Butadiene Styrene Research Articles

Preparation, characterization, and properties of acrylonitrile butadiene styrene / multi walled carbon nanotubes nanocomposites

Preparation, characterization, and properties of acrylonitrile butadiene styrene / multi walled carbon nanotubes nanocomposites

Modified waste rubber powders filled styrene butadiene rubber toward the combination of high elasticity and low mechanical hysteresis

Waste recycled rubber (RR) powders are modified with modifier and low-temperature mechanochemical devulcanization (LTMD) method, and filled into styrene butadiene rubber (SBR) to improve its elasticity and reduce its mechanical hysteresis. The incorporation of modified RR (MRR) could accelerate SBR vulcanization, improve the crosslinking density of SBR and promote the compatibility of MRR in the matrix. Furthermore, it could also improve the tensile strength of SBR vulcanizates and weaken the Mullins effect by reducing their overall hysteresis, softening and energy loss. Such method realizes the high-value recovery of RR, reduces the mechanical hysteresis of rubber composites and improves the elasticity.

Improving Asphalt Binder Durability Using Sustainable Materials: A Rheological and Chemical Analysis of Polymer-, Rubber-, and Epoxy-Modified Asphalt Binders

When exposed to sun radiation and heat, asphalt binders age, resulting in reduced flexibility, cracking, and pavement failure. Given the increasing demands of traffic, environmental concerns, and resource scarcity, highway agencies and researchers are actively seeking solutions that meet performance requirements and demonstrate awareness of using non-renewable resources. Epoxy asphalt (EA) promotes sustainability concepts due to its production at significantly lower mixing and compaction temperatures, enhanced durability, improved serviceability, reduced maintenance needs, and successful recycling and reuse in hot asphalt mixtures. Crumb rubber, a widely recognized recycled waste tire material, is considered a viable option for promoting sustainability and enhancing asphalt binder properties. This study aims to enhance the durability and long-term performance of asphalt binders by utilizing sustainable materials. Six types of asphalt binders were employed: PG 67-22 base asphalt binder; styrene–butadiene–styrene (SBS)-modified PG 76-22 and PG 88-22H (3.5% and 7.0% dosage rates, respectively); a hybrid PG 76-22CS-modified asphalt binder prepared with SBS and crumb rubber modifiers; and 25EAB and 50EAB epoxy-modified asphalt binders prepared at 25 and 50% dosage rates, respectively. Results indicate that the sustainable asphalt binders PG 76-22CS, 25EAB, and 50EAB demonstrated comparable or superior performance compared to SBS-modified asphalt binders, as measured by rutting and fatigue factors. Additionally, epoxy asphalt binders had better anti-aging and cracking resistance, as shown by the outcomes of Fourier-transform infrared spectroscopy and linear amplitude sweep tests, respectively. This study contributes valuable insights into the potential of sustainable materials to enhance the overall performance and resilience of asphalt binders.

Determining friction properties of ABS plastic in contact with loamy soil

The paper explores the feasibility of substituting steel working bodies with polymer ones in soil-cultivating units. (Research purpose) The research aims to investigate how the friction parameters of acrylonitrile butadiene styrene (ABS plastic) are affected by variations in absolute soil moisture and speed of the unit during the interaction of its working body with loamy soil. (Materials and methods) A laboratory unit was developed to examine the friction characteristics of the polymer in contact with loamy soil. The study measures the friction and adhesion properties by altering the absolute moisture of loamy soil. (Results and discussion) Graphs were constructed to illustrate the relationship between of the friction parameters of acrylonitrile butadiene styrene (ABS plastic) on absolute soil moisture. It was determined that at absolute soil moistures of 18, 20 and 26 percent, the friction coefficients of acrylonitrile butadiene styrene are 0.45, 0.5 and 0.6, respectively. The adhesion values were recorded at 100, 145 and 700 pascals for absolute soil moistures of 18, 20 and 28 percent, respectively. A decrease in both friction and adhesion was observed when the soil moisture reached between 26% and 28%. (Conclusions) The friction properties of acrylonitrile butadiene styrene (ABS plastic) are lower than those of steel, yet significantly higher than those of fluoroplastic. Further research in this area is expected to significantly increase the effi ciency of selecting materials for the manufacturing of working parts in soil-cultivating units, while also reducing energy costs.

