

Study on the Preparation and Performance of Silicone-Modified Phenolic Resin Binder for Rail Grinding Wheels.

A scheme for manufacturing heavy-duty rail grinding wheels with silicone-modified phenolic resin (SMPR) as a binder in the field of rail grinding is presented to improve the performance of grinding wheels. To optimize the heat resistance and mechanical performance of rail grinding wheels, an SMPR for industrial production of rail grinding wheels was prepared in a two-step reaction using methyl-trimethoxy-silane (MTMS) as the organosilicon modifier by guiding the occurrence of the transesterification and addition polymerization reactions. The effect of MTMS concentration on the performance of silicone-modified phenolic resin for application in rail grinding wheels was investigated. The molecular structure, thermal stability, bending strength, and impact strength values of the SMPR were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and mechanical property testing, and the effect of MTMS content on the resin properties was investigated. The results indicated that MTMS successfully improved the performance of the phenolic resin. The thermogravimetric weight loss temperature of the SMPR modified by MTMS with 40% phenol mass at 30% weight loss is 66% higher than that of common phenolic resin (UMPR), exhibiting the best thermal stability; in addition, its bending strength and impact strength were enhanced by approximately 14% and 6%, respectively, compared with those of common UMPR. This study utilized an innovative Bronsted acid as a catalyst and simplified several intermediate reactions in the conventional silicone-modified phenolic resin technology. This new investigation of the synthesis process decreases the manufacturing cost of the SMPR, liberates it from the restrictions of grinding applications, and enables the SMPR to maximize its performance in the rail grinding industry. This study serves as a reference for future work on resin binders for grinding wheels and the development of rail grinding wheel manufacturing technology.

The effects of resin rate (wt-%) on different temperature performance of newly designed friction composites for automobile brake lining applications

ABSTRACT Choosing the amount of binder resin in a brake lining composition is important in terms of avoiding structural deterioration of the brake lining composite and resisting mechanical and thermal stresses at different temperatures. This study evaluated the performances of new brake lining composites with 15% and 20% novolac resin additives by performing wear tests in different temperature environments. Friction wear tests were performed according to ASTM G99 using pin-on-disc test devices at temperatures of 23°C, 150°C and 300°C. The hardness and density of the samples increased by 2.4% and 3.7%, respectively, with the increase of the novolac resin ratio in the composition. In general, it was observed that the friction coefficient, thermal conductivity and vibration increased in parallel with the resin ratio. In addition, increasing the test temperature led to an increase in the friction coefficient.