Aging Resistance Research Articles

КАТАЛИТИЧЕСКОЕ ОБЛАГОРАЖИВАНИЕ ТЯЖЕЛЫХ НЕФТЯНЫХ ОСТАТКОВ ДЛЯ ПОЛУЧЕНИЯ НЕОКИСЛЕННЫХ БИТУМОВ ДОРОЖНОГО НАЗНАЧЕНИЯ

This article discusses technologies for the production of non-oxidized bitumen for road use from heavy petroleum residual raw materials by catalytic refining, which concludes that a number of components are added to the heavy petroleum residue, forming a catalytic complex, with the addition of which the resulting bitumen has a number of significantly improved physicochemical properties, compared with traditionally produced oxidized bitumen. Within the framework of this study, the synthesis of multifunctional catalytic complexes (CC) with high structure-forming, plasticizing and, last but not least, adhesive properties in bitumen matrices was carried out due to the cluster effect during the physicochemical interaction of components and bitumen on any types of substrates in various application conditions. The results showed that the non-oxidized bitumen obtained with the addition of 2% by weight. The catalytic complex corresponds to the grade of bitumen BND 70/100, which meets the requirements of GOST 33133-2014. The developed non-oxidized bitumen differs from traditional oxidized bitumen by a high softening temperature of 58.7 °C with a stretchability of 77.6 cm at 25 °C. It should be particularly noted that the process of obtaining non-oxidized bitumen by catalytic refining is superior to traditional methods of obtaining bitumen binders, in that less energy-consuming technological operations are used, for example, the reaction temperature proceeds at 190-230 ° C and the time is about 180-210 minutes. At the same time, the resulting non-oxidized bitumen has resistance to aging, preservation of plasticity at low temperatures and high adhesion to stone materials. Thus, as a result of the conducted research, it can be concluded that the method of catalytic refining of heavy oil residue is one of the most promising ways to obtain high-quality bitumen for road use with improved physicochemical properties, aging resistance.

Exploring the interplay between thermo-oxidative degradation and asphalt aging in thermoplastic polyurethane-modified asphalt: Mechanisms, properties, and performance evolution

The aging behavior of thermoplastic polyurethane-modified asphalt (TPUMA) is intricate and the mechanisms of its thermal degradation are not well understood. This study examines the viscoelastic, chemical and morphological characteristics of thermoplastic polyurethane modified asphalt (TPUMA) under different aging conditions (RTFOT/PAV). The rheological master curve model of the S parameter was used to analyze the fitting effect on TPUMA, with SBS (styrene–butadiene–styrene) modified asphalt serving as the control group. The relationship between the phase angle plateau area and polymer aging degradation was elucidated. This study investigates the impact of polymer degradation on the high-temperature rheological behavior and medium-temperature fatigue properties of asphalt through temperature sweep, multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests. Fourier transform infrared spectrometer (FTIR) and confocal laser scanning microscopy (CLSM) are used to qualitatively and quantitatively analyze the chemical composition and morphological evolution of TPUMA during thermal-oxidative degradation. The findings suggest that TPUMA's performance changes in the aging environment is result from the dual coupling effect of polymer degradation and asphalt oxidative hardening. The closely arranged isocyanate (-NCO) and polar component molecular chains in asphalt slow down its oxidation speed, which enhances the aging and deformation resistance of TPUMA. The successful blending of TPU and asphalt was confirmed, and the degradation degree of the polymer was quantitatively characterized by the percentage of the degraded area. The results provide insights to better understand the interplay between TPU degradation and asphalt oxidation.

Viscous Flow Activation Energy and Short-Term Aging Resistance of SBS-Modified Asphalt Enhanced by PPA Oil-Grinding Activated MoS<sub>2</sub>

Viscous Flow Activation Energy and Short-Term Aging Resistance of SBS-Modified Asphalt Enhanced by PPA Oil-Grinding Activated MoS<sub>2</sub>