Research on Fatigue Performance of Fast-Melting SBS/Epoxy Resin Composite-Modified Asphalt

A high-performance composite modifier ER-SBS-T was prepared through the mixing of epoxy resin with a fast-melting styrene–butadiene–styrene modifier (SBS-T) to enhance material properties. This study evaluated the fatigue characteristics of ER-SBS-T-modified asphalt using a linear amplitude sweep test, and 70# base asphalt, SBS-modified asphalt, and SBS-T-modified asphalt were used as control groups. The fatigue life of ER-SBS-T-modified asphalt was determined according to viscoelastic continuous damage (VECD) theory. The findings indicated that as the ER-SBS-T modifier content increased, both the maximum value and the cumulative damage limit value increased, while the rate of change of decreased. At strain levels of 2.5% and 1%, the fatigue life of the modified asphalt improved with increasing ER-SBS-T content. However, at a strain level of 5%, the modified asphalt exhibited no significant trend in fatigue life across different ER-SBS-T contents. ER-SBS-T-modified asphalt with a modifier content of >10% demonstrated favorable fatigue performance suitable for practical engineering applications.

A sustainable rapeseed oil-based bio-additive designed for hard asphalt binders: Performance, environmental, and economic assessment

The inherent properties of hard asphalt binder give it both mechanical and economic benefits, rendering it a naturally advantageous material for preventing permanent deformation at higher temperatures. However, its poor resistance to thermal and fatigue cracking limits its application in the paving industry. This study aimed to improve the low-temperature and fatigue performance of hard asphalt binders by using the newly developed vegetable oil-based sub-epoxidized rapeseed oil (SERO). Two SEROs with epoxidation degree of 49.1% and 98.1% were synthesized through an oxidation reaction, respectively. Subsequently, the microstructural characteristics of SEROs were examined by Fourier transform infrared spectroscopy (FTIR) and Hydrogen nuclear magnetic resonance tests. The anti-oxidative aging properties of SERO modified hard asphalt binders were investigated through the utilization of mass loss and aging index. Additionally, the comprehensive rheological properties of SERO modified hard asphalt binders were explored via dynamic shear rheometer and bending beam rheometer tests. Furthermore, the modification mechanism of SERO on hard asphalt binders was confirmed through the quantitative analysis using the FTIR test. The findings suggested the improvement in anti-volatilization and anti-oxidative aging performance of bio-modified hard asphalt binders, which was positively related to the epoxidation degree of SERO. A notable softening effect of SERO on the hard asphalt binders was observed, which enhanced their resistance to thermal and fatigue cracking at lower and intermediate temperatures. The epoxy groups within SERO engaged in ring-opening reactions, forming a new oxygen bridge bond by combining with the unsaturated double bond presented in the asphalt. Consequently, this process resulted in the formation of cross-linked structures within bio-modified hard asphalt binders, thereby enhancing the elasticity. Notably, this phenomenon was most conspicuous in the SERO-H modified 50# binder. Finally, the environmental and economic assessment of SERO modified hard asphalt binders were conducted by the techno-economic method and the emission factors technique. The data revealed that the production of one ton of SERO modified hard asphalt binders could reduce the production costs by about 30%, energy consumption and CO2 emissions by around 20% in contrast to styrene–butadiene–styrene block copolymer modified asphalt binders. Hence, the substantial economic and environmental advantages make SERO an attractive bio-renewable additive for sustainable pavements.

