Rubber Binder Research Articles

Exploring the Optimal Binder Content in Composite Electrodes for Sulfide-Based All-Solid-State Lithium-Ion Batteries

All-solid-state batteries (ASSBs) are promising next-generation batteries owing to their improved safety compared with lithium-ion batteries using flammable liquid electrolytes. Among various solid electrolytes, sulfide-based electrolytes exhibit high ionic conductivities, and their ductile properties allow them to be easily processed without high-temperature sintering. In sulfide-based ASSBs, a polymer binder is essential for achieving a good cycling performance by maintaining strong interfacial contacts in the composite electrodes during cycling. In this study, we prepared a composite Si-C anode and a LiNi0.82Co0.1Mn0.08O2 cathode using a nitrile-butadiene rubber binder for ASSB applications, and investigated the effect of the binder content on the mechanical properties and electrochemical performance. The binder content significantly influenced the physical and electrochemical characteristics of the composite electrodes, and the ASSB prepared with 1.5 wt% binder showed the best cycling performance considering capacity retention and rate capability. Furthermore, we investigated how the excess binder adversely affected the cycling performance through time-of-flight secondary ion mass spectrometry analysis.

Zn-Zr substituted M-type Sr-hexaferrites for effective electromagnetic wave absorptions in the 26.5–40 GHz range

This study explores the electromagnetic (EM) wave absorption properties of Zn-Zr substituted M-type Sr-hexaferrites (SrFe12–2xZnxZrxO19, x = 0.3, 0.4, 0.5, 0.6) integrated into polymer composites (10 wt%, epoxy or rubber). The hexaferrite powders were synthesized using solid-state reaction processes with and without the molten-salt (M-S) method. Compared to non-M-S samples, those processed with M-S exhibited larger grain sizes and more defined grain edge shapes without clustering. High-frequency characteristics (ε', ε", μ', and μ") and EM wave absorption properties, specifically reflection loss (RL), were evaluated over the frequency range of 26.5 ≤ f ≤ 40 GHz. Regardless of the M-S method application, hexaferrite-epoxy composites (10 wt%) demonstrated excellent EM wave absorption properties with RLmin < −40 dB and a shifting absorption band corresponding to variations in x, reflecting changes in the ferromagnetic resonance frequency (fFMR). For the x = 0.4 sample, flexible rubber binder (10 wt%) sheets dispersed with hexaferrite powder were fabricated, showing superior broadband absorption characteristics compared to epoxy composites. In rubber sheet form, M-S processed samples exhibited enhanced μ', μ" spectra and improved absorption performance compared to non-M-S samples. The M-S processed hexaferrite-rubber sheet demonstrated broad EM wave performance with RL < −10 dB across the entire frequency range, achieving RLmin = −61 dB at 32 GHz. This study underscores the potential of Zn-Zr-substituted SrM-polymer composites for robust EM wave absorption performance in the Ka-band (26.5–40 GHz), crucial for applications in 5 G communication frequencies.

Effects of Extreme Low Temperatures on Carbon-Based Supercapacitors

This comprehensive study delves into the effects of severe cold exposure, specifically liquid nitrogen temperatures, on the functionality of carbon-based supercapacitors. It identifies a slight reduction in capacitance, a direct consequence of the degradation of electrode materials. This degradation is linked to the glass transition in the styrene butadiene rubber binder, leading to decreased adhesion of the active materials in the electrodes. The study highlights the escalated charge transfer resistance post-exposure, pointing to a decrease in efficiency. Significantly, this research emphasizes the crucial role of binder materials in supercapacitor design for low-temperature environments, suggesting that both electrolytes and binders should be equally considered in the development of supercapacitors for harsh climates. The findings contribute valuable insights into enhancing supercapacitor resilience and performance in extreme conditions, paving the way for more robust energy storage solutions. Figure 1

Energy rod based on the combination of biomasses and biochar with natural rubber binder: Mechanical, thermal, and energy releasing properties

Composite preparation from various biomasses and biochar blended natural rubber (NR) as a binder was produced for proposing an alternative fuel energy rod. Rice straw (RS), sugarcane bagasse (SC), and corncob (CC) were combined with different NR ratios. Properties of the composites, in terms of tensile, impact, and compressive strengths, together with flammability, thermal stability, and heat-releasing analyses from Higher Heating Value (HHV) and Ultimate Analysis (CHN-S), were interpreted. It was found that the increase of NR constituent improves the mechanical properties and HHV. The minimization of NR needs to be designed for the release of carbon monoxide. During the mixing operation with an internal mixer and a two-roll mill, no differences were observed in composites with RS, SC, and CC, and the optimal biomass is 80 phr. After transferring to biochar, the produced composite clarifies the usability of the energy rod using pure NR as the natural binder.