Aging and life control of cross-linked polyethylene as cable insulation material

Cross-linked polyethylene (XLPE) has been widely used in the field of power cables due to its excellent mechanical properties and insulating properties. However, during the manufacturing of high voltage cables, XLPE will inevitably be affected by electrical aging, thermal aging and electro-thermal combined aging, which makes the resistance and life of the material decline. Therefore, it is necessary to enhance the aging resistance of XLPE without affecting its mechanical properties and insulating properties, so as to extend its service life. In this work, the structural characteristics and cross-linking mechanism of XLPE are introduced, the aging process and influencing mechanism are systematically analyzed, and the life decay problems of XLPE due to aging are explored by using methods such as the temperature Arrhenius equation and the inverse power law of voltage. The improvement strategies such as grafting, blending, and nanoparticle modification can be used to enhance the thermal stability, antioxidant properties, and thermal aging resistance of XLPE, thereby extending its service life. Finally, the strategies of adjusting and controlling the service life of XLPE cable insulation materials in the future are discussed, which provide theoretical guidance for further improving long-term stable operation of XLPE cable insulation materials.

Study on morphological, mechanical, thermal, barrier, rheological, and biodegradation properties of poly(butylene adipate‐co‐terephthalate)/thermoplastic starch/poly(propylene carbonate)‐g‐polyurethane biodegradable films

AbstractBioplastic films with excellent physical properties and barrier properties were successfully prepared from poly(butylene adipate‐co‐terephthalate) (PBAT), thermoplastic starch (TPS), and poly(propylene carbonate)‐g‐polyurethane (PPCU). The rheological, mechanical, barrier, dynamic mechanical properties, and microstructure of the PBAT/TPS/PPCU blend films were studied. The proportion of PPCU controlled the morphology and continuous development of PBAT/TPS/PPCU blends. The increase of PPCU led to the formation of different phase morphologies of the PBAT/TPS/PPCU blends, including “island‐sea,” “quasi‐co‐continuous,” and “co‐continuous” structures. This phase transformation of PPCU emerges as a pivotal driver in the improvement of mechanical properties, resulting in a substantial enhancement from 23.4/24.7 MPa to 37.7/35.6 MPa. Furthermore, the addition of 40%PPCU led to a remarkable 29.6% reduction in the water vapor permeability of the PBAT/TPS/PPCU film. Finally, the increase of PPCU can improve the aging resistance of PBAT/TPS/PPCU films. The films exhibit good mechanical properties and barrier performance, indicating PBAT/TPS/PPCU film potential as environmentally viable substitutes for conventional plastics in the packaging domain.

REACTION OF O-PHENYLENEDIAMINE WITH EPICHLOROHYDRIN AND EVALUATION OF THE PRODUCT AS A RUBBER ANTIAGING AGENT

The epichlorohydrin - o-phenylenediamine reaction product has have obtained. With reverse titration the fact has been proven that the epoxy groups were completely used up to produce the adduct. The Shimadzu FTIR-8400S Fourier spectrometer was used to register the IR spectra. Through IR spectroscopy it was demonstrated that the resulting product is a secondary amine. Thus, epichlorohydrin epoxide groups react with the o-phenylenediamine amino groups. The product has been isolated in the form of a solid crystalline substance having the melting temperature range of 104-106 °С. The rubber mixes based on SKS-30ARKM-15 butadiene-styrene rubber containing sulfur, 2-mercaptobenzthiazole, diphenylguanidine, zinc white, industrial stearin, N-550 carbon black and rubber anti-aging agents at 6.6 mmol/100 g were also studied. The epichlorohydrin - o-phenylenediamine reaction product, N-isopropyl-N'-phenyl-p-phenylenediamine, and 2,2-methylene-bis(4-ethyl-6-tert-butylphenol) were used as the anti-aging agents. A rubber mix containing no anti-aging additives was studied. The rubber mixes have been prepared in LB 320 160/160 rollers, at 45-55 °C. The vulcanization properties of the rubber compounds were tested using Prescott Instruments Rheo-Line MDR rheometer at 160 °C. It was established that the studied adduct has virtually no effect on the vulcanization rate. High values of the difference between the maximum and minimum values of the torque of rubber with the adduct under study indicated a high degree of cross-linking of macromolecules. The mixture has been vulcanized in a 600-600 2E hydraulic vulcanization press at 160 ºC for 15 min. Studies of the properties of vulcanized rubber were carried out in accordance with the standards accepted for the rubber industry. High tensile stress values at given elongations for the rubber containing the product studied have also indicated a high degree of vulcanization. The use of the epichlorohydrin - o-phenylenediamine reaction product in the SKS-30ARKM-15 rubber based compounds has ensured high thermal aging resistance as well as dynamic fatigue resistance.

