Influence of montmorillonite on ageing resistance of styrene–ethylene/butylene–styrene-modified asphalt

Storage-stable styrene–ethylene/butylene–styrene (SEBS)-modified (SM) asphalt was prepared by the addition of 4 mass/% SEBS and 3 mass/% organic montmorillonite (OMMT). The physical and rheological properties of SM and stable SEBS/OMMT-modified (SOSM) asphalts before and after short- or long-term thermal ageing were tested. The rheological tests showed that SOSM asphalt was more susceptible to ageing and became more flexible after ageing. The addition of OMMT restricted the swelling of SEBS in asphalt and led to an obvious susceptibility of SEBS to ageing. The structural characteristics of modified asphalt and OMMT before and after ageing were investigated by using optical microscope, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermal analysis, respectively. The microscopic and thermal analysis confirmed the ageing susceptibility of storage-stable SOSM asphalt.     

Thermo-rheological properties and storage stability of SEBS/kaolinite clay compound modified asphalts

Styrene-ethylene-butadiene-styrene block copolymer (SEBS) modified asphalts with improved high-temperature storage stability are prepared by incorporating kaolinite clay (KC) into the SEBS compounds. The effect of KC on the high-temperature storage properties, dynamic rheological and mechanical properties and morphologies of the modified asphalts are studied. It is found that the SEBS/KC ratio in the compound has a great effect on the high-temperature storage behavior. The modified asphalts are stable when the ratio of SEBS/KC is around 2. However, KC decreases the dynamic rheological and mechanical properties of the modified asphalts to some extent. The high-temperature storage property can be increased by improving the compatibility and decreasing the density difference between SEBS and asphalt.     

Influence of different curing systems on the physico-mechanical properties and stability of SBR and NR rubbers

The physical properties of radiation, sulfur and peroxide-cured styrene–butadiene rubber (SBR) and natural rubber (NR) were compared. The dependence of the mechanical properties of the radiation-vulcanized SBR and NR on the coagent concentration and radiation dose was studied. The effect of thermal aging on the mechanical properties of the different rubber formulations was discussed. The radiation-cured formulations of SBR have superior mechanical properties and thermal stability compared with those of the chemically vulcanized compounds. Whereas, the radiation-cured formulations of NR have similar mechanical properties but superior thermal stability (based on the % change in E after thermal aging), when compared with those of the sulfur-vulcanized compounds and slightly better than those of the peroxide-vulcanized compounds.     

The research for low-temperature rheological properties and structural characteristics of high-viscosity modified asphalt

High-viscosity modified (HVM) asphalt was prepared by the addition of styrene–butadiene–styrene, furfural exact oil (FEO, plasticizer), sulphur (crosslinker). The low-temperature rheological properties of HVM asphalt were investigated by using bending beam rheometer, and different analysis ways including Fourier transform infrared (FTIR) analysis, thermal analysis, ¹hydrogen nuclear magnetic resonance (¹NMR) analysis, elemental analysis, optical microscopy were used to investigate the structural characteristics of modified asphalts and FEO. Rheological tests demonstrated the effect of each modifier on low-temperature rheological performances of asphalt and displayed the structural characteristics of each binder to some extent. FTIR analysis indicated the effect of ageing and modifier on the distribution of functional groups of modified asphalt before and after ageing. Morphology observation showed the distribution of polymer in asphalt with different modifications or ageing. The thermal analysis showed the effect of each modifier on thermal behaviour of asphalt before and after ageing and confirmed the result of FTIR analysis and morphology observation further. Besides, the constituents of base asphalt and plasticizer were also investigated and compared further by adopting elemental analysis, and ¹HNMR and FTIR tests.     