Synergistic effect of graphene and carbon black on the mechanical and vibration damping characteristics of styrene-butadiene rubber

Synergistic effect of graphene and carbon black on the mechanical and vibration damping characteristics of styrene-butadiene rubber

Fabrication and development of high temperature resisted bronze composites using 3D printed gate pattern through stir casting route

Fused deposition modeling (Additive manufacturing method) is used for printing the gate pattern by considering Acrylonitrile butadiene styrene (ABS), alumina (Al2O3), and silicon carbide (SiC) as raw material. The three compositions of feedstock filaments are ABS −2% Al2O3 − 0. wt % SiC, ABS −2% Al2O3 − 3. wt % SiC and ABS −2% Al2O3 − 6. wt % SiC, which are produced by using melt flow extruder. The melt flow index of three compositions are determined as 2.413 /10 min, 2.403/10 min and 2.389/10 min which are near to ABS melt flow index of 2.44 / 10 min. The gate pattern is prepared by fusion deposition modeling method by considering parameters such as SiC reinforcement (wt %), raster inclination and infill density and best optimal parameter for producing pattern comprising high tensile strength and high flexural strength using Technique Order Preference Similar to Ideal Solution (TOPSIS). The best set of optimal parameter for printing the gate pattern was found out as ABS −2% Al2O3 −6 wt% SiC, infill density of 50 % and raster inclination 0°. This pattern exhibited average surface roughness of 12.6 µm, tensile strength of 40.5 MPa and flexural strength of 73.1 MPa. The lowest tensile strength of 29.3 MPa was observed for 3 % SiC, 50 % infill density and 30° raster orientation. Using the printed gated pattern via stir casting process, four different compositions of bronze composites are synthesized such as Cu-Sn- 0 wt% B4C, Cu-Sn- 2 wt% B4C, Cu-Sn- 4 wt% B4C and Cu-Sn- 6 wt% B4C. Cu-Sn- 2 wt% B4C composite exhibited maximum hardness, tensile strength and impact strength of 55 HRC, 323 MPa and 279 N/mm2 respectively. The lowest tensile strength, lowest hardness and maximum deviation in dimension of 323 MPa, 38 HRC and 0.144 mm was found out for Cu-Sn-6 wt% B4C. The best optimized pattern: ABS −2% Al2O3 −6 wt% SiC, infill density of 50 % and raster inclination 0° was used as a pattern for producing seven casted cubes (Cu-Sn-2 wt% B4C) which shows average dimension of ± 0.12 mm.

Investigating the influence of stress dependency on the evaluation of high-temperature deformation resistance in SBS-modified asphalt

The rheological responses of Styrene-Butadiene-Styrene (SBS) modified asphalt are stress-dependent, yet the underlying mechanisms and their relationship to the phase structures formed by SBS in the asphalt matrix remain unclear. To address this issue, this study utilized varying dosages of SBS to prepare binders (SBSMA), which were then characterized through fluorescence microscopy, FTIR, and rheological tests including temperature sweeps and Multi-Stress Creep Recovery (MSCR) at four stress levels. Additionally, rutting resistance of the mixtures was evaluated using wheel tracking tests, correlating the results with rheological data. The test results indicate that the formation of a three-dimensional SBS network structure within the asphalt significantly increases the Stress Sensitivity Index (SSI) by 69.5 %, thereby enhancing the binder's stress sensitivity. Based on the theory of entropic elasticity, the stress sensitivity of SBSMA is explained. The cross-linked network structure exhibits superelastic behavior under low stress but may be overstretched and reorganized under high stress, leading to weakened entropic elasticity. Furthermore, the Jnr values obtained at higher stress levels show stronger correlation (r > 0.9) with the Dynamic Stability (DS) from the wheel tracking test results. This finding suggests that entropic elasticity does not significantly improve the rutting resistance performance at the mixture level. Consequently, increasing the stress level in MSCR tests is recommended to more accurately predict the binder’s rutting performance by inhibiting the network's entropic elasticity.