彩色沥青与基质沥青的抗老化性能对比研究

彩色沥青与基质沥青的抗老化性能对比研究

Comparison of elvaloy and styrene-butadiene-styrene added polymer modified bitumen

One of the methods used to produce road pavements resistant to increased traffic volume and harsh environmental conditions is to improve the properties of bituminous binders, such as high temperature resistance and aging resistance, by using various additives. Styrene-Butadiene-Styrene and Elvaloy are two different commercial additives that are frequently used in pavement construction. In this study, the performance of three different B50/70 grade pure bitumens was modified by using Elvaloy at 1.6%, 1.7%, and 1.8%, and five different B50/70 grade pure bitumens were modified using 4.0%, 4.5%, and 5.0% Styrene-Butadiene-Styrene. Penetration, softening point, elastic recovery, flash point, storage stability, dynamic shear rheometer, beam bending rheometer, rotational thin film oven, and pressure aging vessel tests were applied to the binders in accordance with the Polymer Modified Bitumen technical specifications. According to the test results, it was determined that the additive rates for both modifiers are the optimum values in accordance with the specification. The results of the storage stability tests also showed that the non-homogeneous dispersion of the Styrene-Butadiene-Styrene modified binders during mixing had a significant effect on the behaviour of the binder after storage.

Effect of synchronous surface grafting and intercalation bentonite on properties of SBS modified bitumen

To better enhance the improvement effect of natural bentonite on the comprehensive performance of styrene-butadiene-styrene thermoplastic elastomer modified bitumen (SMB), in this study, 3-(trimethoxysilopropyl) dimethyl octadecyl ammonium chloride (DC5700) was used for synchronous surface grafting and intercalation of bentonite (DC5700-Bentonite). Meanwhile, γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) surface grafting bentonite (KH560-Bentonite) and octadecyldimethylbenzylammonium chloride (ODBA) intercalation bentonite (ODBA-Bentonite) were used as comparison samples. The structure and properties of the bentonite and organic bentonites (DC5700-Bentonite, KH560-Bentonite and ODBA-Bentonite) were tested by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), ultraviolet-visible spectrometer and contact angle measurement. The effects of bentonite and organic bentonites on physical, rheological and aging properties of SMB were investigated. FTIR and XRD results showed that KH560 was chemically grafted onto the surface of bentonite, ODBA was organically intercalated into the bentonite, while DC5700 achieved synchronous surface grafting and intercalation on the bentonite. Compared with KH560-Bentonite and ODBA-Bentonite, DC5700-Bentonite had the best lipophilicity and ultraviolet shielding ability. When the bentonite content was 4 wt%, KH560-Bentonite, ODBA-Bentonite and DC5700-Bentonite could increase the rutting factor of SMB by 2.9 ℃, 4.9 ℃ and 6.5 ℃, respectively, and reduce the ductility of SMB by 6.5 cm, 4.2 cm and 3.1 cm. Meanwhile, compared to SMBs containing KH560-Bentonite or ODBA-Bentonite, the SMB containing DC5700-Bentonite had the smallest creep stiffness at − 12 ℃, − 18 ℃, and − 24 ℃. The results indicated that DC5700-Bentonite was more conducive to increasing high-temperature performance of SMB than KH560-Bentonite and ODBA-Bentonite, and its adverse effects on low-temperature ductility and low-temperature cracking resistance of SMB were also significantly reduced. After thermal and ultraviolet aging, the deterioration extent of physical and rheological properties of SMB containing DC5700-Bentonite was significantly smaller than that of SMB containing KH560-Bentonite and ODBA-Bentonite. FTIR revealed that DC5700-Bentonite was more beneficial than KH560-Bentonite and ODBA-Bentonite in inhibiting the increase of carbonyl index and the decrease of butadiene index in SMB during aging. The comprehensive results revealed that compared to KH560 surface grafting bentonite and ODBA intercalation bentonite, DC5700 synchronous surface grafting and intercalation bentonite were more conducive to improving the physical and rheological properties, and aging resistance of SMB.