煤沥青与石油沥青混合调制道路沥青的研究

采用高效剪切分散仪考察了调配温度、调配时间、搅拌方法等工艺对煤沥青混合石油沥青性能的影响,对优选的样品进行了离析实验、抗老化性能及流变性能评价。结果表明,调配工艺对煤沥青在石油沥青中的分散有重要影响,调配温度的升高、调配时间的延长能促进煤沥青在石油沥青中分散但也会导致调配沥青的老化;煤沥青粒径对调配沥青性能有重要影响,对优选样品的进一步评价表明,调配沥青有好的耐高温流变性能和抗热氧老化性能,储存稳定性可以解决。     

Synthesis and performance evaluation of a water-soluble copolymer as high-performance fluid loss additive for water-based drilling fluid at high temperature

Drilling fluids are widely used in the drilling of deep wells to clean and transport the rock cuttings, maintain the sidewall of oil well, lubricate and cool the drilling bit, and control the formation pressures. The present work aims at improving the high-temperature resistance of water-based drilling fluid by using the newly synthesized fluid loss additive named PAASD. This copolymer was obtained through the solution polymerization of four kinds of monomers. The synthesis conditions with the optimal API filtration were studied by single synthetic experiment, and the chemical structure of final product was confirmed by FTIR spectroscopy. The target product was carried out with thermal stability analysis, rheological property, filtrate property, temperature resistant capacity, salt tolerance capacity, micro-crosslink structure property, particle size distribution and the compatibility performance experiment. The results showed that PAASD was an efficient fluid loss additive, and the API filtration of fresh water drilling fluid containing 2% PAASD was only 5.2 mL, it was 10.6 mL after aging at the condition of 200°C and 16 h. Besides, PAASD has a good thermal stability, salt tolerance, and it could improve the rheological property of drilling fluid system obviously. Therefore, it could be used as fluid loss additive of water-based drilling fluid in salty and high-temperature environment.     

A Review of Characteristics of Bio-Oils and Their Utilization as Additives of Asphalts

Transforming waste biomass materials into bio-oils in order to partially substitute petroleum asphalt can reduce environmental pollution and fossil energy consumption and has economic benefits. The characteristics of bio-oils and their utilization as additives of asphalts are the focus of this review. First, physicochemical properties of various bio-oils are characterized. Then, conventional, rheological, and chemical properties of bio-oil modified asphalt binders are synthetically reviewed, as well as road performance of bio-oil modified asphalt mixtures. Finally, performance optimization is discussed for bio-asphalt binders and mixtures. This review indicates that bio-oils are highly complex materials that contain various compounds. Moreover, bio-oils are source-depending materials for which its properties vary with different sources. Most bio-oils have a favorable stimulus upon the low temperature performance of asphalt binders and mixtures but exhibit a negative impact on their high-temperature performance. Moreover, a large amount of oxygen element, oxygen-comprising functional groups, and light components in plant-based bio-oils result in higher sensitivity to ageing of bio-oil modified asphalts. In order to increase the performance of bio-asphalts, most research has been limited to adding additive agents to bio-asphalts; therefore, more reasonable optimization methods need to be proposed. Furthermore, upcoming exploration is also needed to identify reasonable evaluation indicators of bio-oils, modification mechanisms of bio-asphalts, and long-term performance tracking in field applications of bio-asphalts during pavement service life.     

New eco-friendly low-cost binders for Li-ion anodes

In the production of commercial Li-ion batteries, the active materials slurries are generally prepared using polyvinylidene fluoride (PVdF) as binder because of its good adhesion properties and electrochemical stability. Unfortunately, there are some disadvantages related to the use of PVdF: the most important is the use of toxic and environmentally unfriendly solvents, such as N-methyl-pyrrolidone (NMP), and the second is the high costs. In the light of these considerations, it seemed straightforward to investigate the suitability of some water-soluble, inexpensive, and eco-friendly materials to test as alternative binders (sodium alginate, chitosan tragacanth gum, gelatin). The rheological properties of these materials have been investigated in addition to the electrochemical characterization. Furthermore, graphite electrodes with PVdF, carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) binders have been considered for sake of comparison. We found that some of these water-soluble binders, besides good electrochemical performances, showed a high adhesion to the current collector and a good electrochemical stability under the experimental conditions employed, which makes them interesting for the next generation of Li-ion batteries.     