Improving storage stability and rheological performance of asphalt rubber modified with nanosilica and Sasobit

In this study, nanosilica (NS) and Sasobit were incorporated into asphalt rubber (AR) binder to produce Si/Sa-AR binder. Various conventional rheological tests were performed to determine the rheological properties of Si/Sa-AR binder. Microscopic tests and four components test were performed to investigate the interaction mechanism of Sasobit and NS with the AR binder. The results show that the combination of AR binder with Sasobit and NS improves the resistance of asphalt to fatigue cracking and permanent deformation. Microscopic images of the AR binder show a ‘dendritic’ structure consisting of multiple swollen crumb rubber (CR) particles and a three-dimensional (3D) network structure, which is reflected in the excellent rheological properties of AR. The addition of Sasobit and NS breaks up the ‘dendritic’ structure while improving the 3D network structure. NS promotes the formation of a homogeneous multiphase system of the modified asphalt binder, which in turn improves the storage stability.

Exploring Progress and Future Trends in Reducing Traffic Noise: A Scoping Review on the Influence of Pavement Characteristics

This scoping review seeks to summarize current research on reducing traffic noise, focusing on how pavement characteristics affect road-tyre mechanical vibrations, which contribute significantly to urban noise pollution. The present study analyzes numerous research investigations on novel asphalt mixtures and rubber binders to identify current trends in pavement design that help reduce noise. Issues such as the longevity of noise-reducing pavements and the trade-off between noise reduction and other practical needs such as safety and cost-efficiency are examined. This assessment emphasizes the impact of new technologies, such as the Internet of Things (IoT), on improving pavement performance and reducing noise levels. Future directions stress the importance of a multidisciplinary approach involving material science, urban design, and acoustic engineering to create sustainable and effective solutions for traffic noise pollution. This review provides valuable input to the scholarly discussion on reducing traffic noise and also presents useful guidance for politicians and engineers aiming to improve urban livability by decreasing noise levels.

Effect of microwave pretreatment on characteristics of asphalt binders modified with scrap non-tire automotive rubber and waste derived pyrolytic oils after prolonged thermal storage

The use of waste automotive rubber and pyrolytic products has recently gained interest in asphalt binder modification, and it also presents an appealing solution towards waste re-utilization and sustainable asphalt binder modification. Further, composite modification of asphalt binders is now often attempted to achieve a wider range of benefits in the asphalt binder performance through the modifiers. For the petroleum crude-based asphalt binders after their modification with different additives, viz. polymers, rubbers, and oils, the phase separation behavior, usually assessed in terms of storage stability, plays a very important and crucial role in its long-term performance. A modified asphalt binder must possess adequate storage stability to assure homogeneity during storage and hauling at elevated temperatures to achieve the desired performance after construction. The present study firstly evaluated the long-term phase separation behavior/storage stability of asphalt binders modified with waste non-tire rubber granules (ethylene-propylene-diene monomer (EPDM) type) alone and then for composite rubberized asphalt binders formulated with EPDM rubber along with tire pyrolytic oil (TPO) and plastic pyrolytic oil (PPO) after microwave pretreatment. To assess the standard and the long-term phase separation behavior in terms of storage stability, formulated rubberized asphalt binders were subjected to thermal storage at two different scenarios: (a) for 2 and 4 days at163 °C, and (b) for 2, 4, 7, 10, and 14 days at 135 °C. The phase separation behavior and performance of rubberized asphalts post long-term storage were evaluated in terms of chemo-rheological, microstructural, and rubber dissolution tests. A total of 28 asphalt binders with variable modification and thermal storage periods were characterized and evaluated. Both storage temperature and duration were found to play a critical role in dictating the storage stability and chemo-rheological performance of the rubberized asphalts, and the prolonged storage stability of rubberized binders correlates well with their rutting and fatigue performance. The pretreatment of rubber granules with pyrolysis oils using microwave irradiation facilitated the achievement of a composite modified asphalt binder with good storage stability and rheological performance.