Friction properties of graphene reinforced nitrile rubber composites after thermal oxidation aging: Experiment and molecular dynamics simulation

AbstractWe established friction models for pure NBR, GNS/NBR, and GO/NBR composites through molecular dynamics (MD) simulation. Our study focused on the impact of GNS and GO on the friction properties of nitrile rubber (NBR) composite materials after undergoing thermal oxygen aging. Based on the simulation results, it can be observed that the GNS/NBR and GO/NBR composites' coefficient of friction (COF) decreases by 20.8% and 24.8%, respectively, at 348 K. Additionally, the abrasion rate is reduced by 17.4% and 25.7%, respectively, for the same composites. Adding GNS and GO can effectively improve the friction performance of the NBR composite system, and compared with GNS, GO shows a better enhancement effect. Pure NBR and GO/NBR composite materials were prepared by mechanical blending method, and the friction properties of GO‐enhanced NBR composite materials were studied. The experimental results show that the GO/NBR composite material can maintain a low friction and wear coefficient after thermal and oxygen aging. It shows that adding GO can effectively improve the friction properties of NBR composite systems and slow down the weakening effect of aging on the friction properties of NBR composite materials. This is because the GO surface contains wealthy functional groups such as epoxy groups, which enhances the binding strength between the GO and NBR interface so that the GO/NBR composite material exhibits better friction properties and thermal oxygen aging resistance. In addition, the wear surface was characterized by scanning electron microscopy (SEM), revealing the damage mechanism of friction and wear of NBR composite materials.

Preparation and displacement performance of ternary copolymer (HAPEC)/graphene oxide composites

How to deal with high temperature and high salt reservoirs is a great challenge in the field of polymers. In this paper, a functional monomer (APEC) was homemade, copolymerized with acrylic acid and acrylamide to form a terpolymer, and solution blended with graphene oxide (GO) to prepare a terpolymer/graphene oxide composite (HAPEC/GO). The optimal ratio HAPEC/GO = 20:1 (GH20) was screened. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), and electron microscopy (SEM). The temperature sensitivity, salt resistance, rheology, and aging resistance of GH20 were found to be superior to hydrolyzed polyacrylamide (HPAM), as evaluated by the apparent viscosity of the solution. When tested under simulated water conditions of 90 °C and 1.0 × 105 mg/L total mineralization, the GH20 solution demonstrated a further improvement in recovery, reaching 16.99 % compared to water flooding alone. The final recovery was 7.49 % higher than that of HPAM. The results demonstrate that the composite prepared can be effectively utilized in reservoirs with high temperature and high salt conditions, making it a promising method for enhanced oil recovery.

Accelerated aging resistance, abrasion resistance and other properties of alkali-activated slag mortars containing limestone powder

The Earth's crust is widely recognized for its abundance of limestone (LS). Limestone powder (LSP) has a wide range of potential properties that make it suitable for various applications and fields. It has found extensive usage in Portland cement-based materials. Recently, the incorporation of LSP into geopolymers is becoming more of a concern than before and has become a hot topic. In this article, high range of LSP (2.5–50 wt%) was introduced into alkali-activated slag (AAS) mortars activated with NaOH and sodium silicate solution as a substitution of slag. For the first time, the effect of LSP on the accelerated aging resistance and abrasion resistance of AAS mortars was examined. In addition, the typical traditional routine properties such as flowability, setting time, mechanical strength, water absorption, and total porosity were studied. Sophisticated equipment was utilized to observe the changes in crystalline phases, hydration products, and microstructures of selected samples. The results showed higher flowability and longer setting time with including LSP. As the amount of LSP increased as the flowability and setting time increased. The introduction of 2.5–25% LSP positively affected the mechanical strength, aging resistance, abrasion resistance and transport properties. In contrast, the introduction of 35% did not show an essential change, whilst the introduction of 50% LSP negatively affected the mentioned properties.