Aging properties and mechanism of the modified asphalt by packaging waste polyethylene and waste rubber powder

For the consideration of the environmental and economic issues, retrieved packaging waste polyethylene and waste rubber powder were selected as modifiers to modify the ordinary oil asphalt, and the rotating film oven test was adopted to study the aging process of the modified asphalt. The results showed that the performance of the modified asphalt deteriorated, as indicated by the increase in the softening point and the reduced ductility and penetration. However, compared with nonmodified asphalt, the rangeability of the performance indicators of the modified asphalt before and after aging became narrow, indicating that the aging properties of the modified asphalt were improved. In the modified asphalt system, the swelling of the polymer modifiers was caused by the absorption of the light components of the asphalt, thereby reducing the formation of asphaltenes in the aging process. The polymer modifiers absorb the light oil of the asphalt, which can reduce the content of free radicals and improve the aging properties of the asphalt. In addition, the waste rubber power containing antioxidants and anti‐ozone agents effectively improves the antiaging properties of the asphalt. Copyright © 2012 John Wiley & Sons, Ltd.     

高抗冲聚苯乙烯/粘土纳米复合材料的制备、热稳定性及流变性能

用双螺杆挤出共混法制备了高抗冲聚苯乙烯 (HIPS) 有机蒙脱土 (Org MMT)插层纳米复合材料以及HIPS 无机蒙脱土 (MMT)常规复合材料 .分别用TGA和毛细管流变仪研究了它们的热性能与流变性能 ,并比较了两种结构材料的性能差异 .结果表明 ,纳米复合材料比纯HIPS和常规的复合材料具有更好的热稳定性和流动性 ,前者具有更强的剪切变稀行为 .此外 ,当蒙脱土达到纳米级分散时 ,复合材料的表面也变得更加平整光滑 .     

Characterization of effects of thermal-oxidative aging on styrene-butadiene rubber/silica composites with vitamin C-lanthanum complex

A novel rubber antioxidant, vitamin C-lanthanum complex, was prepared and applied in styrene-butadiene rubber (SBR)/silica composites. The anti-aging behavior of SBR/silica composites with vitamin C-lanthanum complex was systematically investigated by mechanical property retention after aging, oxidation induction time, exothermic enthalpies of thermal oxidation, and thermo-oxidative degradation kinetics. The highlight of this work lies in the fact that several thermal analysis techniques were successfully applied to fully evaluate the thermal-oxidative aging of SBR/silica composites and the vitamin C-lanthanum complex was found to endow SBR/silica composites with better protection against aging than commercial antioxidants, which may be beneficial for better characterization of rubber aging and fruitful for the preparation of highly aging-resistant rubber composites, respectively.     

Preparation and characterization of an asphalt-modifying agent with waste packaging polyethylene and organic montmorillonite

In this paper, waste packaging polyethylene (WPE)/organic montmorillonite (OMMT) nanocomposites were prepared and used as an asphalt-modifying agent. The structure and morphology of the nanocomposites and the effects of OMMT on the thermal properties of WPE were investigated. The influence of the microcosmic effects and physical properties of the composite agents on the base asphalt were also studied. The results show that the WPE/OMMT asphalt-modifying agents are exfoliated nanocomposites. When compared with WPE, the melting range of the composites decreases and the thermal stability is improved. In addition, the composite agents not only promote good dispersion of WPE in asphalt, but also improve the low temperature properties of WPE-modified asphalt without adversely affecting its excellent high temperature properties. Therefore, from an environmental and economic standpoint, it is a novel and significant attempt at dealing with waste plastics packaging.     

Preliminary Study on New Alternative Binders through Re-Refined Engine Oil Bottoms (REOBs) and Industrial By-Product Additives