Safety enhanced novel polymer electrolytes for lithium-ion battery: Anomalous output performance with long term cycling stability by doping and polymer blending

Electrolyte with better safety and stability are the primary concern in the present lithium-ion battery (LIB) technology. Herein, a unique polymer blend electrolyte of polyvinylidene difluoride (PVdF)/poly (acrylonitrile butadiene styrene) (ABS) (75: 25) is fabricated by the non-solvent induced phase inversion method. The structural, morphological, and electrochemical performance of the PVdF/ABS blend is enhanced by incorporating the silica nanoparticles as the ceramic filler by the in-situ method. The gel polymer electrolyte (GPE) constitutes 6 wt % of in-situ synthesised silica in PVdF/ABS blend (PASI-06) exhibits better microporous structure with 80 % porosity. The thermal shrinkage, thermogravimetric analysis (TGA) and flammability test safeguards the exceptional thermal stability of the polymer membrane in LIBs. The polymer membrane activated in the liquid electrolyte (1 M LiPF6 in EC:EMC:DMC (1: 1: 1 v/v)) reveals an electrolyte uptake of 400 %, high electrolyte retention (0.82) and a room temperature ionic conductivity of 5.7 mS cm−1. The better oxidative stability exhibited by the PASI-06 (4.5 V) ensures its applicability with high voltage cathodes. Moreover, the electrochemical performance of the coin cell constitutes of Li/GPE/LFP able to exhibits an initial discharge capacity of 143 mAh g−1 and retained a capacity of 115 mAh g−1 even after 200 cycles at 0.1 C-rate at 25 °C. The long term cycling stability evaluated over 500 cycles at 1 C shows that the cell can exhibit an initial discharge capacity 120 mAh g−1 with 77 % capacity retention over 500 cycles that corresponds to 99 % of coulombic efficiency. These excellent performances exhibited by the PASI-06 GPE guarantee its applicability in thermally stable LIBs with better safety and reliability.

Integrating Mechanistic-Empirical Pavement Analysis in the Life Cycle Assessment Use Phase and Monetization of Environmental Impacts to Promote Low Carbon Transportation Materials

This study attempted to integrate the Mechanistic-Empirical Pavement Design Guide (MEPDG) analysis into the life cycle assessment (LCA) framework to explore the potential of terminal blend rubberized bitumen (TBRB) technology as a sustainable alternative to traditional paving materials in the United Arab Emirates (UAE). In addition, the concept of environmental impact monetization is introduced for quantifying shadow prices to be used in cost–benefit analyses and encourage the adoption of sustainable technologies in pavement construction. The findings demonstrate that hot mixed asphalt (HMA) with TBRB outperforms asphalt mixtures with neat bitumen (NB) and polymer-modified bitumen (PMB) containing 7% linear styrene–butadiene–styrene, with respect to durability and environmental impacts. The cradle-to-grave analysis, which includes maintenance and rehabilitation cycles based on the MEPDG results, alters the hierarchy among scenarios compared to conventional cradle-to-gate analyses, highlighting the importance of the use phase in LCA. Overall, the asphalt mixture with TBRB exhibits 83% and 63% less global warming potential than mixtures with NB and PMB, respectively. The monetization process through the distance-to-target approach returned the shadow price of US$157 per metric ton of CO2eq in the UAE. Based on this value, the HMA with TBRB, if selected over those with NB and PMB, offers environmental savings of US$47,186/km-lane and US$15,852/km-lane for the case study investigated.

Ageing tests with high temperatures of prototype vibroacoustic isolators – under ballast mats (UBMs) based on recycled materials

This study focuses on experimental ageing tests with high temperatures carried out on prototype under ballast mats (UBMs) according to the procedure of the European standard EN 17282, which was introduced in late 2020. Most of the analysed UBM samples are based on recycled elastomeric materials, such as styrene-butadiene rubber (SBR) granules and fibres from end-of-life car tyres and rebond polyurethane waste from polyurethane product manufacturing plants. Additionally, two variations of the mat based on mineral wool are analysed. Significant differences in the values of static and dynamic characteristics measured before and after the ageing tests are demonstrated, and permanent deformations of the recycled polyurethane-based mats are shown. Moreover, it is proved that the elastomeric mats based on recycled rubber materials (SBR granules and fibres) have high durability and are an effective solution in terms of protection against vibration and structure-borne noise from railway traffic. In addition, the authors propose criteria for assessing the results of the ageing test with high temperatures of UBMs tested according to the procedure of EN 17282.