Revealing interfacial parasitic reactions of nitrile rubber binders in all-solid-state lithium batteries

The nitrile components in NBR lead to an irreversible side reaction during the initial charging process. However, the problematic chemical stability of NBR has been improved through coordination chemistry, resulting in enhanced battery performance.

Nonflammable Fluorinated Ester-Based Electrolytes for High Voltage Li Batteries with LiCoO2 Positive Electrode

LiCoO2 is widely used as a positive electrode material for LIBs. The theoretical capacity of LiCoO2 is calculated to be 274 mA h g–1 upon full delithiation, but the practical reversible capacity is generally restricted to approximately 140 mA h g–1 to avoid capacity deterioration when cycled at higher voltages (>4.2 V vs Li/Li+). To solve this limitation, functional electrolytes that possess a high oxidative stability and form a stable and effective passivation layer on the LiCoO2, are desired.In this study, we report that the cyclability of LiCoO2 under high-voltage operation is drastically improved by using a fluorinated ester, methyl 3,3,3-trifluoropropionate (MTFP), as an electrolyte solvent.1 Notably, the combined use of MTFP-based electrolyte and mixed sodium carboxymethyl cellulose/styrene-butadiene rubber binder synergistically stabilize the LiCoO2 electrode surface, resulting in the almost no capacity fading for 50 cycles even with the upper cutoff voltage of 4.5 V. Note that, in general, LiCoO2 shows significant capacity deterioration when cycled at higher voltages over 4.2 V vs Li/Li+. Moreover, our study reveals that superior low-temperature performance and higher thermal stability is evidenced for the LiCoO2 with MTFP-based electrolyte when compared with that with conventional electrolyte. XPS analysis reveals that thinner and uniform passivation layer derived from PF6 – anion and MTFP is formed on the LiCoO2 electrode surface, which is the origin for improved cyclability and thermal stability of high-voltage LiCoO2 with MTFP-based electrolyte.Reference[1] Y. Ugata et al., and N. Yabuuchi, Chemistry of Materials, in press.

Interaction mechanism and cohesion strength of colloid structure of reclaimed asphalt modified by rubberized binder on aggregate surface

Asphalt mixture performance is attributed to morphological interlocking and physiochemical interaction between binder and aggregate. Many studies fostered the adhesion and bonding characteristics of many binders without conferring the interfacial interaction. To realistically understand the binder cohesion strength, this study investigates the impact of interfacial interaction on the binder colloid structure. An innovative experimental method was developed using the pull-off and gel permeation chromatography tests to investigate the binder/aggregate interface interaction from molecular and mechanical standpoints. The results showed success for the developed method to pursue the mechanism of the binder/aggregate interface interaction and evaluate the resulting molecular diffusion. Two mechanisms were distinguished for molecular diffusion, depending on the percentage of light components. The abundant light components can mobilize the heavy fractions, whereas binder colloids with limited light components have a molecular diffusion for light fractions only. The binder film portion near the aggregate surface has higher cohesion strength than the upper portion, where a strong correlation was proven between the decrease in the cohesion strength and the molecular diffusion due to the interfacial interaction. A robust prediction model with R2 of 0.90 was developed for the binder cohesion strength, where both the molecular composition and the molecular mobility due to interfacial interaction have significant impacts. As the accretion of heavy fractions strengthens the cohesion strength, the molecular diffusion mechanism, which mobilizes the heavy fractions toward the interface, further improves the cohesion strength of the binder film portion near the interface.