Recent studies have worked towards addressing environmental issues such as global warming and greenhouse gas emissions due to the increasing awareness of the depletion of natural resources. The asphalt industry is seeking to implement measures to reduce its carbon footprint and to promote sustainable operations. The reuse of several wastes and by-products is an example of a more eco-friendly activity that fulfils the circular economy principle. Among all possible solutions, the road pavement sector encourages, on one hand, the use of recycled materials as a partial replacement of the virgin lithic skeleton; on the other hand, it promotes the use of recycled materials to substituting for a portion of the petroleum bituminous binder. This study aims to use Re-refined Engine Oil Bottoms (REOBs) as a main substitute and additives from various industrial by-products as a full replacement for virgin bitumen, producing high-performing alternative binders. The REOBs have been improved by utilizing additives in an attempt to improve their specific properties and thus to bridge the gap between REOBs and traditional bituminous binders. An even larger amount of virgin and non-renewable resources can be saved using these new potential alternative binders together with the RAP aggregates. Thus, the reduction in the use of virgin materials is applied at the binder and the asphalt mixture levels. Rheological, spectroscopic, thermogravimetric, and mechanical analysis were used to characterize the properties, composition, and characteristics of the REOBs, REOB-modified binders, and asphalt mixes. Thanks to the rheological investigations of possible alternative binders, 18 blends were selected, since they behaved like an SBS-modified bitumen, and then they were used for producing the corresponding asphalt mixtures. The preliminary mechanical analysis of the asphalt mixtures shows that six mixes have promising responses in terms of stiffness, tensile resistance, and water susceptibility. Nevertheless, the high variability of recycled materials and by-products has to be taken into consideration during the definition of alternative binders and recycled asphalt mixtures. In fact, this study highlights the crucial effects of the chemical composition of the constituents and their compatibility on the behaviour of the final product. This preliminary study represents a first attempt to define alternative binders, which can be used in combination with recycled aggregates for producing more sustainable road materials. However, further analysis is necessary in order to assess the durability and the ageing tendency of the materials.     

丁苯橡胶／聚丙撑碳酸酯弹性体的结构与性能

聚丙撑碳酸酯（ＰＰＣ）是由ＣＯ２和环氧丙烷在聚合物负载的双金属催化剂作用下共聚而成的一类新型高分子材料［１］，其结构式如下：ＯＨＣＨ２ＣＨＣＨ３ＯＣＯＯｎＣＨ２ＣＨＣＨ３Ｏ］ｍＣＮＯｏＯＨ它的广泛应用对于环境保护和新资源开发具有实际意义．在...     

Styrenated phenol modified nanosilica for improved thermo-oxidative and mechanical properties of natural rubber

The present work aims to prepare thermal and oxidation resistant Natural Rubber (NR) composites using antioxidant-modified nanosilica (MNS). The thermo-oxidative aging performance of the composites was evaluated by the variations in mechanical properties after aging at 100 °C for 24 h. The performance was further monitored through Scanning Electron Microscopy, Fourier Transform Infrared spectroscopy, Thermogravimetric Analysis, and Dynamic Mechanical Analysis. NR nanocomposite with 1–7.5 phr nanosilica (NS) and 3 phr MNS were prepared and its rheological properties were studied. A comparative study of the theoretical models yielded that modified Guth-Gold equation predicted Young's modulus better than other models. Thermal stability of natural rubber MNS composite was improved by 10 °C with pre-eminent mechanical properties like tensile strength and heat build-up. A linear relationship of compression set with modulus of all composites were also established. Equilibrium swelling test revealed improved crosslink density in NR MNS composite. The strong interaction between antioxidant and nanosilica enabled low migration of antioxidant in NR MNS composite. Hence its protective function after aging showed more effective than NR NS composites. These versatile functional properties of NR MNS composite suggest its potential application in electrical, electronic and high performance rubber products.     

Multistage thermal decomposition in films of cadmium chloride-doped PVA–PVP polymeric blend

Several reports exist on the use of natural-oil-based materials as rejuvenators to restore the properties of aged binders—more specifically, regarding their ability to enhance the binders’ low-temperature properties and to reduce their stiffness. Rejuvenators are typically made of low molecular weight constituents which could easily volatilize and thus render the rejuvenated binder thermally unstable. Hence, the study of the thermal stability of rejuvenated binders is of paramount importance. In this research, a binder with a performance grade (PG) of PG58-28 modified with a soybean-derived rejuvenator at 12% by mass is added to an extracted reclaimed asphalt pavement (RAP) binder at a ratio of 1:5 resulting in a rejuvenator dosage rate of 2% by total mass of binder. The PG of the rejuvenated RAP binder is determined using both dynamic shear rheometer and bending beam rheometer. The thermal stability of the rejuvenator and the binders is verified using thermogravimetric analysis (TG). The rejuvenator shows good thermal stability up to a temperature of 302 °C. The RAP binder containing the rejuvenator shows similar thermal stability to the unrejuvenated RAP binder. The evolved gases from the TG analysis are analyzed using Fourier transform infrared (FTIR) to chemically characterize the rejuvenator and the binders. The FTIR spectrum of the rejuvenator reveals characteristic peaks. The intensity of these peaks serves as an indication of the rate of mass loss of the rejuvenator within the rejuvenated RAP binder.     