Compositional analysis and quantitative evaluation of organic emissions from asphalt materials: Improvements and refinements

The organic emissions resulting from the use and application of asphalt materials can pose significant risks to plant, animal life and human health, consequently, it is crucial to conduct compositional analysis and quantitative evaluation of organic emissions from asphalt materials. In this study, the qualitative and quantitative analysis method of organic emissions from asphalt materials was developed based on headspace gas chromatography-mass spectrometry (HS-GC-MS), selected ion monitoring (SIM) mode, internal standard method and calibration curve. The spiked recovery and surrogate standard recovery were employed to validate the method. The results show the excellent accuracy, precision, and reliability of the HS-GC-MS quantitative analysis method. And the results provide confirmation that total volatile organic compounds (TVOCs), polycyclic aromatic hydrocarbons (PAHs), and n-alkanes can indeed be identified as typical organic emissions originating from asphalt materials. Furthermore, the study successfully identifies benzothiazole, cyclohexyl disulfide, and N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine as characteristic emissions in crumb rubber-modified asphalt (CRMA). The inclusion of the styrene-butadiene-styrene (SBS) modifier results in a significant reduction in n-alkane emissions by 41.11%, PAHs emissions by 25.22%, and TVOCs emissions by 47.21% in comparison to the base asphalt, demonstrating the effective inhibitory effect of the SBS modifier on organic emissions. When compared to the base asphalt, the addition of crumb rubber results in increased emissions of n-alkanes by 12.68% and PAHs by 50.60%, as well as the introduction of the emissions associated with CRMA characteristic compounds, indicating that the emission issue of CRMA is particularly prominent.

An efficient method to prepare high grafting montmorillonite with silane coupling agent and its improvements for styrene butadiene rubber composites

AbstractThe quantity of silane chemically bonded to the organoclay's surface significantly influences its dispersion within the polymer matrix, as well as the interfacial interaction. This research presents a groundbreaking method for enhancing the surface properties of montmorillonite (Mt) through the use of γ‐(methacryloxy) propyl trimethoxy silane (KH570) coupled with acid treatment, leading to increased grafting efficiency. Confirmed by FT‐IR, TGA, and XRD, the process effectively bonds organo‐silanes to Mt and achieves a high grafting level of 1.59 mequiv/g. Utilizing a latex compounding method, Mt/rubber nanocomposites are synthesized with thoroughly modified clay for peak performance. Dispersion and interfacial properties are evaluated through XRD, TEM, AFM, and DMTA. The findings reveal that the well‐modified Mt is an exceptional filler, ensuring a high level of dispersion and robust interaction with the rubber matrix. This synergy translates to a marked improvement in the mechanical properties of the composite, with notable enhancements observed in both tensile strength and elongation at break of 9.7 MPa and 1141%, respectively. This innovative approach to the graft modification of clays presents a potent method, offering the potential for the industrial‐scale manufacture of high‐performance clay‐based composites.Highlights A processing method for preparing high grafting clay with a silane coupling agent. Functionalized clay presents better nano‐dispersion in the polymeric matrix. Strong covalent interfacial interaction is constructed between clay and rubber. Tensile Strength and elongation at break of the composites are obliviously improved.

Use of recycled rubber in carbon black as a filler in ternary blends of NR/BR/SBR for the automotive tire industry