A unique redox active ion-electron conductor enabled 5C fast-charging graphite anode for lithium-ion batteries

Enhancing the charging rate of lithium-ion batteries is poised to accelerate the rapid promotion of electric vehicles, decrease greenhouse gas emissions, and reduce the energy crisis worldwide. However, during the fast-charging process, the slow transport of ions and electrons in the graphite anode makes it challenging to achieve a high capacity and good reversible capability. A multifunctional binder that can realize redox reactions with excellent ionic/electronic conduction is reported herein. The electronic/ionic conductance composition is analyzed for the Li-SPODs binder. Thereinto, the total conductivity of Li-SPODs (0.82 mS cm−1) is divided into three parts: lithium sulfonate ionic conductivity (0.54 mS cm−1) in the eigenstate state, electronic conductivity (1.7 × 10−4 mS cm−1) in the doped state, and doping lithium ionic conductivity(0.27 mS cm−1) in the doped state. The conductivity splitting of Li-SPODs binder can reveal the distinct effect of both conductances on graphite electrodes. Benefiting from the high conductive Li-SPODs binder, the contact resistance of the graphite electrode decreased by 54.4 % compared to the carboxymethyl cellulose/butadiene styrene rubber (CMC/SBR) binder. Meanwhile, the full cell based on the lithium iron phosphate cathode and graphite anode (the areal capacity of 2 mAh cm−2) exhibits an extraordinary capacity and outstanding cycling stability (0.04 % capacity decay per cycle during 500 cycles) even at 5C. More importantly, this novel design strategy provides new insight into preparing a multifunctional binder for fast-charging electrodes with high power and energy.

Effect of Crumb Rubber Modifier Particle Size on Storage Stability of Rubberized Binders

This research study aimed to assess the influence of different particle sizes of crumb rubber modifier on phase separation when mixed with virgin asphalt binder (PG 64-22). Both Superpave and multiple stress creep recovery (MSCR) tests were conducted to determine the optimal particle size. Three sizes of crumb-rubber particles (≤0.5 mm, ≤1 mm, and 1–2 mm) were individually incorporated into the binder at a weight proportion of 10%. The findings revealed that an increase in particle size resulted in higher viscosity, which reduced workability. However, the use of particles with a size of ≤0.5 mm effectively decreased viscosity. Furthermore, larger particle sizes enhanced resistance to rutting and improved the lifespan of the pavement. Multiple shear creep recovery (MSCR) tests confirmed that larger crumb-rubber particles exhibited a higher load-bearing capacity. Additionally, phase separation studies demonstrated that larger particle sizes were associated with increased phase separation. Notably, particles with a size of ≤0.5 mm performed exceptionally well in reducing phase separation across all combinations. In conclusion, crumb-rubber particles with a size of ≤0.5 mm were identified as the most effective in minimizing phase separation when blended with virgin asphalt binder. These findings provide solid scientific evidence related to the effects of crumb-rubber particles on the storage stability of rubberized asphalt binder and have significant implications for future research in this field.

Investigation of rejuvenation mechanisms of reclaimed asphalt rubber pavement through mortar tests

ABSTRACT Conventional rejuvenation methods recover the rheological properties of aged bitumen by adding rejuvenators to supplement the content of light fractions of bitumen. However, these methods cannot fully restore the microstructure and advantages of aged asphalt rubber (AR) binder due to the dissolution of rubber particles. Aiming at discovering a more suitable rejuvenation strategy for reclaimed asphalt rubber pavement (RARP), this study investigates the rejuvenation mechanisms of RARP through a series of chemical and rheological tests at the mortar level. A chemistry-based method was proposed to estimate the rubber dissolution in RARP mortar. AR mortars containing 40% of RARP mortar (RARP40%) were prepared. Three rejuvenation schemes were adopted for RARP40%, namely recovering the light fractions, supplementing the swelling rubber content, and both recovering and supplementing, respectively. The results indicate that adding rejuvenator only can effectively soften the aged RARP binder but it fails to slow down the rheological evolution of RARP40% mortar in the secondary aging. The incorporation of AR binder with extra rubber content notably improved the aging resistance but significantly compromised the workability of RARP40% mortar. The compound rejuvenation scheme was the optimum solution that balanced the rejuvenation effectiveness, aging resistance and workability.

Mitigation of Binder Migration Behavior during the Drying Process by Applying an Electric Field for Fast‐Charging in Lithium‐Ion Batteries

AbstractThe binder migration due to the capillary force‐driven solvent evaporation during the drying process in the electrode manufacturing process induces inhomogeneous binder distribution in the electrode, which deteriorates Li‐ion kinetics and corresponding poor fast‐charging properties in lithium‐ion batteries (LIBs). Here, we report an effective strategy to mitigate the binder migration behavior by applying an electric field during the drying process. As the employed carboxymethyl cellulose (CMC) and styrene‐butadiene rubber (SBR) binders have a negative charge in an aqueous anode slurry system (pH 7), the binder migration behavior could be mitigated by generating an electrical attraction force into the bottom direction by positive electrification of the current collector. The anode prepared with electric field exhibits homogeneous binder distribution in the longitudinal direction, which enhances Li‐ion kinetics, corresponding constant current charging capacity, and cycling stability compared to those of the anode prepared without electric field.