Casting poly(urethane‐imide) elastomers with improved thermoviscoelasticity

AbstractPolyurethane (PU) is a versatile material that can be customized to meet specific commercial requirements in different industries because of its favorable mechanical properties. However, it is not resistant to high temperatures, and it requires structural modifications before it can be used in high‐temperature structural materials. In this study, isocyanates and anhydrides are copolymerized at high temperatures to obtain a solvent‐free oligomer, thus eliminating the risks associated with highly polar aprotic solvents. A casting technique is used to synthesize a solid poly(urethane‐imide) (PUI) elastomer. According to the results, casting PUI (CPUI) exhibits optimal physical properties at a hard segment content of 30.5%. Incorporating an ether, symmetric, or imide structure into CPUI may reduce its hysteresis and improve its thermal creep performance. Compared with PU, CPUI exhibits considerably higher creep aging resistance. In dynamic load application tests, CPUI wheels take a substantially longer time to reach failure compared with PU wheels. Overall, CPUI is an environmentally friendly material with high elasticity, low creep, and high heat aging resistance and is suitable for static and dynamic manufacturing applications.

Resilience to aging drives personalized intervention strategies for Alzheimer's disease.

There has been little progress in reducing the incidence and mortality of Alzheimer's disease (AD). Prevention of onset, more accurate diagnostic tools, and prediction of health outcomes have all been identified as critical issues, but more and better basic research approaches are needed. The single greatest risk factor associated with AD is aging. It follows that if aging can be delayed, there should be an equivalent delay or even prevention of the onset of AD neuropathology. Therefore, targeting multiple pathways of aging would be a powerful way to enhance resilience to aging and slow or prevent the onset of AD neuropathology and dementia in a personalized manner. More effective and predictive animal models, such as the aging pet cat that spontaneously develops neuropathology similar to human AD patients, are necessary to help validate noninvasive and inexpensive biomarkers for identifying individuals at risk. Resilience to aging and its ability to delay or prevent the onset of age-related diseases should be the focus for preventing brain aging and enhancing resistance to AD.

Zirconium phosphate modified by polydopamine as anti-aging filler for improving thermal oxidative aging resistance of nitrile butadiene rubber

Zirconium phosphate modified by polydopamine as anti-aging filler for improving thermal oxidative aging resistance of nitrile butadiene rubber

Simulated evaluation of the degradation of hydrophobically associative polymers in the formation

AbstractIn this work, indoor physical simulation experiments were used to examine the effects of shear, thermal, chemical, and microbial degradation on the properties of the hydrophobic associative polymer AP‐P4. It was discovered that the viscosity of the polymer solution generally decreased as the shear time was extended. The larger the shear strength, the lower the solution viscosity. Fitting of the nonlinear equation of solution viscosity with shear time, η = 12,988 t−1.08. When thermal degradation started, the solution viscosity first started to rise, however, this phase was just a short one. The viscosity of the solution gradually started to decrease as the thermal degradation period grew. In addition, the trends of properties like hydrokinetic radius, hydrophobic connectivity, and hydrolysis essentially followed the same patterns as those of solution viscosity. At the beginning of the degradation process, the viscosity retention of the polymer solution without oxygen is significantly higher than that of the aerobic environment. However, the difference between the two becomes smaller as the degradation time increases. In addition, the AP‐P4 had good temperature resistance and aging resistance capabilities when iron ions were present. Finally, it was discovered that AP‐P4 had a strong antibacterial effect, which decreased the viscosity brought on by microbial action.

Cooling efficiency of thermochromic asphalt pavement material and its contribution to field performance enhancement of asphalt mixture

The thermochromic asphalt pavement material (TAPM) has the potential to bilaterally regulate the pavement temperature according to seasonal environment, which is beneficial to heat island effect mitigation and pavement performance enhancement. However, studies on quantifying the cooling efficiency and verifying the field performance of TAPM are still limited. This study aims to more extensively verify the cooling efficiency of TAPM in different climatic regions and to reveal its cooling mechanism in the field. The key thermophysical parameter, solar albedo, of TAPM was back-calculated using an interpolation methodology to match the numerical simulation results with the specimen temperature data monitored experimentally. The cooling efficiency of TAPM in broader climatic regions was demonstrated through the numerical simulation combined with real meteorological conditions. In view of the cooling characteristics of TAPM as well as the temperature dependency attribute of asphalt mixture, various field performance properties of TAPM were characterized. It was found that at a temperature larger than 31 ℃, the solar albedo of TAPM is 0.30, which is six times larger than that of the conventional asphalt pavement material, indicating a strong reflection ability to solar radiation. The average temperature reduction of TAPM compared with the conventional asphalt pavement material in different regions is 6.26 ℃ with a standard deviation of 0.79 ℃, demonstrating the effective, universal and stable cooling effect of TAPM in summer across China. The cooling function of TAPM contributes to the improvement of high-temperature stability, aging resistance and low-temperature cracking performance of asphalt mixture. Therefore, it is necessary to consider the unique cooling function of TAPM for a more objective evaluation of its field performance.