AbstractThis work aims to find the optimal ratio of recycled rubber (RR) in carbon black (CB)/RR filler and determine its influence on the mechanical properties, thermal behavior, and activation energy of ternary rubber based on polyisoprene (natural rubber [NR]), polybutadiene (butadiene rubber [BR]), and styrene–butadiene rubber (SBR) with a constant ratio of 40/40/20 parts per 100 of rubber (phr). The filler used was N330 (60 phr) and a mixture of CB/RR filler in the following proportions: 55/5, 50/10, and 40/20 phr. The activation energy of the examined samples was determined by the rheometric method. The samples were subjected to thermo‐oxidative (at 100°C after 168 h) and γ‐radiation aging (200 kGy). Hardness, tensile strength, and elongation at break were evaluated before and after thermo‐oxidative and γ‐radiation aging. SEM, attenuated total reflectance fourier‐transform infrared (ATR‐FTIR), and TG/DTG techniques were used to characterize NR/BR/SBR composites.The results show that the most optimal CB/RR ratio is 55/5 phr, which is confirmed by the mechanical properties before and after aging and the results for the activation energies of cross‐linking and reversion. The thermal stability of the composite containing 60 phr of the CB and the composite reinforced with 5 phr of the RR in CB/RR filler is almost the same.The results of this research may be applicable in the automotive tire industry since NR/BR/SBR composites are used for automotive tire treads. Another benefit of this research is that the partial replacement of CB with RR contributes to the reduction of tire waste, and thus to the preservation of environmental protection.Highlights Rubber composite NR/BR/SBR = 40/40/20 phr reinforced with CB/RR filler The amount of RR in the CB/RR filler has been changed to 5, 10 and 20 phr The lowest value for Eac has the sample containing filler CB/RR = 55/5 phr The most thermally stable sample is the sample with 5 phr RR in CB/RR filler RR (5 phr) can be applied in CB/RR filler to reinforce NR/BR/SBR composites

Effect of waste engine oil and warm mix additive on the physical, rheological, and short-term aging attributes of Styrene–Butadiene Rubber-modified asphalt binders

Styrene-butadiene rubber (SBR) latex is used widely to increase the low-temperature resistance of asphalt binders. However, the high content of butadiene copolymer in SBR-treated asphalt causes oxidation and aging. Furthermore, following the SBR modification, the compatibility and thermal storage stability of SBR-modified asphalt is not satisfactory. Therefore, the best approach to improve the quality of short-term aged SBR-modified asphalt is to lower the manufacturing temperatures of the SBR-modified asphalt mixture. In this study, to reduce the preparation temperatures of SBR-modified asphalt mixes and improve their performance after short-term aging, several additives i.e., waste engine oil (WEO), warm mix agent i.e., ZycoTherm, and WEO/ZycoTherm combination (WEO+ ZycoTherm) were selected. The rheological properties and aging performance of binder samples were evaluated through the rational viscosity, dynamic shear rheometer, bending beam rheometer and Fourier transform infrared spectroscopy tests. The results showed that adding WEO together with ZycoTherm into an SBR-modified binder contributed to reducing the compaction and mixing temperatures. The chemical analysis showed that the three additives i.e., WEO, ZycoTherm, and ZycoTherm/WEO declined the aromaticity and chemical aging indicators of aged SBR-modified binders. Furthermore, it was demonstrated that both the ZycoTherm and WEO/ZycoTherm improved the asphalt resistance to rutting at elevated temperatures in both conditions i.e., before and after short-term aging. In addition, the findings revealed ZycoTherm /WEO compound yielded the best performance to improve the minimal-temperature cracking resistance of the SBR-modified binder, resulting in lower short-term aging temperatures. In summary, this study highlights the necessity of lowering preparation temperatures in asphalt mixes containing SBR to enhance binder resistance to rutting and cracking and reduce susceptibility to oxidation during short-term aging.

Investigating the influence of infill patterns and mesh modifiers on fatigue properties of 3D printed polymers

This research examines the structural performance of Tough Polylactic Acid (PLA) components made through material extrusion, focusing on tensile and fatigue behaviors. Tough PLA, similar to regular PLA, exhibits improved toughness comparable to acrylonitrile butadiene styrene (ABS). As the application of 3D printed parts for functional use expands, understanding the mechanical attributes of materials under both static and dynamic loading conditions is crucial. This study investigates the impact of infill pattern/density and localized reinforcement on the tensile and fatigue strength of Tough PLA samples. Digital image correlation (DIC) and optical micrographs were used to acquire surface-strain data. The findings highlight the influence of localized reinforcement and infill density. Increased infill density is associated with higher tensile strength and Young’s modulus, with specimens at 90 % infill achieving a tensile strength of 28 MPa and Young’s modulus of 0.46 GPa. Incorporating mesh modifiers can enhance tensile properties by up to 20 %. An Analysis of Variance (ANOVA) confirmed the significant effects of these factors on tensile strength. Fatigue test results show a grid pattern without modifiers exhibits the best fatigue life, with specimens enduring up to forty-two thousand cycles at 45 % UTS, while a line modifier balances fatigue strength and tensile properties.