SBR composites reinforced with <Emphasis Type="Italic">N</Emphasis>-isopropyl-<Emphasis Type="Italic">N</Emphasis>′-phenyl-<Emphasis Type="Italic">P</Emphasis>-phenylenediamine-modified clay

SBR compounds including the N-isopropyl-N’-phenyl-p-phenylenediamine-modified clay(organoclay) were prepared.Effects of modified clay and antioxidant(IPPD) contents on mechanical and rheological properties of SBR composites were studied.FTIR results confirmed that the clay was chemically modified by IPPD and changed into an organoclay.X-ray diffraction(XRD) results confirmed the increase in interlayer distance of the clay due to the insertion of IPPD.Rheological and cure characteristics of SBR compounds were determined using RPA(Rubber Process Analyzer) and rheometer.Scorch time and cure time of SBR compounds decreased with introduction of the organoclay.Mechanical properties and heat aging resistance of the SBR composites were improved significantly by incorporation of the organoclay.     

Prevention of oxide aging acceleration by nano-dispersed clay in styrene-butadiene rubber matrix

In order to minimize the oxidative degradation of SBR at high temperature, the nano-dispersed clay layers were introduced by using the SBR/clay (100/80) nanocompound to prepare SBR/clay/carbon black (CB) nanocomposites, then the effects of nano-clay on the properties of SBR nanocomposites are investigated. The clay layers and CB are uniformly dispersed in the SBR matrix at nano-scale. The mechanical properties of the SBR/clay/CB nanocomposites mostly decrease with the increase of clay loading, however, with the increase of clay loading, the change rate of the mechanical properties of the nanocomposites decreases and the aging coefficient of the nanocomposites rises, and the length and depth of the cracks of the aged nanocomposites after bending decrease, which means that the clay layers can provide the nanocomposites excellent thermal aging resistance and heat resistance. The experiment of aging with air and without air proved the importance of oxygen during rubber aging process. The FTIR spectra show the generation of oxygen-containing group on the external surface of the nanocomposites during aging. The DSC results indicate the differences between the internal layer and the external layer of the aged nanocomposites.     

Natural rubber composites reinforced with basic magnesium oxysulfate whiskers: Processing and ultraviolet resistance/flame retardant properties

The Magnesium sulfate whiskers (MOSw) were first modified by Stearic acid or Si69, and Natural rubber (NR)/modified-MOSw composites were prepared by blending the modified-MOSw with natural rubber latex. By adding modified-MOS_W into NR, the mechanical properties, the anti-ultraviolet aging property, flammability, and thermal stability of composites were improved obviously. The mechanical properties, crosslink density and thermal stability of composites reach the highest value at 4 wt% Si69-MOS_W. The composite with MOS_W addtion had a higher retention rate after ultraviolet irradiation and the MOS_W could improve the anti-ultraviolet aging property of rubber matrix. The modified MOS_W can effectively improve the oxygen index and the flame retardant grade of rubber composites.     

Thermal analysis and mechanical methods applied to studying properties of SBR compounds containing ionic liquids

The goal of this work was to study new systems for activating sulphur vulcanisation of butadiene-styrene elastomer (SBR) using thermal analysis techniques complementarily with rheological and mechanical properties measurements. New activating systems consist of nanosized zinc oxide and ionic liquids (ILs) – benzalkonium or alkylammonium salts. In this article, we discuss the effect of zinc oxide and ILs on the cure characteristics, vulcanisation kinetics, crosslink density, mechanical properties, damping behaviour and thermal stability as well as resistance to thermooxidative and UV ageing of SBR.Nanosized zinc oxide with ILs reduced the vulcanisation time and temperature of rubber compounds. Their application results in increased vulcanisate crosslink density as well as the improvement of mechanical properties such as tensile strength and vibration damping ability. The influence of ionic liquids on SBR properties depends mainly on the anion present in the molecule. The most active ILs seem to be those with the lactate anion.