Enhancing rheological and aging performance of matrix asphalt through thermoplastic phenol-formaldehyde resin-based intercalated clay nanocomposites: Mechanisms and effects

This research presents a comprehensive investigation into the development of advanced asphalt materials fortified with PF/OMMT nanocomposites, emphasizing the synergistic effects of melt blending and nano intercalation. Through meticulous characterization, including SEM, FT-IR, and XRD analyses, the study unveils the microstructural evolution, affirming the formation of highly oriented interlayer structures within the asphalt matrix. The incorporation of OMMT, known for its hydrophobicity, significantly enhances the interfacial interactions between PF and asphalt, thereby bolstering the material's mechanical resilience, specifically its tensile, shear, and high-temperature rutting resistance properties. The presence of PF imparts notable improvements in the asphalt's thermal stability and aging resistance, attributed to its inherent antioxidative properties and the establishment of a robust three-dimensional polymer network with OMMT. These advancements herald a promising avenue for the production of high-performance, durable asphalt with superior anti-aging characteristics, optimized for demanding environmental conditions and heavy-duty applications.

Effect of blend ratio on the phase structure and ozone aging resistance of ethylene-propylene-diene, butyl, and chlorobutyl rubber blends

ABSTRACT In the present study, the effect of elastomer ratios in solution-based mixtures on the formation of the phase structure and properties of compositions based on butyl rubber, chlorobutyl rubber, and ethylene-propylene-diene rubber was investigated. This work determined the influence of the elastomer ratios in uncured blends and their impact on the patterns of phase structure formation in multicomponent polymer systems, alterations in molecular mobility, and their influence on ozone resistance. Attenuated total reflectance – Fourier transform infrared spectroscopy was employed to analyze the chemical structure of the polymer surfaces. The influence of blend ratio (mass percentage ratios of 100/0, 80/20, 60/40, 50/50, 40/60, 20/80, and 0/100) on the phase structure and surface ozone oxidation was studied. The green strengths of the blends of ethylene-propylene-diene rubber and butyl/chlorobutyl rubbers were studied over a wide range of blend ratios.

Changes in rheological and low-temperature characteristics of rubberized asphalt containing castor-based bio-oil under thermal-oxidative exposure

The proposed bio-modified rubberized asphalt (BMRA) technology integrates bio-oil and crumb rubber modifications, offering cost savings, waste reuse, improved asphalt performance, and reduced asphalt consumption. Like traditional asphalt, BMRA ages over time due to external environmental factors, impacting its pavement performance. This study examines the alterations in rheological and low-temperature characteristics of BMRA during thermal-oxidative aging. Results indicate that incorporating bio-oil minimizes alterations to the complex modulus and phase angle in aged asphalt. BMRA's crossover modulus significantly surpasses that of unaged rubberized asphalt (RA), showcasing the mitigating effect of bio-oil and crumb rubber on asphalt's rheological properties during aging. BMRA demonstrates comparable or enhanced peak load, fracture displacement, fracture toughness, and fracture energy relative to RA. BMRA's glass transition temperature remains lower than that of other unaged asphalts, signifying enhanced resistance to low-temperature cracking even after aging. Bio-oil, characterized by low molecular weight and abundant light components, counteracts performance deterioration attributed to volatile constituents and destabilization of asphalt's colloid structure during aging. Crumb rubber facilitates the absorption and subsequent release of specific light components, augmenting BMRA's resistance to aging. These findings enhance our understanding of the mechanisms governing the aging resistance and performance of bio-modified rubberized asphalt, thereby supporting the development of sustainable and durable asphalt materials.