The effect of microwave irradiation on the molecular diffusion of the ethyl acetate (EA) into the blend of styrene-butadiene rubber (SBR)/ethylene-propylene-diene monomer rubber (EPDM)

The effect of microwave irradiation on the molecular diffusion of the ethyl acetate (EA) into the blend of styrene-butadiene rubber (SBR)/ethylene-propylene-diene monomer rubber (EPDM)

Characterization of the Chemical Resistance of Two Non-Vulcanized Styrene-Butadiene Rubbers (SBR).

The objective of this series of tests is to characterize the alkali and water resistance of two non-vulcanized formulations based on co-polymerizing styrene-butadiene rubbers (SBR1 and SBR2). The relative merits of the two polymer systems as impregnating agents for alkali-resistant glass reinforcement in cementitious binders are assessed. For this purpose, polymer films were synthesized and then chemically conditioned for up to half a year at temperatures of 23 °C and 50 °C in sodium hydroxide and potassium hydroxide solutions as well as in salt and distilled water. Changes in mass, tensile strength, and material hardness were evaluated to assess the chemical resistance of the two polymer systems. The different test liquids generally led to swelling (increase in mass) and degradation (reduction in mass) of the polymer structures. These two processes occurred simultaneously. The liquid absorption capacity of the SBR1 impregnation system was between 25.05% and 51.60% by weight, depending on the test liquids. In contrast, the SBR2 impregnation system exhibited a lower liquid absorption capacity, with a weight increase from 21.19% to 42.90%. The chemical conditioning resulted in a maximum mass reduction of the polymer structure SBR1 of 8.82% by weight. The polymer SBR2, on the other hand, only lost up to 2.88% by weight. The tensile strengths of the unconditioned samples of the polymer systems SBR1 and SBR2 were 55.49 ± 7.47 N and 80.87 ± 15.96 N, respectively. The test liquids caused a reduction in strength over the storage period which was accelerated by increased temperatures. The loss of strength of the polymer structure SBR2 was lower over the entire conditioning period. In this context, a correlation was found between strength and material hardness. Overall, the polymeric impregnation system SBR2 had a lower liquid absorption capacity and a lower degree of damage caused by the degrading test liquids. Furthermore, the tensile strength was generally higher and more robust over the entire conditioning period. The results of the durability tests indicate that the SBR2 polymer system is more suitable for use in cementitious binders, as it exhibits less degradation of the polymer structure in response to chemical aging processes.

Effect of Salt Solution Environment on the Aging of Styrene-Butadiene-Styrene (SBS)-Modified Asphalt.

The aim of this paper is to investigate the aging mechanism of asphalt in the sea salt erosion environment from a rheological point of view. In order to simulate the real pavement aging process in the sea salt erosion environment, base asphalt and Styrene-Butadiene-Styrene (SBS)-modified asphalt were selected for salt environment aging tests. The asphalt samples were aged via a thin film oven test (TFOT) and a pressure aging vessel (PAV) test. Then, thermo-oxidizing conditions were created after the samples were immersed in salt solution, mixed with four different concentrations of sodium chloride (NaCl) and sodium sulphate (Na2SO4), to investigate the aging state of asphalt. Temperature scan (TS), frequency scan (FS), and multiple stress creep and recovery (MSCR) tests performed using a Dynamic Shear Rheometer (DSR) were used to investigate the effects on the rheological properties of aged asphalt in a salt environment. The results showed that both base asphalt and SBS-modified asphalt were aged to different degrees under mixed salt solutions. The two asphalt samples aged in a salt environment showed increased hardness. SBS-modified asphalt exhibited higher aging resistance compared with base asphalt in the sea salt environment. However, due to the degradation of the SBS modifier and the aging of base asphalt, the properties of the SBS-modified asphalt showed more obvious complexity with changes in salt solution concentrations.