Poly(methyl methacrylate) Grafted Natural Rubber Binder for Anodes in Lithium-Ion Battery Applications

Poly(methyl methacrylate) Grafted Natural Rubber Binder for Anodes in Lithium-Ion Battery Applications

High and intermediate temperature performance of warm asphalt rubber containing conventional warm mix additives and novel chemical surfactant

Warm mix asphalt (WMA) technology is widely used to address the workability concerns of rubberized asphalt paving materials. In this study, a novel chemical surfactant – alube– is proposed for the production of warm asphalt rubber (WAR) binders. To assess its suitability, the high and intermediate temperature performances of the resultant alube-WAR binder (AWAR) was compared with those of two conventionally produced WAR binders, namely sasobit-WAR binder (SWAR) and rediset-WAR binder (RWAR). An economic evaluation of the WAR binders was also done in order to assess their cost-competitiveness. For the high-temperature performance study, the high-temperature viscosity, viscosity-temperature susceptibility (VTS), rutting resistance, and stress sensitivity were investigated, while for the intermediate-temperature performance, the fatigue resistance factor was evaluated. Different findings were obtained from the performance and cost investigation. Alube was found to successfully lower the high temperature viscosity of AR binder but not as effective as the two conventional WMA additives. The VTS property of AR binder was only improved by the organic WMA additive (sasobit), while the chemical additives (rediset and alube) showed negative effects. In terms of rutting resistance, AWAR was superior to RWAR and AR, but was outperformed by SWAR. Also, SWAR was the least susceptible to stress changes, while AWAR and RWAR showed comparable performance. Based on the G*sin δ test, the fatigue resistance of the AR binder improved after the incorporation of the chemical additives and deteriorated after sasobit was added, and the performance ranking was determined as RWAR > AWAR > AR > SWAR. Overall, only SWAR had a better high-temperature performance than AWAR, whereas for intermediate temperature performance, only RWAR was better. Furthermore, economic analysis showed that AWAR is the most cost effective of the three WAR binders. The findings of this study indicate that alube has the potential of being utilized as a WMA additive for AR binders and can be utilized in wide range of road projects due to its cost-effectiveness.

Styrene-butadiene rubber patterned current collector for improved Li-ion kinetics of the anode for high energy density lithium-ion batteries

The styrene-butadiene rubber (SBR) binder migration caused by the capillary force-driven solvent evaporation during the drying process results in the concentration gradient of SBR binder in the anode, which deteriorates the adhesion strength at the interface between the anode film and Cu current collector and Li-ion kinetics, respectively. Here, we report SBR patterned Cu current collector (SPC) to overcome problems caused by the SBR binder migration behavior. Pre-patterned SBR strongly adheres to the Cu current collector, which suppresses its migration during the drying process. Homogeneous SBR distribution in the longitudinal direction of the anode improves the adhesion strength and Li-ion kinetics. Enhanced adhesion strength enables the reduction of the SBR content in the anode, which further improves Li-ion kinetics. The anode employing SPC exhibits improved constant current charging capacity retention and cycling stability compared to those of the anode with a pristine Cu current collector.

Effect of Kaolinite and Cloisite Na+ on Storage Stability of Rubberized Binders.

This study aimed to evaluate the impact of a two-step modification process involving kaolinite and cloisite Na+ on the storage stability of rubberized binders. The process involved the manual combination of virgin binder PG 64-22 with crumb rubber modifier (CRM), which was heated to condition it. The preconditioned rubberized binder was then modified for two hours at a high speed of 8000 rpm using wet mixing. The second stage modification was performed in two parts, with part 1 using only crumb rubber as the modifier and part 2 involving the use of kaolinite and montmorillonite nano clays at a replacement percentage of 3% to the original weight of the binder along with the crumb rubber modifier. The Superpave and multiple shear creep recovery (MSCR) test methods were used to calculate the performance characteristics and separation index % of each modified binder. The results showed that the viscosity properties of kaolinite and montmorillonite improved the performance class of the binder, with montmorillonite demonstrating greater viscosity values than kaolinite even at high temperatures. Additionally, kaolinite with rubberized binders showed higher resistance to rutting, and the % recovery value from multiple shear creep recovery testing indicated that kaolinite with rubberized binders was more effective than montmorillonite with rubberized binders, even at higher load cycles. The use of kaolinite and montmorillonite reduced phase separation between the asphaltene phase and rubber-rich phase at higher temperatures, but the performance of the rubber binder was affected by higher temperatures. Overall, kaolinite with the rubber binder generally demonstrated greater binder performance.

Characterization of Storage Stability of EPDM Rubberized Asphalt with Tire Pyrolytic Oil and Sulfur

Automobile/industrial waste ethylene-propylene-diene monomer (EPDM) rubber has attracted considerable interest as a potential asphalt binder modifier. A rubberized asphalt binder must have adequate storage stability to assure homogeneity during storage and hauling and attain the desired performance after construction. This study focused on the application of tire pyrolytic oil (TPO) derived from the pyrolysis of scrap tires as an additive for composite modification to enhance the storage stability of the EPDM rubberized binder. Sequential and pretreatment were the two different approaches employed to produce the TPO-EPDM rubberized asphalt binders in this work. Furthermore, the effect of a crosslinking agent (sulfur) on the compatibility of the TPO-EPDM rubberized binder was investigated for both sequential and pretreatment approaches. In all total, 18 different combinations of rubberized binders with EPDM, TPO, and sulfur were fabricated for storage stability characterization. Various empirical, rheological, chemical, and microstructural analyses based separation parameters indicated that TPO usage enhanced the storage stability of rubberized asphalt binder. Both sequential and pretreatment approaches increased the storage stability of EPDM rubberized binders with an increase in TPO dosages; however, the pretreatment approach outperformed the sequential approach. The addition of sulfur further improved the compatibility of rubberized binders. The results of Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM)–based separation parameters were similar to those found using empirical and rheological tests. Grey relational analysis (GRA) was used to rank the binders according to their separation parameters. GRA showed the best results in both sequential and pretreatment approaches with and without sulfur for an optimal TPO dosage of 6%. The enhanced storage stability performance of rubberized binders with the incorporation of TPO in the pretreatment approach of binder preparation was attributed to the achieved preswelling of rubber particles during premixing and conditioning processes.

Storage stability performance of composite modified asphalt with scrap non-tire automotive rubber, waste plastic pyrolytic oil and sulfur.

Composite asphalt binder has emerged as a potential solution for improving asphalt functionality at a wide spectrum of temperatures. Storage stability of modified binder remains a main concern to ensure homogeneity during various stages including its storage, pumping, transportation, and construction. The aim of this study was to assess the storage stability of composite asphalt binders fabricated using non-tire waste ethylene-propylene-diene-monomer (EPDM) rubber and waste plastic pyrolytic oil (PPO). The influence of addition of a crosslinking additive (sulfur) was also investigated. Two different approaches were employed in the fabrication of composite rubberized binders: (1) sequential introduction of PPO and rubber granules, and (2) inclusion of rubber granules pre-swelled with PPO at 90°C to the conventional binder. Based on the modified binder fabrication approaches and the addition of sulfur, four categories of modified binders were prepared, namely sequential (SA), sequential with sulfur (SA-S), pre-swelled (PA), and pre-swelled with sulfur (PA-S). For variable modifier dosages (EPDM:16%, PPO: 2, 4, 6, and 8%, and sulfur: 0.3%), a total of 17 combinations of rubberized asphalt were subjected to two durations of thermal storage (48 and 96 hours) and then characterized for their storage stability performance through various separation indices (SIs) based on conventional, chemical, microstructural, and rheological analyses. The optimal storage stability performance was achieved at a PPO dosage of 6% under the four candidate approaches. It was also observed that the SIs based on chemical analysis and rubber extraction test had a good correlation with rheology-based SIs compared to the conventionally used softening point difference. A composite modified binder with PPO and EPDM rubber having adequate storage stability is a promising step in the use of sustainable composite-modified binders in asphalt pavement construction.